Abstract
Objectives
To investigate the relation between the risk of Alzheimer’s disease and exposure to benzodiazepines started at least five years before, considering both the dose-response relation and prodromes (anxiety, depression, insomnia) possibly linked with treatment.
Design
Case-control study.
Setting
The Quebec health insurance program database (RAMQ).
Participants
1796 people with a first diagnosis of Alzheimer’s disease and followed up for at least six years before were matched with 7184 controls on sex, age group, and duration of follow-up. Both groups were randomly sampled from older people (age >66) living in the community in 2000-09.
Main outcome measure
The association between Alzheimer’s disease and benzodiazepine use started at least five years before diagnosis was assessed by using multivariable conditional logistic regression. Ever exposure to benzodiazepines was first considered and then categorised according to the cumulative dose expressed as prescribed daily doses (1-90, 91-180, >180) and the drug elimination half life.
Results
Benzodiazepine ever use was associated with an increased risk of Alzheimer’s disease (adjusted odds ratio 1.51, 95% confidence interval 1.36 to 1.69; further adjustment on anxiety, depression, and insomnia did not markedly alter this result: 1.43, 1.28 to 1.60). No association was found for a cumulative dose 180 prescribed daily doses) and with the drug half life (1.43 (1.27 to 1.61) for short acting drugs and 1.70 (1.46 to 1.98) for long acting ones).
Conclusion
Benzodiazepine use is associated with an increased risk of Alzheimer’s disease. The stronger association observed for long term exposures 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. Unwarranted long term use of these drugs should be considered as a public health concern.
Sources and More Information:
- Benzodiazepine use and risk of Alzheimer’s disease: case-control study, BMJ 2014;349:g5205, 09 September 2014.
- Anxiety and sleeping pills ‘linked to dementia’, BBC News Health, health-29127726, 10 September 2014.
- Sleeping pills taken by millions linked to Alzheimer’s, The Daily Telegraph Health, healthnews/11083674, 10 Sep 2014.
- Prescription sleeping pills taken by more than one million Britons ‘can raise chance of developing Alzheimer’s by 50%’, Daily Mail, health/article-2750042, 10 September 2014.
- Prescription sleeping pills linked to Alzheimer’s risk, NHS Choices, Neurology, September 10, 2014.