Taking benzodiazepines for anxiety and insomnia is not associated with an increased dementia risk in older adults, according to US researchers – but they still advise caution when prescribing them.
The results do not support a direct link between benzodiazepine use and dementia or cognitive decline, said the researchers in the British Medical Journal.
“Overall, our results do not support a causal association between benzodiazepine use and dementia”
However, they advised healthcare providers to still try and avoid benzodiazepines in older adults to prevent important adverse health outcomes.
Some previous studies have suggested that benzodiazepine use could be associated with an increased risk of dementia, thought results are conflicting, said the researchers at the University of Washington and Group Health in Seattle. They suggested a better understanding of the potential cognitive risks of cumulative benzodiazepine use was needed, given the public health implications.
Their study involved 3,434 participants aged 65 and older without dementia at the start of the study, who were followed for an average of seven years.
Cognitive screening was carried out when participants entered the study and again every two years. Benzodiazepine use was assessed using computerised pharmacy data over a 10-year period.
Factors such as age, sex, and presence of other conditions were recorded and participants were also asked about smoking, exercise and self-rated health.
During follow-up, 797 participants (23%) developed dementia, of whom 637 (80%) developed Alzheimer’s disease.
The team, led by Professor Shelly Gray, found no association between the highest level of benzodiazepine use – equivalent to about one year of daily use – and dementia or cognitive decline.
“Healthcare providers are still advised to avoid benzodiazepines in older adults”
Contrary to expectations, they found a small increased risk for dementia in people with low or moderate use – daily pills for a month or four months, respectively.
The study authors said: “Overall, our pattern of findings does not support the theory that cumulative benzodiazepine use at the levels observed in our population is causally related to an increased risk for dementia or cognitive decline.
“It should be noted that our study did not examine the acute cognitive adverse events that can occur when treatment with a benzodiazepine is started in older adults and careful monitoring is recommended in this situation,” they said.
But they added: “Nonetheless, given the mixed evidence regarding benzodiazepines and risk of dementia and that these drugs are associated with many adverse events, healthcare providers are still advised to avoid benzodiazepines in older adults to prevent important adverse health outcomes, withdrawal, and dependence.”
Last year, the same research team published findings showing a link between dementia and the heavy use of medications with anticholinergic activity.