This is a hot subject on another health group and thought I'd post it FYI.

Common anticholinergic drugs like Benadryl linked to increased dementia risk - Harvard Health Blog - Harvard Health Publications

Benzodiazepine use may raise risk of Alzheimer's disease - Harvard Health Blog - Harvard Health Publications

I've never taken Benadryl but was taking Lorazepam 1/2mg at a point and when I was informed of the Alz connection, I ran from it.

There are many alternatives for these two drugs, just have to find them and work with them.