I want to insult a friend
Do you have a reason for wanting to insult your friend?
Yeah, I'm jealous of his life. I think it's sad how he tries to find peace in drugs.
I see how you feel, but you can't just insult your friend because of your jealousy. Support your friend instead and help him with his drug issues instead!
I don't care, I'm going to criticize him. Fuck him
Criticizing your friend may cause him to seek even more solace in drug abuse.  Addiction is often a response to feelings of isolation and that could be worsened by having you calling him out!