People with co-occurring mental illness and substance use are often actively excluded from services. You will hear many excuses; “too intoxicated to assess”, “suffering from drug-induced psychosis” or “too complex for our drug-rehab”.

Those who are able to access services may find that they are treated based on what is considered their primary need, be that alcohol use, mental ill health or offending rather than as a set of related and interconnected issues.

NICE’s key message is that helping severely mentally ill people cope with substance use problems should be the business of any NHS and social care staff they come across.