A Comparison of Neurocognitive Decline in Older Adults in Same-Sex and Opposite-Sex Relationships

Background: Individuals from sexual minorities experience health inequalities that have detrimental impacts on their health, especially in the elderly, by exacerbating care needs and symptoms of chronic conditions such as Alzheimer’s disease (AD). Neurocognitive decline due to AD in the sexual minority population remains under-investigated. However, being in a relationship may mitigate the risk of experiencing cognitive impairment. Objective: The aim of this study was to investigate whether cognitive decline and brain atrophy may differ in people from sexual minorities. Methods: Clinical data for this study were selected from the National Alzheimer’s Coordinating Center’s Uniform Data Set and structural MRI data collected across 14 Alzheimer’s Disease Centers. Eighty participants including 20 patients with AD and 20 healthy controls (HC) in same-sex relationships were identified and matched to groups of participants (20 AD and 20 HC) in opposite-sex relationships. The effects of diagnosis and relationship were investigated on all measures. Results: No diagnosis-by-relationship interactions were found on any variable. However, post hoc analyses revealed that the opposite-sex group had grey matter atrophy mainly in medio-temporal areas. In the same-sex group, atrophy also extended to pre-frontal and cingulate areas. The severity of neuropsychiatric symptoms correlated with volume of pre-frontal and insular/temporal areas only in the same-sex group. Conclusion: Neurocognitive decline due to AD may express similarly across individuals, independently of relationship type, thus suggesting a protective role of relational status. However, the same-sex group appeared to be more likely to experience at least one neuropsychiatric symptom and to have atrophy extending to fronto-limbic areas.