NICE Guideline CG120: Psychosis and co-existing substance misuse

This guideline covers the assessment and management of adults and young people (aged 14 years and older) who have a clinical diagnosis of psychosis with coexisting substance misuse.

The term psychosis is used to describe a group of severe mental health disorders characterised by the presence of delusions and hallucinations that disrupt a person’s perception, thoughts, emotions and behaviour. The main forms of psychosis are schizophrenia (including schizoaffective disorder, schizophreniform disorder and delusional disorder), bipolar disorder or other affective psychosis.

Substance misuse is a broad term encompassing, in this guideline, the harmful use of any psychotropic substance, including alcohol and either legal or illicit drugs. Such use is usually, but not always, regarded as a problem if there is evidence of dependence, characterised by psychological reinforcement of repeated substance-taking behaviour and, in some cases, a withdrawal syndrome. However, substance misuse can be harmful without dependence, especially among people with a coexisting psychosis.

Implementation priorities

  • When working with adults and young people with known or suspected psychosis and coexisting substance misuse, take time to engage the person from the start, and build a respectful, trusting, non-judgemental relationship in an atmosphere of hope and optimism.
  • Be direct in your communications, use a flexible and motivational approach, and take into account that:
    • stigma and discrimination are associated with both psychosis and substance misuse
    • some people will try to conceal either one or both of their conditions
    • many people with psychosis and coexisting substance misuse fear being detained or imprisoned, being given psychiatric medication forcibly or having their children taken into care, and some fear that they may be ‘mad’.
  • Routinely ask adults and young people with known or suspected psychosis about their use of alcohol and/or prescribed and non-prescribed (including illicit) drugs.
  • If the person has used substances ask them about all of the following:
    • particular substance(s) used
    • quantity, frequency and pattern of use
    • route of administration
    • duration of current level of use.
  • Conduct an assessment of dependency

More information:

NICE Clinical Guideline 120: Psychosis with coexisting substance misuse