Grenon, R., Schwartze, D., Hammond, N., Ivanova, I., Mcquaid, N., Proulx, G., & Tasca, G. A. (2017). Group psychotherapy for eating disorders: A meta-analysis. International Journal of Eating Disorders. DOI: 10.1002/eat.22744
Group therapy has an evidence base indicating its efficacy for many disorders. Groups represent a social microcosm in which interpersonal factors that underlie psychological distress and symptoms can be effectively addressed. Group therapeutic factors include peer interpersonal feedback, social learning, emotional expression, and group cohesion. Theories of eating disorder symptoms include interpersonal problems and affect dysregulation as maintenance factors. Many treatment guidelines indicate that individual and group CBT are the treatments of choice for eating disorders. However, there are no meta analyses that specifically look at the efficacy of group therapy for eating disorders. In this study, Grenon and colleagues assess if: (a) group psychotherapy for eating disorders is efficacious compared to wait-list controls, (b) group therapy is effective compared to other active treatments (self help, individual therapy, medications), and (c) group CBT is more effective than other types of group therapy (group interpersonal therapy [GIPT], group psychodynamic-interpersonal psychotherapy [GPIP], or group dialectical behavior therapy [GDBT]). The authors reviewed 27 randomized controlled trials with over 1800 patients that provided direct comparisons of group therapy for eating disorders. The mean drop out rate from group therapy was 16.47% (SD = 13.46), which is similar to what is reported for psychotherapy trials in general. Group therapy was significantly more effective than wait list controls in achieving abstinence from binge eating and purging (RR = 5.51, 95% CI: 3.73, 8.12), decreasing the frequency of binge eating and/or purging (g = 0.70, 95% CI: 0.51, 0.90), and reducing related psychopathology (g = 0.49, 95% CI: 0.32, 0.66). Group psychotherapy had an overall rate of abstinence from binge eating of 51.38%, while wait-list control conditions had an overall abstinence rate of 6.51%. Similar findings were achieved a follow-ups. The effects of group psychotherapy and other active treatments (e.g., behavioral weight loss, self-help, individual psychotherapy) did not differ on any outcome at post-treatment or at follow-ups. Group CBT and other forms of group psychotherapy did not differ significantly on outcomes at any time point.
The results add to a growing body of research that indicates that group psychotherapy is as effective as other treatments, including individual therapy, to treat mental disorders. Despite the fact that practice guidelines indicate that CBT is the treatment of choice for eating disorders, this meta analysis did not provide evidence that group CBT was more effective than other types of group treatments. Clinicians considering group interventions for eating disorders or other mental health problems will do well to make use of group therapeutic factors like interpersonal learning, peer feedback, emotional expression, and group cohesion to improve patient outcomes.