My dad is a high functioning alcoholic. He claims he did coke once in the seventies and never did it again because he liked it so much after that one time. That an acute addict avoided an addiction out of fear of pleasure is pretty amazing. I try not to give him credit for anything though. He's just awful.
Dated a girl for a long while whose father and grandfather were both psychiatrists. The grandfather, in order to get the father through medical school, wrote him prescriptions for amphetamines to stay up, quaaludes to come down and thorazine because occasionally the acid was a little too much and he needed to get back to work. They both snorted coke recreationally but oddly enough, the one thing they both ended up addicted to was alcohol. Mutherfuckin' all-drug olympics but for studying back then.