Premorbid personality and behavioral and psychological symptoms in probable Alzheimer disease.

OBJECTIVES: Previous research investigating the influence of premorbid personality on behavioral and psychological symptoms in dementia (BPSD) has produced mixed findings. Addressing some limitations of previous studies, the authors aimed to investigate whether some of the common individual symptoms of BPSD (depression, anxiety, irritability, and aggression) were associated with key aspects of previous personality (neuroticism and agreeableness); and also to perform an exploratory investigation into the broader influence of personality factors on behavioral and psychological syndromes. METHODS: Two hundred eight patients with a diagnosis of probable Alzheimer disease were assessed for the presence of BPSD over the disease course using the caregiver-rated Neuropsychiatric Inventory (NPI). One or two knowledgeable informants rated patients' midlife personalities using a retrospective version of the NEO-FFI questionnaire. RESULTS: Premorbid neuroticism was correlated with anxiety and total NPI score, although not with depression. Premorbid agreeableness was negatively correlated with agitation and irritability. Principal components analysis of the 10 NPI behavioral domains identified three syndromes: "agitation/apathy," "psychosis," and "affect." In stepwise linear regression analyses, including personality domains from the Five-Factor Model and a range of potential confounders as independent variables; the only significant personality predictor of a behavioral syndrome was "agitation/apathy," predicted by lower premorbid agreeableness. CONCLUSION: Lower premorbid agreeableness is associated with agitation and irritability symptoms in Alzheimer disease and also predicts an "agitation/apathy" syndrome. The relationship between premorbid neuroticism and BPSD is less straightforward, and premorbid neuroticism does not appear to be associated with depression in Alzheimer disease or predict an "affect" syndrome.