I know of two people that this supposedly happened to and it was in the 80’s.
One was the brother of a girl I worked with when I was a teen and another is the brother of one of my mother’s good friends.
I don’t know much beyond they put the blame on smoking tons of weed.
All I'm saying is that if someone smoked tons of weed, then they dropped acid and used any number of other illicit pharmaceuticals.
Hint: that's why they called cannabis a gateway drug.
Another hint: it wasn't the cannabis that jacked their brains.