Efficacy Of Computer- And/or Internet-based Cbt Self-help Treatment With Minimal Guidance
In this meta-analysis we analyzed the efficacy of computer- and/or internet-based CBT self-help programs for depression with minimal guidance through 18 samples (17 RCTs) with a total of 3134 participants. The results revealed that the participants in the intervention group, who participated in CBT self-help programs with weekly minimal guidance, significantly improved their depression symptoms with medium to large effect size of -0.60 at post-intervention compared with those in the control group. This result approximates the effect size of 0.64 [57] and effect size of 0.63 [58] reported in previous meta-analyses. In a recent systematic review and meta-analysis [59] from 2021, it was also found that guided internet-based CBT was associated with more effectiveness in reducing depressive symptoms than control conditions.
Moreover, analyses of depression outcomes, using post-intervention end-point scores for individual scales of depression, also showed that the intervention group was favored significantly (PHQ-9 [26] _ SMD − 0.54; BDI-II [27] _ SMD − 0.81; CES-D [31] _ SMD − 0.52) over the control group.
In addition, the results of this analysis indicate a high degree of heterogeneity (I2 = 83%).
Hence, computer- and/or internet-based CBT self-help for depression with minimal weekly guidance (up to 10 minutes) can be useful in reducing depression symptoms for adults and adolescents. Firstly, this information can help patients with depression to receive a suitable self-help treatment and to bridge the waiting time for professional face-to-face treatment. Secondly, it would help the clinicians to make the decision about using CBT-based self-help treatments for patients who do not need urgent professional treatment, or to combine it with face-to-face therapy [13].
Comparison of the effectiveness of computer- and/or internet-based self-help treatment for depression by the type of minimal guidance
A total of 17 Studies (18 samples) with 2732 participants were included for this analysis. Six studies (with a total 1164 participants) assessed the efficacy of e-mail-supported computer/internet-based CBT self-help programs among 1164 participants. Four studies (total five samples with 882 participants) assessed the efficacy of depression treatment supported by telephone calls. 467 participants in five studies were guided by e-mails and telephone calls together. 219 participants in two studies received face-to-face minimal guidance.
The findings of this analysis revealed that CBT-based self-help treatments for depression, provided by computer or internet, can be beneficial in reducing depression symptoms by every single type of guidance (described above). Although the participants in the treatment condition, who received weekly minimal guidance by e-mail (SMD − 0.63), by e-mail and telephone calls together (SMD − 0.74), or face-to-face (SMD − 0.66); showed significant improvements, with medium to large effect sizes in reducing their depression symptoms compared to participants in the control condition. The participants in the treatment group supported by weekly telephone calls only (SMD − 0.33) showed no statistically significant difference in reducing depression symptoms compared to the control group. Furthermore, the intervention group with a combination of guidance types, e.g. e-mails and telephone calls together, showed more statistically significant reduction of depression symptoms than any other treatment group compared to control group.
There are some studies [16, 43, 60, 61] or meta-analyses [59, 62, 63] in this field studying the necessity of guidance for more effectiveness of CBT-based self-help treatments for depression.
To our knowledge, no previous meta-analysis on self-help treatments for depression has compared the potential differences of the treatment groups, whilst distinguishing types of minimal guidance, e.g. by e-mail, by telephone calls, by e-mail and telephone calls together, or face-to-face minimal support. We could find only one study [64] that compared the effectiveness of internet-based CBT self-help guided either by telephone calls or e-mail correspondence (approx. 15 minutes per participant and week) among patients with major depression at post-treatment. In this study, no difference between these two groups was found. However, it should be noted that the previous study had a small sample size, limiting the statistical power to detect between-group differences.
Therefore, our findings may be very important for planning and making decisions about the support type of future computer- and/or internet-based CBT self-help interventions for depression.
Acceptability of computer- and/or internet-based CBT self-help with minimal guidance
Participant drop-outs were reported in 14 studies (15 samples). The analysis of treatment acceptability showed that the participants in the treatment condition were 1.35 times more likely to drop out from the intervention condition than the participants in the control condition. In total, 19.49% of participants dropped out from the intervention and 15.98% from the control condition. These findings are consistent with the majority of studies or meta-analyses examining internet-based CBT self-help treatments [14, 65–68].
