Making the MOST of Relapse Prevention in Anorexia Nervosa: A Treatment Optimization Study Targeting Habits

Anorexia nervosa (AN) is a serious disorder with a mortality rate among the highest of any psychiatric illness, and relapse rates range from 40-80% after acute treatment. Restriction of food intake is a central behavioral disturbance, and this persistent behavior is promoted by entrenched thoughts, feelings, and routines. Even with full weight restoration treatment, restrictive eating persists and has been linked to relapse. While many treatment approaches have been tried, there is little information about what elements of care contribute to maintaining remission. Relapse Prevention and Changing Habits (REACH+) targets the habitual control of maladaptive behavior to support patients with AN in the 6 months after acute treatment, a time of high vulnerability to relapse. Using the Multiphase Optimization STrategy (MOST) framework, we seek to identify an optimized, finalized, treatment package for relapse prevention in AN. The MOST framework is an ideal means for improving treatment efficacy by simultaneously and efficiently evaluating multiple possible intervention components to determine which contribute to positive treatment outcomes and thereby merit inclusion in a robust treatment package for relapse prevention. We have completed the Preparation Phase of the MOST framework and have shown feasibility and acceptability of REACH+, as well as preliminary support for treatment efficacy and target engagement. In this proposal, we conduct the next step: an Optimization Experiment to evaluate the components of REACH+ that will interrupt the habitual control of maladaptive behavior and, thereby, decrease relapse and improve outcomes. We will test competing versions of four components that together target habits: 1) Behavioral, 2) Cognitive, 3) Motivation, and 4) Food Monitoring. We will provide 6 months of REACH+ for 120 individuals with AN or atypical AN who have completed an acute weight-restoration treatment. REACH+ sessions are conducted via telehealth, to increase access and generalizability, and are augmented with psychoeducation and skill building through an online platform. Participants will be randomly assigned to different versions of each treatment component. Optimization criteria focus on the contribution of the component to weight maintenance (main effect), and will additionally consider effect sizes, treatment adherence, and end-of-treatment status. To ensure that the final treatment package will reach the patients we seek to help, we will obtain input from key end-users to plan for future effectiveness research. Project Number: 1R01MH141008-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Mental Health (NIMH) | Principal Investigator: JOANNA STEINGLASS (+1 co-PI) | Institution: NEW YORK STATE PSYCHIATRIC INSTITUTE DBA RESEARCH FOUNDATION FOR MENTAL HYGIENE, INC, NEW YORK, NY | Award Amount: $922,289 | Activity Code: R01 | Study Section: Special Emphasis Panel[ZMH1 ERB-N (04)] View on NIH RePORTER: https://reporter.nih.gov/project-details/11216013