Risk Aversion and Alzheimer Disease in Old Age

Abstract

To test the hypothesis that late-life risk aversion is partly a prodromal sign of dementia. The authors' design was a longitudinal clinical-pathologic cohort study. The setting included participants' residences in the Chicago area, and a total of 874 older persons without dementia were enrolled. At baseline, risk aversion was assessed with questions involving choices between certain smaller rewards and uncertain larger rewards. At annual intervals thereafter, participants underwent evaluations that included cognitive testing and diagnosis of mild cognitive impairment (MCI) and dementia. At death, a neuropathologic examination was done to quantify common pathologies linked to dementia. Risk aversion at study onset ranged from 0.05-0.91 (mean: 0.32, standard deviation: 0.31). During a mean of 4.6 years of follow-up, 123 (of 874) developed dementia. Higher risk aversion was associated with higher dementia incidence (hazard ratio [HR]: 2.08; 95% confidence interval: 1.18, 3.65) and more rapid decline in episodic (estimate: -0.062; standard error [SE]: 0.019; t [3677]: -3.33; p < 0.001) and semantic (estimate: -0.039; SE: 0.015; t [3655]: -2.61; p = 0.009) memory but not in other cognitive systems. Of 702 people without cognitive impairment at baseline, 223 developed incident MCI. Higher risk aversion was associated with higher incidence of MCI (HR: 2.10; 95% confidence interval: 1.34, 3.29) and more rapid episodic memory decline. In 181 neuropathologically examined individuals, higher risk aversion was associated with higher levels of plaques, tangles, and cerebral amyloid angiopathy. The results support the hypothesis that high risk aversion in old age is partly an early sign of the pathology of Alzheimer disease.