Use of benzodiazepines and risk of dementia over a 15-year follow-up period

Evaluation of: Billioti de Gage S, Bègaud B, Bazin F et al. Benzodiazepine use and risk of dementia: prospective population based study. 345, e6231 (2012). The use of benzodiazepines is highly prevalent in older people. It is well established that benzodiazepines can impair cognitive function. However, it is not clear whether benzodiazepines can cause dementia. Billioti de Gage et al. used three different epidemiological approaches to assess whether benzodiazepine use is associated with incident dementia in a population-based community-dwelling sample of people aged 65 years and older. In the main analysis, benzodiazepine use was associated with a hazard ratio of 1.60 (95% CI: 1.08–2.38) for the development of dementia over a 15-year follow-up period when compared with nonuse of benzodiazepines. The key strengths of the study included the new user design, long-term follow-up, and confirmation of dementia diagnoses by neurologists. The possibility of reverse causation arising from use of benzodiazepines for prodromal symptoms of dementia cannot be excluded. However, this study provides additional evidence about the risks of benzodiazepine use in older people. Jenni Ilomäki, Sally Johns, Sepehr Shakib and J Simon Bel