Course of depression and cognitive decline at 3-year follow-up: The role of age of onset.

We determined whether the course of depression was associated with accelerated decline or deficits in verbal episodic memory and verbal fluency in depressed older adults compared with controls, and whether this was modified by age of onset. There were 1,027 Spanish community-dwelling adults aged 60+ who participated at baseline and at 3-year follow-up. Word-list recall and animal naming tasks were performed at the two time points. Participants were classified according to the Diagnostic and Statistical Manual of Mental Disorders-Fourth Edition-Text Revised (DSM-IV-TR) criteria for 12-month depression at baseline and follow-up: controls, lifetime, remittent, incident, and persistent depression. Adjusted mixed regression models were fitted and interactions time*depression groups explored. Compared with controls, remittent, incident, and persistent depression were significantly related to worse verbal fluency, and remittent and incident depression to worse verbal episodic memory. In the subsample of subjects with depression, interactions were not significant, and age of onset was not related to either accelerated decline or cognitive deficits. Findings suggest that a history of depression per se might not be associated with cognitive deficits. Older people with late life depression are at higher risk for persistent cognitive deficits, even after the affective episode has remitted, and cognitive deficits might be detectable long before the episode appears. Overall, these findings would support the idea that depression during lifetime would not be a risk factor for cognitive impairment whereas late life depression could represent a prodrome for future dementia. Monitoring the neuropsychological functioning of older people with remittent, incident, and persistent depression is indicated, regardless of the age of onset. (PsycINFO Database Record (c) 2019 APA, all rights reserved).