PROJECT SUMMARY Skills in emotional regulation (ER), defined as “strategies used to influence, experience, and modulate emotions” are important for decision-making processes and can help support the navigation of complex and chaotic settings. These skills may be especially important for the estimated one-in-ten young adults, aged 18- 25, who experience homelessness over the course of one year as they navigate frequently reported traumatic experiences related to homelessness, such as emotional, physical, and sexual abuse; institutional involvement through the foster care or juvenile justice systems; and violence and victimization before and after entering homelessness. Unfortunately, these traumatic experiences themselves can result in difficulties with ER, which in turn, can lead to mental health problems which are already higher among emerging adults who have experienced homelessness. To date few studies have examined ER skills, a transdiagnostic component underlying psychopathology, among emerging adults with history of homelessness, a heterogenous population with diverse mental health diagnoses. There is some evidence that skills in emotional regulation may be protective against suicidality and violence within this population; however, we do not have a clear, broad understanding of the role of emotional regulation in navigating the social and physical environments associated with homelessness. To increase understanding of the dynamics of ER difficulties and the role of social and physical environments, the current proposal poses to use data from the Log My Life Study, a NIMH-funded dataset (1R01 MH110206), which employed geographically explicit ecological momentary assessment (GEMA). GEMA integrates ecological momentary assessment (EMA) and geographic information systems science allowing for cross-validation and enrichment of research on place, well-being, and health. The aim of this work is to better understand how the social and physical contexts of homelessness may be related to ER difficulties and will be achieve through use of GEMA data. The sample consists of both formerly homelessness (residing in supportive housing) and currently homeless (street- or shelter-based) young adults who completed questionnaires and GEMA for a period of 7 days, with an average of 7 EMA prompts daily. Housing status will serve as a main analytic axis to understand ER as the analytic sample (n=224) includes both housed (n=122) and unhoused (n=102) young adults. The findings from this work will be used to develop recommendations for mental health service providers, direct service practitioners, and policymakers regarding how to further adapt service environments to meet the complex needs of at-risk young people, including interventions for homeless young adults. As part of the proposed study, the PI will develop skills to increase capacity for mental health services research, including expertise in use of EMA that includes use of geographic and spatial applicat...