Project Summary With over 6 million people in the United States diagnosed with Alzheimer’s disease (AD) in 2021, dementia and dementia caregiving are now major public health concerns. As dementia advances, it becomes increasingly difficult for the person with dementia (PwD) to recall past events and for these “care pairs” to enjoy activities and time together. AD caregivers also experience “ambiguous loss”– when the PwD is still physically present but mentally absent. Research has shown that such losses can exacerbate caregiver pre-loss grief – a painful yearning for the PwD as s/he used to be, loneliness, and role confusion. Caregiver pre-loss grief is associated with depression, poor quality of life, impaired medical decision-making on the PwD’s behalf. Caregivers grieve not just the PwD’s loss of memory and identity, but also the loss of the relationship that they shared. Our micro- sociological theory of adaptation to loss suggests that caregivers’ well-being benefits from filling the psychosocial voids created by significant interpersonal loss. In the context of AD, such voids might be filled by activities enabling caregivers to share memories with the PwD of their common past, reminding them of happy times, proud moments, feelings of belonging, and of former roles and relationships, while providing an opportunity to show affection, appreciation, respect, and “play”. Reminiscence Therapy (RT), which uses cues to trigger recall of significant life events, may address such psychosocial deprivations. Our Living Memory Home (LMH) web application is an online bereavement resource that we propose to adapt to address AD caregiver psychosocial deprivations and, thereby, reduce caregiver pre-loss grief while improving the caregiver-PwD relationship. Aim 1: We propose to adapt LMH for caregivers of patients with early-stage dementia. The LMH will be adapted to include RT activities led by caregivers. Input from 30 stakeholders (e.g., current/ bereaved AD caregivers, PwD, dementia experts) will inform the creation of the LMH-4-Dementia Care Pairs (LMH-4-DCP). Aim 2: To evaluate LMH-4-DCP feasibility, acceptability, and explore effects on outcomes. Care pairs (n=70) will be randomized to LMH-4-DCP (n=35) or an attention control condition (LMH excluding reminiscence activities; n=35). User interaction (e.g., logins, feature usage) and satisfaction will be assessed as will primary outcomes. Hypothesis: >70% of caregivers will find it acceptable, and its use associated with lower caregiver pre-loss grief and improved relationship quality (primary outcomes) at 1-month follow-up. Effects on caregiver psychosocial deprivations (e.g., sense of belonging) (mediators) at 2-weeks will be explored. Impact: LMH-4- DCP will prove acceptable and associated with reduced caregiver pre-loss grief and improved quality of the care- pair relationship via targeting the reduction of psychosocial deprivations. Results will be used to seek NIH R01 funding of a larger randomize...