Abstract
OBJECTIVE: HabitWorks (HW) is a personalized, transdiagnostic, smartphone-based interpretation bias intervention for depression and anxiety that has demonstrated feasibility and acceptability in prior pilot studies. This preregistered randomized controlled trial (https://doi.org/10.17605/OSF.IO/EJ89T; Silverman, Kovarsky Rotta, et al., 2025) tested the effectiveness of HW compared with a symptom tracking (ST) control condition. METHOD: A nonclinical community sample of U.S. adults with at least mild anxiety and depression symptoms (N = 340; Mage = 33.04 years, 57.4% women, 60.6% White, 14.7% Black, 11.2% Asian, 10.9% Multiracial, 22.1% Hispanic/Latine) were randomly assigned to complete three weekly interpretation bias exercises and once weekly depression and anxiety symptom surveys (HW) or three weekly depression and anxiety symptom surveys (ST) for 4 weeks. RESULTS: A priori benchmarks for retention, adherence, and satisfaction were achieved: 77.8% of HW participants were still using the app in Week 4, 43.7% achieved perfect adherence, and app usability and acceptability were rated positively. As hypothesized, HW was superior to ST at improving negative and benign interpretation biases (Word-Sentence Association Paradigm) and functional impairment (Work and Social Adjustment Scale); and HW (vs. ST) participants reported significantly greater global improvement (Clinical Global Impressions Scale-Improvement Self-Report) and subjective engagement (Twente Engagement with eHealth Technologies Scale) at postintervention. Unexpectedly, while depression and anxiety symptoms (Patient Health Questionnaire-8 and Generalized Anxiety Disorder Scale-7) improved significantly, these changes were not unique to HW. CONCLUSIONS: HW is an engaging and scalable intervention that may be effective for improving overall severity and functioning. Further validation of effectiveness for specific symptom domains is needed. (PsycInfo Database Record (c) 2026 APA, all rights reserved).