HooRU My concern is how deep cognition is affected, is it cumulative, is it something during the dose period, or does it extend into the rest of the time.
Here’s a good review from last year, done in plain language.
https://www.scientificamerican.com/article/does-long-term-benadryl-use-increase-dementia-risk/
A lot is uncertain.
Common sense would tell us that if diphenhydramine (US Benadryl) is being used (whether for sleep or allergies), alternatives should be sought IF possible.
But likewise, intermittent or short-term use is different from chronic use.