Alcohol misuse is strongly associated with suicide crises (i.e., acute suicidal ideation or attempts) and death. The standard care for a suicide crisis, including for persons who misuse alcohol, is acute psychiatric hospitalization. Acute psychiatric hospitalization focuses on stabilization and crisis resolution prior to quickly discharging at-risk patients back into their stressful environments with a referral for outpatient care. Outpatient- based interventions focused on emotion regulation training have been shown to simultaneously reduce alcohol misuse and suicidal behavior. Yet, less than 50% of psychiatric inpatients follow through with outpatient treatment, which creates a dangerous gap in care; risk for suicide is the highest among recently discharging patients who misuse alcohol. This Mentored Patient-Oriented Research Career Development Award (K23) involves the development of a novel adjunctive intervention to (1) enhance standard care for at-risk psychiatric inpatients who misuse alcohol, and (2) create an opportunity for sustained recovery and reduced risk for a subsequent suicide crisis during the post-discharge period. This intervention, entitled mHealth-supported Skills Training for Alcohol and Related Suicidality (mSTARS), combines emotion regulation skills training implemented in the acute setting with a mHealth app designed to encourage utilization of these skills during the risky post-discharge period. The research plan for this K23 has two phases: development (Phase 1: AIMS 1 and 2) and evaluation of feasibility and acceptability of mSTARS (Phase 2: AIM 3). To inform mHealth app development, we will conduct a 6-week ecological momentary assessment (EMA) study on suicidal psychiatric inpatients who misuse alcohol (N = 35) to elucidate time-varying predictors for alcohol consumption and suicidal ideation, and examine the role of specific emotion regulation deficits. Analyses will facilitate adjustments to the app to make empirically-based recommendations for emotion regulation skills in real time (AIM 1). mSTARS, including the inpatient skills training component and mHealth app, will be iteratively refined per patient-driven modifications over two successive cohorts (n = 5 in each) of suicidal psychiatric inpatients who misuse alcohol (AIM 2). The finalized version of mSTARS, while incorporating AIM 1 findings, will be evaluated in AIM 3 in a three-arm feasibility/acceptability randomized control trial comparing mSTARS (n = 15) to inpatient skills training (n = 10) and treatment as usual (TAU) only (n = 10). The research plan for this K23 is closely tied to the PI’s training goals, which are to gain experience with (1) advanced longitudinal modeling of EMA data, (2) mHealth-supported treatment development, and (3) clinical trials design and management. Over the 5-year K23 award period, these training goals will facilitate the PI’s overarching career goal of becoming an independent clinical researcher. Beginning with this K23, th...