I've seen Ministry (American industrial metal band) several times over the years and singer Al Jorgensen has always been a great performer and was a heroin addict for most of his career but the last couple times I saw them, he'd kicked the heroin and was on weed and performing better than ever. He seemed more energetic than before despite being really old. According to the man himself, he just got bored of heroin and just stopped one day and started smoking weed instead.
Personally, I've always avoided drugs because I lost a couple mates to addiction and ultimately death. Ibuprofen is my only drug of choice due to many old injuries.