Ok so I watched a couple of documentries last night and I thought I'd share them, I hope it's the right place. It isn't exactly about drugs but both are about altered perceptions.
The first link is to 'Derek Tastes Of Earwax' about people who have mixed up senses, they see colours, taste sounds kind of like some psychedelics.
The second is total isolation where subjects are placed in a darkened room with no sound for 48 hours, they go insane and begin to hallucinate.