BACKGROUND

There may be important public health implications of increasing our knowledge of factors associated with age of dementia onset. The pre-morbid personality domain of Neuroticism constituted an interesting and theoretically plausible, yet uninvestigated, candidate for such an association. We aimed to examine whether midlife Neuroticism was associated with earlier age of onset of Alzheimer's disease (AD).

METHOD

This was a case-comparison study of 213 patients with probable AD. Detailed clinical information was collected for all patients including age of onset of dementia symptoms. One or two knowledgeable informants rated each patient's midlife personality retrospectively using the Neuroticism, Extraversion, Openness Five-Factor Inventory (NEO-FFI) questionnaire. The relationship between midlife Neuroticism and age of dementia onset was evaluated using both correlational analysis and backward linear regression analysis.

RESULTS

Midlife Neuroticism predicted younger age of dementia onset in females but not in males. The association found in females was independent of pre-morbid history of affective disorder.

CONCLUSIONS

This finding and its potential mechanism warrant further investigation.