0282 Shared Sleep, Uneven Effects: Asymmetric Links Between Sleep, Mood, and Relationship Functioning in Couples Facing Mild Cognitive Impairment

Abstract Introduction Sleep and relationship functioning are interdependent, particularly in couples coping with cognitive decline. This study examined how sleep patterns relate to daily mood and relationship quality among couples in which one partner is at risk for mild cognitive impairment (MCI; hereafter referred to as “patient”). The goal was to assess both within-person (day-to-day) and between-person (average) associations, as well as interdependence (cross-partner effects) between patient and partners’ sleep, mood, and relationship functioning. Methods Married or cohabiting couples (N= 165 couples; mean age= 64.07; SD= 10.56), with one partner at risk for MCI i.e., patient), participated in a seven-day assessment protocol involving actigraphy and diaries to measure sleep duration and efficiency, alongside daily diary reports of relationship quality and mood. Multi-level actor–partner interdependence models were used to test both within-person (daily fluctuations) and between-person (average across days) associations. Results Across diary and actigraphy data, results revealed distinct and interdependent links between sleep efficiency and daily affect. Diary findings primarily suggested links between sleep efficiency and affective outcomes. For patients, higher daily sleep efficiency predicted their own lower same-day positive affect, but higher positive affect in their partners. At the average level, patients who slept more efficiently on average reported lower overall positive mood, whereas partners with higher average sleep efficiency reported higher overall positive mood. Actigraphy findings primarily related to relationship functioning. Patients’ average sleep efficiency was unrelated to their own perceptions of support, but when they slept more efficiently, their partners reported higher perceived support. In contrast, partners with higher average sleep efficiency perceived lower levels of support. Conclusion Together, these findings demonstrate that daily sleep quality in couples affected by MCI has asymmetric associations with mood and relationship functioning. Sleep efficiency among those at-risk for MCI appears beneficial for their partners’ mood and perceived support, while for partners, better sleep may coincide with reduced perceptions of support. These findings highlight sleep as a shared but uneven determinant of emotional and interpersonal well-being in aging couples. Support (if any) R01AG08530