At the end of the day our minds are made up of a very complex circuit of electrical signals and chemical signals, so adjusting the chemical balance in the brain is going to have a major effect on your thoughts, the same as taking a soldering iron to your Pentium (I speak metaphorically as I don't think you can get soldering irons that small!) will change your computer's performance.
I'd heard that anti-depressants like Prozac can hinder artistic creativity, can anyone else elaborate on/disprove this? Meanwhile my experience with people who use controlled substances (which is a lot of people) is that the effect they have on them varies depending on what they are mentally - if they couldn't handle it they ended up screwed, those that could handle it are fine. Bear in mind the influence of Burroughs on contemporary literature and also bear in mind the amount of drugs he took...
Personally I think a lot of artistic vision comes from an ability to see things differently to most people (whether chemically stimulated or not), for example Bacon's agonised, mutated figures, Dali's surreal distorted objects and landscapes, the new Natwest adverts (UK) or Buggy G. Riphead's computer-manipulated images are hardly what your average Joe would see if looking at the world. To this end I feel that chemical stimulants are just another tool, effective if only used carefully.
-james
www.twisted-animator.co.uk/