Published oninVol 25(2023)

Preprints (earlier versions) of this paper are available athttps://preprints.www.mybigtv.com/preprint/39029, first published.
抑郁症状Amon时间变化g Control Participants in Digital-Based Psychological Intervention Studies: Meta-analysis of Randomized Controlled Trials

抑郁症状Amon时间变化g Control Participants in Digital-Based Psychological Intervention Studies: Meta-analysis of Randomized Controlled Trials

抑郁症状Amon时间变化g Control Participants in Digital-Based Psychological Intervention Studies: Meta-analysis of Randomized Controlled Trials

Review

中文大学心理学系,of Hong Kong, New Territories, Hong Kong

Corresponding Author:

Winnie WS Mak, PhD

Department of Psychology

The Chinese University of Hong Kong

Rm 354, Sino Building

New Territories

Hong Kong

Phone: 852 39436577

Fax:852 26035019

Email:wwsmak@cuhk.edu.hk


Background:Digital-based psychological interventions (DPIs) have been shown to be efficacious in many randomized controlled trials (RCTs) in dealing with depression in adults. However, the effects of control comparators in these DPI studies have been largely overlooked, and they may vary in their effects on depression management.

Objective:This meta-analytical study aimed to provide a quantitative estimate of the within-subject effects of control groups across different time intervals and explore the moderating effects of control types and symptom severity at baseline.

Methods:A systematic literature search was conducted in late September 2021 on selected electronic databases: PubMed; ProQuest; Web of Science; and the Ovid system with MEDLINE, PsycINFO, and Embase. The control conditions in 107 RCTs with a total of 11,803 adults with depressive symptoms were included in the meta-analysis, and effect sizes (Hedgesg) were calculated using the standardized mean difference approach. Study quality was assessed using the Cochrane risk-of-bias tool for randomized trials version 2.

Results:The control conditions collectively yielded small to moderate effects in reducing depressive symptoms within 8 weeks since the baseline assessment (g=−0.358, 95% CI −0.434 to −0.281). The effects grew to moderate within 9 to 24 weeks (g=−0.549, 95% CI −0.638 to −0.460) and peaked atg=−0.810 (95% CI −0.950 to −0.670) between 25 and 48 weeks. The effects were maintained at moderate to large ranges (g=−0.769, 95% CI −1.041 to −0.498) beyond 48 weeks. The magnitude of the reduction differed across the types of control and severity of symptoms. Care as usual was the most powerful condition of all and produced a large effect (g=−0.950, 95% CI −1.161 to −0.739) in the medium term. The findings showed that waitlist controls also produced a significant symptomatic reduction in the short term (g=−0.291, 95% CI −0.478 to −0.104), refuting the previous suspicion of a nocebo effect. In addition, a large effect on depressive symptom reduction in the long term (g=−1.091, 95% CI −1.210 to −0.972) was noted among participants with severe levels of depressive symptoms at baseline.

Conclusions:This study provided evidence that depressive symptoms generally reduced over time among control conditions in research trials of DPIs. Given that different control conditions produce variable and significant levels of symptomatic reduction, future intervention trials must adopt an RCT design and should consider the contents of control treatments when investigating the efficacy of DPIs. The results of waitlist controls confirmed previous findings of spontaneous recovery among people with mild to moderate depressive symptoms in face-to-face studies. Researchers may adopt watchful waiting as participants wait for the availability of digital-based psychological services.

J Med Internet Res 2023;25:e39029

doi:10.2196/39029

Keywords



Digital-Based Psychological Interventions for Depression

Depressive disorders are among the most frequently occurring mental disorders, with a prevalence rate of 10.7% within a 12-month period [1]。They affect >280 million people worldwide [2] and are ranked fourth in terms of disease burden [3]。At the individual level, they have adverse effects on one’s cognitive functioning, quality of life, mortality, and other health outcomes [4-6]。At the macro level, they have tremendous economic costs worldwide [7,8]。

心理干预,尤其是认知behavioral therapy (CBT), have demonstrated to be efficacious in treating depressive disorders [9-12]。They are not only as efficacious as antidepressant medications [13], but they are also preferred by people with depression [14]。Despite its demonstrated efficacy, the uptake of psychotherapy has been poor, with only 13.8% of those who experience mood disorders receiving psychological interventions [15]。With the emergence of digital-based psychological interventions (DPIs), the uptake of evidence-based psychotherapy may be expedited through access over the internet.

A psychological intervention is considered digital when technology is used in its delivery [16]。Although varying in forms, DPIs typically use a software program, website, or app to disseminate therapeutic contents displayed in texts, audios, or videos [17]。Although most modern DPIs run on the internet, offline interventions may also be considered digital whenever technology is involved, for example, a therapy program installed on a web-free computer or that runs on a CD-ROM [18]。Nonetheless, some DPIs would also come with human support, for instance, having clinicians to review homework assignments and provide feedback on users’ progress [19]。

DPIs have overcome major help-seeking barriers by reducing time and costs [20] and mitigating stigma through anonymity and privacy [21]。DPIs’ effectiveness in treating common mental health conditions was found to be comparable with that of face-to-face psychological interventions [22,23]。Previous meta-analytic studies [24-27] have demonstrated their efficacy in alleviating depressive symptoms among adults when compared with a control group, with between-group effect sizes ranging fromg=−0.41 tog=−0.90.

The Overlooked Value of Control Groups

Changes in depression during treatment can be attributed to at least 5 distinct sources of effects [28]。These include the treatment-specific effect, which is the net effectiveness of a treatment; the nonspecific treatment effects such as attention, support, and expectations of being treated; spontaneous remission; regression to the mean; and other treatment-unrelated factors. Unlike pharmacological trials, where blinding is relatively easy to carry out, participants in psychological intervention trials know immediately the results of assignment upon allocation. Any changes in the outcome can be regarded as a blend of true treatment effects and an array of other non–treatment-specific effects. In other words, a proportion of changes experienced by the clients or users during the therapy process may come from sources other than the designated treatment.

Ideally, randomized controlled trials (RCTs) that use adequate control conditions should have controlled for these nontreatment effects [29]。The established evidence we have today is largely generated by RCTs and has been consolidated in meta-analyses that focused on between-group effects comparing an intervention with a control group. In a recent meta-analysis, Moshe et al [27] found that the types of control conditions significantly moderated the effect sizes of DPIs, implying a therapeutic potential in these control conditions.

Previous Reviews on Control Groups

Mohr et al [30] conducted a comprehensive review of the control conditions in RCTs examining the efficacy of psychological treatments for depression. They found that the choice of control condition can have a very large impact on the outcome of a study. In general, studies that used a waitlist or treatment-as-usual control produced the largest between-group effect favoring the examined treatment, whereas those with no-treatment or pill or psychological placebo controls found moderate effects in active treatment conditions, and those with active controls found the least effects in active treatment conditions.

Cuijpers et al [31] attempted to estimate the effects of nontreatment factors in a meta-analysis by investigating the effects of face-to-face nondirective supportive therapy. They found that nearly one-third of the observed changes in depression could be attributed to spontaneous remission and nearly half of the contribution could be accounted for by nonspecific factors. Subsequently, in their meta-analysis investigating remission in people receiving face-to-face psychological treatment, they noted an 18% reduction in depression (Beck Depression Inventory-II) scores among people in the control conditions [32]。More recently, in light of the high heterogeneity of the commonly used care-as-usual (CAU) controls, Cuijpers et al [33] investigated the different categories of CAU and found that the effects of psychotherapies did not differ significantly across CAU variants.

Another meta-analytic study conducted by Whiteford et al [34] examined the probability of remission from untreated depression across 19 studies and reported a high rate of spontaneous remission (53% within 12 months) among participants in waitlists and primary care settings. It was noteworthy that Furukawa et al [35] compared waitlist, no-treatment, and psychological placebo controls with face-to-face CBT and also found that different control conditions lead to substantial but different treatment effect estimates. The waitlist was regarded by the authors as a “nocebo” condition given its inferiority as compared with the no-treatment controls, in which the participants do not expect to receive any active treatment after the study period is over.

Rationale and Research Questions

The aforementioned findings indicate a potential moderating effect of the control treatment on the reported effect sizes of face-to-face psychotherapies. Given that investigations have focused primarily on face-to-face psychotherapies, how control conditions perform in general in RCTs of DPIs has not been systematically investigated. In the past decade, the use of DPIs for health care has become a burgeoning area of investigation. A massive demand on the use of DPIs has been particularly evident since the COVID-19 pandemic lockdowns, when face-to-face services were stalled [36]。

Participants who joined face-to-face psychotherapies might have had different demographic profiles and preferences from those who were willing to receive DPIs. The latest research on the digital divide has shown that digital use is greatly influenced by sociodemographic factors and lifestyle differences [37]。Thus, participants in DPI studies may represent a heterogeneous subgroup of individuals different from those who opt for face-to-face therapies. Updated insights into the characteristics of these individuals are warranted. Nevertheless, an in-depth understanding of how control conditions in RCTs of DPIs fare is necessary for researchers, practitioners, and consumers to evaluate the current evidence on DPIs.

This systematic review and meta-analysis aimed to investigate the possible effects of common control comparators in studies on DPIs for depression among adults. The primary objective of this meta-analytic review was to provide answers to the following research questions: (1) What are the sizes of the within-subject effects of the control conditions over time? (2) How do different types of control conditions differ in terms of time effects? and (3) How does baseline severity affect the change trajectory in control condition participants over time?


This study adhered to the PRISMA-P (Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols) [38] and has been registered in PROSPERO (CRD42021261620).

Inclusion and Exclusion Criteria

This meta-analysis included studies that fulfilled the following criteria pertaining toparticipants,intervention,andpublication type.

Participants

We included studies on adults with any severity of symptoms along the depressive disorder spectrum, ranging from a formal diagnosis of major depressive disorder or persistent depressive disorder to the presence of depressive episodes (major depressive episode) to elevated depressive symptoms. The exclusion criteria included being adolescents or children (aged <18 years) or older adults (aged >65 years) and having comorbid general medical conditions (eg, cancer and diabetes) and other psychiatric disorders (eg, posttraumatic stress disorder, bipolar disorder, and psychotic disorder) except for generalized anxiety disorder as it has been found to be highly comorbid with depression in the real world.

Intervention

We included RCTs in which the efficacy of a DPI treatment was compared with that of a control group. The operational definition of a DPI is a nonpharmacological therapeutic procedure that uses at least one therapeutic approach (eg, CBT, psychodynamic therapy, or positive psychology). The intervention must be non–face to face, delivered either through the internet using any device, including a computer, tablet, or smartphone, or offline via a computerized platform (eg, using a CD-ROM). Furthermore, we excluded studies that targeted changing participants’ physical exercise, diet, or lifestyle purposefully. Studies solely with telephone support from a health care professional were also excluded as we did not consider the telephone as a form of technology, and therefore, it did not qualify for the operational definition of DPI in this study.

Publication Type

We included only peer-reviewed RCTs published in an English academic journal, excluding qualitative studies, dissertations, protocols, and review papers. For controlled trials comparing 2 active interventions, we checked whether the control group delivered the same intervention but in different formats (eg, internet-based CBT with vs without support). We excluded these studies if a stand-alone control group was not present. For nonprimary studies (eg, moderator analysis and economic analysis), we checked whether a record of change in depressive symptoms over time was available.

Study Identification

A systematic literature search was carried out on September 28, 2021, on selected electronic databases: PubMed; ProQuest; Web of Science; and the Ovid system with MEDLINE, PsycINFO, and Embase. Details of the search strategy are presented inMultimedia Appendix 1. This search strategy resulted in a total of 9249 titles and abstracts across the different databases. All search results were entered into Zotero (Corporation for Digital Scholarship), a reference manager for review and removal of duplicate citations [39]。After the removal of duplicates, a total of 49.41% (4570/9249) of the records were retained.

A total of 3 researchers (AT, FH, and OC) then screened the titles and abstracts to eliminate records that obviously did not meet the inclusion criteria (eg, studies with children or older persons, not related to depression, and not on DPIs). Excellent interrater reliability was established (intraclass correlation coefficient=0.964) between the 3 reviewers based on the first 2.19% (100/4570) of screened articles.

A total of 256 records that potentially met the inclusion criteria were identified, and the reviewers then read the full texts of these records to confirm their eligibility. Eventually, 41.8% (107/256) of these studies were left for data extraction.Figure 1介绍了棱镜(首选报告项目Systematic Reviews and Meta-Analyses) flowchart of the selection process.

Figure 1. Flowchart of the study selection process. RCT: randomized controlled trial.

Data Extraction and Coding

Participant characteristics in each study, including age, the percentage of female participants, and tertiary education, were recorded. The percentage of participants taking antidepressant medications at the time of the study and previous exposure to psychotherapy were also extracted.

In addition to the therapeutic approach (eg, CBT, psychodynamic therapy, or positive psychology) of the comparator intervention (in the intervention group), information related to the control group, including types (see detailed descriptions in theResultssection), a description of the intervention received by the control participants, and the mode of delivery, was also extracted. In the event of studies having more than one control group (eg, a waitlist and an active control), we extracted both conditions as separate data as the results for these subsamples were considered to reflect the outcomes of 2 studies. The time passed (in weeks) since the baseline assessment and the retention rate among the controlled participants at each assessment time point were also recorded.

