My primary care doctor picked up on it in my late 20’s. It was impressive - I think he suspected, so asked 3 questions/statements about my behaviour as a kid and teenager, things that nobody, not my parents, siblings or friends knew. They were formed as “you did X, Y, Z, as a teen, didn’t you?”.

They were questions regarding self control and specific drug use. In particular, he said “you did come coke as a teen, and you felt it calmed you down”. Mind. Blown.