Benzodiazepines, which are widely prescribed to treat anxiety and insomnia, have been associated with a heightened risk of developing the condition, particularly for long-term users, a new study suggests.
Researchers cautioned that unwarranted long-term use of the drugs should be considered a public health concern.
The study, published on thebmj.com, examined data from a health insurance database in Quebec.
French and Canadian researchers identified 1,700 elderly people with Alzheimer’s disease and more than 7,000 healthy people for comparison.
They found that past use of benzodiazepines for three months or more was associated with an increased risk of developing Alzheimer’s. The risk varied between 43% and 51%, they found.
The strength of association increased with the longer exposure, they found. It also increased if people used long-acting benzodiazepines rather than short-acting ones.
“Our study reinforces the suspicion of an increased risk of Alzheimer-type dementia among benzodiazepine users, particularly long-term users, and provides arguments for carefully evaluating the indications for use of this drug class.
“Our findings are of major importance for public health, especially considering the prevalence and chronicity of benzodiazepine use in older people and the high and increasing incidence of dementia in developed countries.”
Dr Liz Coulthard, consultant senior lecturer in dementia neurology, University of Bristol, said: “This work provides yet another reason to avoid prescription of benzodiazepines for anything other than very short-term relief of insomnia or anxiety.”
Dr Eric Karran, director of research at Alzheimer’s Research UK, added: “This study shows an apparent link between the use of benzodiazepines and Alzheimer’s disease… We need more long-term research to understand this proposed link and what the underlying reasons behind it may be.”