Psychological treatment of depression with other comorbid mental disorders: systematic review and meta-analysis

Most people with a mental disorder meet criteria for multiple disorders. We conducted a systematic review and meta-analysis of randomized trials comparing psychotherapies for people with depression and comorbid other mental disorders with non-active control conditions. We identified studies through an existing database of randomized trials on psychotherapies for depression. Thirty-five trials (3,157 patients) met inclusion criteria. Twenty-seven of the 41 interventions in the 35 trials (66%) were based on CBT. The overall effect on depression was large (g = 0.65; 95% CI: 0.40 ~ 0.90), with high heterogeneity (I² = 78%; 95% CI: 70 ~ 83). The ten studies in comorbid anxiety showed large effects on depression (g = 0.90; 95% CI: 0.30 ~ 1.51) and anxiety (g = 1.01; 95% CI: 0.28 ~ 1.74). For comorbid insomnia (11 comparisons) a large and significant effect on depression (g = 0.99; 95% CI: 0.16 ~ 1.82) and insomnia (g = 1.38; 95% CI: 0.38 ~ 2.38) were found. For comorbid substance use problems (12 comparisons) effects on depression (g = 0.25; 95% CI: 0.06 ~ 0.43) and on substance use problems (g = 0.25; 95% CI: 0.01 ~ 0.50) were significant. Most effects were no longer significant after adjustment for publication bias and when limited to studies with low risk of bias. Therapies are probably effective in the treatment of depression with comorbid anxiety, insomnia, and substance use problems.