The treatment of chronic depression with cognitive behavioral analysis system of psychotherapy: a systematic review and meta‐analysis of randomized‐controlled clinical trials

BACKGROUND: Chronic depression is a severe and disabling condition. Compared to an episodic course, chronic depression has been shown to be less responsive to psychopharmacological and psychological treatments. The cognitive behavioral analysis system of psychotherapy (CBASP) has been developed as a specific psychotherapy for chronic depression. However, conflicting results concerning its efficacy have been reported in randomized‐controlled trials (RCT). Therefore, we aimed at examining the efficacy of CBASP using meta‐analytical methods. METHODS: Randomized‐controlled trials assessing the efficacy of CBASP in chronic depression were identified by searching electronic databases (PsycINFO, PubMed, Scopus, Cochrane Central Register of Controlled Trials) and by manual searches (citation search, contacting experts). Searching period was restricted from the first available entry to October 2015. Identified studies were systematically reviewed. The standardized mean difference Hedges' g was calculated from posttreatment and mean change scores. The random‐effects model was used to compute combined overall effect sizes. A risk of publication bias was addressed using fail‐safe N calculations and trim‐and‐fill analysis. RESULTS: Six studies comprising 1.510 patients met our inclusion criteria. The combined overall effect sizes of CBASP versus other treatments or treatment as usual (TAU) pointed to a significant effect of small magnitude (g = 0.34–0.44, P < 0.01). In particular, CBASP revealed moderate‐to‐high effect sizes when compared to TAU and interpersonal psychotherapy (g = 0.64–0.75, P < 0.05), and showed similar effects when compared to antidepressant medication (ADM) (g = −0.29 to 0.02, ns). The combination of CBASP and ADM yielded benefits over antidepressant monotherapy (g = 0.49–0.59, P < 0.05). LIMITATIONS: The small number of included studies, a certain degree of heterogeneity among the study designs and comparison conditions, and insufficient data evaluating long‐term effects of CBASP restrict generalizability yet. CONCLUSIONS: We conclude that there is supporting evidence that CBASP is effective in the treatment of chronic depression.