The primary outcome of interest was the within-subject change in depressive symptoms over time. Wherever available, the observed means and SDs of depressive symptoms at baseline, postintervention measurement, and follow-ups were extracted. SEs were converted into SDs by multiplying the square root of the sample size. When the aforementioned information was not available, we checked whether effect sizes with CIs and mean changes with SDs were available. In cases where more than one depressive symptom measure was used, all of them were extracted and aggregated in the meta-analysis.

Quality Assessment

Study quality was assessed using the Cochrane risk-of-bias tool for randomized trials version 2 (RoB 2) [40]。The RoB 2 is a structured tool that assesses possible sources of bias in a trial across five different domains: (1) the randomization process, (2) deviation from the intended interventions, (3) missing outcome data, (4) measurement of the outcomes, and (5) selection of the reported results. A high-quality study should be at low risk in all 5 domains. In total, 2 reviewers (FH and OC) independently assessed the studies based on the RoB 2, and a third reviewer (AT) made the final decision whenever there was disagreement between the reviewers.

Data Synthesis and Meta-analysis

Meta-analyses were performed using Comprehensive Meta-Analysis (version 3; Biostat, Inc) [41] to determine the mean differences in depressive symptoms across different time durations (in weeks) since baseline. The duration was divided into four intervals: (1) immediate (≤8 weeks), (2) short term (9-24 weeks), (3) medium term (25-48 weeks), and (4) long term (>48 weeks). These time cutoffs were chosen based on the distribution of the assessment time points throughout the selected studies. In cases where more than one assessment time point fell within the same interval (eg, 18 and 24 weeks), we used the one closer to the far end of that interval (ie, 24 weeks).

The correlation between pre-post scores on the outcome measures was assumed to ber=0.59 with reference to Balk et al [42]。Effect sizes (Hedgesg) were calculated using the standardized mean difference (SMD) approach. The interpretation of effect size follows Cohen [430.2),代表一个小效果,0.5 reprents a moderate effect, and 0.8 represents a large effect. The extent of heterogeneity between the studies was assessed using theI2统计,代表signif值≥75%icant heterogeneity. Random-effects models were calculated assuming significant heterogeneity [44]。

Publication bias was examined using funnel plot inspection and Egger regression [45]。Symmetry of the funnel plot and a nonsignificant Egger regression indicated an absence of publication bias. Whenever publication bias was detected, the trim-and-fill procedure by Duval and Tweedie [46] was used to obtain a sensitivity estimate of the effect size.

Apart from the differences in effect sizes at various time intervals, subgroup analyses were performed to explore the differential impacts of control group types on severity of depressive symptoms in effect sizes. Only subgroups that comprised ≥2 studies were interpreted to ensure the stability of the effect size estimates.

Depressive symptom severity was categorized into 3 levels—mild, moderate, and severe—based on the proposed cutoffs provided in the respective publications (seeMultimedia Appendix 1for the cutoffs). Finally, we also explored the meta-regression effects of age, sex ratio, and higher education as an exploratory analysis in explaining the heterogeneity across the studies.


Overview of the Included Studies

107包括同行评审的相关会议usion criteria with an aggregation of 11,803 control participants were included in this meta-analysis. The studies were conducted between 2003 and 2021. The years with the most publications were 2020 and 2021, each with 13.1% (14/107) of the studies included. More than half of them (60/107, 56.1%) were conducted in Europe (eg, the Netherlands, Germany, and Sweden) and the United Kingdom. Australia (17/107, 15.9%) and the United States (18/107, 16.8%) also contributed substantially. Other regions included China, Singapore, Japan, Nigeria, Oman, and Colombia. Most of these studies recruited participants from the community (52/107, 48.6%) and in clinics (36/107, 33.6%).

The reported mean age of the participants was 38.48 (SD 7.69) years, and the mean percentage of female participants was 71.54% (SD 15.38%). Approximately half of the participants (mean 54.1%, SD 20.66%) attained higher education, as defined by having finished college or university, and were either married or living with partners (mean 52.26%, SD 19.98%), and 68.19% (SD 19.12%) were employed (including being a student) at the time of the study. Although not reported in many studies, the mean percentage of participants taking antidepressant medication was 44.86% (SD 23.59%), and 51.55% (SD 22.41%) had experience receiving psychotherapy before the study, as reported in 52.3% (56/107) and 38.3% (41/107) of the studies, respectively. The most frequently used assessments of depressive symptoms were the Patient Health Questionnaire-9 (43/107, 40.2%) and the Beck Depression Inventory-II (40/107, 37.4%). Key features of the 107 included studies are summarized inTable 1.

Table 1. Summary of the included studies (N=107).
Study, year Country Setting Selection criteria (depression) Comparator intervention Control type Scale Time interval
Al-Alawi et al [47], 2021 Oman Community PHQ-9a≥12 iCBTb+iACTc Information PHQ-9 Id
Andersson et al [48], 2005 Sweden Community MDDe(CIDIf);MADRS-Sg=15-30 iCBT Active BDIhand MADRS-S Siand Mj
Beevers et al [49], 2017 United States Community QIDSk>10 iCBT CAUl QIDS-SRmand HDRSn I
Berger et al [50], 2018 Switzerland Clinic BDI-II >13 iCBT Active BDI-IIo S and M
Birney et al [51], 2016 United States Workplace PHQ-9=10-19 iCBT (mindfulness-enhanced) Information PHQ-9 S
Bohlmeijer et al [52], 2021 The Netherlands Community CES-Dp<34 Gratitude intervention Active CES-D I, S, and M
Bohlmeijer et al [52], 2021 The Netherlands Community CES-D <34 Gratitude intervention WLq CES-D I and S
Boschloo et al [53], 2019 The Netherlands Multiple PHQ-9=5-14 iCBT CAU PHQ-9 S
Braun et al [54], 2021 Germany Workplace PHQ-9 ≥5 iCBT Information QIDS-SR S
Browning et al [55], 2012 United Kingdom Community Recurrent depression (SCIDr) Attentional bias modification Sham BDI-II and HDRS I
Buntrock et al [56], 2015 Germany Workplace CES-D ≥16 iCBT Information CES-D I and M
Calkins et al [57], 2015 United States University BDI-II score=17-34 CCTs Sham BDI-II I
Choi et al [58], 2012 Australia Community MDD (DSM-IVt) iCBT WL BDI-II and PHQ-9 S
Clarke et al [59], 2005 United States Community MDD iCTu Information CES-D I, S, and M
Clarke et al [60], 2009 United States Community MDD iCBT Information PHQ-8v I, S, M, and Lw
Dainer-Best et al [61], 2018 United States Community CES-D >13 PSRTx Sham CES-D I
Day et al [62], 2013 Canada University DASS-21-Dy>10 iCBT WL DASS-21-D I
De Graaf et al [63], 2011 The Netherlands Community BDI-II >16 iCBT; iCBT+CAU CAU BDI-II I, S, and M
Eriksson et al [64], 2017 Sweden Clinic MDD (MINIz);MADRS-S<35 iCBT; iCBT+CAU CAU BDI-II S and M
Flygare et al [65], 2020 Sweden Clinic MADRS-S=15-30 iCBT Sham BDI-II and MADRS-S I, M, and L
Fonseca et al [66], 2020 Portugal Clinic PDPI-Raa≥5.5; EPDSab≥10 iCBT CAU EPDS I
Geraedts et al [67], 2014 The Netherlands Workplace CES-D >16 iPSTac+iCT CAU CES-D I, M, and L
Gilbody et al [68], 2015 United Kingdom Clinic PHQ-9 ≥10 iCBT CAU PHQ-9 S, M, and L
Gili et al [69], 2020 Spain Clinic PHQ-9=5-14 Healthy lifestyle program, mindfulness program, and positive affect promotion program CAU PHQ-9 I and M
Hallford et al [70], 2021 Australia Community PHQ-9 ≥10; MDEad Memory Specificity Training WL PHQ-9 I and S
Hallgren et al [71], 2016 Sweden Clinic PHQ-9 ≥9 iCBT CAU MADRS-S S and L
Hange et al [72], 2017 Sweden Clinic MADRS-S<35; MDD (MINI) iCBT CAU MADRS-S S, M, and L
Harrer et al [73], 2021 Germany University CES-D ≥16 Stress intervention Information CES-D I and S
Hatcher et al [74], 2018 Canada Clinic MDD; dysthymia iCBT+PSTae Information PHQ-9 I and S
Heim et al [75], 2021 Switzerland Community PHQ-9 ≥10 iCBT Information PHQ-9 I and S
Hirsch et al [76], 2018 United Kingdom Community PHQ-9 ≥10 CBMaf Sham PHQ-9 I
Hobfoll et al [77], 2016 United States Veteran service CED-D=8-25 iCBT WL CES-D-10ag I and S
Høifødt et al [78], 2013 Norway Clinic BDI-II=14-29 iCBT CAU BDI-II I and M
Holländare et al [79], 2011 Sweden Community MDD in remission; MADRS-S=7-19 iCBT Monitoring MADRS-Sand BDI-II S and M
Holst et al [80], 2018 Sweden Clinic Mild and moderate depression (DSM-IV); MADRS-S <35 iCBT CAU BDI-II S and M
Hoorelbeke and Koster [81], 2017 Belgium Community MDD in remission CCT Active BDI-II I and S
Jelinek et al [82], 2020 Germany Community PHQ-9 >4 BAah Active PHQ-9 I
Jelinek et al [82], 2020 Germany Community PHQ-9 >4 BA CAU PHQ-9 I
约翰斯on et al [83], 2019 Sweden Clinic MDD iCBT CAU MADRS-Sand HADS-Dai S
约翰斯on et al [84], 2013 Sweden Community MDD Psychodynamic therapy Active PHQ-9 S
约翰斯on et al [85], 2012 Sweden Community MADRS-S=15-35 Psychodynamic therapy Active BDI-II S
约翰斯on et al [86], 2012 Sweden Community MADRS-S=15-35 iCBT Active BDI-II and MADRS-S S
Kessler et al [87], 2009 United Kingdom Clinic BDI ≥14; MDD and MDE iCBT CAU BDI-II I and M
Kivi et al [88], 2014 Sweden Clinic MADRS-S<35; MDD iCBT CAU BDI-II and MADRS-S S
Kladnitski et al [89], 2020 Australia Community PHQ-9 >9; MDD iCBT CAU PHQ-9 I and S
Klein et al [90], 2017 Germany Multiple PHQ-9=5-14 iCBT CAU PHQ-9 and HDRS-24aj S, M, and L
Kok et al [91], 2015 The Netherlands Multiple MDD in remission iCT CAU IDS-SRak I and S
Levesque et al [92], 2011 United States Clinic PHQ-9 ≥5; BDI=14-28 TTMal CAU BDI-II M
Levin et al [93], 2011 United States Clinic Depressed mood; anhedonia WW-CWDam CAU SCID and CES-D I and M
Lindegaard et al [94], 2021 Sweden Community Elevated symptoms of depression iCBT WL PHQ-9 I
Lokman et al [95], 2017 The Netherlands Community IDS-SR=14-38 CDMIsan WL IDS-SR S
Loughnan et al [96], 2019 Australia Community PHQ-9 >9; EPDS ≥13 iCBT CAU EPDS and PHQ-9 I and S
Loughnan et al [97], 2019 Australia Community PHQ-9 ≥10 iCBT CAU EPDS and PHQ-9 I and S
Lu et al [98], 2021 Singapore Clinic Mild to moderate depressive symptoms iCBT CAU PHQ-9 I
Lüdtke et al [99], 2018 Germany Clinic PHQ-9 >4 iCBT CAU PHQ-9 I
Lukas, and Berking [100], 2021 Germany Community PHQ-9 ≥5 Approach-avoidance biases and approach-avoidance modification training+CBT WL PHQ-9 and ADSao I and S
McCloud et al [101], 2020 United Kingdom University HADSap>8 Stress intervention CAU HADS I and S
Meglic et al [102], 2010 Slovenia Clinic MDD (ICD-10aq);BDI-II >14 Information+therapist support CAU BDI-II S
Meyer et al [103], 2015 Germany Multiple PHQ-9 >14 CAU+iCBT CAU PHQ-9 S
Milgrom et al [104], 2016 Australia Community EPDS=11-23 iCBT Information BDI-II S
Mira et al [105], 2017 Spain Community BDI-II ≤28 iCBT WL BDI-II and ODSISar S
Moberg et al [106], 2019 United States Community PHQ-8=5-14 iCBT WL DASS-21-D and PHQ-8 I
Monteiro et al [107], 2020 Portugal Community PDPI-R <5.5 iCBT CAU EPDS I
Montero-Marin et al [108], 2016 Spain Clinic BDI-II=14-28 iCBT CAU BDI-II S and L
Morgan et al [109], 2012 Australia Community Subthreshold depression symptoms Cognitive training Information PHQ-9 I
Morgan et al [110], 2013 Australia Community 抑郁症状 Cognitive training Information PHQ-9 I
Moritz et al [111], 2012 Germany Community Elevated depression symptoms iCBT WL BDI-II I
Mullin et al [112], 2015 Australia University 抑郁症状(MINI) iCBT WL PHQ-9 I
Newby et al [113], 2013 Australia Community Mild or moderate MDD; mixed anxiety and depressive disorder; PHQ-9 scores above clinical threshold iCBT WL BDI-II and PHQ-9 S
Newby et al [114], 2014 Australia Community BDI-II >12 CBM or CBaseducation Sham BDI-II I
Noguchi et al [115], 2017 Japan Community CES-D ≥16; PHQ-9 ≥5 iCBT or sEFMat WL PHQ-9 and CES-D I and S
Nygren et al [116], 2019 Sweden Community 抑郁症状 iCBT WL BDI-II and PHQ-9 I
O’Mahen et al [117], 2014 United Kingdom Community EPDS >12 BA CAU EPDS S
Oehler et al [118], 2020 Germany Community Mild to moderate depressive symptoms or dysthymia (MINI); PHQ-9=5-14 iCBT Active PHQ-9 and IDS-SR I, S, and M
Ofoegbu et al [119], 2020 Nigeria University MDD iCBT CAU BDI-II S
Pfeiffer et al [120], 2020 United States Clinic PHQ-9 ≥10 iCBT Sham QIDS-SR S
Phillips et al [121], 2014 United Kingdom Workplace PHQ-9 ≥2 on 5 items iCBT Sham PHQ-9 I and S
Pictet et al [122], 2016 Switzerland University BDI ≥14 Imagery CBM Sham BDI-II I
Pictet et al [122], 2016 Switzerland University BDI ≥14 Imagery CBM WL BDI-II I
Pots et al [123], 2016 The Netherlands Community CES-D ≥10 ACTau Active CES-D S
Pots et al [123], 2016 The Netherlands Community CES-D ≥10 ACT WL CES-D S
Proudfoot et al [124], 2003 United Kingdom Clinic MDD; mixed anxiety and depression iCBT CAU BDI-II S and M
Proudfoot et al [125], 2004 Australia Clinic GHQ-12av≥4; CIS-Raw≥12 iCBT CAU BDI-II I and S
Proudfoot et al [126], 2013 Australia Community DASS-21ax≥27-63 iCBT (blended with IPTay, PST, and PPaz) WL DASS-21 I
Proudfoot et al [126], 2013 Australia Community DASS-21 ≥27-63 直肠(混合了IPT, PST和PP) Information DASS-21 I and S
Reins et al [127], 2019 Germany Community MDD (SCID) iCBT Information HRSD I and S
Richards et al [128], 2015 Ireland Community BDI-II=14-28 iCBT WL BDI-II I
Richards et al [129], 2020 United Kingdom Clinic 抑郁症状 iCBT CAU PHQ-9 I
Ritvo et al [130], 2021 Canada Clinic BDI-II ≥14; MDD (MINI) iCBT (mindfulness-based)+CAU CAU QIDS, HDRS, and BDI-II S
Robichaud et al [131], 2020 Canada Community PHQ-9 ≥10 iCBT CAU PHQ-9 I
Roepke et al [132], 2015 United States Community CES-D ≥16 iCBT+PP CAU CES-D I and S
Rollman et al [133], 2018 United States Clinic MDD iCBT CAU PROMISba S and M
Romero-Sanchiz et al [134], 2017 Spain Clinic BDI-II=14-28 iCBT CAU BDI-II L
Rosso et al [135], 2016 United States Community MDD; PHQ-9=10-23 iCBT Monitoring HDRS and PHQ-9 S
Ruehlman and Karoly [136], 2021 United States University PHQ-8 ≥10 Transdiagnostic behavioral health skill training WL PHQ-8 I
Salamanca-Sanabria et al [137], 2020 Colombia University PHQ-9=10-19 iCBT WL PHQ-9 I
Salisbury et al [138], 2016 United Kingdom Clinic PHQ-9 ≥10; MDD (CIS-R) iCBT CAU PHQ-9 S and M
Sandoval et al [139], 2017 United States Community MDD; PHQ-9 ≥10 PST WL BDI-II I and S
Schure et al [140], 2019 United States Community PHQ-9 >5 iCBT Information PHQ-9 I
Segal et al [141], 2020 Canada Clinic MDD; PHQ-9=5-9 MBCTbb+标出 CAU PHQ-9 S and L
Smith et al [142], 2017 Australia Clinic PHQ-9=5-23 iCBT, CBT self-help book, and meditation self-help book CAU PHQ-9 S
Sun et al [143], 2021 China Clinic EPDS >9; PHQ-9 >4 Mindfulness-based intervention Monitoring EPDS I and S
Terides et al [144], 2018 Australia Community PHQ-9 ≥5 iCBT WL PHQ-9 I
Titov et al [145], 2010 Australia Community MDD (MINI) iCBT WL BDI-II and PHQ-9 I
Titov et al [146], 2013 Australia Community Self-identified depression iCBT WL PHQ-9 I
Tönnies et al [147], 2021 Germany Clinic PHQ-9 >9 Video consultations CAU PHQ-9 S
Tønning et al [148], 2021 Denmark Clinic Unipolar depressive disorder (ICD-10) MiCBTbc CAU HDRS-6bd/17, HAM-D6be, and BDI-II S
Tulbure et al [149], 2018 United States Community BDI-II=14-50; MDD and dysthymia (DSM-IV) iCBT; iCBT (religion-focused) Monitoring BDI-II S
Twomey et al [150], 2014 Ireland Clinic Symptoms of depression iCBT CAU DASS-21-D I
Warmerdam et al [151], 2009 The Netherlands Community CES-D ≥16 iCBT WL CES-D I and S
Yeung et al [152], 2018 China Clinic Significant depressive symptoms iCBT CAU CES-D I
Zwerenz et al [153], 2017 Germany Clinic BDI-II ≥13; MDD iCBT+PP Information BDI-II S

