Insight and danger in Alzheimer's disease.

To determine the frequency, and demographic and clinical correlates of dangerous behaviours in Alzheimer's disease (AD). We assessed a consecutive series of 278 patients with AD and 45 age-comparable healthy controls with a comprehensive psychiatric and neuropsychological evaluation. Caregivers rated the frequency of patients' exposure to dangerous situations or commission of dangerous behaviours. The frequency of dangerous behaviours was 16% in the AD group and 2% in the healthy control group. The presence of anosognosia was associated with a threefold increase in the risk of dangerous behaviours, but there was no significant association between dangerous behaviours and patients' age, years of education, diagnosis of major or minor depression and presence of suicide ideation. Sixteen per cent of a consecutive series of patients with AD had dangerous behaviours during the month preceding the clinical evaluation. Anosognosia was the main clinical correlate of dangerous behaviours in this population.