Hallucinogens – one of the most curious and, at the same time, the most strange group of drugs. They are of particular interest because of their ability to deeply change the consciousness in a very bizarre way. At the same time, many unclear things are connected with them, because they are extremely diverse and differ in the mechanism of action. Originally called “fiction”, over the years they have undergone a dozen different renames. Some researchers used the term “psychomimetics” because they were thought to mimic the symptoms of functional mental disorders, such as schizophrenia. Currently, they are rarely used for this purpose, because it turned out that despite the curious similarities, the effects of hallucinogen exposure are very different from natural psychoses. During the 60s, advocates of hallucinogens called them “psychedelics.” This term was introduced by one of the first LSD researchers Humphrey Osmond. Osmond defined psychedelics as “mind-expanding,” but whether LSD and other hallucinogens have similar properties in reality is a very controversial issue.
In the end, it became customary to call this group of drugs hallucinogens, but this term is not entirely accurate. He focuses our attention on hallucinations and other changes in perception and, indeed, substances in this category cause sensory disturbances called hallucinogenic. However, it is absolutely certain that this is not their only effect. Hallucinogens greatly affect mood, thought processes, and mental activity. Hallucinogens change almost all aspects of psychological functioning, and the expression “altered consciousness” describes the effect of these drugs best.
An additional complication is the fact that there are more than 90 plant species and even more synthetic drugs that can be used to trigger similar effects. To somehow navigate this complex group of drugs, divide them into 4 subgroups based on their effects and mechanism of action and consider each subgroup separately.
The first and historically most important group are serotonergic hallucinogens. This category includes the synthetic substance lysergic acid diethylamide (LSD) and related drugs such as mescaline (extracted from the peyote cactus) and psilocybin found in some mushrooms. These substances cause pronounced visual hallucinations, as well as other changes in consciousness. Recent experiments suggest that, despite the different chemical structure, they all affect the transmission of serotonin in the brain.
The second group of hallucinogens includes MDA and MDMA (Ecstasy), related to methyl amphetamines. As the name implies, by chemical structure they are amphetamines (like mescaline), but they cause changes in mood and consciousness and very little, or do not affect the sensory sensations at all. It is believed that, like amphetamine and cocaine, they affect the dopamine and noradrenaline synapses.
Although, obviously, they also affect serotonin.
The third group of hallucinogens is called anticholinergic hallucinogens, less common and include substances such as atropine and scopolamine, contained in mandrake, belen, belladonna and dope. These substances immerse a person in a hypnotic trance, after which a person remembers little or nothing. Substances of this class act on cholinergic synapses of the brain.
And finally, the fourth group includes phencyclidine (PCP or angel dust) and such a compound as ketamine. They are often called dissociative anesthetics because of their ability to cause pain relief during the operation, while the patient does not completely lose consciousness. PCP is thought to act on a receptor that affects the activity of the neurotransmitter glutamine.
Serotonergic hallucinogens: LSD and similar substances