A recent study linked Alzheimer’s to benzodiazepine usage. The findings are striking. Taking the drug for three to six months raised the risk of developing Alzheimer’s by 32%, and taking it for more than six months boosted the risk by 84%. In the study, the greater people’s cumulative dose of benzodiazepines, the higher their risk.
A secondary study, with conflicting outcomes from the University of Washington came out refuting the risk, stating that only those on moderate or lower doses developed Alzheimer’s.
We were expecting to find a higher risk only in those individuals that had high use of benzodiazepines. So contrary to our expectations, we did find the small increased risk for dementia in people with low or moderate use.
Some notable things were missing from that secondary study that immediately stood out to me. They found high doses and no doses were evenly correlated with Alzheimer’s. The lower and medium doses were correlated. My guess is because the lower and medium doses are daily users, while the higher doses were not. None of this was clarified. It seems essential to state the length of time and dosing for an accurate picture. However, this study did not. “The investigators were unable determine the impact of the use of individual benzodiazepines on dementia risk.” Because of this, the study title Benzodiazepines: No Dementia Risk? seems misleading.
The study also did not quantify what constitutes a “low dose”, “high dose”, or “medium dose” of a benzodiazepine. That seems pertinent as well to be a sound study. It was also not known if the control participants who developed Alzheimer’s were ever users of benzodiazepines. They did not ask that when qualifying the control. The sample only included a few participants that had ‘heavy” benzodiazepine use, and overall, the participants might have had lower levels of exposure than in some other studies.
So where is the truth? What is the best course of action? It would be irresponsible to dismiss the first study for the second study, but we recommend seeking further studies, specifically on those taking benzodiazepines daily, regardless of the size of the dose.