Disorders due to use of dissociative drugs including ketamine and phencyclidine [PCP]

Disorders Due to Use of Dissociative Drugs including Ketamine and Phencyclidine (PCP) are characterized by the pattern and consequences of dissociative drug use. Dissociative drugs include ketamine and phencyclidine (PCP) and their (comparatively rare) chemical analogues. Ketamine is an intravenous anaesthetic widely used in low- and middle-income countries, particularly in Africa, and in emergency situations. Ketamine is also undergoing evaluation for treatment of some mental disorders (e.g., treatment resistant Depressive Disorders). It is also a widespread drug of nonmedical use in many countries and may be taken by the oral or nasal routes or injected. It produces a sense of euphoria but depending on the dose, emergent hallucinations and dissociation are recognised as unpleasant side effects. Phencyclidine has a more restricted worldwide distribution and also has euphoric and dissociative effects. Its use may result in bizarre behaviour uncharacteristic for the individual, including self-harm. Dissociative Drug Dependence is described but a withdrawal syndrome is not recognized by most authorities. Several Dissociative Drug-Induced Mental Disorders are recognized.

Diagnostic Categories that Apply to Dissociative Drugs including Ketamine and PCP

Following is a list of specific diagnostic categories of that apply to dissociative drugs including ketamine and PCP:

• 6C4D.0 Episode of Harmful Use of Dissociative Drugs including Ketamine and PCP
• 6C4D.1 Harmful Pattern of Use of Dissociative Drugs including Ketamine and PCP
• 6C4D.2 Dissociative Drug Dependence, including Ketamine and PCP
• 6C4D.3 Dissociative Drug Intoxication, including Ketamine and PCP
• 6C4D.4 Dissociative Drug-Induced Delirium, including Ketamine and PCP
• 6C4D.5 Dissociative Drug-Induced Psychotic Disorder, including Ketamine and PCP
• 6C4D.60 Dissociative Drug-Induced Mood Disorder, including Ketamine and PCP
• 6C4D.61 Dissociative Drug-Induced Anxiety Disorder, including Ketamine and PCP
• 6C4D.Y Other Specified Disorder Due to Use of Dissociative Drugs including Ketamine and PCP
• 6C4D.Z Disorder Due to Use of Dissociative Drugs including Ketamine and PCP, 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 Dissociative Drugs including Ketamine and PCP, Harmful Pattern of Use of Dissociative Drugs including Ketamine and PCP, and Dissociative Drug Dependence) describe the pattern of dissociative drug use. One of these three diagnoses, or Disorder Due to Use of Dissociative Drugs including Ketamine and PCP, 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 Dissociative Drug Use.

The remaining diagnoses reflect the impact of the pattern of dissociative drug 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, 6C4D.1/ 6C4D.5 is Harmful Pattern of Use of Dissociative Drugs including Ketamine and PCP associated with Dissociative Drug-Induced Psychotic Disorder, 6C4D.2/6C4D.70 is Dissociative Drug Dependence associated with Dissociative Drug-Induced Mood Disorder, 6C4Z/6C4D.3 is Disorders Due to Substance Use, Unspecified associated with Dissociative Drug Intoxication (i.e., the pattern of use in this last case is unknown).

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