aPHQ-9: 9-item Patient Health Questionnaire.

biCBT: internet-based or computerized cognitive behavioral therapy.

cIACT: internet-based acceptance and commitment therapy.

dI: immediate—<8 weeks since baseline.

eMDD: major depressive disorder.

fCIDI: Composite International Diagnostic Interview.

gMADRS-S: Montgomery-Åsberg Depression Rating Scale–Self-reported.

hBDI: Beck Depression Inventory.

iS: short term—9 to 24 weeks.

jM: medium term—25 to 48 weeks.

kQIDS: Quick Inventory of Depressive Symptomatology.

lCAU: care as usual.

mQIDS-SR: Quick Inventory of Depressive Symptomatology (Self-Report).

nHDRS: Hamilton Depression Rating Scale.

oBDI-II: Beck Depression Inventory-II.

pCES-D: Center for Epidemiologic Studies Depression Scale.

qWL: waitlist.

rSCID: Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.

sCCT: cognitive control training.

tDSM-IV: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition.

uiCT: internet-based cognitive therapy.

vPHQ-8: 8-item Patient Health Questionnaire.

wL: long term—>48 weeks.

xPSRT: Positive Self-Reference Training.

yDASS-21-D: Depression, Anxiety, and Stress Scale–21 items–Depression subscale.

zMINI: Mini International Neuropsychiatric Interview.

aaPDPI-R: Postpartum Depression Predictors Inventory–Revised.

abEPDS: Edinburgh Postnatal Depression Scale.

aciPST: internet-based problem-solving treatment.

adMDE: major depressive episode.

aePST: problem-solving training.

afCBM: cognitive bias modification.

agCES-D-10: Center for Epidemiologic Studies Depression Scale Revised.

ahBA: web-based behavioral activation intervention.

aiHADS-D: Hospital Anxiety and Depression Scale (depression subscale).

ajHDRS-24: Hamilton Depression Rating Scale–24 items.

akIDS-SR: Inventory of Depressive Symptomatology–Self-Report.

alTTM: transtheoretical model of behavior change.

amWW-CWD: wellness workshop CD-ROM based on the coping with depression intervention model.

anCDMI: complaint-directed mini-intervention.

aoADS: The General Depression Scale.

apHADS: Hospital Anxiety and Depression Scale.

aqICD-10: International Classification of Diseases, 10thRevision.

arODSIS: Overall Depression Severity and Impairment Scale.

asCB: cognitive behavioral education.

atsEFM: simplified emotional-focused mindfulness.

auACT: acceptance and commitment therapy.

avGHQ-12: 12-item General Health Questionnaire.

awCIS-R: Clinical Interview Schedule–Revised.

axDASS-21: Depression, Anxiety, and Stress Scale–21 items.

ayIPT: interpersonal therapy.

azPP: positive psychology–based intervention.

baPROMIS: Patient-Reported Outcomes Measurement Information System.

bbMBCT: mindfulness-based cognitive therapy.

bcMiCBT: mobile-based cognitive behavioral therapy.

bdHDRS-6: Hamilton Depression Rating Scale–6 items subscale.

beHAM-D6: Hamilton Depression Self-rating Scale–6 items.

Study Quality

The overall quality of the included studies was not optimal according to the assessed results of the RoB 2 (Multimedia Appendix 2[47-153]). Of the 107 publications, 11 (10.3%) were judged as having a high risk of bias. Most studies (91/107, 85%) were judged as having “some concerns,” as defined by the RoB 2. Most of these concerns were related to the lack of blinding, either to the participants or to the assessor, and therefore, this posed some concerns over the risk of bias associated with the measurement of the outcome. Only 4.7% (5/107) of the studies were considered high-quality.

Characteristics of the Control Groups

A total of 113 control arms (some studies included multiple control arms) were coded in the included studies. In total, 6 distinct types were identified based on the contents and delivery modes stated in the articles.

Waitlist (26 Arms)

Participants in the waitlist control group waited for the commencement of the intervention. In cases where the study was conducted in a clinical setting, the control group was coded as a waitlist whenever the participants were restricted from contacting a therapist or receiving any interventions (psychological or pharmacological) provided by professionals (eg, general practitioners, psychologists, and psychiatrists) during the waiting period.

CAU (47 Arms)

研究用标出对照组没有休息rict the receipt of treatment; therefore, participants in these studies continued with their planned treatment. Note that the waitlist control groups in studies on health care settings (eg, mental health services, clinics, or primary care) were considered as CAU when there was no mention of restriction of care.

Information (16 Arms)

Participants in the information control group received information in addition to their usual care. This information could be psychoeducational material; health tips; or anything provided on websites, on a pamphlet, or in other media.

Active (10 Arms)

Participants received procedures that were expected to bring about improvements on their depression. These included attending a discussion forum, expressive writing exercises, and nondirective supportive therapy provided by an assigned therapist who was independent of their usual care.

Sham (10 Arms)

A sham control group was highly similar to the comparator intervention but was intentionally designed to remove active therapeutic elements. For example, in cognitive training, a sham control condition used the same procedure as the intervention group but with modified stimuli.

Monitoring (4 Arms)

Participants in a monitoring control group were constantly assessed on their depressive symptoms during the study period in addition to the major assessment time points. For instance, they completed questionnaires repeatedly or received prompted messages asking about their mood throughout the study.

Assessment Time and Retention

The mean time interval was 8.88 (SD 6.06) weeks between baseline and the postassessment time point, 21.87 (SD 12.5) weeks between baseline and the first follow-up, and 41.38 (SD 30.31) weeks between baseline and the second follow-up. The mean retention rate was 79.54% (SD 17.05%) at the postassessment time point, 75.13% (SD 17.56%) at the first follow-up, and 66.76% (SD 16.90%) at the second follow-up. The retention rates did not differ significantly across control types at the postassessment time point (F5,92=0.8;P=.53) and at the first (F5,48=0.7;P=.63) and second (F5,14=0.8;P=.57) follow-ups.

Time-Dependent Effects on Depressive Symptoms

Overview

The primary focus of this study was the pre-post changes in depressive symptoms across different time durations among the controlled participants.Table 2summarizes the detailed results of the meta-analysis.Figure 2shows the trend in effects across the 4 time intervals outlined in the following sections. SeeMultimedia Appendix 3[47-153] for the forest plots.

