Importance US military personnel and veterans have higher rates of suicide than the general population. Previous trials support the efficacy of brief cognitive behavioral therapy (BCBT) for reducing suicide attempts among military personnel compared with treatment as usual, and replication of these findings is needed. Objective To test the efficacy of BCBT for reducing suicide attempts and suicidal ideation among high-risk military personnel and veterans. Design, Setting, and Participants This was a 2-arm, parallel randomized clinical trial comparing BCBT with present-centered therapy (PCT), conducted from 2020 to 2025. The setting was 3 US-based outpatient psychiatric clinics and included US military personnel and veterans reporting suicidal ideation during the past week and/or suicidal behavior during the past month who were either self-referred or referred by their mental health clinicians. Interventions Participants were randomly assigned to either BCBT, a psychotherapy that teaches emotion regulation skills, or PCT, a problem-solving psychotherapy, using a computerized algorithm with stratification for sex and number of prior suicide attempts. Main Outcomes and Measures The primary outcome was suicide attempt, assessed with the Self-Injurious Thoughts and Behaviors Interview–Revised. Results Of 154 individuals assessed for eligibility, 108 (mean SD age, 32.8 12.8 years; 79 male 73.1%) were enrolled. Fewer patients receiving BCBT (n = 2, estimated proportion = 5.6%) than PCT (n = 8, estimated proportion = 27.9%) attempted suicide during follow-up. Mean time to first suicide attempt was 638.6 (90% CI, 557.8-719.3) days in the PCT group vs 755.9 (90% CI, 715.1-796.8) days in the BCBT group (log-rank χ 2 1 = 3.6; P = .03). BCBT significantly reduced the risk of any suicide attempt (hazard ratio HR, 0.25; 90% CI, 0.07-0.90; P = .04) as well as the rate of follow-up suicide attempts (0.06 vs 0.18 attempts per participant-year, risk ratio, 0.24; 90% CI, 0.08-0.70; P = .02). Suicidal ideation significantly decreased in both groups ( F 8,264 = 7.2, P lt; .001) with no differences between groups ( F 8,266 = 0.2; P = .49). Conclusions and Relevance This randomized clinical trial found that BCBT reduced suicide attempts among US military personnel and veterans reporting recent suicidal ideation and/or suicidal behaviors compared with an active comparator. These results replicate earlier findings. Trial Registration ClinicalTrials.gov Identifier: NCT03769259
Bryan et al. (Wed,) studied this question.