# 159 - 6C4Z Disorders due to substance use, unspecif

# 6C4Z Disorders due to substance use, unspecified

Clinical Descriptions and Diagnostic Requirements for ICD-11 Mental, Behavioural or Neurodevelopmental Disorders
Boundary with normality (threshold)
• The diagnosis of harmful pattern of use of non-psychoactive substances requires clinically 
significant harm to the individual’s physical or mental health. Examples of impact on 
physical or mental health that would not be considered clinically significant include mild 
hangover, brief episodes of vomiting or transient depressed mood.
• A pattern of non-psychoactive substance use may also cause social problems that do not 
constitute clinically significant harm to physical or mental health (e.g. arguments with 
loved ones). A diagnosis of harmful pattern of use of non-psychoactive substances should 
not be assigned in these circumstances.
Boundaries with other disorders and conditions (differential diagnosis)
Boundary with episode of harmful non-psychoactive substance use
If the harm to health is a result of a single episode of non-psychoactive substance use rather than 
an episodic or continuous pattern of substance use, episode of harmful use of non-psychoactive 
substances is the appropriate diagnosis rather than harmful pattern of non-psychoactive 
substance use. Substance use is generally considered to be following a pattern if there has been 
at least episodic or intermittent use over a period of at least 12 months, or continuous use over 
at least 1 month. If harm is caused by use of a non-psychoactive substance but no information is 
available about the pattern or history of substance use, a diagnosis of episode of harmful use of 
non-psychoactive substances may be assigned until such time as evidence for a pattern of use is 
ascertained.
Boundary with injury, poisoning or certain other consequences of external causes
When use of a non-psychoactive substance results in injury or life-threatening symptoms (e.g. 
coma, severe cardiac or respiratory symptoms), a diagnosis from the grouping of harmful effects 
of substances in Chapter 22 on injury, poisoning or certain other consequences of external causes 
should also be assigned.
Disorders due to substance use, unspecified
6C4Z
Substance-induced mental disorders | Disorders due to use of non-psychoactive substances