Social Connection & Suicide Risk in ADRD Caregivers Providing care for a family member or friend with Alzheimer’s Disease and Related Dementias (ADRD, ‘caregivers’) is a common experience for adults in mid- and later-life and can foster experiences that are beneficial to mental health (e.g., purpose, mastery), but can also lead to anxiety, depression, and suicide ideation. Our scientific premise is that social disconnection—the quality and quantity of social ties with others— contributes to the most severe mental health problems during caregiving, including suicide ideation and behavior. Social disconnection is a common experience among caregivers and is one of the strongest risk factors for suicide ideation, attempts, and deaths. The Interpersonal Theory of Suicide proposes that stressors such as caregiving increase suicide risk by impacting two forms of social disconnection—feeling lonely (also termed low belonging) and like one is a burden on others (perceived burden). In line with NIA priorities of promoting well-being in caregivers and understanding mechanisms, our objective is to examine loneliness (and low belonging) and perceived burden on others as mechanisms that increase suicide risk in ADRD caregivers. This study builds on our team’s work on social connection in ADRD caregivers via the Rochester Roybal Center for Social Ties & Aging Research. Our pilot studies routinely assess suicide risk given the robust link between social disconnection and suicide risk. We found that at least 10% of caregivers screened for our pilot studies report suicide ideation in the past month. We propose an observational study of n=200 ADRD caregivers who report caregiving stress, loneliness, and recent suicide ideation in which subjects complete baseline interviews (to characterize caregiving and obtain histories of suicide ideation and behavior), 10 days of smartphone-based ecological momentary assessment (daily caregiving stressors and benefits, social connection, and suicide ideation), and 6-month follow-up (changes in care receiver functional status). Our first aim is to examine whether daily caregiving experiences are associated with daily variations in loneliness and perceived burden. We hypothesize that caregiving mastery and sense of purpose in life will be associated with lower loneliness and greater perceived burden, while caregiving strain, losses, and relationship conflict will be associated with greater loneliness and perceived burden. Our second aim examines whether loneliness and perceived burden predict daily variation in suicide ideation. We hypothesize that caregiving stressors will predict suicide ideation via increases in loneliness and perceived burden. Our third aim is to examine whether suicide ideation in caregivers is associated with worse caregiving outcomes in the short-term (next day caregiving stress, fewer positive interactions) and longer-term (functional decline at 6-month follow-up). Understanding mechanisms whereby caregivi...