- This study found no causal association between benzodiazepines or Z-drugs use and the risk for dementia.
Why this matters
- Benzodiazepines and Z-drugs have dose-related effects on memory and other aspects of cognitive function, but no biological mechanism has been established underlying the association with dementia incidence.
- 40,770 patients with dementia (cases) diagnosed between April 2006 and July 2015 were matched to 283,933 participants without dementia (controls) using UK Clinical Practice Research Datalink (CPRD).
- The number of defined daily doses (DDDs) prescribed for benzodiazepines and Z-drug users (new and prevalent) was determined during the drug-exposure period (DEP) of 4-20 years before dementia diagnosis.
- Funding: UK Alzheimer’s Society.
- Adjusting for confounders measured at the start of the DEP showed an inverse association between benzodiazepines and dementia risk (for ≥4 years DDDs; OR, 0.88 [95% CI, 0.82-0.95]) which was stronger at the end of the DEP (for any use; OR, 0.81 [95% CI, 0.75-0.87]).
- There was little evidence of an association between any new prescription of benzodiazepines and dementia risk at the start of DEP (OR, 1.03; 95% CI, 1.00-1.07), but the negative association was prevalent in prevalent users (OR, 0.91; 95% CI, 0.87-0.95).
- There was an inverse association between new (OR, 0.91; 95% CI, 0.88-0.95) and prevalent (OR, 85; 95% CI, 0.81-0.89) users of benzodiazepines and dementia risk at the end of DEP.
- No association was observed between Z-drugs use and dementia risk at the start and end of DEP.