How does dual diagnosis develop?
The relationship between mental health and substance misuse is complex and varies from individual to individual.
This information comes from the Rethink Advice and Information Service's Dual diagnosis factsheet (228 kb) ![[pdf]](http://www.rethink.org/display_images/document_icons/pdf.gif){kind=icon}
The relationship between drugs and mental illness
The Department of Health has identified four possible relationships between drugs and mental health:
- A mental illness can lead to substance misuse.
For example, a person may use alcohol or drugs to ‘self-medicate’ and relieve their symptoms, or their illness may make them more likely to engage in risky behaviour such as taking excessive amounts of drugs. - The use of alcohol or drugs can make a mental health condition worse or alter its course. For example, using substances may make people more likely to take part in risky behaviour or have worse psychotic symptoms.
- Use of drugs or alcohol may lead to psychological symptoms.
- Substance misuse or withdrawal may trigger mental health problems. For example there is some evidence that cannabis use increases the risk of developing a psychotic illness .
See our page on Cannabis and schizophrenia for more details.
Who is most at risk?
It is likely that a range of factors make some people more vulnerable to either or both mental health and substance misuse problems.
This might include genetic factors, the impact of the environment someone grows up in or difficult or traumatic life events such as bereavement or abuse.
