Mental illness is widespread in Australia, as it is in other developed countries, and has substantial impact at the personal, social and economic levels. Results from the 2007 National Survey of Mental Health and Wellbeing, conducted by the Australian Bureau of Statistics (ABS), indicate that one in five people aged 16 to 85 years experience one of the common forms of mental illness (anxiety, affective or mood disorders, and substance use disorders) in any one year. Prevalence rates vary across the lifespan and are highest in the early adult years, the period during which people are usually establishing families and independent working lives (figure 2). Earlier surveys of children and adolescents aged 4–17, conducted in 1998, found 14% to have a mental illness.

Anxiety related and affective disorders are the most common, affecting approximately 14% and 6%, respectively, of adults each year, with about a quarter having more than one disorder. Collectively referred to as 'high prevalence' illnesses, these disorders include diverse conditions (e.g. post traumatic stress disorder, obsessive compulsive disorder, depression, bipolar disorder) that have different treatment requirements and outcomes.

Mental illness includes 'low prevalence' conditions such as schizophrenia and other psychoses that affect another 1 to 2% of the adult population that were not included in the ABS 2007 survey of adults. Although relatively uncommon, people affected by these illnesses often need many services, over a long period, and account for about 80% of Australia's spending on mental health care.

Mental illness impacts on people's lives at different levels of severity. Depending on definitions, an estimated 3% of Australian adults have severe disorders, judged according to the type of illness (diagnosis), intensity of symptoms, duration of illness (chronicity),and the degree of disability caused. This group represents approximately half a million Australians. About 50% have a psychotic illness, primarily schizophrenia or bipolar affective disorder. The remainder mainly comprise individuals with severe depression or severe anxiety disorders.

For most people, the mental illness they experience in adult life has its onset in childhood or adolescence. For example, of those who will experience an anxiety or affective disorder, two thirds will have had their first episode by the time they are 21 years of age (figure 3).

Because many illnesses affect the individual's functioning in social, family, educational and vocational roles, the early age of onset can have long term implications. Mental illnesses are the largest single cause of disability in Australia, accounting for 24% of the burden of non-fatal disease (measured by total years of life lived with disability, figure 4). This has a major impact on youth and people in their prime adult working years.Top of page

People who live with a mental illness are also more at risk of experiencing a range of adverse social, economic and health outcomes. Analysis by the Productivity Commission found that of six major health conditions (cancer, cardiovascular, major injury, mental illness, diabetes, arthritis), mental illness is associated with the lowest likelihood of being in the labour force. For those affected by severe illnesses, particularly those with psychotic disorders, average life expectancy is shorter and is second only to Indigenous Australians, due mainly to high levels of untreated comorbid physical illness.

People with mental illness are also over represented in the homeless and prison populations. Australian data suggests that up to 75% of homeless adults have a mental illness and, of these, about a third (approximately 29,000 people) are affected by severe disorders. Additionally, Australian studies have found that around 40% of prisoners have a mental illness and that 10–20% are affected by severe disorders.

The economic costs of mental illness in the community are high. Outlays by governments and health insurers to provide mental health services in 2006–07 totalled $4.7 billion, representing 7.3% of all government health spending. Mental health as a share of overall government spending on health has remained stable over the 15 year course of the National Mental Health Strategy.

These figures reflect only the cost of operating the specialist mental health service system and do not indicate the full economic burden of mental illness and costs to government. