What is the chief effect of hallucinogens?

Answer 1

As the word implies, they make you hallucinate. Against contrary belief, hallucinating does not mean seeing things that aren't there, but percieving things differently from what they really are. For example, an item may appear to be warping or it's outline may appear to ripple, you might see colourfull fractal and geometric patterns, but you won't see purple elephants floating through the air or UFO's invading planet earth. Seeing things that really aren't there is called a delirium, and substances which cause this effect are called deliriants. Known deliriants are Jimson weed, Datura, Belladonna and Brugmansia which are all plants containing Atropine. Other well known deliriants are the antihistamines such as Promethazine, Diphenhydramine and Diphenhydrinate. Well known hallucinogens are LSD, Mescaline cactii such as San Pedro and Peyote, Psylocybin containing mushrooms such as Psilocybe Tampanensis, Psilocybe Cubensis and Psilocybe Semilanceata and DMT containing plants such as Mimosa Hostilis and Banistereopsis Caapi.