Background Cognitive behavior therapy (CBT) and psychodynamic-interpersonal therapies (PIT) are two widely used and conceptually different outpatient treatments for eating disorders (EDs). To better understand how these treatments works, for whom, and under what circumstances, there is a need for knowledge about how outcomes are affected by diagnosis, comorbidity, changes in psychopathology, and study design. Method Reports on the effects of CBT and PIT for eating disorders were searched. Rates of remission and changes in ED specific- and general psychopathology were computed. Regression models were made to predict event rates by changes in specific- and general psychopathology, as well as ED diagnosis and study design. Results The remission rate of CBT for binge eating disorder was 50%, significantly higher than the effect for other diagnostic groups (anorexia = 33%, bulimia: 28%, mixed samples 30%). The number of studies found for PIT was limited. All effect sizes differed from zero (binge eating disorder = 27%, anorexia = 24%, bulimia = 18%, mixed samples = 15%), but the precision of the estimates was low, with some lower-bound confidence intervals close to zero. For CBT, change in ED specific psychopathology predicted remission only when controlling for ED diagnosis, while change in general psychopathology did not predict remission at all. The predictive value of change in psychopathology for PIT, and the potential impact of comorbid personality disorders could not be analyzed due to a lack of studies. There was no difference in effects between randomized controlled trials and observational studies. Conclusions CBT showed consistent remission rates for all EDs but left a substantial number of patients not in remission. Extant evidence suggest that PIT is not consistently effective in achieving remission for patients with EDs, although this finding is uncertain due to a small number of eligible studies. A group of patients with eating disorders may, however, require therapy aimed at strengthening deficits in self functions not easily ameliorable by cognitive behavioral techniques alone. Further research should be aimed at identifying treatment interventions that helps patients change behavior, while strengthening self-functions to substitute eating-disordered behavior in the long-term.

Background: Cognitive behavior therapy (CBT) and psychodynamic-interpersonal therapies (PIT) are the most used outpatient treatments for eating disorders. Knowledge about the outcomes of these therapies in terms of remission is limited. Also, there is a lack of knowledge about how different therapeutic changes and patient characteristic affects outcomes. Method: Reports on the effects of CBT and PIT for eating disorders were searched. Rates of remission and changes in eating disorder specific and general psychopathology were computed and meta-analytically synthesized. Regression models were made to predict summary event rates by patient characteristics and changes in specific and general psychopathology. Results: Only CBT produced remission rates (34.2%) significantly different from waitlist conditions, and only CBT led to significantly greater change in specific psychopathology than waitlist/nutritional counseling conditions. However, CBT and PIT were equally effective in changing general psychopathology. For CBT, change in specific psychopathology predicted remission only when controlling for differences between diagnostic categories. Change in general psychopathology predicted remission only for PIT. The presence of comorbid personality disorder decreased the effect of CBT. Conclusions: A group of patients with eating disorders may require therapy aimed at strengthening deficits in self functions not easily ameliorable by cognitive behavioral techniques alone. However, although effective in changing specific and general psychopathology, PIT is not effective in producing behavioral change. Further research should be aimed at identifying treatment interventions that effectuate both behavioral change and strengthening self-functions to substitute eating-disordered behavior to meet psychological needs in the long-term.