Overview: Dual Diagnosis
Dual Diagnosis Overview
Dual Diagnosis refers to people who are affected by both substance abuse problems and mental health problems. People with a substance abuse disorder display a greater rate of mental health problems than the general population, and developing either problem means that a person has a greater chance of developing the other disorder.
Dual Diagnosis is often referred to as comorbidity, but comorbidity can also mean other forms of co-occurence of diseases or disorders. Dual diagnosis is coming to be the term used specifically to refer to the comorbidity of mental illness and substance abuse.
- Around 25% of persons with an anxiety, affective or substance abuse disorder also have at least one other Mental Illness
- Among those with psychotic disorders, 30% have a history of alcohol abuse or dependence, 25.1% of cannabis abuse, and 13.2% of other substance abuse or dependence
- Approximately 64% of psychiatric in-patients have a current or previous drug use problem 
- Approximately 75% of people with a drug or alcohol abuse problem may have a mental illness
In cases of dual diagnosis, the mental health disorder and the substance abuse disorder often influence each other, leading to:
- enhanced severity of both disorders
- affect upon the individual's response to treatment
- difficulty in diagnosing which problem is causing particular symptoms and behaviours
- difficulty in diagnosing which problem arose first
Dual diagnosis amongst young people in Australia is rising. The Australian Division of General Practice reports with relation to people aged 15-24 years that "the recent Australian burden of disease and injury study found that nine out of the ten leading causes of burden in young males, and eight out of ten leading causes in young females were substance use disorders or mental disorders. Co-morbidity of these disorders is high with over 50 per cent having co-morbid disorders".
- Many people with mental illness or mood disorders turn to drugs or alcohol in an attempt to relieve the effects of their mental illness
- Among young people, drugs and alcohol may be abused under the assumption that being identified as drunk or drugged is more socially acceptable than being mentally ill
- Illicit drugs may be used in an attempt to counteract the side effects of prescribed medication
- Drugs and alcohol are sometimes used as a temporary escape from the stigma of mental illness, or in an attempt to counteract negative feelings and moods
People with dual diagnosis have often suffered from multiple traumas, abuse and social disloacation. There are high rates of dual diagnosis among Indigenous Australians, among young people who have been in foster care or other out of home care, and among the homeless .
Individuals with dual diagnosis often face greater difficulties in treatment and recovery, and have difficulty in following a treatment regime. They may display more challenging behaviours than people who have a mental illness without associated substance abuse. They are also often reluctant to participate in programs which will lessen their dependence on drugs, associating the drug with relief of unpleasant symptoms of their mental illness.
People with a dual diagnosis also come into contact with the criminal justice system more often than people with only a mental health disorder. The rate of criminal conviction for persons with schizophrenia with substances abuse problems was found to be 68.1 per cent, compared to those without substance disorders at just 11.7 per cent..
People with dual diagnosis may also be hospitalised more often or taken to accident and emergency departments more often.
Attempts to develop integrated programs which treat mental disorders and substance abuse disorders have been relatively recent developments; generally services which treat mental health problems, and those which treat substance abuse, are in separate "silos" and do not overlap. Mental health professionals may consider the drug or alcohol abuse problem as a relatively minor side effect of the mental illness, and drug and alcohol agencies are generally not set up to deal with mental illness issues.
Access to services is particuarly difficult for certain groups, most particularly incarcerated prisoners (who do not have access to Medicare) and young people who are no longer eligible for child and adolescent services but who find adult services not responsive to their needs.
A number of government and nonprofit agencies are working to establish programs and guidelines for working with people with dual diagnosis.
- The Connexions program established by Jesuit Social Services was seed funded by The Hugh Williamson Trust, The Myer Foundation, The William Buckland Foundation, VicHealth and the Australian Youth Foundation. Connexions provides intensive outreach and counselling support to young people with a dual diagnosis of mental illness and substance misuse believed to be at risk of suicide or self-harm. It aims to offer education, employment and training pathways in seeking to engage alienated youth; to facilitate change in the health services system and to provide support and training to workers in the field.
A summary of a report on the program can be found at Evaluation of the Connexions Youth Suicide Prevention Initiative
Department of Community Services NSW Dual Diagnosis Support Kit - including downloadable booklets and publications for parents, children, teenagers and caseworkers.