Truth is, I think that there's a word that's useful in regards to understanding the "artistic temperament" (as referred to in this discussion). The word is "sensual". It's not that artistic people are more sensual -- it's that sensual people are more drawn to the arts.

Those who can't as easily control their drive for sensory stimulation are only inclined toward the type of discipline that will afford them more stimulation in the practicing.

They don't do drugs because they are tortured artists. The do drugs because they are driven by their sensual nature. The drugs make their lives tortured.