A new study has suggested that taking drugs for anxiety and sleep problems is not associated with an increased dementia.

These results from the University of Washington (UW) and Group Health in Seattle do not support a direct (causal) association between benzodiazepine (widely used drugs to treat anxiety and insomnia) use and dementia, say the researchers.

However, the researchers suggest that healthcare providers should avoid benzodiazepines in older adults to prevent important adverse health outcomes.

Benzodiazepines are widely prescribed among older adults to manage sleep, anxiety and depressive disorders. Some studies have suggested that benzodiazepine use could be associated with an increased risk of dementia, but results are conflicting.

The study involved 3,434 participants at Group Health aged 65 and older without dementia at study entry, who were followed for an average of seven years.

During follow-up, 797 participants developed dementia, of whom 637 developed Alzheimer's disease.

The team found no association between the highest level of benzodiazepine use (the median level of use in this group was equivalent to about one year of daily use) and dementia or cognitive decline.

Contrary to expectations, they found a small increased risk for dementia in people with low (up to one month) or moderate (one to four months) use.

The study appears in The BMJ.