Baseline memory performance as a predictor of neurocognitive outcome of first-episode late-onset depression

Abstract

There is high comorbidity of depression and cognitive impairment in the elderly, and it would be important to explore the relationship between cognitive decline and late-life depression. This study was designed to prospectively explore the neurocognitive outcome of first-episode late-onset depression (LOD) at 6-month follow-up interval, and to explore the potential predictors of cognitive decline. Forty-nine LOD patients were recruited at Dementia Care & Research Center, Peking University Institute of Mental Health. Thirty-one with remission completed the neurocognitive examination at 6-month follow-up. A comprehensive neuropsychological test was administered at baseline and follow-up, including general cognitive function (measured with mini-mental state examination (MMSE) and cognitive abilities screening instrument (CASI)), memory (immediate object memory, 5-min delayed recall of objects, 30-min delayed recall of objects, logical memory, visual copy and recall), and executive function (verbal fluency, trail making test-A). The severity of depression was rated with geriatric depression scale (GDS-30). Subjects were imaged with a 3.0-Tesla whole-body MRI system and FLAIR images were acquired for the measurement of white matter hyper intensity (WMH). The polymorphism of ApoE gene was derived with PCR-RFLP. According to the GDS and MMSE score at follow-up the subjects were classified into cognitively stable group (GDS < 9, MMSE > 26, n=18) and cognitively progressive group (GDS < 9, MMSE < 26, n=13). The score of MMSE and total score of CASI of cognitively progressive group were significantly lower than cognitively stable group (P < 0.05). Relative to cognitively stable group, the performance of immediate object memory, 5-min delayed recall of objects, 30-min delayed recall of objects, visual copy and recall were significantly poorer in cognitively progressive group (P < 0.05). In the multivariate model, the score of immediate object memory test at baseline was inversely associated with the cognitive progression among late-onset depression (OR=0.31, 95% CI=0.13-0.70). Late-onset depressive patients with poorer immediate memory performance may be at greater risk of cognitive decline.