Lots more of his photos here: http://bryanlewissaunders.org/drugs/ Also, it's worth noting that only a small # of his portraits were painted while "under the influence" (though it sounds as if many were done while medicated). Though I have experience with but a small fraction of his ... influences? ... his portraits definitely capture bits of the experiences I've shared. Clever. Setting aside the artistically product…
It's difficult to evaluate the "intentionally" part (once you know its effects, is it intentional ?) but absynthe comes to mind for XIX century painters, LSD and heroin for a lot of writers, painters and musicians in XX: Dalí, Parker, Huxley...
If alcohol counts, then that list includes just about every artist of the past several centuries who isn't either Muslim or Henry Rollins.
Which it does, IMO.