Does heavy drinking over time make you dumber?

Oh, it definitely does. My mom drank something like 12-24 beers a day for 20+ years, and at the end of that she was obviousy far dumber and less with it.

She had a very high (150+) IQ to start with so she had far to fall. But I’d guess by year 20 of heavy drinking, she had around a 100-105 IQ. She was not the same person at all. (And no, she didn’t have dementia and was not even 50.)