Benzodiazepine use and risk of dementia: a nested case-control study.

The objective of this article was to examine the possible association between benzodiazepine use and the risk of dementia in the elderly. This was a nested case--control study set in community settings in Bordeaux area, France. The participants were a representative sample of 3,777 elderly persons (65 years of age and older) followed from 1989 to 1997. The main outcome measures were the use of benzodiazepines in incident cases of dementia versus nondemented controls. On the basis of medical and psychological data, 150 patients were diagnosed with dementia according to the criteria of the third revision of the Diagnostic and Statistical Manual of Mental Disorders. Information on benzodiazepine use was obtained by face-to-face interview and visual assessment of patient's medicine chest by a trained neuropsychologist. After controlling for age, gender, education level, living alone, wine consumption, psychiatric history, and depressive symptomatology, ever use of benzodiazepines was associated with a significantly increased risk of dementia [adjusted odds ratio (OR), 1.7; 95% confidence interval, 1.2-2.4]. Former use was associated with a significantly increased risk of dementia (adjusted OR, 2.3; 95% CI,1.2-4.5). No association was found between dementia and the current use of benzodiazepines (adjusted OR, 1.0; 95% CI, 0.6-1.6). Our finding suggest that former use of benzodiazepines could be a risk factor for dementia, but more detailed investigation are needed.