Benzodiazepines and risk of dementia: what is the evidence?

Abstract

Aim: To determine if long-term use of benzodiazepines on people aged ≥ 65 years is associated with an increased dementia risk. Data sources: National Guideline Clearinghouse, NHS Evidence, CMA InfoBase, Cochrane, DARE, MEDLINE/PubMed. Review methods: Guidelines, systematic reviews, meta-analyses and observational studies in English and Portuguese, published between January of 2006 and March of 2016, were searched, using the MeSH terms ‘benzodiazepines’ and ‘dementia’. Strength of Recommendation Taxonomy (SORT) scale from the American Family Physician was applied to evaluate the levels of evidence (LE) and the strength of recommendation (SR). Results: There were obtained 209 articles and five of these met the inclusion criteria. The meta-analysis and systematic review revealed an association between benzodiazepines use and increased risk of dementia (LE 3). This risk increases with treatment duration, cumulative doses of benzodiazepines and benzodiazepines with long duration of action (LE 3). Nonetheless, observational studies did not reveal this association (LE 3). Conclusions: There is limited evidence (SR C) for the association between benzodiazepines use and risk of dementia. Therefore, more prospective cohort studies, with a long follow-up and adjusted for confounding variables, is needed to clarify the existence of a possible causal association and to decrease the reverse causality bias. However, the implementation of these studies presents several methodological difficulties. This study reinforces the already existing concern about the chronic use of benzodiazepines in the elderly population, in the treatment of anxiety and sleep disorders and emphasize the role of the Family Physician as a longitudinal health care provider.