6C4G.1

ICD-11 MMS 2026-01

Harmful pattern of use of unknown or unspecified psychoactive substance

Description

A pattern of use of an unknown or unspecified psychoactive substance that has caused damage to a person’s physical or mental health or has resulted in behaviour leading to harm to the health of others. The pattern of substance use is evident over a period of at least 12 months if use is episodic or at least one month if use is continuous (i.e., daily or almost daily). Harm to health of the individual occurs due to one or more of the following: (1) behaviour related to intoxication; (2) direct or secondary toxic effects on body organs and systems; or (3) a harmful route of administration. Harm to health of others includes any form of physical harm, including trauma, or mental disorder that is directly attributable to behaviour related to substance intoxication on the part of the person to whom the diagnosis of Harmful pattern of use of unknown or unspecified psychoactive substance applies.

Excludes

  • 6C4G.0 – Episode of harmful use of unknown or unspecified psychoactive substances
  • 6C4G.2 – Unknown or unspecified psychoactive substance dependence

Exclusions from above levels

  • QE62 – Uncomplicated bereavement
  • QE84 – Acute stress reaction

Child codes

  • 6C4G.10 – Harmful pattern of use of unknown or unspecified psychoactive substance, episodic
  • 6C4G.11 – Harmful pattern of use of unknown or unspecified psychoactive substance, continuous
  • 6C4G.1Z – Harmful pattern of use of unknown or unspecified psychoactive substance, unspecified

Sibling codes

  • 6C4G.0 – Episode of harmful use of unknown or unspecified psychoactive substances
  • 6C4G.2 – Unknown or unspecified psychoactive substance dependence
  • 6C4G.3 – Intoxication due to unknown or unspecified psychoactive substance
  • 6C4G.4 – Withdrawal due to unknown or unspecified psychoactive substance
  • 6C4G.5 – Delirium induced by unknown or unspecified psychoactive substance
  • 6C4G.6 – Psychotic disorder induced by unknown or unspecified psychoactive substance
  • 6C4G.7 – Certain unknown or unspecified psychoactive substance-induced mental or behavioural disorders
  • 6C4G.Y – Other specified disorders due to use of unknown or unspecified psychoactive substances
  • 6C4G.Z – Disorders due to use of unknown or unspecified psychoactive substances, unspecified

Foundation entity

Harmful pattern of use of unknown or unspecified psychoactive substance – http://id.who.int/icd/entity/341458101

Allowed postcoordination axes

Part of: 6C4G: Disorders due to use of unknown or unspecified psychoactive substances › 06: Mental, behavioural or neurodevelopmental disorders