Table 2. Effect summary of the meta-analysis.a

手臂,n Participants, N Hedgesg(95% CI) Q I2 Qbetween Pvalue
Immediate (≤8 weeks)

Overall effect 72 7400 −0.358 (−0.434 to −0.281) 802.62 91.15 N/Ab N/A

By control type 10.48c .03


WLd 23 2038 −0.234 (−0.348 to −0.120) 159.12 86.17



CAUe 23 1703 −0.390 (−0.522 to −0.257) 182.56 87.95



Information 12 2612 −0.527 (−0.703 to −0.350) 199.25 94.48



Sham 9 650 −0.462 (−0.673 to −0.251) 44.90 82.18



Active 4 313 −.207 (−0.458 to −0.043) 14.43 79.21


By severity 19.65f <.001


Mild 11 854 −0.122 (−0.285 to 0.041) 64.31 84.45



Moderate 38 3793 −0.317 (−0.406 to −0.228) 289.84 87.23



Severe 21 2415 −0.572 (−0.699 to −0.444) 168.04 88.10

Short term (9-24 weeks)

Overall effect 67 6927 −0.549 (−0.638 to −0.460) 915.17 92.79 N/A N/A

By control type 10.06 .07


WL 12 1132 −0.291 (−0.478 to −0.104) 111.22 90.11



CAU 29 3402 −0.652 (−0.814 to −0.489) 608.54 95.40



Information 11 1138 −0.585 (−0.756 to −0.414) 82.83 87.93



Active 9 582 −0.543 (−0.777 to −0.310) 63.58 87.42



Monitoring 4 192 −0.519 (−0.702 to −0.335) 5.07 40.83



Sham 2 481 −0.614 (−0.746 to −0.483) 2.07 51.59


By severity 9.02c .01


Mild 10 1064 −0.241 (−0.486 to 0.004) 156.23 94.24



Moderate 34 3436 −0.602 (−0.712 to −0.493) 324.53 89.83



Severe 18 1695 −0.696 (−0.880 to −0.511) 232.66 92.69

Medium term (25-48 weeks)

Overall effect 24 2861 −0.810 (−0.950 to −0.670) 291.46 92.11 N/A N/A

By control type 7.85c .02


CAU 14 1900 −0.950 (−1.161 to −0.739) 228.74 94.32



Information 3 381 −0.407 (−0.758 to −0.055) 24.82 91.94



Active 4 343 −0.653 (−0.871 to −0.435) 11.13 73.06


By severity 7.69c .02


Mild 2 115 −0.473 (−0.694 to −0.251) 1.55 35.44



Moderate 13 1324 −0.894 (−1.132 to −0.657) 181.71 93.40



Severe 8 1246 −0.808 (−0.997 to −0.619) 69.37 89.91

Long term (>48 weeks)

Overall effect 9 1641 −0.769 (−1.041 to −0.498) 207.39 96.14 N/A N/A

By control type


CAU 7 1517 −0.827 (−1.133 to −0.521) 179.57 96.66 N/A N/A

By severity 1.18 .28


Moderate 5 553 −0.775 (−1.332 to −0.219) 131.04 96.95



Severe 2 354 −1.091 (−1.210 to −0.972) .57 N/A

aA subgroup of <2 studies was not included in the subgroup analysis.

bN/A: not applicable.

cP<.05.

dWL: waitlist.

eCAU: care as usual.

fP<.001.

Figure 2. Effect sizes by time since baseline assessment.
Immediate Effect

The results showed that, within the first 8 weeks since the baseline assessment, the overall effect of the control groups, as estimated among 67.3% (72/107) of the studies with a total of 7400 participants, wasg=−0.358 (95% CI −0.434 to −0.281), indicating a small to moderate effect. Funnel plot symmetry (Multimedia Appendix 4) and a nonsignificant ranked correlation (P=.95) and Egger regression (P=.14) suggested no significant publication bias for the effect size obtained.

Short-term Effect

The overall effect during weeks 9 to 24 weeks since baseline was estimated among 62.6% (67/107) of the studies with a total of 6927 participants, and the pooled effect size wasg=−0.549 (95% CI −0.638 to −0.460), indicating a moderate effect. Minimal funnel plot asymmetry was observed (Multimedia Appendix 4), and the Egger regression was significant (P=.02), indicating publication bias. In the trim-and-fill procedure by Duval and Tweedie [46], 15 effect sizes were imputed to the right of the mean using the fixed-effects model, resulting in an adjusted effect size ofg=−0.404 (95% CI −0.496 to −0.312).

Medium-term Effect

Within the 25th to 48th weeks, the effect across 22.4% (24/107) of the studies (n=2861 participants) was estimated to beg=−0.810 (95% CI −0.950 to −0.670), which is considered a large effect. A significant Egger regression (P=.008) and funnel plot asymmetry (Multimedia Appendix 4) suggested substantial publication bias. A total of 9 effect sizes were imputed to the right of the mean by looking for missing studies using the fixed-effects model, resulting in an adjusted effect size ofg=−0.573 (95% CI −0.720 to −0.426).

Long-term Effect

Finally, the overall effect flattened approximately a year later beyond 48 weeks among 8.4% (9/107) of the studies with a pooled sample size of 1641, maintaining a close-to-large effect range ofg=−0.769 (95% CI −1.041 to −0.498). Funnel plot symmetry (Multimedia Appendix 4) and a nonsignificant Egger regression (P=.60) suggested an absence of publication bias.

Differential Effect of Control Type

Considering the differential effect of control type, the difference between subgroups was significant in the immediate (Qbetween=10.48;P=.03) and medium term (Qbetween=7.85;P=.02) but not in the short term (Qbetween=10.06;P=.07), and there were insufficient data to compare in the long term. As illustrated inFigure 3, the CAU control type (thick dashed line and circle markers) produced the strongest effect overall after 8 weeks, reaching its peak ofg=−0.950 (95% CI −1.161 to −0.739) in the medium term. The waitlist control (thick solid line and diamond markers) produced relatively smaller effects as compared with the other control types.

Figure 3. Effect sizes by control type. CAU: care as usual; WL: waitlist.

The effect of active controls (thin solid line and star markers) was small shortly after the baseline assessment (g=−0.207) but strengthened to a moderate effect in the medium term (g=−0.653). Sham controls (thin dotted line and “+” markers) consistently produced close-to-moderate effects from the immediate term (g=−0.462) to the short term (g=−0.614).

Although most control types have accumulating effects over time, information controls (thin solid line and cross markers) showed a drop from a moderate effect (g=−0.585) to a small effect (g=−0.407) in the medium term. Finally, only 3.7% (4/107) of the studies (n=192 participants) used a monitoring control type (triangle marker), which was assessed in the short term in all cases. The pooled effect of these monitoring controls was moderate (g=−0.519).

Differential Effect of Severity

Considering the differential effect of severity, subgroup analysis results showed significant differences across levels of severity in the immediate (Qbetween=19.65;P<.001), short (Qbetween=9.02;P=.01), and medium (Qbetween=7.69;P=.02) term but not in the long term (Qbetween=1.18;P=.28). As illustrated inFigure 4, studies in which there were lower levels of severity at baseline appeared to produce smaller effects in reducing depressive symptoms in the immediate, short, and long term but not in the medium term.

抑郁症状did not change significantly among studies in which there were mild levels of baseline symptoms in the immediate (P=.14) and short (P=.05) term. Studies in which there were moderate levels of depressive symptoms were estimated to produce the largest effect on symptom reduction in the medium term (g=−0.894). In addition, an opposite trend between studies in which there were moderate (solid line inFigure 4) and severe (dotted line) levels of symptoms in the medium and long term was observed. Specifically, the effect started to shrink in the moderate-severity subgroup but started to grow in the severe subgroup beyond 48 weeks.

Figure 4. Effect sizes by severity.

Meta-regression on Demographics

As the heterogeneity was very high (>75%) even after subgrouping, a series of meta-regression analyses were performed to examine whether participants’ age, gender, and education level accounted for some of the heterogeneity. As shown inTable 3, in terms of unique variance, female participants (z=−2.37;P=.02) and education level (z=1.98;P=.047) in the short term as well as age (z=2.15;P=.03) in the medium term appeared to significantly explain some variance in the effect sizes. Specifically, the coefficients indicated that the higher the proportion of female participants and the lower the proportion of participants who had a higher education in a study, the smaller the effect in the short term; studies with older participants were found to obtain larger effect sizes in the medium term. However, when considering all covariates collectively, none of the regression models were significant, indicating that the moderating effect of the covariates was very limited and that these covariates together were unable to explain the variance in effect sizes at each of the time intervals.

Table 3. Summary of meta-regression results.
Time interval and variable b(SE) 95% CI z Pvalue
Immediatea

Age −0.002 (0.01) −0.014 to 0.010 −0.32 .75

Female participants −0.005 (0.003) −0.010 to 0.001 −1.66 .01

Higher education −0.001 (0.003) −0.004 to 0.006 0.03 .79
Short termb

Age −0.005 (0.01) −0.019 to 0.008 −0.76 .45

Female participants −0.008 (0.003) −0.014 to −0.001 −2.37c .02

Higher education −0.005 (0.003) <−0.001 to 0.001 1.98c .047
Medium termd

Age 0.04 (0.02) 0.004 to 0.081 2.15c .03

Female participants −0.003 (0.01) −0.016 to 0.011 −0.41 .68

Higher education 0.005 (0.01) −0.005 to 0.014 0.94 .35
Long terme

Age 0.138 (0.10) −0.056 to 0.332 1.40 .16

Female participants −0.001 (0.04) −0.072 to 0.071 −0.01 .99

Higher education −0.015 (0.02) −0.051 to 0.021 −0.81 .42

aModel summary:τ2=0.091;R2=17%;Q(3)=3.08;P=.38.

bModel summary:τ2=0.110;R2=7%;Q(3)=7.41;P=.06.

cP<.05.

dModel summary:τ2=0.102;R2<.001%;Q(3)=6.77;P=.08.

eModel summary:τ2=0.156;R2<.001%;Q(3)=2.23;P=.53.


Principal Findings

This meta-analytic study examined the magnitude of the effects associated with different types of control conditions in DPI trials targeting depressive symptoms among adults. On the basis of the 107 included studies, we observed a U-shaped trend in depressive symptom reduction over time. Specifically, the effect sizes were small to moderate (g=−0.358) in the first 8 weeks since the baseline assessment; then, a moderate effect (g=−0.549) was noted between the 9th and 24th weeks, which was approximately half a year later. After adjusting for publication bias, this short-term effect was reduced to a small to moderate effect (g=−0.404). Within the second half of the same year (25th to 48th weeks), the effect peaked atg=−0.810 (adjusted:g=−0.573), indicating a large (moderate after adjustment) effect. Although the effect shrank slightly beyond 48 weeks (a year later), it was maintained at a close-to-large effect range (g=−0.769).

To the best of our knowledge, this study is the first attempt that looked at the longitudinal trajectory of depressive symptoms among control participants in DPI studies. Undoubtedly, the effect sizes obtained in the control conditions were generally smaller than those of the intervention conditions that were reported [22-27]。However, the findings concur with those of previous studies on face-to-face interventions that, even without active interventions, symptomatic remission is possible [31,33,34]。Considering people in the waitlist control group who were highly restricted on the receiving of treatment procedures, the reduction in depressive symptoms reflected a collective variance explained by spontaneous recovery and regression to the mean, at least to some extent. Although this subtype of control yielded relatively weaker effects than other control conditions given its passivity, the improvement was still significant and meaningful.

Regarding the suspicion of Furukawa et al [35] that people being assigned to a waitlist control may hinder their self-healing behaviors and, thus, experience a nocebo effect (ie, worsening of depression while waiting), our findings did not support this claim as waitlist control groups in our meta-analysis reduced depressive symptoms significantly within the first 24 weeks. However, given that the authors separated waitlist from no-treatment control groups, whereas we did not identify a purely no-treatment condition, our findings could not refute the nocebo hypothesis entirely. The authors of that study investigated face-to-face CBT; it may also be possible that the nocebo effect only applies to people who are willing to receive face-to-face psychotherapy but not to those receiving DPIs.

Moreover, the results concerning CAU were difficult to interpret given the broad definition of “usual treatment” used. Of the 44 studies that used a CAU control group, surprisingly, only 2 (5%) [71,80] detailed the care procedures involved. After all, CAU has been at best summarized as a blend of psychosocial and pharmacotherapy treatments. Regardless of the heterogeneity, it was suggested that the differential effect among subtypes of CAU was not significant [33]; therefore, we interpreted the effects of CAU as a collective therapeutic strength of existing services, and encouragingly, CAU was able to produce strong improvement in symptoms of depression in the medium term (g=−0.956), which is comparable with the low end of the within-group effect sizes as estimated in the active intervention arms in DPI studies [26]。

The information control was an interesting type of control to consider given that reading educational materials is sometimes regarded as a stand-alone passive intervention. Our results showed that the information control was quite a strong intervention that produced a moderate effect immediately after the intervention period and in the short term. This is in line with previous meta-analytic findings showing that psychoeducational interventions were able to reduce symptoms of depression [154]。The effect of information controls shrank after 6 months in our study, indicating that the effect of passively receiving mental health–related information may dissipate over time. Although psychoeducation generally forms the core of most large-scale campaigns, for example, public awareness campaigns that disseminate mental health information, campaign holders may consider hosting booster sessions or setting up reminder prompts from time to time to maintain the effect in the long run.

Other control types, including sham, monitoring, and active controls, were also found to have moderate effects in the short term, and the effect was larger than that of waitlist controls. We acknowledge that the number of studies in each control category was very small and may have been subject to a small study bias. Nonetheless, the pattern of results points to the possibility that, regardless of the content of the control condition that the participants received, engagement or taking some action may help alleviate depression under the principle of behavioral activation, and these approaches fared better than simply waiting.

