This meta-analysis found that the Coping with Depression course was effective for preventing new cases of major depressive disorders in people without a disorder at baseline and was also effective for treating existing depression. These conclusions were supported by the analysis results, but their reliability is unclear due to the lack of reporting of the review methods.

To review the effectiveness of the Coping with Depression course.

Studies were identified in the following ways: from those conducted by the review authors and their colleagues; from a database of studies on the psychological treatment of depression, which was developed from a comprehensive literature search for articles from 1966 to December 2007 in PsycINFO, PubMed, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and DAI; and from those identified in earlier meta-analyses. The search terms were partially reported and the reference lists of identified articles were searched.

Randomised controlled trials of the Coping with Depression course used for the prevention or treatment of depression were eligible for inclusion if they compared the intervention with a control or another treatment for adult depression, which could be psychotherapy or pharmacotherapy.

In trials of prevention, Coping with Depression was used for participants with subthreshold depression (symptoms that did not meet the criteria for a depressive disorder) that was established by a diagnostic interview. The control groups received care as usual and the outcome was the incidence of new depressive disorders. In treatment trials, most of the participants met the criteria for a depressive disorder, based on a diagnostic interview, while the other participants were classified using a self-rated depression score. The outcome was the reduction in depressive symptoms. Interventions were delivered to groups, individuals, or both and were compared with care as usual, waiting list, relaxation, or life skills. The participants in prevention and treatment trials were adolescents, adults, minority adults, older adults (aged over 50 years), alcoholics, or women with post-natal depression. Where reported, the number of sessions ranged from five to 16, with sessions lasting from five minutes to two hours.

The authors did not state how many reviewers selected the trials.

The authors did not state that they assessed validity.

For prevention trials, the incidence rate ratio was calculated by the incidence rate of new depressive disorders with Coping with Depression, relative to the control group, divided by the number of person-years at risk (to account for different lengths of follow-up across trials). For treatment trials, the means and standard deviations for post-test outcomes were extracted for Coping with Depression and control groups and these were used to calculate Cohen's d effect sizes. If a study reported more than one depression measure, the mean of all effect sizes was calculated.

The authors did not state how many reviewers extracted the data.

The incidence rate ratios and effect sizes were pooled using random-effects meta-analysis. Statistical heterogeneity was assessed using the I² and Cochran Q statistics. Subgroup analyses were performed, using random-effects models, with the differences between subgroups compared, using a fixed-effect model. The subgroups were: depression measurement tools, which were the Beck Depression Inventory (BDI), the Center for Epidemiologic Studies Depression Scale (CES-D), and the Hamilton Rating Scale for Depression (HRSD); target populations, which were adolescents, older adults, and minority groups; and Coping with Depression as a self-help intervention, with or without professional support. Coping with Depression was also compared with other psychotherapy programmes. Sensitivity analyses were used to explore the impact of using the highest or lowest effect size, for each trial, where more than one effect size was reported.

Twenty-five trials were included, six of which were prevention (n=724 participants) and 19 were treatment (n=3,012), with 24 comparisons of treatment against control.

Prevention: Participants receiving Coping with Depression had a lower incidence of depressive disorder development compared with controls (IRR 0.62, 95% CI 0.43 to 0.91, six trials) and there was no evidence of statistical heterogeneity (I²=0%).

Treatment: Coping with Depression reduced the symptoms of depression, compared with controls (ES 0.28, 95% CI 0.18 to 0.38; 18 trials) with trials showing low-to-moderate statistical heterogeneity (I²=31.9%). Sensitivity analyses using only the highest or lowest effect size per study showed similar results. Studies using the CES-D to measure depression showed the largest effect size of 0.62 (95% CI 0.35 to 0.88; eight comparisons), followed by the HRSD (ES 0.31, 95% CI 0.15 to 0.46; eight comparisons) and BDI (ES 0.47, 95% CI 0.23 to 0.71; 11 comparisons), with low-to-moderate statistical heterogeneity (I²=14.5% to 54.0%). Coping with Depression showed statistically significant reductions in symptoms in adolescents (ES 0.35, 95% CI 0.05 to 0.66; seven comparisons) and older adults (ES 0.39, 95% CI 0.19 to 0.59; four comparisons), but not for minority groups, with moderate statistical heterogeneity (I²=42% to 60%). Coping with Depression delivered as a guided self-help (ES 0.52) was significantly more effective than when delivered without guidance (ES 0.18, p<0.05). The comparison of Coping with Depression with other psychotherapy programmes (seven comparisons) was not statistically significant.

The authors' conclusions were that Coping with Depression was effective in the prevention of new cases of major depressive disorders, in people who did not meet criteria for this disorder at baseline, and it was also effective for treating existing depression.

This was a meta-analysis of the effects of a course for preventing or treating depression. The search used a specialist database, formed from searches of other relevant databases and created by the authors. It is difficult to comment on this database, with the information given, but the authors stated that the literature searches were comprehensive. Brief details of the inclusion criteria were reported, but the details of any steps taken to reduce errors in the trial selection and data extraction, by two or more people performing them, were not reported. There was also no assessment of the quality of the included trials. The methods of meta-analysis appear to have been appropriate, between-study heterogeneity was assessed, and sensitivity analyses were used to assess the effects of some trials having multiple effect sizes.

Based on the results of the meta-analysis, the authors' conclusions seem appropriate, but more details of the review methods are needed to judge their reliability.

Practice: The authors stated that Coping with Depression should be considered to be the first step in a stepped-care model for the treatment of depression.

Research: The authors stated that more research was needed to examine who will or will not benefit from Coping with Depression and whether offering only one module would be as effective as the full course.

Not stated.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.