A randomized clinical trial of app cognitive behavior therapy vs. HealthWatch for obsessive compulsive disorder.

App-based cognitive behavioral therapy (app-CBT) addresses many treatment barriers. We randomized 120 U.S. adults with primary OCD (82.4% female, 77.5% White, mean age 40.1) between 7/2021 and 7/2023 to 12-weeks of coach-guided Perspectives (n = 60; app-CBT) or coach-guided HealthWatch (n = 60; an online well-being program). OCD severity (Yale-Brown Obsessive Compulsive Scale; primary outcome) analyzed using a pre-registered mixed linear model showed a trend level group difference at post-treatment (ES = -0.47; p = 0.079). However, results from secondary and sensitivity analyses showed significantly better outcomes in Perspectives after adjusting for baseline differences or varying missing data assumptions (ps < 0.05). Response rates among completers were 65% in Perspectives and 41% in HealthWatch. Perspectives was also associated with greater pre-to-post-treatment improvement in functioning (ES = -0.55; p = 0.014). 83% of completers in Perspectives were mostly/very satisfied and 91% recommended the program vs. 43% and 53% in HealthWatch. Results highlight app-CBT as an effective and feasible treatment option for OCD that addresses dissemination obstacles.Clinicaltrials.gov identifier: NCT04136626 (Registration Date: 10/17/2019).