Rationale
Mental illness and co-existing substance misuse are associated with more severe problems, poorer outcomes from interventions and higher rates of dropout. The challenges of working together to help and support this group through early identification, intervention, integrated care and supported recovery are among the most pressing issues currently facing services in Scotland. Given that a wide range of disciplines and agencies may be involved, clarity of responsibilities and co-ordination of care is essential. Many individuals with co-existing problems may not meet the criteria set by specialist substance misuse services, and may also fall below the level at which a referral might be accepted by a secondary mental health service. Nonetheless, these service users may have many difficulties which may affect local services and their ability to implement HEAT targets.

• There are high rates of antidepressant prescribing in people with alcohol dependence.
• There is a strong relationship between substance misuse, mental illness and suicide.
• A substantial proportion of those re-admitted to a psychiatric hospital misuse substances or have alcohol problems in addition to a mental illness.

The needs of those who have co-existing problems and who require interventions should be met by a process of consultation and co-working between substance misuse and mental health services.

Examples of evidence required to meet standard 19:
- Local agreements with substance misuse services
- Referral protocols