Written by Chrystal Moulton, Staff Writer. Researchers found that the use of benzodiazepines significantly increased the risk of Alzheimer’s disease by 43%.
Benzodiazepines are a class of drugs used to treat anxiety, insomnia, and seizures. However, due to very serious side effects and symptoms related to their use, public concern on the risks associated with benzodiazepines, especially among the medical research community, is high. (1)
In order to investigate the possible link between the use of benzodiazepines and Alzheimer’s disease, researchers compared the data of 1796 elderly residents who have Alzheimer’s with 7184 controls who did not. (2) Both groups were randomly sampled older individuals who were matched for age, sex, and duration of follow-up. All participants were over 66 years old and part of the public drug plan in Quebec from 2000-2009. To determine an association between benzodiazepine use and Alzheimer’s, researchers measured the use of benzodiazepines over a period of 6 to 10 years prior to diagnosis of Alzheimer’s and calculated the cumulative dose for each participant. Cumulative doses were converted to the number of prescribed daily doses (PDD) representing an average dose of benzodiazepine for each person taken daily. Thus, one prescribed daily dose (PDD) corresponds to one day of exposure (or use) of benzodiazepines. Prescribed daily doses (PDD) were then categorized into 3 levels of exposure:
- 1-90 PPDs [meaning use of benzodiazepine for 1 to 90 days (3 months)]
- 91-180 PPDs [3-6 months]
- ≥ 180 PPDs [considered long-term users]
With this information along with questionnaires and data made available to them through the prescription and medical services database in Quebec, researchers attempted to see if there was a correlation between benzodiazepine use and Alzheimer’s disease.
At the end of the study, researchers found that the use of benzodiazepines significantly increased the risk of Alzheimer’s disease by 51% (p<0.05). When the data was further adjusted for anxiety, depression, and insomnia, the risk of Alzheimer’s disease was 43% (p<0.05). No significant association was found between Alzheimer’s and benzodiazepine for exposure under 90 days. When examining the half life*of benzodiazepines used in relation to Alzheimer’s, they found that the risk of Alzheimer’s was 43% for benzodiazepines with a shorter half-life (<20h) versus 70% for those with a longer half-life (>20h) [p<0.05].
Overall, it was found that benzodiazepine use was strongly associated with the risk of Alzheimer’s.
- Half life is the time until the level of the substance under consideration is reduced to half of its initial concentration.
Source: de Gage, Sophie Billioti, et al. “Benzodiazepine use and risk of Alzheimer’s disease: case-control study.” Bmj 349 (2014): g5205.
Creative Commons Attribution Non Commercial (CC BY-NC 3.0) license, http://creativecommons.org/licenses/by-nc/3.0/.
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Posted March 5, 2015.
Chrystal Moulton BA, PMP, is a 2008 graduate of the University of Illinois at Chicago. She graduated with a bachelor’s in psychology with a focus on premedical studies and is a licensed project manager. She currently resides in Indianapolis, IN.
References:
- Paquin AM, Zimmerman K, Rudolph JL. Risk versus risk: a review of benzodiazepine reduction in older adults. Expert Opin Drug Saf. 2014 Jul;13(7):919-34.
- Billioti de Gage S, Moride Y, Ducruet T et al. Benzodiazepine use and risk of Alzheimer’s disease: case-control study. BMJ 2014;349:gs5205
