I wasn't thinking getting "high" referred only to heroin. Nearly any creative influence seems to have, at many points in their career, been high with alcohol or different drugs, and when they get clean, they tend to suck.
However, I would by no means say that getting high in any way helps the creative process or is the cause of the creative process; I think, rather, that people who are very creative tend to have brains that lead in a certain direction, and unfortunately, that direction tends to be drugs and alcohol.
Here are some examples:
Johnny Cash, Ernest Hemingway, Trent Reznor (note that last few albums after not drinking/drugging), Kurt Cobain.
I love Bill Hicks.