Benzodiazepine use not causally linked to dementia risk

  • Richardson K & al.
  • Am J Epidemiol
  • 27 Mar 2019

  • curated by Sarfaroj Khan
  • UK Clinical Digest
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Takeaway

  • 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.

Study design

  • 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.

Key results

  • 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.