Hallucinogens, dissociative drugs, and empathogens

Abstract Chapter 16 of Addiction Medicine covers hallucinogens, dissociative drugs, and empathogens. Hallucinogens, also termed psychedelics, are a large and diverse group of substances, some of which occur in fungi and plants and some which are chemically synthesized. Some have psychostimulant properties as well. They include psilocybin, mescaline, dimethyltryptamine (DMT), ayahuasca, lysergic acid diethylamide (LSD), and NBOMes and tryptamines. Dissociative drugs include ketamine, phencyclidine (PCP), and nitrous oxide. The term empathogens covers MDMA and similar drugs. The prevalence and mode of use of these drugs are described together with their pharmacological effects. Clinical syndromes include acute intoxication and chronic use, flashbacks (characteristic of psychedelic use in particular), psychosis, acute anxiety state, and acute and chronic brain syndromes. The principles of diagnosis and management are then outlined. Dependence is uncommon with hallucinogens, although with regular consumption of microdoses of LSD, it is increasingly recognized. It is well recognized for ketamine and derivatives.