Why would that make you mad?
Plently of musical, visual and physical artists draw inspiration from hallucinogenic drugs.
I for one do, and they help me immensely.
If you're a true lover of art you'd realize that it's not about the artist, it's about his/her artwork,
A true artist would sacrifice anything for his art, his body, his mind his very soul.
It depends on the drug as well.
Most drugs will screw up your mind and your body, however Mushrooms are relatively safe as is marijuana.