Subgroup analysis results also showed that, regardless of baseline severity, depressive symptoms reduced over time, although participants who started off with mild levels of severity consistently recorded a smaller effect size, possibly because of the floor effect. Studies in which there were moderate levels of depressive symptoms at baseline were associated with a steeper drop in symptoms until the medium term, and symptoms then bounced back in the long term. This implies that the participants in those studies may have reached the maximum potential for spontaneous recovery at approximately 48 weeks. Finally, the strongest effect noted in the severe subgroup beyond 48 weeks could be attributed to the exceptional efficacy of the CAU control type that dominated in this set of studies being analyzed.

Limitations

As with any study, this meta-analysis had several limitations. First, the use of pre-post (within-subject) SMD may result in biased outcomes [155]。A reason is that the estimation of pre-post SMD depends on the correlation between pre-post outcomes, which is often not reported in studies. In our meta-analysis, we used a conservative correlation ofr=0.59, which was based on the median within-group correlation found across 123 studies in the study by Balk et al [42]。然而,鉴于每个研究中可能会有所不同correlation estimate, there may be measurement error. Second, the quality of the included studies was not optimal. Almost all the studies (91/107, 85%) demonstrated some concerns associated with blinding issues given the nature of psychological interventions, be they face to face or digital [156], and possible underreporting of blinding procedures [157]。Only 4.7% (5/107) could be judged as high-quality, which was disappointing but understandable. It has been suggested that studies of poor quality generally inflate their effect sizes [158,159]; therefore, our interpretation of the findings should be taken with caution. Although it is difficult to truly blind participants in DPIs, blinding other key persons, including data managers, statisticians, and conclusion makers, is comparatively practical. Nonetheless, researchers should make an effort to blind all parties whenever possible. Mataix-Cols and Andersson [160] recently detailed 10 practical recommendations on blinding that future DPI studies should attend to.

In addition, the high degree of heterogeneity (>75%) among almost all sets of analyses made interpretation very difficult [44]。尽管我们努力回归了cts on age, gender, and education, these individual characteristics were insufficient to explain the heterogeneity. A possible reason for this high heterogeneity may be the use of a relatively broad inclusion criterion that encompassed people with any depressive symptoms along the spectrum, even though studies targeting obvious comorbid conditions, for instance, physical medical conditions, posttraumatic stress disorders, and psychotic disorders, had already been excluded. Nonetheless, we included studies with comorbid anxiety given that it is highly common and can enhance the external validity of our findings. Future analyses may try to narrow down the depression subtypes and focus on people without comorbid conditions.

Some may believe that there is no point in pooling effect sizes of such different conditions and that effect sizes should not be pooled in case of substantial statistical heterogeneity. However, we argue that those who agree to participate in a DPI RCT represent an overarching group of individuals that share a similar mentality, for instance, being open to receiving interventions and self-motivated to change. Moreover, the high heterogeneity provided important insights on the documentation of control procedures and contents. We also recommend future trials to gather information regarding external help-seeking behaviors exhibited by control participants during the study period.

Implications

Despite these limitations, this study is the first comprehensive meta-analytic review that focuses primarily on the control groups of DPI studies. It provides valuable information regarding the magnitude of improvements in depressive symptoms in various control conditions over time. We quantified the within–control-group effect sizes among a fairly large number of DPI RCTs. Our findings have important implications for intervention research and practice. In psychosocial intervention research, studies that adopt a quasi-experimental design might overstate the treatment efficacy by not being able to account for the highly significant nontreatment effects, as quantified in this study. To uphold scientific rigor, we advocate that an RCT design should be perceived as the minimum requirement, not a high standard, for conducting intervention research. Strictly speaking, a quasi-experimental design should be abandoned for this type of research.

This study also provided evidence that depressive symptoms generally decrease over time. The severity of the symptoms reduced significantly within a few weeks even without structural treatment. Here, we must clarify that it is not our intention to discourage help-seeking behaviors or discredit the values of established evidence-based treatments. Instead, we hope that, by informing of a natural remitting trajectory of depression, researchers and practitioners and, most importantly, people who are experiencing various levels of depressive symptoms themselves do not see depression as a never-changing condition and negate the possibility of spontaneous recovery. They may consider adopting watchful waiting when active mental health services are not readily available given that waitlists were found to be efficacious in the short term.

Conclusions

In summary, this meta-analysis focused on the effects of control groups in DPI studies. The results concurred with previous findings on face-to-face psychotherapy studies that control conditions were able to produce small to moderate reductions in depressive symptoms within and beyond 48 weeks. Future studies should continue to investigate the nonspecific effects in intervention studies and explore meaningful moderators to explain the heterogeneity in DPI studies.

Conflicts of Interest

None declared.

Multimedia Appendix 1

Search strategy and severity cutoffs.

PDF File (Adobe PDF File), 127 KB

Multimedia Appendix 2

Quality assessment (Cochrane risk-of-bias tool for randomized trials version 2).

PDF File (Adobe PDF File), 176 KB

Multimedia Appendix 3

Forest plots.

PDF File (Adobe PDF File), 311 KB

Multimedia Appendix 4

Funnel plots.

PDF File (Adobe PDF File), 74 KB

  1. Baumeister H, Härter M. Prevalence of mental disorders based on general population surveys. Soc Psychiatry Psychiatr Epidemiol 2007 Jul 21;42(7):537-546. [CrossRef] [Medline]
  2. Depression. World Health Organization. 2021 Sep 13. URL:https://www.who.int/news-room/fact-sheets/detail/depression[accessed 2022-04-19]
  3. Mathers CD, Loncar D. Projections of global mortality and burden of disease from 2002 to 2030. PLoS Med 2006 Nov;3(11):e442 [FREE Full text] [CrossRef] [Medline]
  4. Hammar A, Ardal G. Cognitive functioning in major depression--a summary. Front Hum Neurosci 2009;3:26 [FREE Full text] [CrossRef] [Medline]
  5. Angermeyer MC, Holzinger A, Matschinger H, Stengler-Wenzke K. Depression and quality of life: results of a follow-up study. Int J Soc Psychiatry 2002 Sep;48(3):189-199. [CrossRef] [Medline]
  6. 井KB。的功能和幸福着sed patients. JAMA 1989 Aug 18;262(7):914. [CrossRef]
  7. Chisholm D, Sweeny K, Sheehan P, Rasmussen B, Smit F, Cuijpers P, et al. Scaling-up treatment of depression and anxiety: a global return on investment analysis. Lancet Psychiatry 2016 May;3(5):415-424 [FREE Full text] [CrossRef] [Medline]
  8. 维特森解释,雅可比F,雷姆曾为此写过J, Gustavsson,斯文son M, Jönsson B, et al. The size and burden of mental disorders and other disorders of the brain in Europe 2010. Eur Neuropsychopharmacol 2011 Sep;21(9):655-679. [CrossRef] [Medline]
  9. Cuijpers P, Berking M, Andersson G, Quigley L, Kleiboer A, Dobson KS. A meta-analysis of cognitive-behavioural therapy for adult depression, alone and in comparison with other treatments. Can J Psychiatry 2013 Jul;58(7):376-385 [FREE Full text] [CrossRef] [Medline]
  10. Barth J, Munder T, Gerger H, Nüesch E, Trelle S, Znoj H, et al. Comparative efficacy of seven psychotherapeutic interventions for patients with depression: a network meta-analysis. Focus (Am Psychiatr Publ) 2016 Apr;14(2):229-243 [FREE Full text] [CrossRef] [Medline]
  11. Cuijpers P, Quero S, Dowrick C, Arroll B. Psychological treatment of depression in primary care: recent developments. Curr Psychiatry Rep 2019 Nov 23;21(12):129 [FREE Full text] [CrossRef] [Medline]
  12. Cuijpers P, Karyotaki E, Eckshtain D, Ng MY, Corteselli KA, Noma H, et al. Psychotherapy for depression across different age groups: a systematic review and meta-analysis. JAMA Psychiatry 2020 Jul 01;77(7):694-702 [FREE Full text] [CrossRef] [Medline]
  13. Hollon SD. The efficacy and acceptability of psychological interventions for depression: where we are now and where we are going. Epidemiol Psychiatr Sci 2015 Aug 27;25(4):295-300. [CrossRef]
  14. McHugh RK, Whitton SW, Peckham AD, Welge JA, Otto MW. Patient preference for psychological vs pharmacologic treatment of psychiatric disorders. J Clin Psychiatry 2013 Jun 15;74(06):595-602. [CrossRef]
  15. Alonso J, Angermeyer MC, Bernert S, Bruffaerts R, Brugha TS, Bryson H, ESEMeD/MHEDEA 2000 Investigators‚ European Study of the Epidemiology of Mental Disorders (ESEMeD) Project. Use of mental health services in Europe: results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project. Acta Psychiatr Scand Suppl 2004(420):47-54. [CrossRef] [Medline]
  16. Fu Z, Burger H, Arjadi R, Bockting CL. Effectiveness of digital psychological interventions for mental health problems in low-income and middle-income countries: a systematic review and meta-analysis. Lancet Psychiatry 2020 Oct;7(10):851-864. [CrossRef]
  17. Andersson G. Internet interventions: past, present and future. Internet Interv 2018 Jun;12:181-188 [FREE Full text] [CrossRef] [Medline]
  18. Selmi PM, Klein MH, Greist JH, Sorrell SP, Erdman HP. Computer-administered cognitive-behavioral therapy for depression. Am J Psychiatry 1990 Jan;147(1):51-56 [FREE Full text] [CrossRef] [Medline]
  19. Andersson G, Carlbring P, Berger T, Almlöv J, Cuijpers P. What makes Internet therapy work? Cogn Behav Ther 2009;38 Suppl 1:55-60. [CrossRef] [Medline]
  20. Griffiths KM, Christensen H. Internet-based mental health programs: a powerful tool in the rural medical kit. Aust J Rural Health 2007 Apr;15(2):81-87. [CrossRef] [Medline]
  21. Gega L, Smith J, Reynolds S. Cognitive behaviour therapy (CBT) for depression by computer vs. therapist: patient experiences and therapeutic processes. Psychother Res 2013 Mar;23(2):218-231. [CrossRef] [Medline]
  22. Andersson G, Cuijpers P, Carlbring P, Riper H, Hedman E. Guided Internet-based vs. face-to-face cognitive behavior therapy for psychiatric and somatic disorders: a systematic review and meta-analysis. World Psychiatry 2014 Oct;13(3):288-295 [FREE Full text] [CrossRef] [Medline]
  23. Carlbring P, Andersson G, Cuijpers P, Riper H, Hedman-Lagerlöf E. Internet-based vs. face-to-face cognitive behavior therapy for psychiatric and somatic disorders: an updated systematic review and meta-analysis. Cogn Behav Ther 2018 Jan;47(1):1-18. [CrossRef] [Medline]
  24. Andersson G, Cuijpers P. Internet-based and other computerized psychological treatments for adult depression: a meta-analysis. Cogn Behav Ther 2009;38(4):196-205. [CrossRef] [Medline]
  25. Richards D, Richardson T. Computer-based psychological treatments for depression: a systematic review and meta-analysis. Clin Psychol Rev 2012 Jun;32(4):329-342. [CrossRef] [Medline]
  26. Josephine K, Josefine L, Philipp D, David E, Harald B. Internet- and mobile-based depression interventions for people with diagnosed depression: a systematic review and meta-analysis. J Affect Disord 2017 Dec 01;223:28-40. [CrossRef] [Medline]
  27. Moshe I, Terhorst Y, Philippi P, Domhardt M, Cuijpers P, Cristea I, et al. Digital interventions for the treatment of depression: a meta-analytic review. Psychol Bull 2021 Aug;147(8):749-786. [CrossRef] [Medline]
  28. Ormel J, Kessler R, Schoevers R. Depression: more treatment but no drop in prevalence: how effective is treatment? And can we do better? Curr Opin Psychiatry 2019 Jul;32(4):348-354. [CrossRef] [Medline]
  29. Mohr DC, Spring B, Freedland KE, Beckner V, Arean P, Hollon SD, et al. The selection and design of control conditions for randomized controlled trials of psychological interventions. Psychother Psychosom 2009;78(5):275-284. [CrossRef] [Medline]
  30. Mohr DC, Ho J, Hart TL, Baron KG, Berendsen M, Beckner V, et al. Control condition design and implementation features in controlled trials: a meta-analysis of trials evaluating psychotherapy for depression. Transl Behav Med 2014 Dec 2;4(4):407-423 [FREE Full text] [CrossRef] [Medline]
  31. Cuijpers P, Driessen E, Hollon SD, van Oppen P, Barth J, Andersson G. The efficacy of non-directive supportive therapy for adult depression: a meta-analysis. Clin Psychol Rev 2012 Jun;32(4):280-291. [CrossRef] [Medline]
  32. Cuijpers P, Karyotaki E, Weitz E, Andersson G, Hollon SD, van Straten A. The effects of psychotherapies for major depression in adults on remission, recovery and improvement: a meta-analysis. J Affect Disord 2014 Apr;159:118-126. [CrossRef] [Medline]
  33. Cuijpers P, Quero S, Papola D, Cristea IA, Karyotaki E. Care-as-usual control groups across different settings in randomized trials on psychotherapy for adult depression: a meta-analysis. Psychol Med 2021 Mar 17;51(4):634-644. [CrossRef] [Medline]
  34. Whiteford HA, Harris MG, McKeon G, Baxter A, Pennell C, Barendregt JJ, et al. Estimating remission from untreated major depression: a systematic review and meta-analysis. Psychol Med 2012 Aug 10;43(8):1569-1585. [CrossRef]
  35. Furukawa TA, Noma H, Caldwell DM, Honyashiki M, Shinohara K, Imai H, et al. Waiting list may be a nocebo condition in psychotherapy trials: a contribution from network meta-analysis. Acta Psychiatr Scand 2014 Sep;130(3):181-192. [CrossRef] [Medline]
  36. Torous J, Jän Myrick K, Rauseo-Ricupero N, Firth J. Digital mental health and COVID-19: using technology today to accelerate the curve on access and quality tomorrow. JMIR Ment Health 2020 Mar 26;7(3):e18848 [FREE Full text] [CrossRef] [Medline]
  37. Cao L, Chongsuvivatwong V, McNeil EB. The sociodemographic digital divide in mobile health app use among clients at outpatient departments in inner Mongolia, China: cross-sectional survey study. JMIR Hum Factors 2022 May 19;9(2):e36962 [FREE Full text] [CrossRef] [Medline]
  38. Moher D, Shamseer L, Clarke M, Ghersi D, Liberati A, Petticrew M, PRISMA-P Group. Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) 2015 statement. Syst Rev 2015 Jan 01;4(1):1 [FREE Full text] [CrossRef] [Medline]
  39. Mueen Ahmed KK, Dhubaib BE. Zotero: a bibliographic assistant to researcher. J Pharmacol Pharmacotherapeutics 2022 Apr 11;2(4):304-305. [CrossRef]
  40. Sterne JA, Savović J, Page MJ, Elbers RG, Blencowe NS, Boutron I, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ 2019 Aug 28;366:l4898 [FREE Full text] [CrossRef] [Medline]
  41. Comprehensive Meta-Analysis Software (CMA). Comprehensive Meta-Analysis. URL:https://www.meta-analysis.com/index.php?cart=BB9R6657653[accessed 2022-04-23]
  42. U. S. Department Human Services, Agency for and Quality. Empirical Assessment of Within-Arm Correlation Imputation in Trials of Continuous Outcomes. Scotts Valley, California, US: CreateSpace Independent Publishing Platform; 2013.
  43. Lachenbruch PA, Cohen J. Statistical power analysis for the behavioral sciences (2nd ed.). J Am Stat Assoc 1989 Dec;84(408):1096. [CrossRef]
  44. Higgins JP, Thompson SG, Deeks JJ, Altman DG. Measuring inconsistency in meta-analyses. BMJ 2003 Sep 06;327(7414):557-560 [FREE Full text] [CrossRef] [Medline]
  45. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ 1997 Sep 13;315(7109):629-634 [FREE Full text] [CrossRef] [Medline]
  46. Duval S, Tweedie R. Trim and fill: a simple funnel-plot-based method of testing and adjusting for publication bias in meta-analysis. Biometrics 2000 Jun;56(2):455-463. [CrossRef] [Medline]
  47. Al-Alawi M, McCall RK, Sultan A, Al Balushi N, Al-Mahrouqi T, Al Ghailani A, et al. Efficacy of a six-week-long therapist-guided online therapy versus self-help internet-based therapy for COVID-19-induced anxiety and depression: open-label, pragmatic, randomized controlled trial. JMIR Ment Health 2021 Feb 12;8(2):e26683 [FREE Full text] [CrossRef] [Medline]
  48. Andersson G, Bergström J, Holländare F, Carlbring P, Kaldo V, Ekselius L. Internet-based self-help for depression: randomised controlled trial. Br J Psychiatry 2005 Nov;187:456-461. [CrossRef] [Medline]
  49. Beevers CG, Pearson R, Hoffman JS, Foulser AA, Shumake J, Meyer B. Effectiveness of an internet intervention (Deprexis) for depression in a united states adult sample: a parallel-group pragmatic randomized controlled trial. J Consult Clin Psychol 2017 Apr;85(4):367-380. [CrossRef] [Medline]
  50. Berger T, Krieger T, Sude K, Meyer B, Maercker A. Evaluating an e-mental health program ("deprexis") as adjunctive treatment tool in psychotherapy for depression: results of a pragmatic randomized controlled trial. J Affect Disord 2018 Feb;227:455-462. [CrossRef] [Medline]
  51. Birney AJ, Gunn R, Russell JK, Ary DV. MoodHacker mobile web app with email for adults to self-manage mild-to-moderate depression: randomized controlled trial. JMIR Mhealth Uhealth 2016 Jan 26;4(1):e8 [FREE Full text] [CrossRef] [Medline]
  52. Bohlmeijer ET, Kraiss JT, Watkins P, Schotanus-Dijkstra M. Promoting gratitude as a resource for sustainable mental health: results of a 3-armed randomized controlled trial up to 6 months follow-up. J Happiness Stud 2020 May 07;22(3):1011-1032. [CrossRef]
  53. Boschloo L, Cuijpers P, Karyotaki E, Berger T, Moritz S, Meyer B, et al. Symptom-specific effectiveness of an internet-based intervention in the treatment of mild to moderate depressive symptomatology: the potential of network estimation techniques. Behav Res Ther 2019 Nov;122:103440. [CrossRef] [Medline]
  54. Braun L, Titzler I, Terhorst Y, Freund J, Thielecke J, Ebert DD, et al. Effectiveness of guided internet-based interventions in the indicated prevention of depression in green professions (PROD-A): results of a pragmatic randomized controlled trial. J Affect Disord 2021 Jan 01;278:658-671. [CrossRef] [Medline]
  55. Browning M, Holmes EA, Charles M, Cowen PJ, Harmer CJ. Using attentional bias modification as a cognitive vaccine against depression. Biol Psychiatry 2012 Oct 01;72(7):572-579 [FREE Full text] [CrossRef] [Medline]
  56. Buntrock C, Ebert D, Lehr D, Riper H, Smit F, Cuijpers P, et al. Effectiveness of a web-based cognitive behavioural intervention for subthreshold depression: pragmatic randomised controlled trial. Psychother Psychosom 2015;84(6):348-358. [CrossRef] [Medline]
  57. Calkins AW, McMorran KE, Siegle GJ, Otto MW. The effects of computerized cognitive control training on community adults with depressed mood. Behav Cogn Psychother 2014 Mar 03;43(5):578-589. [CrossRef]
  58. Choi I, Zou J, Titov N, Dear BF, Li S, Johnston L, et al. Culturally attuned Internet treatment for depression amongst Chinese Australians: a randomised controlled trial. J Affect Disord 2012 Feb;136(3):459-468. [CrossRef] [Medline]
  59. Clarke G, Eubanks D, Reid E, Kelleher C, O'Connor E, DeBar LL, et al. Overcoming Depression on the Internet (ODIN) (2): a randomized trial of a self-help depression skills program with reminders. J Med Internet Res 2005 Jun 21;7(2):e16 [FREE Full text] [CrossRef] [Medline]
  60. Clarke G, Kelleher C, Hornbrook M, Debar L, Dickerson J, Gullion C. Randomized effectiveness trial of an internet, pure self-help, cognitive behavioral intervention for depressive symptoms in young adults. Cogn Behav Ther 2009;38(4):222-234 [FREE Full text] [CrossRef] [Medline]
  61. Dainer-Best J, Shumake JD, Beevers CG. Positive imagery training increases positive self-referent cognition in depression. Behav Res Ther 2018 Dec;111:72-83 [FREE Full text] [CrossRef] [Medline]
  62. Day V, McGrath PJ, Wojtowicz M. Internet-based guided self-help for university students with anxiety, depression and stress: a randomized controlled clinical trial. Behav Res Ther 2013 Jul;51(7):344-351. [CrossRef] [Medline]
