Acid has no correlation to causing dementia.
In fact, they are now using acid to TREAT dementia.
Far out, man.
Your mistake is thinking it is an either/or thing. He fried his noodle 6 ways to Sunday on Acid. Among other recreational pharmaceuticals. Today, 50 years later he has Dementia on top of it.
Is it your contention that LSD would be good for Brian Wilson right now? Good luck with that, Doc.