In a recent American Journal of Geriatric Psychiatry study, Robert Wilson and colleagues from the Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL examined the relation of different facets of neuroticism to risk of developing AD.
Emerging research implicates a consistent reciprocal relationship between late-life anxiety and cognition, and that severe anxiety may predict future cognitive decline.
Recent population-based prospective study indicates that anxiety is a risk factor for cognitive impairment not dementia (CIND) and dementia, although the extent to which the association is independent of depression remains unidentified (Gallacher et al., Psychosomatic Medicine 2009, 71:659).
Anxiety has also been implicated in the progression from mild cognitive impairment to Alzheimer’s disease (AD). In addition, high level of chronic psychological distress is associated with increased incidence of mild cognitive impairment, and proneness to experience psychological distress is a risk factor for dementia or AD.
In old age, anxiety is often part of a more complex personality trait such as neuroticism, which includes anxiety, depression, self-consciousness and impulsiveness. High levels of neuroticism has been associated with lower level of cognitive function, more rapid cognitive decline, and increased risk of developing mild cognitive impairment and dementia. It is unclear; however, which components of neuroticism are primarily responsible for its association with late-life dementia.
The American Journal of Geriatric Psychiatry study used data are from the Rush Memory and Aging Project, a longitudinal clinical pathologic study of risk factors for common chronic conditions of old age.
In this prospective study of more than 700 old persons the authors demonstrate that neuroticism’s association with AD risk primarily reﬂects two components: vulnerability to stress and anxiety. The association of perceived vulnerability to stress with AD risk is consistent with previous data linking stressful life events and reactivity to stress with late-life dementia or cognitive decline.
The authors discuss that high perceived stress and anxiety has been associated with reduced hippocampal volume and decreased density of dendrites and spines in the CA3 region of the hippocampus. Thus, according to the authors, their observations suggest that perceived stress and anxiety in humans may eventually damage selective circuits supporting stress-related behavior, thereby contributing to cognitive impairment and dementia.