What soft drugs would a person that suffers from psychopathy use?

18 YO here. Never tried anything that isn't alcohol. But I like psychology a lot. I am trying to write my first book and it's going really well after many tries. The protagonist suffers from psychopathy and I think I should make him take some light drug for the plot. But what drug or type of drug would a psychopath use for pure entertainment? I don't think I found anything useful on the internet, so maybe this can be the right place to ask.

(It feels strange to ask something in a sub about things that I have always stayed away from)