ABSTRACT
Dementia is a global health concern often treated as an individual disease. Informed by the Dyadic Illness Management Theory, we posit that dementia is a relational condition that impacts the cognitive, physical, and emotional health of both spousal care-recipients and caregivers. We conducted a critical review of Western and East Asian literature on the dyadic effects of dementia in older couples and found several themes: First, spousal caregivers of those with dementia risk experiencing cognitive decline themselves, a phenomenon we refer to as reciprocal cognitive decline. Second, collectivist and patriarchal values disproportionately place caregiving burdens on East Asian women, contributing to gender differences in caregiving stress. Third, marital quality differentially relates to cognitive functioning among spousal caregivers and care-recipients, with marital loneliness, relationship satisfaction, and depression emerging as potential mechanisms. We underscore the necessity of culturally-relevant, dyadic dementia research and interventions in East Asia. We call for global research to clarify the mechanisms underpinning reciprocal cognitive decline. Clinical recommendations include considering dyadic ramifications of cognitive change in older couples throughout assessment, care-planning, and systemic health management. A case example illustrates key themes and gaps in research and practice.