ICD-11

Disorders due to use of unknown or unspecified psychoactive substances are characterised by the pattern and consequences of psychoactive substance use when the specific substance is unknown or unspecified. These categories may be used in clinical situations in which it is clear that the disturbance is due to substance use but the specific class of substance is unknown. Once the relevant substance is identified, the disturbance should be recoded under the appropriate substance class.

Delirium induced by unknown or unspecified psychoactive substance is characterised by an acute state of disturbed attention and awareness with specific features of delirium that develops during or soon after substance intoxication or withdrawal or during the use of an unknown or unspecified substance. The symptoms are not better explained by a primary mental disorder, by use of or withdrawal from another substance, or by another health condition that is not classified under Mental, behavioural and neurodevelopmental disorders.