Response to "Considerations in selecting comparison conditions in psychotherapy trials: Recommendations for future research".

Several researchers who have evaluated Interpersonal Psychotherapy (IPT) wrote a commentary arguing that the group-delivered IPT treatment for eating disorders that we adapted and used in a recent trial (Stice, Rohde, et al., 2023) was less effective than the new dissonance-based eating disorder treatment (Body Project Treatment) because the group-delivered IPT did not contain all core elements, was not developmentally appropriate, was not tailored for people with eating disorders, and because our team lacked sufficient IPT expertise. In response, we note that the group-delivered IPT that we evaluated produced higher abstinence from binge eating and compensatory weight control behaviors (40%) than did individually delivered IPT in the only trial that also evaluated this treatment with a broad range of eating disorders (33%; Fairburn et al., 2015). The fact that the group-delivered IPT produced a higher abstinence rate than individually delivered IPT for a similar spectrum of patients appears to refute the stated concerns regarding the group-delivered version of IPT because it was not less effective than individually delivered IPT. We argue it is critical to establish that a treatment significantly outperforms alternative treatments with a distinct intervention target because only an active comparator controls for the potential confounds that can drive improvement in trials, including expectancies, demand characteristics, and nonspecific therapeutic effects. We also note that IPT for the treatment of eating disorders has not significantly outperformed three alternative treatments and that the evidence base for IPT may thus be driven by expectancies, demand characteristics, and nonspecific effects. (PsycInfo Database Record (c) 2025 APA, all rights reserved).