Abstract
Depressive symptoms are prevalent among those aged 90 and above, the oldest old, but studies examining associations with neuroimaging markers of brain health are sparse. Therefore, we tested the association between depressive symptoms and neuroimaging outcomes, and assessed whether these associations differ by gender. This cross-sectional study used data from 225 participants with imaging data from the LifeAfter90 study (mean [SD] age=93.1 [2.2] years, 56 % female, 22 % African American/Black, 25 % Asian, 18 % Hispanic/Latino, 28 % White, 7 % multiracial/other). Depressive symptoms were measured using the 15-item Geriatric Depression Scale (GDS), and neuroimaging markers were collected via 3T magnetic resonance imaging and amyloid positron emission tomography (PET) scans. Average GDS score was 2.6 ± 2.3. Greater GDS scores were associated with lower total (β=-0.06; 95 % CI -0.12,>-0.01; p = 0.04) and right (β=-0.07; 95 % CI -0.13,-0.01; p = 0.02) hippocampal volumes. While GDS-by-gender interactions were not significant (p's interaction>0.05), estimates of GDS with lower total and right hippocampal volume were stronger among women compared with men in gender-stratified models. GDS was not associated with other measures of cortical volume, amyloid PET, nor white matter integrity. In a racially and ethnically diverse cohort, greater depressive symptoms were cross-sectionally associated with lower hippocampal volume among participants aged 90+.