Transdiagnostic Reward System Dynamics and Social Disconnection in Suicide - PROJECT SUMMARY/ABSTRACT This resubmitted project evaluates the role of the positive valence system (PVS) in the interpersonal processes of disclosure, help-seeking, and safety planning in a transdiagnostic sample at risk for suicide. Interpersonal factors are central to contemporary models of the transition from suicide ideation to behavior, and social resources are key to effective suicide safety planning. Yet, interventions to promote informal help-seeking have been ineffective to date, and almost half of people do not disclose suicidal thoughts to anyone prior to attempt. Basic research on the mechanisms underlying social approach or avoidance behaviors in suicide could help identify new targets for more effective suicide prevention interventions. Here, we focus on investigating how the reward system (i.e., valuation, responsiveness and/or learning) is involved in engaging in social outreach behaviors before and during crises. In this proposal, we will recruit participants with either affective or psychotic disorders, stratified by current active suicidal ideation. Purposive sampling of both affective and psychotic diagnoses enables inclusion of a group with a similar high background risk of suicide, yet varying PVS and negative valence system (NVS) profiles. We will use a measurement burst longitudinal design which integrates lab-based tasks with bouts of ecological momentary assessment and passive sensing. Participants will be followed longitudinally for 12 months. Among lab-based tasks, we will administer our validated dyadic paradigm that simultaneously evaluates PVS and NVS components in a simulated social affiliation and disclosure context, and enables facial emotion coding and natural language processing of speech. In Aim 1, we will administer lab-based tasks and focus on evaluating the impact of PVS on suicide- related social affiliation, including social elements of the standard safety plan (e.g., people to contact in crisis) and help seeking opportunity within each individual’s social network. In Aim 2, we will use mobile assessments to model short-term dynamics of suicidal ideation and whether and to whom ideation is disclosed. In Aim 3, we will integrate lab-based and ecological momentary assessment data streams to build and test integrated predictive models of suicidal behavior over 12 months, evaluating stability of effects across affective or psychotic syndromes. We will evaluate whether social affiliation dynamics mediate the relationship between PVS components and suicidal ideation and behavior. The intended products of this research include an integrated dataset informative for translational interventions to improve long-term and acute suicide prevention. Innovative aspects of the proposed study include the lab-based dyadic social affiliation task, use of mobile health and computational methods to model dynamic aspects of help seeking, and the focal comparison of psychotic and affective syndromes. This proposal aligns with RDoC by probing connections across domains (PVS, NVS and Social Processes) in a transdiagnostic sample, and is also responsive to the NIMH Strategic Plan (Aim 2.2, Aim 3.2) and the NIMH Notice of Special Interest in Digital Mental Health.