or did he take drugs bc his life was shit? why did you decide to establish this direction of causality?
But it cuts both ways. There's a phrase "high-functioning alcoholic", meaning someone who still holds down a job, wears respectable clothes and all that. I grew up with a drunk: "high-functioning alcoholic" just means the worms are well concealed inside the can.
Especially at high doses for long periods of time, which is how Hunter S. Thompson got his name.