Why do artists feel they need drugs to feed their craft?

Salon

I was dumbstruck yesterday to hear that Amy Winehouse had died. She was only 27 years old. Jimi Hendrix, Janis Joplin and more preceded her in the same drug filled road to stardom.

Why? I just do not understand the need. Do the drugs add to the creative nexus? I loved her music, and although her songs were often dark and melancholy, I felt there were real. I am very sad today.

I may pull her up on Pandora today and do a little painting.