A meta-analysis of randomized trials of behavioural treatment of depression

Background. Depression is a common, disabling condition for which psychological treatments, in particular cognitive behavioural therapies are recommended. Promising results in recent randomized trials have renewed interest in behavioural therapy. This systematic review sought to identify all randomized trials of behavioural therapy for depression, determine the effect of such interventions and examine any moderators of such effect. Method. Randomized trials of behavioural treatments of depression versus controls or other psychotherapies were identified using electronic database searches, previous reviews and reference lists. Data on symptom-level, recovery/ dropout rate and study-level moderators (study quality, number of sessions, severity and level of training) were extracted and analysed using meta-analysis and meta-regression respectively. Results. Seventeen randomized controlled trials including 1109 subjects were included in this meta-analysis. A random-effects meta-analysis of symptom-level post-treatment showed behavioural therapies were superior to controls [standardized mean difference (SMD)-0.70, 95% CI -1.00 to -0.39, k=12, n=459], brief psychotherapy (SMD -0.56, 95% CI -1.0 to -0.12, k=3, n=166), supportive therapy (SMD -0.75, 95% CI -1.37 to -0.14, k=2, n=45) and equal to cognitive behavioural therapy (SMD 0.08, 95% CI -0.14 to 0.30, k=12, n=476). Conclusions. The results in this study indicate behavioural therapy is an effective treatment for depression with outcomes equal to that of the current recommended psychological intervention. Future research needs to address issues of parsimony of such interventions.