This article reports on a systematic review to assess the efficacy and clinical effectiveness of group analysis and analytic/dynamic (A/D) group psychotherapy. Systematic literature searches were undertaken; 34 primary studies and 19 reviews met the inclusion criteria and their data was extracted. Of the primary studies, the randomized controlled trials provided evidence for the efficacy and clinical effectiveness of group therapy approaches in a range of clinical problems, but not for specific benefits of any particular theoretical approach. The controlled studies and observational studies gave support for the use of group psychotherapy in a variety of conditions.
The review of reviews confirms that group therapies in general are more effective than wait list or standard care controls. Methodological challenges encountered and recommendations for further research are presented, along with a more detailed discussion of the implications of the review for the research community.