The Therapeutic Process in Psychological Treatments for Eating Disorders: A Systematic Review

Objective: For eating disorders, a vast number of investigations have demonstrated the efficacy of psychological treatments. However, evidence supporting the impact of therapeutic process aspects on outcome (i.e., process-outcome research) has not been disentangled. Method: Using the Generic Model of Psychotherapy (GMP) to organize various process aspects, a systematic literature search was conducted on psychological treatment studies for anorexia nervosa, bulimia nervosa, binge-eating disorder, and eating disorders not otherwise specified. Results: Improved outcomes resulted for family-based treatment compared to individual treatment, for individual compared to group treatment, booster sessions, and positive patient expectations (GMP contract aspect); for nutritional counseling and exercising but not exposure with response prevention as adjunct interventions (therapeutic operations); for highly motivated patients and, to a lesser extent, for therapeutic alliance (therapeutic bond); as well as for rapid response and longer overall treatment duration (temporal patterns). Regarding other GMP aspects, studies on self-relatedness were completely lacking and in-session impacts were rarely investigated. Discussion: As most studies assessed only a limited number of process aspects, the ability to draw conclusions about their overall impact regarding outcome is rather limited. Therefore, future processoutcome research is needed beyond investigations of treatment efficacy for eating disorders. (C) 2014 Wiley Periodicals, Inc.