Hallucinogens are undoubtedly the most interesting of all the psychotropic substances. Many substances, when taken in a sufficiently high, often toxic dose, produce illusions, hallucinations and other psychological effects which superficially resemble the symptoms displayed by psychotic patients. These substances also produce strong physical effects. Genuine hallucinogens, however, exercise a strong influence on the human psyche without significant physical effects. Hofmann (note 83) defined hallucinogens as substances 'which in a specific way bring about changes in the perception and experience of the exterior and interior world, whcih can turn to hallucinations with a higher dose, while consciousness and memory are fully retained and without disturbances of vegative functioning. Halluconogens lead us into a sort of dream world, but one which is experienced in full consciousness. It is only after his discovery of LSD that science has taken a serious interest in these substances. By now it has become clear that many groups of substances which differ from one another chemically and which have been used by humanity for centuries possess hallucinogenic properties:

a. the dibenzopyrans
the most well known representative of which is tetrahydrocannabinol, active ingredient of cannabis.

b. the indolamines
substances derived from tryptamine, like the alkyl derivatives dimethyltryptamine (DMT) and diethyltryptamine (DET) and the hydroxy derivatives like psilocybin and lysergic acid diethylamide (LSD)

c. the carbolines
harmaline, harmine etc.

d. the phenethylamines
mescaline, dimethoxymethylamphetamine (DOM, also knowkn as STP) and DMA, as well as MDMA (XTC), all derived from amphetamine

e. the isoxazols
the best known representaive of this group is muscimol, the active ingredient of fly agaric

f. the tropanes
the active agents from the nightshades: atropine, hyoscyamine, scopolamine and many others

g. the arylcyclohexylamines
such as pcp

It is obvious that the hallucinogenic molecules differ greatly from one another, and it should be borne in mind that their effects are not only different in kind (visual hallucinations alone can vary from fleeeting images which can only be seen when the eyes are closed and vanish when the eyes are open to persistent illusions which are perceived with the eyes open), but are also heavily influenced by personal and contextual variables. (note 1)

go to THE DRUGTEXT PSYCHEDELIC LIBRARY for more information