Six RCTs with parallel design were included in the review. The number of patients in each treatment arm of included trials ranged from fewer than 30 to 120. The quality scores of trials ranged from 20 to 33, with an mean score of 27. The mean follow-up was 11.3 months.
Compared with any control, group psychotherapy treatment was associated with a significant reduction in depression symptoms (WMD -3.92, 95% CI -6.18 to -1.67). Compared with waiting-list control only, group psychotherapy treatment was associated with a significant reduction in depression symptoms (WMD -6.29, 95% CI -8.95 to -3.62). There was a non-significant reduction in depression symptoms with psychotherapy treatment compared with other active interventions. There was no significant difference in depression scores between group psychotherapy treatment and active control groups at the completion of the intervention and at follow-up.
No substantial heterogeneity was observed for these outcomes.
Subgroup analyses by different depression outcome measures did not markedly alter the results.