Substance misuse and mental illness – dual diagnosis

People who experience problems with alcohol and other drugs may also experience mental health issues. This is called 'dual diagnosis’.

The rate of mental health problems in people with alcohol and other drug problems is higher than that in the general community. This includes increased instances of anxiety and depression.

In many cases, it is hard to tell which problem came first. Perhaps the mental illness prompted the person to misuse drugs, or else the drug problem pre-dated the mental illness. The substance use could also worsen the symptoms of the person’s mental illness – for example, smoking marijuana can trigger a psychotic episode in some people.

Unfortunately, many services for mental health issues and alcohol and other drug issues don’t overlap, which means that healthcare for the person with dual diagnosis is often managed through separate systems. This can make diagnosis and treatment difficult.

Dual diagnosis – a major issue

Estimates on the scale of dual diagnosis in Australia vary, but research indicates:

• About 20 per cent of Australians with a substance use disorder also experience affective disorders (such as depression or bipolar disorder)
• About 11 per cent of Australians with a substance use disorder also experience generalised anxiety disorder
• About 35 per cent of Australians with a substance use disorder also experience any mental health disorder
• Among Australians who are clients of alcohol and other drug services, between 50-78% meet diagnostic criteria for at least one comorbid mental disorder

Integrated treatment and care of people with dual diagnoses

Effective management of either substance use disorders or mental health disorders is challenging. Dual diagnosis adds complexity to assessment, diagnosis, treatment and recovery, and can be associated with increased incidences of relapse, poorer physical health, and risks of homelessness, violence and other challenges.

Research suggests that people with a dual diagnosis respond well to integrated programs that address both their mental illness and their substance misuse. Treatment can help people manage their alcohol or drug use, improve physical and mental health, and improve their general functioning.

However, these programs were uncommon until recent years. Some of the reasons for this include:

• Diagnosis can be difficult, because it isn’t always clear which problem has the more severe symptoms. Health services are getting better at recognising dual diagnosis.
• Mental health services sometimes need to prioritise for people who are in crisis or experiencing severe problems, so dual diagnosis clients who experience less severe mental health problems may not get treatment. They should, however, be referred to a suitable service.
• A person who experiences a mental illness may receive treatment, but their problematic substance use could be dismissed as a minor side effect of their illness.
• Training and services for mental health and substance misuse generally don’t overlap, so professionals in one field aren’t always knowledgeable about the issues in the other field. It can be hard to find professionals who are skilled in treating both substance misuse and mental illness, but numbers are slowly increasing.

Importantly, people who experience dual diagnosis are affected in different ways and therefore have individual needs. In practice, what is effective for one person may not be effective for another.

Issues for people with dual diagnosis and their families

The lack of professional knowledge about dual diagnosis can be frustrating for those affected and their families. Common experiences may include:

• Health care providers may blame the client for being difficult and unresponsive to treatment, rather than questioning whether the health care system is failing to provide effective treatments and support for people with dual diagnoses.
• If a dual diagnosis client first seeks treatment for substance misuse, the alcohol and other drug clinician may consider their mental illness as a secondary issue or side effect. Similarly, if they first seek treatment for their mental illness, then the mental health clinician may consider their substance misuse as a secondary issue or side effect. The relationships between the two problems may not be recognised or addressed.
• Specialist and early intervention treatments are often not available when they are needed.
• Health care professionals may not involve the family or significant support people in treatment, even though the family is frequently much more familiar with the problems and experiences of the person with dual diagnosis.

Where to get help

• Your GP (doctor)
• DirectLine Tel. 1800 888 236 – for free and confidential alcohol and other drug information, counselling and referral (24 hours)
• Connect with SANE’s free counselling service online or on 1800 187 263, between 10am-10pm Monday to Friday AEST/AEDT.
• Self Help Addiction Resource Centre (SHARC) Tel. 1300 660 068 – for information and support for people concerned about a relative or friend using drugs
• Youth Drug and Alcohol Advice (YoDAA) Tel. (03) 9415 8881 – for information, counselling and referral to youth-specific alcohol and other drug services