Abstract
OBJECTIVES: Living apart together (LAT)-intimate partners living in separate households-is a common partnership type among older adults. Although the mental health benefits of intimate partnerships are widely documented, how LAT relates to older adults' mental health remains understudied. METHODS: Analyzing Waves 3-13 (2011-2023) of the United Kingdom Household Longitudinal Study, we use fixed effects models to examine (a) how older adults' mental health varies with LAT, marriage, cohabitation, and singlehood (never married, widowed, divorced/separated) and (b) how transitions into and out of LAT, compared with marriage and cohabitation, relate to older adults' mental health. RESULTS: Overall, older adults have better mental health when LAT than when single, but little difference in mental health is found across LAT, cohabitation, and marital partnerships. Whereas older singles moving into LAT experience mental health improvements, those moving from LAT to singlehood suffer mental health declines. Although the mental health benefits of moving into LAT are smaller than those of entering cohabitation and particularly marriage, exiting LAT is associated with smaller mental health declines compared with exiting cohabitation and marriage. No statistically significant gender difference is found in the mental health benefits of LAT. DISCUSSION: The findings underscore LAT as a key form of family diversity in later life. They problematize the long-held ideal of coresidence in couple relationships and its role in sustaining older adults' mental health. They encourage researchers to go beyond the household as a default unit of analysis and examine interhousehold intimate connections in older adults' lives.