A systematic review and meta-analysis of group treatments for adults with symptoms associated with complex post-traumatic stress disorder

Background: No previous meta-analyses have specifically investigated the effectiveness of psychological group therapy for symptoms associated with complex interpersonal trauma, including whether trauma memory processing (TMP) therapies are superior to psychoeducational approaches alone. Methods: A systematic review identified 36 randomised control trials (RCTs) which were included in the meta-analysis. Results: Large significant effect sizes were evident for TMP interventions when compared to usual care for three outcome domains including: PTSD (k= 6, g= -0.98, 95% CI -1.53, -0.43), Depression (k= 7, g= -1.12, 95% CI -2.01, -0.23) and Psychological Distress (k= 6, g= -0.98, 95% CI 1.66, -0.40). When TMP and psychoeducation interventions were directly compared, results indicated a small non-significant effect in favour of the former for PTSD symptoms, (k= 4, g= -0.34, 95% CI -1.05, 0.36) and small non-significant effect sizes in favour of the latter for Depression (k= 3, g= 0.29, 95% CI -0.83, 1.4) and Psychological Distress (k= 6, g= 0.19, 95% CI -0.34, 0.71). Limitations: Heterogeneity and a limited number of high quality RCTs, particularly in the Substance Misuse and Dissociation domains, resulted in uncertainty regarding meta-analytical estimates and subsequent conclusions. Conclusions: Results suggest that TMP interventions are useful for traumatic stress whereas non-TMP interventions can be useful for symptoms of general distress (e.g. anxiety and depression). Thus, both TMP and psychoeducation can be useful for the treatment of complex interpersonal trauma symptoms and further research should unravel appropriate sequencing and dose of these interventions