The case-control study, published in Acta Psychiatrica Scandinavica, found that the use of benzodiazepines and Z drugs such as zolpidem and zopiclone was associated with a 6% increase in the odds of developing Alzheimer's disease.
Despite the modest level of the association, the authors conclude that the use of benzodiazepines and Z drugs should be avoided where possible and the drugs should be prescribed only when the benefit outweighs the risk of adverse effects.
Further informationActa Psychiatr Scand article
The study included data on all 70,719 community-dwelling Finnish people diagnosed with Alzheimer's disease between 2005 and 2011 and compared them with 282,862 matched controls without Alzheimer's disease, in terms of benzodiazepine and related drug use since 1995.
The study found a dose-response relationship between benzodiazepine and Z drug use and Alzheimer's risk for both duration and cumulative use. This association disappeared when use of other psychotropic drugs such as antidepressants and antipsychotics was taken into account, suggesting it could be partially explained by these medicines or their concomitant use.
No major differences in the association with Alzheimer's disease were found between the different subcategories of benzodiazepines, such as long or short-acting agents.
Risks of benzodiazepines and Z drugs
The findings of the study are important, say the authors, because benzodiazepines are commonly prescribed to older people. Although Z drugs are non-benzodiazepine hypnotics they act at the benzodiazepine receptor and have similar effects.
Both classes of drugs can have negative short-term effects, particularly in older people. These include ataxia and confusion, leading to an increased risk of falls, fractures and injuries.