Associations among depressive symptoms, hippocampal volume and cognition in community‐dwelling older Latinos

Abstract

AbstractBackgroundLatinos are the fastest growing subpopulation of older adults in the U.S. and have a higher risk for dementia than non‐Latino Whites. Depressive symptoms are prevalent among US Latinos. However, these symptoms often go undiagnosed and are undertreated. Depressive symptoms may be early manifestations of Alzheimer’s Disease (AD) before the onset of mild cognitive impairment and dementia. It’s unclear whether depressive symptoms in the presence of incipient neurodegeneration are associated with cognitive function in older Latino adults. Here, we examined the associations among depressive symptoms, cognition and hippocampal volume in older Latinos.MethodA total of 65 Spanish‐speaking Latinos enrolled in the Boston Latino Aging Study (BLAST) and the Harvard Aging Brain Study (HABS) were included. Depressive symptoms were assessed with the 30‐item‐Geriatric Depression Scale (GDS) and cognition with the Preclinical Alzheimer’s Cognitive Composite (PACC5), which includes the Mini‐Mental State Examination (MMSE), Digit Symbol Coding, Free and Cued Selective Reminding Test, Category Fluency (animals) and Logical Memory Delayed Recall (NEUROPSI Stories for BLAST participants). A subset of 34 participants also underwent a structural brain MRI on a 3T scanner. Spearman correlations were used to determine cross‐sectional associations among depressive symptoms, hippocampal volume, and cognition. Models were adjusted for age and education.ResultsParticipants had a mean age of 66 +/‐ 7.2 years, a mean education of 12.9 +/‐ 5.1 years, and 74% were female. They had a mean MMSE score of 26.7 +/‐ 2.8, a mean GDS score of 6.1 +/‐ 5.5 and a mean adjusted hippocampal volume of 7836.5 +/ = 630.9 mm3. Correlation analyses revealed that higher depressive symptoms were associated with lower years of education (r = ‐0.39, p<0.001), worse performance on cognitive measures (r = ‐0.33, p = 0.009) and smaller hippocampal volume (r = ‐0.61, p = <0.001).ConclusionsPreliminary results of this ongoing biomarker study suggest that depressive symptoms in older Latinos are associated with markers of neurodegeneration (i.e., hippocampal volume) and worse cognition. Future work will focus on investigating predictors of long‐term emotional and cognitive functioning in Spanish‐speaking, older Latino populations.