Anhedonia and Dysphoria Are Differentially Associated with the Risk of Dementia in the Cognitively Normal Elderly Individuals: A Prospective Cohort Study

Objective: We investigated the impact of depressed mood (dysphoria) and loss of interest or pleasure (anhedonia)on the risk of dementia in cognitively-normal elderly individuals. Methods: This study included 2,685 cognitively-normal elderly individuals who completed the baseline and 4-year follow-up assessments of the Korean Longitudinal Study on Cognitive Aging and Dementia. We ascertained the presence of dysphoria and anhedonia using the Mini International Neuropsychiatric Inventory. We defined subjective cognitive decline as the presence of subjective cognitive complaints without objective cognitive impairments. We analyzed the association of dysphoria and anhedonia with the risk of cognitive disorders using multinomial logistic regression analysis adjusted for age, sex, education, Cumulative Illness Rating Scale score, Apolipoprotein E genotype, and neuropsychological test performance. Results: During the 4-year follow-up period, anhedonia was associated with an approximately twofold higher risk of mild cognitive impairment (OR=2.09, 95% CI=1.20–3.64, p=0.008) and fivefold higher risk of dementia (OR=5.07, 95% CI=1.44–17.92, p=0.012) but was not associated with the risk of subjective cognitive decline. In contrast, dysphoria was associated with an approximately twofold higher risk of subjective cognitive decline (OR=2.06, 95% CI=1.33–3.19, p=0.001) and 1.7-fold higher risk of mild cognitive impairment (OR=1.75, 95% CI=1.00–3.05, p=0.048) but was not associated with the risk of dementia. Conclusion: Anhedonia, but not dysphoria, is a risk factor of dementia in cognitively-normal elderly individuals.