Harm avoidance and risk of Alzheimer's disease.

TL;DR: A high level of the harm avoidance trait, indicating a tendency toward behavioral inhibition, is related to the risk of developing AD and its precursor, MCI.

Abstract: Harm avoidance is a personality trait indicative of behavioral inhibition (1). Persons with a high level of the trait tend to be pessimistic, apprehensive, shy, and easily fatigued and to avoid new and potentially aversive situations. In prospective studies of children and young adults, higher harm avoidance has been associated with better health-related behavior (2,3) and health outcomes (4,5), possibly because those low in the trait tend to be daring and impulsive. The relation of the trait to health in old age is not well understood, however, with some cross-sectional data linking higher level of the trait to increased likelihood of disability (6) and chronic illness (7–9). In the present study, we test the hypothesis that higher level of the trait is associated with increased risk of Alzheimer’s disease (AD) in old age. The hypothesis is based on the observation that harm avoidance is associated with lifestyle patterns (e.g., reduced physical activity (10) and emotional predispositions (e.g., anxiety proneness [11,12]) which have been associated with more rapid cognitive decline and increased risk of dementia in old age. To examine the relation of harm avoidance to the development of AD, we used data from the Rush Memory and Aging Project. Participants aged 55 years and older completed a standard self report measure of the trait. At annual intervals thereafter, they had evaluations that included cognitive function testing and clinical classification of AD and its precursor, mild cognitive impairment (MCI). Those who died during the study period had a brain autopsy and uniform neuropathological examination to quantify pathologic burden of AD. In analyses, we tested the hypothesis that higher level of the trait is associated with increased risk of MCI and AD and more rapid decline in cognitive function. We also examined whether higher level of harm avoidance was a symptom of the underlying neuropathologic burden of AD rather than a risk factor for its occurrence.