Efficacy of psychological interventions for adult PTSD in reducing comorbid depression: systematic review and meta-analysis of randomised controlled trials

Background – Post-traumatic stress disorder (PTSD) and depression are highly comorbid. A comprehensive meta-analysis on the efficacy of PTSD-specific psychotherapies in reducing comorbid depression is lacking. Aims – To examine the short-, mid- and long-term efficacy of PTSD-specific psychotherapies in reducing comorbid depression. Method – We performed a preregistered (Prospero-ID: CRD42023479224) meta-analysis and followed PRISMA guidelines. PsycINFO, MEDLINE, Web of Science and PTSDpubs were searched. Randomised controlled trials (RCTs) examining psychotherapies for PTSD in samples with ≥70% PTSD diagnosis rate, mean age of sample ≥18 years, ≥10 participants per group and reporting of depression outcome data were included in the meta-analysis. Results – In total, 136 RCTs (N = 8868) assessed depression. Most data concerned trauma-focused cognitive behaviour therapy (TF-CBT), followed by eye movement desensitisation and reprocessing and non-trauma-focused and other trauma-focused interventions. At post-treatment, TF-CBT was associated with large reductions in depression relative to passive controls (Hedges’ g = 0.97, 95% CI 0.80–1.14, k = 46 trials) and moderate reductions relative to active controls (Hedges’ g = 0.50, 95% CI 0.35–0.65, k = 29). Effects relative to control conditions were similar across the other interventions. Response rates for comorbid depression were three times higher in psychological interventions relative to passive controls (odds ratio 3.07, 95% CI 1.18–7.94, k = 4). In head-to-head comparisons, there was evidence for TF-CBT producing higher short-, mid- and long-term reductions in depression than non-trauma-focused interventions. Results at mid- and long term were generally similar to those at treatment end-point. Conclusions – PTSD-specific psychotherapies are effective in reducing depression. TF-CBT presented with the highest certainty of results. More long-term data for other interventions are needed. Results are encouraging for clinical practice. © The Author(s), 2025. Published by Cambridge University Press on behalf of Royal College of Psychiatrists