Abstract
IMPORTANCE: Suicide is a leading cause of death in the US. Suicide-specific cognitive behavior therapy (CBT) is effective for reducing suicide attempts but is difficult to implement. OBJECTIVE: To evaluate the efficacy of a smartphone-based digital therapeutic intervention designed to deliver suicide-focused CBT in reducing suicidal behavior among patients hospitalized for a suicide attempt or suicidal ideation. DESIGN, SETTING, AND PARTICIPANTS: This multisite, double-blind, randomized clinical trial was conducted in 6 psychiatric inpatient units across the US. Adult patients admitted with elevated suicide risk from April 2022 to April 2024 were included. Participants completed a baseline assessment and were randomly assigned to either the digital therapeutic group or control application group. The trial was stopped early by the Data Management Safety Board because it surpassed the prespecified futility boundary for the primary end point. Statistical analysis followed the intention-to-treat principle. INTERVENTIONS: The digital therapeutic intervention includes 12 sessions of smartphone-based educational modules (lasting 10-15 minutes each) drawn from CBT for suicide prevention. The active control is a 12-session smartphone-based application that delivers safety planning and psychoeducation about suicide. For both interventions, the first session was completed prior to hospital discharge and the remaining self-paced sessions could be completed after discharge. All participants also received treatment as usual, which included suicide risk assessment, supportive listening, crisis resources, clinician assessment, safety planning, and referral to outpatient treatment. MAIN OUTCOMES AND MEASURES: The primary end point was time (days) to first actual suicide attempt during follow-up. The secondary end points were change in suicidal ideation from baseline to week 24 (quantified as a change in the Scale for Suicide Ideation total score) and clinician-rated clinical improvement at week 24. The nonprespecified sensitivity analysis end point for suicide attempts was the rate of suicide attempts (actual, aborted, and interrupted). Prespecified subgroup analyses were also conducted to examine treatment effects among patients with vs without prior suicide attempts. RESULTS: A total of 339 participants (mean [SD] age, 27.9 [10.7] years; 224 females [66.1%]) were included. Follow-up data were available from 266 participants (78.5%). Time to first actual suicide attempt, the primary end point, was not significantly different across treatment groups (log-rank χ21 = 3.6; P = .06). Among the 170 participants with prior suicide attempts, nonprespecified sensitivity analyses indicated that the adjusted rate of follow-up suicide attempts was 58.3% lower in the digital therapeutic group than the control application group (0.70 vs 1.68 attempts per person-year; rate ratio [RR], 0.42 [95% CI, 0.18-0.95]; P = .04), and the odds of clinical improvement were higher in the digital therapeutic group than the control application group (97.9% vs 87.5%; odds ratio, 7.59; 95% CI, 1.14-153.62; P = .04). Trajectories of suicidal ideation significantly differed between the digital therapeutic and control application groups (F3,206 = 2.9, P = .04), with decreased suicidal ideation through week 24 in the digital therapeutic group, but in the control application group, suicidal ideation decreased through week 12 and then increased at week 24. Nonprespecified dose-response analyses indicated the suicide attempt rate among patients with a prior suicide attempt decreased by 14.0% for every digital therapeutic module completed (adjusted RR, 0.86; 95% CI, 0.76-0.98; P = .02). CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, the digital therapeutic intervention did not change the time to first actual suicide attempt but helped to sustain reductions in suicidal ideation among inpatients with elevated suicide risk. However, among patients with prior suicide attempts, the digital therapeutic intervention helped reduce recurrent suicide attempts and increased the percentage of inpatients with clinician-rated clinical improvement. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05144685.