The association of late-life depressive symptoms with brain amyloid-β deposition: the ARIC-PET study

Late-life depression is associated with an increased risk of developing dementia related to Alzheimer's disease, yet the mechanism underlying this relationship remains poorly understood. This study investigated the association of late-life depressive symptoms (LLDS) with brain amyloid deposition by PET. 334 dementia-free individuals from the Atherosclerosis Risk in Communities Study had Florbetapir-PET scans in late-life (ages 67-89). Elevated global and regional brain amyloid deposition was defined as a Florbetapir standardized uptake value ratio (SUVR) > 1.2. LLDS was assessed using the 11-item Center for Epidemiological Studies Depression Scale (CES-D) and defined as late-life CES-D ≥ 9. Several secondary depression measures (e.g., antidepressant use) were also explored. Stratified analyses across race, sex, and cognitive status groups were conducted. Participants (median age 76 years; 57.2 % female; 42.5 % Black; 26.9 % mild cognitive impairment) showed no association of LLDS with global amyloid deposition. Although antidepressant use was not associated with global amyloid overall, antidepressant use was associated with elevated global amyloid in individuals with normal cognition but not mild cognitive impairment. There was no effect modification by race and sex. Overall, our findings suggest that LLDS are generally not associated with global amyloid deposition, but further investigation of this relationship in larger sample sizes is warranted.