Summary

  • People who experience problems with alcohol and other drugs may also experience mental health issues. This is called 'dual diagnosis'.
  • In many cases, it is hard to tell which problem came first; perhaps the mental illness led to the person misusing drugs, or else the drug problem started before the mental illness.
  • Research suggests that people who experience dual diagnosis respond well to integrated programs that address both substance misuse and mental illness.
 

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 managed through separate systems. This can make diagnosis and treatment difficult. 

Dual diagnosis – a major issue

The realisation that substance misuse and mental illness can be linked is quite recent, so research is scant. Estimates on the scale of dual diagnosis in Australia vary, but include:

  • About 25 per cent of people with anxiety disorders, affective disorders and substance use disorders also have another mental disorder.
  • Around 64 per cent of psychiatric in-patients may have a current or previous drug use problem.
  • Around 75 per cent of people with alcohol and substance use problems may have a mental illness.
  • About 90 per cent of males with schizophrenia may have a substance use problem.

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. 

Research suggests that people with a dual diagnosis respond well to integrated programs that address both their mental illness and their substance misuse. 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 are usually reserved for people with 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.
  • The services for mental health and substance misuse generally don’t overlap, so professionals in one field aren’t knowledgeable about the issues in the other field. It is 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.

The future of treatment for people with dual diagnosis

Victoria’s specialist mental health and alcohol and other drug services are working together to better meet the complex needs of people with dual diagnosis. Integrated service delivery and collaborative treatment to meet complex needs is becoming core business for many services.

The Department of Health and Human Services, public mental health and alcohol and other drug treatment services, the Victorian Dual Diagnosis Initiative and organisations such as SANE Australia and the Mental Health Council of Australia continue to work together to make dual diagnosis a health care priority.

Where to get help

More information

Mental illness

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Mental illness explained

Types of mental illness

Living with mental illness

Content Partner

This page has been produced in consultation with and approved by: SANE Australia

Last updated: May 2019

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