High use of benzodiazepines is not associated with an increased risk for dementia or Alzheimer’s disease according to a large prospective study published in the British Medical Journal.
Previous research had suggested that there might be a link and we all know that single doses of benzodiazepines impair cognition and memory so it made sense that there might be such a link. However conducting research like this is complicated because many early manifestations of dementia such as sleep disruption and agitation may be initially treated with benzodiazepines so it is important to control for risk factors.
A total of 4724 people were followed prospectively for 10 years or more and screened every two years for signs of cognitive impairment using the Cognitive Abilities Screening Instrument (CASI).
Minimal use of benzodiazepines, such as might occur when trying to treat insomnia or other early symptoms of dementia, was associated with a slightly higher risk of dementia than no use, but heavy use of benzodiazepines was not associated with an increased risk of dementia.
The authors of the study conclude, “These results do not support a causal association between benzodiazepine use and dementia.”
This study is the best designed study to date and is reassuring.
Of course dementia is not the only risk associated with use of benzodiazepines in an older population. There is no doubt that benzodiazepine use is associated with an increased risk of falls and fractures including hip fractures that can be fatal.
Overall, however, the results from this study are reassuring for those older patients with chronic anxiety or insomnia.
In a review of the study, Dr. Peter Roy-Byrne, Editor-in-Chief of NEJM Journal Watch Psychiatry, commented: “Most experts in both geriatrics and use of benzodiazepines never believed the previous poorly controlled study suggesting this relationship. At the same time, adverse effects from these medications are more common in older adults and clinicians need to work harder to provide alternatives, especially psychosocial treatments, for managing anxiety and insomnia in the aging population.”
Gray Shelly L, Dublin Sascha, Yu Onchee, Walker Rod, Anderson Melissa, Hubbard Rebecca A et al. Benzodiazepine use and risk of incident dementia or cognitive decline: prospective population based study BMJ 2016; 352 :i90
This reference is to an earlier study that suggested that there was a risk –
Billioti de Gage S et al. Benzodiazepine use and risk of Alzheimer’s disease: Case-control study. BMJ 2014 Sep 9; 349:g5205. (http://dx.doi.org/10.1136/bmj.g5205)