Stress experiences as markers of person-level vulnerability and temporal risk for near-term suicidal ideation - PROJECT SUMMARY Suicide is a leading cause of global mortality and rising suicide rates have been particularly steep in the United States. Accordingly, NIMH is investing heavily in prevention, including calls for improved precision care— interventions delivered based on specific, granular understanding of person-level vulnerabilities and their interaction with local environments. Although stress, a well-established concurrent and prospective risk factor for suicidal ideation (SI), is experienced by all, it varies at both group- (e.g., discrimination, local events) and person- (e.g., arguments, accidents) levels in timing, frequency, and experience. Thus, there is a significant need to improve the accuracy in detailing the stressful events – SI relationship, as well as elucidate person-level markers that increase vulnerability to this association. Tonic (trait-like) and phasic (state) impulsivity (IMP) and emotion dysregulation (ED) are well-established predispositions for suicide risk. IMP and ED alone are insufficient markers of SI risk, yet each may increase risk for SI in the context of stressful life events. Their joint effects may also potentiate the relationship between changes in person-level stress and risk for momentary SI; however, this has yet to be tested, leaving little known about person-level, moment-to-moment SI prediction. The overarching objective of this research is to specify person-level conditions that portend imminent SI, information that has the potential to inform the development of effective just-in-time interventions, consistent with precision care objectives of the NIMH Strategic Plan. This research will: (1) evaluate the direct effect of real-time stressful events on concurrent and prospective momentary SI, (2) evaluate the moderating effects of tonic (trait-like) and phasic (state) IMP and ED on the prospective relationship between real-time stressful events and momentary SI, and (3) explore the propensity to experience SI in response to prior stress as a potential moderator of the proximal relationship between real-time stressful events and momentary SI. A sample of individuals at high risk for suicide (i.e., adults age ≥18 with persistent lifetime SI and SI during the past 6-months) will complete a baseline session and 30-day period of ecological momentary assessment to evaluate tonic and phasic IMP and ED, real-time stressful events, and momentary SI. Goals of the fellowship training plan, which will take place at the University of Notre Dame, include: (1) enhance knowledge of emotional, personality, and cognitive components of suicide risk; (2) develop advanced knowledge of the assessment of suicide risk factors; (3) enhance knowledge of advanced statistical analyses for within- and between-persons research; (4) engage in professional development activities and develop advanced research skills; (5) enhance knowledge of ethical research practices with high-risk populations.