  63. de Graaf L, Gerhards S, Arntz A, Riper H, Metsemakers J, Evers S, et al. One-year follow-up results of unsupported online computerized cognitive behavioural therapy for depression in primary care: a randomized trial. J Behav Ther Exp Psychiatry 2011 Mar;42(1):89-95. [CrossRef] [Medline]
  64. Eriksson MC, Kivi M, Hange D, Petersson E, Ariai N, Häggblad P, et al. Long-term effects of Internet-delivered cognitive behavioral therapy for depression in primary care - the PRIM-NET controlled trial. Scand J Prim Health Care 2017 Jun 06;35(2):126-136 [FREE Full text] [CrossRef] [Medline]
  65. Flygare,我,Hasselgren M, Jansson-Frojmark M, Frejgrim R, Andersson G, et al. Internet-based CBT for patients with depressive disorders in primary and psychiatric care: is it effective and does comorbidity affect outcome? Internet Interv 2020 Mar;19:100303 [FREE Full text] [CrossRef] [Medline]
  66. Fonseca A, Alves S, Monteiro F, Gorayeb R, Canavarro MC. Be a mom, a web-based intervention to prevent postpartum depression: results from a pilot randomized controlled trial. Behav Ther 2020 Jul;51(4):616-633. [CrossRef] [Medline]
  67. Geraedts AS, Kleiboer AM, Twisk J, Wiezer NM, van Mechelen W, Cuijpers P. Long-term results of a web-based guided self-help intervention for employees with depressive symptoms: randomized controlled trial. J Med Internet Res 2014 Jul 09;16(7):e168 [FREE Full text] [CrossRef] [Medline]
  68. Gilbody S, Littlewood E, Hewitt C, Brierley G, Tharmanathan P, Araya R, REEACT Team. Computerised cognitive behaviour therapy (cCBT) as treatment for depression in primary care (REEACT trial): large scale pragmatic randomised controlled trial. BMJ 2015 Nov 11;351:h5627 [FREE Full text] [CrossRef] [Medline]
  69. Gili M, Castro A, García-Palacios A, Garcia-Campayo J, Mayoral-Cleries F, Botella C, et al. Efficacy of three low-intensity, internet-based psychological interventions for the treatment of depression in primary care: randomized controlled trial. J Med Internet Res 2020 Jun 5;22(6):e15845. [CrossRef]
  70. Hallford D, Austin D, Takano K, Fuller-Tyszkiewicz M, Raes F. Computerized Memory Specificity Training (c-MeST) for major depression: a randomised controlled trial. Behav Res Ther 2021 Jan;136:103783. [CrossRef] [Medline]
  71. Hallgren M, Helgadóttir B, Herring MP, Zeebari Z, Lindefors N, Kaldo V, et al. Exercise and internet-based cognitive-behavioural therapy for depression: multicentre randomised controlled trial with 12-month follow-up. Br J Psychiatry 2016 Nov 02;209(5):414-420 [FREE Full text] [CrossRef] [Medline]
  72. Hange D, Ariai N, Kivi M, Eriksson M, Nejati S, Petersson E. The impact of internet-based cognitive behavior therapy on work ability in patients with depression – a randomized controlled study. IJGM 2017 May;Volume 10:151-159. [CrossRef]
  73. Harrer M, Apolinário-Hagen J, Fritsche L, Salewski C, Zarski A, Lehr D, et al. Effect of an internet- and app-based stress intervention compared to online psychoeducation in university students with depressive symptoms: results of a randomized controlled trial. Internet Interv 2021 Apr;24:100374 [FREE Full text] [CrossRef] [Medline]
  74. Hatcher S, Whittaker R, Patton M, Miles WS, Ralph N, Kercher K, et al. Web-based therapy plus support by a coach in depressed patients referred to secondary mental health care: randomized controlled trial. JMIR Ment Health 2018 Jan 23;5(1):e5 [FREE Full text] [CrossRef] [Medline]
  75. Heim E, Ramia JA, Hana RA, Burchert S, Carswell K, Cornelisz I, et al. Step-by-step: feasibility randomised controlled trial of a mobile-based intervention for depression among populations affected by adversity in Lebanon. Internet Interv 2021 Apr;24:100380 [FREE Full text] [CrossRef] [Medline]
  76. Hirsch CR, Krahé C, Whyte J, Loizou S, Bridge L, Norton S, et al. Interpretation training to target repetitive negative thinking in generalized anxiety disorder and depression. J Consult Clin Psychol 2018 Dec;86(12):1017-1030. [CrossRef] [Medline]
  77. Hobfoll SE, Blais RK, Stevens NR, Walt L, Gengler R. Vets prevail online intervention reduces PTSD and depression in veterans with mild-to-moderate symptoms. J Consult Clin Psychol 2016 Jan;84(1):31-42. [CrossRef] [Medline]
  78. Høifødt RS, Lillevoll KR, Griffiths KM, Wilsgaard T, Eisemann M, Waterloo K, et al. The clinical effectiveness of web-based cognitive behavioral therapy with face-to-face therapist support for depressed primary care patients: randomized controlled trial. J Med Internet Res 2013 Aug 05;15(8):e153 [FREE Full text] [CrossRef] [Medline]
  79. Holländare F, Johnsson S, Randestad M, Tillfors M, Carlbring P, Andersson G, et al. Randomized trial of internet-based relapse prevention for partially remitted depression. Acta Psychiatr Scand 2011 Oct;124(4):285-294. [CrossRef] [Medline]
  80. Holst A, Björkelund C, Metsini A, Madsen J, Hange D, Petersson EL, et al. Cost-effectiveness analysis of internet-mediated cognitive behavioural therapy for depression in the primary care setting: results based on a controlled trial. BMJ Open 2018 Jun 14;8(6):e019716 [FREE Full text] [CrossRef] [Medline]
  81. Hoorelbeke K, Koster EH. Internet-delivered cognitive control training as a preventive intervention for remitted depressed patients: evidence from a double-blind randomized controlled trial study. J Consult Clin Psychol 2017 Feb;85(2):135-146. [CrossRef] [Medline]
  82. Jelinek L, Arlt S, Moritz S, Schröder J, Westermann S, Cludius B. Brief web-based intervention for depression: randomized controlled trial on behavioral activation. J Med Internet Res 2020 Mar 26;22(3):e15312 [FREE Full text] [CrossRef] [Medline]
  83. 约翰斯on O, Bjärehed J, Andersson G, Carlbring P, Lundh L. Effectiveness of guided internet-delivered cognitive behavior therapy for depression in routine psychiatry: a randomized controlled trial. Internet Interv 2019 Sep;17:100247 [FREE Full text] [CrossRef] [Medline]
  84. 约翰斯on R, Björklund M, Hornborg C, Karlsson S, Hesser H, Ljótsson B, et al. Affect-focused psychodynamic psychotherapy for depression and anxiety through the Internet: a randomized controlled trial. PeerJ 2013;1:e102 [FREE Full text] [CrossRef] [Medline]
  85. 约翰斯on R, Ekbladh S, Hebert A, Lindström M, Möller S, Petitt E, et al. Psychodynamic guided self-help for adult depression through the internet: a randomised controlled trial. PLoS One 2012 May 29;7(5):e38021 [FREE Full text] [CrossRef] [Medline]
  86. 约翰斯on R, Sjöberg E, Sjögren M, Johnsson E, Carlbring P, Andersson T, et al. Tailored vs. standardized internet-based cognitive behavior therapy for depression and comorbid symptoms: a randomized controlled trial. PLoS One 2012;7(5):e36905 [FREE Full text] [CrossRef] [Medline]
  87. Kessler D, Lewis G, Kaur S, Wiles N, King M, Weich S, et al. Therapist-delivered Internet psychotherapy for depression in primary care: a randomised controlled trial. Lancet 2009 Aug 22;374(9690):628-634. [CrossRef] [Medline]
  88. Kivi M, Eriksson MC, Hange D, Petersson E, Vernmark K, Johansson B, et al. Internet-based therapy for mild to moderate depression in Swedish primary care: short term results from the PRIM-NET randomized controlled trial. Cogn Behav Ther 2014 Jun 09;43(4):289-298 [FREE Full text] [CrossRef] [Medline]
  89. Kladnitski N, Smith J, Uppal S, James MA, Allen AR, Andrews G, et al. Transdiagnostic internet-delivered CBT and mindfulness-based treatment for depression and anxiety: a randomised controlled trial. Internet Interv 2020 Apr;20:100310 [FREE Full text] [CrossRef] [Medline]
  90. Klein JP, Späth C, Schröder J, Meyer B, Greiner W, Hautzinger M, et al. Time to remission from mild to moderate depressive symptoms: one year results from the EVIDENT-study, an RCT of an internet intervention for depression. Behav Res Ther 2017 Oct;97:154-162. [CrossRef] [Medline]
  91. Kok G, Burger H, Riper H, Cuijpers P, Dekker J, van Marwijk H, et al. The three-month effect of mobile internet-based cognitive therapy on the course of depressive symptoms in remitted recurrently depressed patients: results of a randomized controlled trial. Psychother Psychosom 2015 Feb 21;84(2):90-99. [CrossRef] [Medline]
  92. Levesque DA, Van Marter DF, Schneider RJ, Bauer MR, Goldberg DN, Prochaska JO, et al. Randomized trial of a computer-tailored intervention for patients with depression. Am J Health Promot 2011 Nov 01;26(2):77-89. [CrossRef]
  93. Levin W, Campbell DR, McGovern KB, Gau JM, Kosty DB, Seeley JR, et al. A computer-assisted depression intervention in primary care. Psychol Med 2010 Oct 20;41(7):1373-1383. [CrossRef]
  94. Lindegaard T, Seaton F, Halaj A, Berg M, Kashoush F, Barchini R, et al. Internet-based cognitive behavioural therapy for depression and anxiety among Arabic-speaking individuals in Sweden: a pilot randomized controlled trial. Cogn Behav Ther 2021 Jan 30;50(1):47-66 [FREE Full text] [CrossRef] [Medline]
  95. Lokman S, Leone SS, Sommers-Spijkerman M, van der Poel A, Smit F, Boon B. Complaint-directed mini-interventions for depressive complaints: a randomized controlled trial of unguided web-based self-help interventions. J Med Internet Res 2017 Jan 04;19(1):e4 [FREE Full text] [CrossRef] [Medline]
  96. Loughnan SA, Sie A, Hobbs MJ, Joubert AE, Smith J, Haskelberg H, et al. A randomized controlled trial of 'MUMentum Pregnancy': internet-delivered cognitive behavioral therapy program for antenatal anxiety and depression. J Affect Disord 2019 Jan 15;243:381-390. [CrossRef] [Medline]
  97. Loughnan SA, Butler C, Sie AA, Grierson AB, Chen AZ, Hobbs MJ, et al. A randomised controlled trial of 'MUMentum postnatal': internet-delivered cognitive behavioural therapy for anxiety and depression in postpartum women. Behav Res Ther 2019 May;116:94-103. [CrossRef] [Medline]
  98. Lu SH, Assudani HA, Kwek TR, Ng SW, Teoh TE, Tan GC. A randomised controlled trial of clinician-guided internet-based cognitive behavioural therapy for depressed patients in Singapore. Front Psychol 2021 Jul 29;12:668384 [FREE Full text] [CrossRef] [Medline]
  99. Lüdtke T, Westermann S, Pult LK, Schneider BC, Pfuhl G, Moritz S. Evaluation of a brief unguided psychological online intervention for depression: a controlled trial including exploratory moderator analyses. Internet Intervent 2018 Sep;13:73-81. [CrossRef]
  100. Lukas CA, Berking M. Blending group-based psychoeducation with a smartphone intervention for the reduction of depressive symptoms: results of a randomized controlled pilot study. Pilot Feasibility Stud 2021 Feb 24;7(1):57 [FREE Full text] [CrossRef] [Medline]
  101. McCloud T, Jones R, Lewis G, Bell V, Tsakanikos E. Effectiveness of a mobile app intervention for anxiety and depression symptoms in university students: randomized controlled trial. JMIR Mhealth Uhealth 2020 Jul 31;8(7):e15418 [FREE Full text] [CrossRef] [Medline]
  102. Meglic M, Furlan M, Kuzmanic M, Kozel D, Baraga D, Kuhar I, et al. Feasibility of an eHealth service to support collaborative depression care: results of a pilot study. J Med Internet Res 2010 Dec 19;12(5):e63 [FREE Full text] [CrossRef] [Medline]
  103. 迈耶B, Bierbrodt J,施罗德J,伯杰T, Beevers CG, Weiss M, et al. Effects of an Internet intervention (Deprexis) on severe depression symptoms: randomized controlled trial. Internet Intervent 2015 Mar;2(1):48-59. [CrossRef]
  104. Milgrom J, Danaher BG, Gemmill AW, Holt C, Holt CJ, Seeley JR, et al. Internet cognitive behavioral therapy for women with postnatal depression: a randomized controlled trial of MumMoodBooster. J Med Internet Res 2016 Mar 07;18(3):e54 [FREE Full text] [CrossRef] [Medline]
  105. Mira A, Bretón-López J, García-Palacios A, Quero S, Baños RM, Botella C. An internet-based program for depressive symptoms using human and automated support: a randomized controlled trial. Neuropsychiatr Dis Treat 2017 Mar;Volume 13:987-1006. [CrossRef]
  106. Moberg C, Niles A, Beermann D. Guided self-help works: randomized waitlist controlled trial of pacifica, a mobile app integrating cognitive behavioral therapy and mindfulness for stress, anxiety, and depression. J Med Internet Res 2019 Jun 08;21(6):e12556 [FREE Full text] [CrossRef] [Medline]
  107. Monteiro F, Pereira M, Canavarro MC, Fonseca A. Be a mom's efficacy in enhancing positive mental health among postpartum women presenting low risk for postpartum depression: results from a pilot randomized trial. Int J Environ Res Public Health 2020 Jun 29;17(13):4679 [FREE Full text] [CrossRef] [Medline]
  108. Montero-Marín J, Araya R, Pérez-Yus MC, Mayoral F, Gili M, Botella C, et al. An internet-based intervention for depression in primary care in Spain: a randomized controlled trial. J Med Internet Res 2016 Aug 26;18(8):e231 [FREE Full text] [CrossRef] [Medline]
  109. Morgan AJ, Jorm AF, Mackinnon AJ. Email-based promotion of self-help for subthreshold depression: mood memos randomised controlled trial. Br J Psychiatry 2012 May;200(5):412-418. [CrossRef] [Medline]
  110. Morgan AJ, Jorm AF, Mackinnon AJ. Self-help for depression via e-mail: a randomised controlled trial of effects on depression and self-help behaviour. PLoS One 2013 Jun 21;8(6):e66537 [FREE Full text] [CrossRef] [Medline]
  111. Moritz S, Schilling L, Hauschildt M, Schröder J, Treszl A. A randomized controlled trial of internet-based therapy in depression. Behav Res Ther 2012 Aug;50(7-8):513-521. [CrossRef] [Medline]
  112. Mullin A, Dear BF, Karin E, Wootton BM, Staples LG, Johnston L, et al. The UniWellbeing course: a randomised controlled trial of a transdiagnostic internet-delivered cognitive behavioural therapy (CBT) programme for university students with symptoms of anxiety and depression. Internet Intervent 2015 May;2(2):128-136 [FREE Full text] [CrossRef]
  113. Newby JM, Mackenzie A, Williams AD, McIntyre K, Watts S, Wong N, et al. Internet cognitive behavioural therapy for mixed anxiety and depression: a randomized controlled trial and evidence of effectiveness in primary care. Psychol Med 2013 Feb 18;43(12):2635-2648. [CrossRef]
