The Association Between Dementia and Long-Term Use of Benzodiazepine in the Elderly: Nested Case-Control Study Using Claims Data

Objectives: The aim of this study was to examine the association between long-term benzodiazepines (BZDs) use and the risk of dementia. Design: Population-based nested case-control study of dementia. Setting: All subjects were aged 45 and older and enrolled in the National Health Insurance Research Database in Taiwan, 1997-2004. Participants: Cases (N = 779) were patients who were identified with dementia at least two times in their outpatient claims. They were individually matched to six comparison subjects ( N = 4,626) based on age and gender. Measurements: BZD usage ( average dosage per year, average days per year, and cumulative dose and periods) and potential confounding comobidities, including cardiovascular and psychiatric diseases. Results: Subjects with dementia had higher cumulative dose, longer duration of BZDs exposure, and more likelihood to be long-term BZDs users. Conclusion: Our findings suggest that long-term use of BZDs is associated with an increased risk for dementia, but the underlying mechanisms remain unclear, and further investigations are needed. Long-term use of BZDs should be avoided among the elderly, who may be at a higher risk for developing dementia, in addition to other health problems. (Am J Geriatr Psychiatry 2009; 17:614-620)