Disorders due to use of hallucinogens

Disorders Due to Use of Hallucinogens are characterized by the pattern and consequences of hallucinogen use. Several thousand compounds have hallucinogenic properties, many of which are found in plants (e.g., mescaline) and fungi (e.g., psilocybin) or are chemically synthesized (e.g., lysergic acid diethylamide [LSD]). These compounds have primarily hallucinogenic properties, but some may also be stimulants. Much of the morbidity associated with these compounds arises from the acute effects related to Hallucinogen Intoxication. Hallucinogen Dependence is rare and Hallucinogen Withdrawal is not described. Among the mental disorders related to hallucinogen use, Hallucinogen-Induced Psychotic Disorder is the most frequently seen, although worldwide it is still fairly uncommon.

Diagnostic Categories that Apply to Hallucinogens

Following is a list of specific diagnostic categories of that apply to hallucinogens:

• 6C49.0 Episode of Harmful Use of Hallucinogens
• 6C49.1 Harmful Pattern of Use of Hallucinogens
• 6C49.2 Hallucinogen Dependence
• 6C49.3 Hallucinogen Intoxication
• 6C49.5 Hallucinogen-Induced Delirium
• 6C49.6 Hallucinogen-Induced Psychotic Disorder
• 6C49.60 Hallucinogen-Induced Mood Disorder
• 6C49.61 Hallucinogen-Induced Anxiety Disorder
• 6C49.Y Other Specified Disorder Due to Use of Hallucinogens
• 6C49.Z Disorder Due to Use of Hallucinogens, Unspecified

An additional category of disorder induced by psychoactive substances is included in another part of the ICD-11 chapter on Mental, Behavioural, and Neurodevelopmental Disorders. This is cross-listed in the section below on Substance-induced Mental Disorders for reference:

• 6A41 Catatonia Induced by Substances or Medications

The first three diagnoses listed above (Episode of Harmful Use of Hallucinogens, Harmful Pattern of Use of Hallucinogens, and Hallucinogen Dependence) describe the pattern of hallucinogen use. One of these three diagnoses, or Disorder Due to Use of Hallucinogens, Unspecified, for cases in which the use pattern in unknown at the time of evaluation, is considered to be the primary diagnosis. That is, one of these four diagnoses should be assigned when making a diagnosis of a Disorder Due to Hallucinogen Use.

The remaining diagnoses reflect the impact of the pattern of hallucinogen use and are thus considered to be associated with one of the primary use pattern diagnoses. These diagnoses should therefore be assigned together with the relevant primary diagnosis. For example, 6C49.1/ 6C49.5 is Harmful Pattern of Use of Hallucinogens associated with Hallucinogen-Induced Psychotic Disorder, 6C49.2/6C49.70 is Hallucinogen Dependence associated with Hallucinogen-Induced Mood Disorder, 6C4Z/6C49.3 is Disorders Due to Substance Use, Unspecified associated with Hallucinogen Intoxication (i.e., the pattern of use in this last case is unknown).

Hallucinogen-induced Mental Disorders are characterized by psychological, cognitive, or behavioural symptoms that develop during or soon after hallucinogen intoxication or use. The duration or severity of the symptoms is substantially in excess of the characteristic syndrome of Hallucinogen Intoxication.