  114. Newby JM, Lang T, Werner-Seidler A, Holmes E, Moulds ML. Alleviating distressing intrusive memories in depression: a comparison between computerised cognitive bias modification and cognitive behavioural education. Behav Res Ther 2014 May;56(100):60-67. [CrossRef] [Medline]
  115. Noguchi R, Sekizawa Y, So M, Yamaguchi S, Shimizu E. Effects of five-minute internet-based cognitive behavioral therapy and simplified emotion-focused mindfulness on depressive symptoms: a randomized controlled trial. BMC Psychiatry 2017 Mar 04;17(1):85 [FREE Full text] [CrossRef] [Medline]
  116. Nygren T, Brohede D, Koshnaw K, Osman SS, Johansson R, Andersson G. Internet-based treatment of depressive symptoms in a Kurdish population: a randomized controlled trial. J Clin Psychol 2019 Jun 31;75(6):985-998. [CrossRef] [Medline]
  117. O'Mahen HA, Richards DA, Woodford J, Wilkinson E, McGinley J, Taylor RS, et al. Netmums: a phase II randomized controlled trial of a guided internet behavioural activation treatment for postpartum depression. Psychol Med 2014 Jun;44(8):1675-1689 [FREE Full text] [CrossRef] [Medline]
  118. Oehler C, Görges F, Rogalla M, Rummel-Kluge C, Hegerl U. Efficacy of a guided web-based self-management intervention for depression or dysthymia: randomized controlled trial with a 12-month follow-up using an active control condition. J Med Internet Res 2020 Jul 14;22(7):e15361 [FREE Full text] [CrossRef] [Medline]
  119. Ofoegbu T, Asogwa U, Otu M, Ibenegbu C, Muhammed A, Eze B. Efficacy of guided internet-assisted intervention on depression reduction among educational technology students of Nigerian universities. Medicine (Baltimore) 2020 Feb;99(6):e18774 [FREE Full text] [CrossRef] [Medline]
  120. Pfeiffer PN, Pope B, Houck M, Benn-Burton W, Zivin K, Ganoczy D, et al. Effectiveness of peer-supported computer-based CBT for depression among veterans in primary care. Psychiatr Serv 2020 Mar 01;71(3):256-262. [CrossRef] [Medline]
  121. 菲利普斯R,施耐德J, Molosankwe我Leese M,佛roushani PS, Grime P, et al. Randomized controlled trial of computerized cognitive behavioural therapy for depressive symptoms: effectiveness and costs of a workplace intervention. Psychol Med 2014 Mar;44(4):741-752 [FREE Full text] [CrossRef] [Medline]
  122. Pictet A, Jermann F, Ceschi G. When less could be more: investigating the effects of a brief internet-based imagery cognitive bias modification intervention in depression. Behav Res Ther 2016 Sep;84:45-51. [CrossRef] [Medline]
  123. Pots WT, Fledderus M, Meulenbeek PA, ten Klooster PM, Schreurs KM, Bohlmeijer ET. Acceptance and commitment therapy as a web-based intervention for depressive symptoms: randomised controlled trial. Br J Psychiatry 2016 Jan;208(1):69-77. [CrossRef] [Medline]
  124. Proudfoot J, Goldberg D, Mann A, Everitt B, Marks I, Gray JA. Computerized, interactive, multimedia cognitive-behavioural program for anxiety and depression in general practice. Psychol Med 2003 Feb 14;33(2):217-227. [CrossRef] [Medline]
  125. Proudfoot J, Ryden C,埃维里特B,夏皮罗达,Goldberg D, Mann A, et al. Clinical efficacy of computerised cognitive-behavioural therapy for anxiety and depression in primary care: randomised controlled trial. Br J Psychiatry 2004 Jul 01;185(1):46-54. [CrossRef] [Medline]
  126. Proudfoot J, Clarke J, Birch M, Whitton AE, Parker G, Manicavasagar V, et al. Impact of a mobile phone and web program on symptom and functional outcomes for people with mild-to-moderate depression, anxiety and stress: a randomised controlled trial. BMC Psychiatry 2013 Nov 18;13:312 [FREE Full text] [CrossRef] [Medline]
  127. Reins JA, Boß L, Lehr D, Berking M, Ebert DD. The more I got, the less I need? Efficacy of Internet-based guided self-help compared to online psychoeducation for major depressive disorder. J Affect Disord 2019 Mar 01;246:695-705. [CrossRef] [Medline]
  128. Richards D, Timulak L, O'Brien E, Hayes C, Vigano N, Sharry J, et al. A randomized controlled trial of an internet-delivered treatment: its potential as a low-intensity community intervention for adults with symptoms of depression. Behav Res Ther 2015 Dec;75:20-31. [CrossRef] [Medline]
  129. Richards D, Enrique A, Eilert N, Franklin M, Palacios J, Duffy D, et al. Erratum: author correction: a pragmatic randomized waitlist-controlled effectiveness and cost-effectiveness trial of digital interventions for depression and anxiety. NPJ Digit Med 2020 Jun 30;3(1):91 [FREE Full text] [CrossRef] [Medline]
  130. Ritvo P, Knyahnytska Y, Pirbaglou M, Wang W, Tomlinson G, Zhao H, et al. Online mindfulness-based cognitive behavioral therapy intervention for youth with major depressive disorders: randomized controlled trial. J Med Internet Res 2021 Mar 10;23(3):e24380 [FREE Full text] [CrossRef] [Medline]
  131. Robichaud M, Talbot F, Titov N, Dear BF, Hadjistavropoulos HD, Hadjistavropoulos T, et al. Facilitating access to iCBT: a randomized controlled trial assessing a translated version of an empirically validated program using a minimally monitored delivery model. Behav Cogn Psychother 2019 Aug 16;48(2):185-202. [CrossRef]
  132. Roepke AM, Jaffee SR, Riffle OM, McGonigal J, Broome R, Maxwell B. Randomized controlled trial of SuperBetter, a smartphone-based/internet-based self-help tool to reduce depressive symptoms. Games Health J 2015 Jun;4(3):235-246. [CrossRef] [Medline]
  133. Rollman BL, Herbeck Belnap B, Abebe KZ, Spring MB, Rotondi AJ, Rothenberger SD, et al. Effectiveness of online collaborative care for treating mood and anxiety disorders in primary care: a randomized clinical trial. JAMA Psychiatry 2018 Jan 01;75(1):56-64 [FREE Full text] [CrossRef] [Medline]
  134. Romero-Sanchiz P, Nogueira-Arjona R, García-Ruiz A, Luciano JV, García Campayo J, Gili M, et al. Economic evaluation of a guided and unguided internet-based CBT intervention for major depression: results from a multi-center, three-armed randomized controlled trial conducted in primary care. PLoS One 2017;12(2):e0172741 [FREE Full text] [CrossRef] [Medline]
  135. Rosso IM, Killgore WD, Olson EA, Webb CA, Fukunaga R, Auerbach RP, et al. Internet-based cognitive behavior therapy for major depressive disorder: a randomized controlled trial. Depress Anxiety 2017 Mar 23;34(3):236-245 [FREE Full text] [CrossRef] [Medline]
  136. Ruehlman L, Karoly P. A pilot test of Internet-delivered brief interactive training sessions for depression: evaluating dropout, uptake, adherence, and outcome. J Am Coll Health 2021 Sep 01:1-9. [CrossRef] [Medline]
  137. Salamanca-Sanabria A, Richards D, Timulak L, Connell S, Mojica Perilla M, Parra-Villa Y, et al. A culturally adapted cognitive behavioral internet-delivered intervention for depressive symptoms: randomized controlled trial. JMIR Ment Health 2020 Jan 31;7(1):e13392 [FREE Full text] [CrossRef] [Medline]
  138. Salisbury C, O'Cathain A, Edwards L, Thomas C, Gaunt D, Hollinghurst S, et al. Effectiveness of an integrated telehealth service for patients with depression: a pragmatic randomised controlled trial of a complex intervention. Lancet Psychiatry 2016 Jun;3(6):515-525. [CrossRef]
  139. Sandoval LR, Buckey JC, Ainslie R, Tombari M, Stone W, Hegel MT. Randomized controlled trial of a computerized interactive media-based problem solving treatment for depression. Behav Ther 2017 May;48(3):413-425 [FREE Full text] [CrossRef] [Medline]
  140. Schure MB, Lindow JC, Greist JH, Nakonezny PA, Bailey SJ, Bryan WL, et al. Use of a fully automated internet-based cognitive behavior therapy intervention in a community population of adults with depression symptoms: randomized controlled trial. J Med Internet Res 2019 Nov 18;21(11):e14754 [FREE Full text] [CrossRef] [Medline]
  141. Segal ZV, Dimidjian S, Beck A, Boggs JM, Vanderkruik R, Metcalf CA, et al. Outcomes of online mindfulness-based cognitive therapy for patients with residual depressive symptoms: a randomized clinical trial. JAMA Psychiatry 2020 Jun 01;77(6):563-573 [FREE Full text] [CrossRef] [Medline]
  142. Smith J, Newby JM, Burston N, Murphy MJ, Michael S, Mackenzie A, et al. Help from home for depression: a randomised controlled trial comparing internet-delivered cognitive behaviour therapy with bibliotherapy for depression. Internet Interv 2017 Sep;9:25-37 [FREE Full text] [CrossRef] [Medline]
  143. Sun Y, Li Y, Wang J, Chen Q, Bazzano AN, Cao F. Effectiveness of smartphone-based mindfulness training on maternal perinatal depression: randomized controlled trial. J Med Internet Res 2021 Jan 27;23(1):e23410 [FREE Full text] [CrossRef] [Medline]
  144. Terides MD, Dear BF, Fogliati VJ, Gandy M, Karin E, Jones MP, et al. Increased skills usage statistically mediates symptom reduction in self-guided internet-delivered cognitive-behavioural therapy for depression and anxiety: a randomised controlled trial. Cogn Behav Ther 2018 Jan;47(1):43-61. [CrossRef] [Medline]
  145. Titov N, Andrews G, Davies M, McIntyre K, Robinson E, Solley K. Internet treatment for depression: a randomized controlled trial comparing clinician vs. technician assistance. PLoS One 2010 Jun 08;5(6):e10939 [FREE Full text] [CrossRef] [Medline]
  146. Titov N, Dear BF, Johnston L, McEvoy PM, Wootton B, Terides MD, et al. Improving adherence and clinical outcomes in self-guided internet treatment for anxiety and depression: a 12-month follow-up of a randomised controlled trial. PLoS One 2014 Feb 25;9(2):e89591 [FREE Full text] [CrossRef] [Medline]
  147. Tönnies J, Hartmann M, Wensing M, Szecsenyi J, Peters-Klimm F, Brinster R, et al. Mental health specialist video consultations versus treatment-as-usual for patients with depression or anxiety disorders in primary care: randomized controlled feasibility trial. JMIR Ment Health 2021 Mar 12;8(3):e22569 [FREE Full text] [CrossRef] [Medline]
  148. Tønning ML, Faurholt-Jepsen M, Frost M, Martiny K, Tuxen N, Rosenberg N, et al. The effect of smartphone-based monitoring and treatment on the rate and duration of psychiatric readmission in patients with unipolar depressive disorder: the RADMIS randomized controlled trial. J Affect Disord 2021 Mar 01;282:354-363. [CrossRef] [Medline]
  149. Tulbure BT, Andersson G, Sălăgean N, Pearce M, Koenig HG. Religious versus conventional internet-based cognitive behavioral therapy for depression. J Relig Health 2018 Oct 24;57(5):1634-1648. [CrossRef] [Medline]
  150. Twomey C, O'Reilly G, Byrne M, Bury M, White A, Kissane S, et al. A randomized controlled trial of the computerized CBT programme, MoodGYM, for public mental health service users waiting for interventions. Br J Clin Psychol 2014 Nov;53(4):433-450. [CrossRef] [Medline]
  151. Warmerdam L, van Straten A, Twisk J, Riper H, Cuijpers P. Internet-based treatment for adults with depressive symptoms: randomized controlled trial. J Med Internet Res 2008 Nov 20;10(4):e44 [FREE Full text] [CrossRef] [Medline]
  152. Yeung A, Wang F, Feng F, Zhang J, Cooper A, Hong L, et al. Outcomes of an online computerized cognitive behavioral treatment program for treating Chinese patients with depression: a pilot study. Asian J Psychiatr 2018 Dec;38:102-107. [CrossRef] [Medline]
  153. Zwerenz R, Becker J, Knickenberg RJ, Siepmann M, Hagen K, Beutel ME. Online self-help as an add-on to inpatient psychotherapy: efficacy of a new blended treatment approach. Psychother Psychosom 2017;86(6):341-350. [CrossRef] [Medline]
  154. Donker T, Griffiths KM, Cuijpers P, Christensen H. Psychoeducation for depression, anxiety and psychological distress: a meta-analysis. BMC Med 2009 Dec 16;7:79 [FREE Full text] [CrossRef] [Medline]
  155. Cuijpers P, Weitz E, Cristea IA, Twisk J. Pre-post effect sizes should be avoided in meta-analyses. Epidemiol Psychiatr Sci 2016 Oct 28;26(4):364-368. [CrossRef]
  156. Greenwood H, Krzyzaniak N, Peiris R, Clark J, Scott AM, Cardona M, et al. Telehealth versus face-to-face psychotherapy for less common mental health conditions: systematic review and meta-analysis of randomized controlled trials. JMIR Ment Health 2022 Mar 11;9(3):e31780 [FREE Full text] [CrossRef] [Medline]
  157. Juul年代,Gluud C,西蒙森年代,Frandsen弗兰克-威廉姆斯,我樱桃白兰地, Jakobsen JC. Blinding in randomised clinical trials of psychological interventions: a retrospective study of published trial reports. BMJ Evid Based Med 2021 Jun 30;26(3):109. [CrossRef] [Medline]
  158. 特纳Savovic J R, Mawdsley D,琼斯他,BeynonR, Higgins JP, et al. Association between risk-of-bias assessments and results of randomized trials in cochrane reviews: the ROBES meta-epidemiologic study. Am J Epidemiol 2018 May 01;187(5):1113-1122 [FREE Full text] [CrossRef] [Medline]
  159. Cuijpers P, van Straten A, Bohlmeijer E, Hollon SD, Andersson G. The effects of psychotherapy for adult depression are overestimated: a meta-analysis of study quality and effect size. Psychol Med 2009 Jun 03;40(2):211-223. [CrossRef]
  160. Mataix-Cols D, Andersson E. Ten practical recommendations for improving blinding integrity and reporting in psychotherapy trials. JAMA Psychiatry 2021 Sep 01;78(9):943-944. [CrossRef] [Medline]


CAU:care as usual
CBT:cognitive behavioral therapy
DPI:digital-based psychological intervention
PRISMA:Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PRISMA-P:Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols
RCT:randomized controlled trial
RoB 2:Cochrane risk-of-bias tool for randomized trials version 2
SMD:standardized mean difference


Edited by A Mavragani; submitted 26.04.22; peer-reviewed by J Sung, H Ayatollahi; comments to author 31.08.22; revised version received 30.11.22; accepted 21.02.23; published 12.04.23

Copyright

©Alan CY Tong, Florence SY Ho, Owen HH Chu, Winnie WS Mak. Originally published in the Journal of Medical Internet Research (//www.mybigtv.com), 12.04.2023.

This is an open-access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work, first published in the Journal of Medical Internet Research, is properly cited. The complete bibliographic information, a link to the original publication on //www.mybigtv.com/, as well as this copyright and license information must be included.


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