Overview of disorders of hallucinogen use

Hallucinogens include lysergic acid diethylamide (LSD), psilocybin (from ‘magic’ mushrooms) and certain analogues of amfetamine. They are usually taken orally. A wide range of novel drugs including phenethylamines and tryptamines can also induce hallucinogenic effects. Ketamine, an anaesthetic, also has hallucinogenic properties; for the management of ketamine use, see Overview of disorders of ketamine use.

The spectrum of substance use in these guidelines is described by the terms ‘hazardous use’ and ‘harmful use’ as outlined in Terminology describing the spectrum of substance use.

Intoxicating effects of hallucinogens include hallucinations, depersonalisation, hypersensitivity to external stimuli and changes in perception of time; psychotic behaviour may be observed. Panic, feelings of loss of control and labile mood may be prominent. Sympathomimetic effects (eg hypertension, tremor) may be prominent in overdoseHardaway, 2016. For advice on hallucinogenic drug toxicity, see Sympathomimetic toxidrome and Novel hallucinogenic drug poisoning.

The duration of hallucinogen action depends on the drug consumed and the dose taken. In some instances, hallucinations and other effects may persist for several days.

Hallucinogenic drugs are normally used sporadically and withdrawal symptoms are not seen. Flashbacks may occur; these are recurrence of experiences simulating those of the previous intoxicated state but occurring after the intoxication episode.