Greater drop-outs in the treatment condition compared to the control condition could be caused by many factors: first, the self-help treatment with minimal guidance may have helped patients to reduce their depression severity before post-treatment measurements and they therefore had no need to continue the treatment. Second, self-help treatment required too much time and energy, or they had technical difficulties, e.g. in using the computer/internet. As far as the acceptability in the control group is concerned, one of the reasons why patients were less likely to drop out from the study compared to the treatment condition may be the promise of receiving adequate treatment after the waiting time (wait list control condition).
The drop-out rate for computer- and/or internet-based treatment condition found in this meta-analysis (19.49%) or in another meta-analysis (22%) [65] was even lower than the drop-out rate (24.63%) of a meta-analysis, which explored the effectiveness and drop-out rate of face-to-face CBT in outpatients [69].
Strengths, limitations and implications for future search
In our reality with the world pandemic situation since 2020, computer-based programs for mental health, and not only in this field, are gaining more and more relevance. Working from home or arranging everyday tasks from home became very popular and actual in 2020 to combat the spread of Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2 virus) [70]. The still existing pandemic situation or the fear of being infected may be one of the biggest influencing factors why people with depression symptoms would avoid seeking a face-to-face treatment. So, due to the pandemic and with it associated changed contact situations there is now, more than ever, a need of alternatives of face-to-face interventions like self-help.
In this pandemic situation (or for future possible pandemics) computer-based self-help programs for people who are suffering from depression symptoms might be a smart healthcare offer to reduce these symptoms, or to prevent an increase in the severity of depression. As this meta-analysis includes studies until 2018, it would be useful to conduct reviews or meta-analyses that would include studies on efficacy of self-help programs during the pandemic.
In order to minimize bias during the literature search and selection of publications, a clearly defined set of inclusion and exclusion criteria was used. The current review had clearly defined criteria regarding participants, intervention, study design, and outcomes.
Funnel plots were inspected for the outcomes measures to assess the likely presence of publication bias. There was no evidence of possible funnel plot asymmetry for either outcome. The graphs appeared to be symmetrical.
A low to moderate risk of bias was due to insufficient details reported in included studies. Moderate to high risk of bias was detected only in case of performance bias. However, it is very difficult or sometimes even impossible to achieve total blinding of personnel and participants in such psychotherapeutic studies.
This meta-analysis has several limitations that also may present an opportunity for areas of future research and practice. The most compelling limitations of the present meta-analysis are the limitations of the individual studies included.
Firstly, the included RCTs had been assessed as moderate to high in methodologic quality, which allows to conclude that the present meta-analysis is relatively free from critical bias. But, the risk of bias classification as high, low or unclear may have led to over- or underestimation in the results. The assessment of any risk of bias as ‘unclear risk of bias’, in reality, may have included potential of ‘high risk of bias’ or ‘low risk of bias’. A lack of detailed information described in some original studies about selection, performance, detection, attrition and outcome process could make it difficult to be assessed as a real risk of bias.
Secondly, although there were significant positive effects of self-help treatments in reducing depression symptoms, there were high drop-out rates reported in the original studies. Given that the number of dropped out participants from the study was higher in the treatment group than in the control condition, it would be very important for future research to examine the reasons provoking high drop-out rates in treatment as well as in control conditions.
Thirdly, different programs with different number of sessions of computer- and/or internet-based CBT self-help tend to report different effect sizes.
Fourthly, we evaluated the efficacy of CBT-based self-help programs only at post-treatment, i.e. only short-term benefits of computer- and/or internet-based CBT self-help programs with minimal guidance were investigated. The long-term benefits of these kind of programs remain unclear. For future research it would be very important to explore not only short-term but also long-term benefits.
In addition, our findings may be at risk of availability bias due to 36 studies, that are either ongoing or still awaiting assessment due to insufficient information for their inclusion or exclusion. Therefore, the possibility of missing data due to this insufficient information may limit our results.
Finally, the current meta-analysis included only published studies, out of which may arise the chance for publication bias. The potential for studies reporting small or null findings and not being published through either the reluctance from authors or journal editors dismissing them may be a problem. Publication bias is, however, a problem for all researchers and not only for this meta-analysis.