A new study links benzodiazepines, a popular class of drugs used to treat anxiety and insomnia, with a increased risk of developing Alzheimer's. The study -- published today in the online journal The BJM -- found the correlation especially strong among long-term users.
During the large and long-term case-control study, a team of French and Canadian researchers -- from the University of Bordeaux and the University of Montreal -- looked at incidents of Alzheimer's among more than 1,796 patients in Quebec. These patients were then compared to 7,184 healthy Canadians matched for age, sex, and duration of follow-up.
They found that use of benzodiazepines, a large class that includes Xanax and Valium, for three months or longer was strongly correlated with an increased risk of developing Alzheimer's. Longer periods of drug use and using long-acting benzodiazepines rather than short-acting ones both increased the chance of Alzheimer's.
More than 36 million people around the world are currently dealing with the effects of Alzheimer's disease. That number is expected to triple by 2050.
In their paper, researchers wrote that though the link does not show causation, the fact that longer-term drug use heightened the risk of dementia "reinforces the suspicion of a possible direct association, even if benzodiazepine use might also be an early marker of a condition associated with an increased risk of dementia."
Benzodiazepines are "indisputably valuable tools for managing anxiety disorders and transient insomnia" the scientists wrote, but recommended that treatments "should be of short duration and not exceed three months."
In 2012, the American Geriatrics Society added benzodiazepines to its list of drugs they consider inappropriate for older adults, citing their association with unwanted cognitive side effects. But many older patients continue to be prescribed and continue to take these drugs.