A Mobile Intervention for Suicide Prevention For Middle-aged And Older Adults After a Suicide-Related Hospitalization - ABSTRACT The goal of this project is to refine and test WellPATH-PREVENT, a novel, mobile, principally stand-alone psychosocial intervention designed to improve cognitive reappraisal ability (target) and reduce suicide risk (outcome) in middle-aged and older adults (50-90 years old) who have been discharged after a suicide-related hospitalization (i.e. for suicidal ideation or suicide attempt). Suicide rates in this group are alarmingly high, and reducing suicide rates in at-risk populations is a major NIMH priority. Our conceptual framework views suicidal ideation and behavior as failed attempts to regulate negative emotions, and by improving cognitive reappraisal, an effective emotion regulation strategy, we expect to reduce suicide risk. WellPATH-PREVENT focuses on the training, coaching, and use of WellPATH app, a tablet-app that incorporates triggers, negative emotions, and personalized easy-to-use cognitive reappraisal techniques. The patient uses the tablet during emotionally charged situations and scheduled training sessions. The R61 phase is a proof-of-concept phase and its goals are to test WellPATH-PREVENT’s target engagement and optimization (6 vs. 12 weeks duration). Interventionists will administer WellPATH-PREVENT to 40 middle-aged and older adults (50-90 years old) after a suicide-related hospitalization. Research assistants, unaware of the study aims, will conduct assessments at study entry (admission/during hospitalization), discharge, 6 and 12 weeks post-discharge. Target engagement will be assessed with electrocortical measures (i.e. late positive potential, LPP), self-reported affect during an emotion regulation task, and Emotion Regulation Questionnaire (ERQ), an interviewer-administered instrument of cognitive reappraisal. The R33 phase aims to provide further evidence of target engagement of the optimized WellPATH- PREVENT in a larger sample, evaluate the relationship of cognitive reappraisal with suicide risk as measured with Columbia Suicide Severity Rating Scale (C-SSRS), examine preliminary signal of efficacy, and obtain implementation parameters for a large-scale clinical trial. A unique sample of 75 middle-aged and older adults (using the same inclusion/exclusion criteria as for the R61 phase) will be randomized (2 to 1) to WellPATH- PREVENT (N=50) or to Attention Control Usual Care (AC-UC) (a control condition with parallel delivery and a tablet that doesn’t include WellPATH) (N=25). Assessments will be conducted at study entry (admission/during hospitalization), discharge, 6, 12 and 24 weeks post-discharge. Primary aims are: 1) WellPATH-PREVENT participants will show improvement in cognitive reappraisal from discharge to end of treatment; 2) improvement in cognitive reappraisal in WellPATH-PREVENT participants will be associated with suicide risk over 24 weeks; and 3) examination of preliminary signal of efficacy of WellPATH-PREVENT vs. AC-UC on cognitive reappraisal and on suicide risk over 24 weeks.