Depressive Symptoms Increase the Risk of Mild Neurocognitive Disorders among Elderly Chinese

Depression is prevalent among patients with late life neurocognitive disorders but its role as an independent risk factor is not established. We aimed to examine the longitudinal relationship between depression and the incidence of mild neurocognitive disorders (NCD) in a Chinese population.

We analyzed data from 889 community-living Chinese elderly in the Singapore Longitudinal Aging Study (SLAS) cohort. All subjects were cognitively normal at baseline based on their performance on the Mini-Mental State Examination (MMSE). Depression was defined as total score of 5 or more on the 15-item Geriatric Depression Scale. Incident cases of mild NCD were ascertained at follow up after an average of 45 moths (range: 10-62). Odds ratios (OR) of associations were calculated in logistic regression models that adjusted for potential confounders.

A total of 59 mild NCD cases were identified. Increased risk of mild NCD was observed for subjects who had depressive symptom at baseline (OR=2.56, 95%CI 1.17-5.60) after controlling for age, gender, education, hypertension, diabetes mellitus, heart disease, APOE genotype and length of follow-up. The interaction between depression and APOE genotype was not statistically significant.

Depressive symptom was independently associated with increased risk of mild NCD among Chinese elderly. Effective management of late life depression may potentially reduce incident cases of NCD in the population.