Benzodiazepine use and risk of incident dementia or cognitive decline

Benzodiazepines are commonly prescribed for the treatment of insomnia and anxiety. Approximately 9-12% of older adults in the United States report to be using benzodiazepines. These medications are associated with deleterious effects such as falls, fractures, and delirium. Furthermore, previous single dose studies have shown that benzodiazepines impair aspects of cognition, such as memory and attention. Some studies suggest that long term use of benzodiazepines do not increase the risk of cognitive decline, but the results are conflicting. Thus,the objective of this research study is to determine whether higher use of benzodiazepines is associated with a higher risk of dementia or more rapid cognitive decline.

The cognitive abilities screening instrument (CASI) was administered every two years to screen for dementia and was used to examine cognitive trajectory. In addition, every two years the  cognitive function, collect demographic characteristics, health behaviors, and health status of patients are examined. Incident dementia and alzheimer’s disease were determined. At the end of the study, 797 participants  (23.2%) developed dementia, and 637 of them developed alzheimer’s disease. The risk of dementia was only slightly higher in people with minimal exposure to benzodiazepines but not with the highest level of exposure. The low risk observed may represent treatment of prodromal symptoms. Overall, this pattern does not support a causal relationship between benzodiazepine use and risk of dementia.

This study was particularly interesting because there has already been several research articles that have found a relationship between benzodiazepines and dementia. Despite that, these researchers still pursued this topic because they observed conflicting results in multiple studies. With this knowledge, patients may feel relieved to find out that benzodiazepines will not cause a decline in cognitive function. Do you think it is important to develop research projects that focus on topics that were addressed in the past? Why or why not?
Gray SL, Dublin S, Yu O, et al. Benzodiazepine use and risk of incident dementia or cognitive decline: a prospective population based study. BMJ. 2016;352:i90