For patients with severe mental illness (SMI), a smartphone intervention is highly usable and acceptable and improves outcomes, according to a study published in the Journal of Medical Internet Research. Dror Ben-Zeev, Ph.D., and colleagues conducted a trial of CORE, a smartphone intervention that includes daily exercises designed to promote reassessment of dysfunctional beliefs. The study team randomly assigned 315 individuals from 45 states to either active intervention or wait-list control groups. Participants were assessed at baseline, 30 days, and 60 days with the Beck Depression Inventory-Second Edition (BDI-II), Generalized Anxiety Disorder-7 (GAD-7), Hamilton Program for Schizophrenia Voices, Green Paranoid thought to Scale, Recovery Assessment Scale (RAS), Rosenberg Self-Esteem Scale (RSES), Friendship Scale, and Sheehan Disability Scale (SDS). Participants had self-reported bipolar disorder, major depressive disorder, and schizophrenia or schizoaffective disorder (35.2%, 43.2%, and 21.6%, respectively) and displayed moderate-to-severe symptoms and disability levels at baseline. CORE was rated as acceptable and highly usable. Significant treatment by-time interactions were seen for the BDI-II, GAD7, RAS, RSES, and SDS in intent-to-treat analyses. Large effect sizes were seen for the BDI-II, RAS, and RSES, while the SDS had a moderate effect size and A small effect size was seen for GAD-7.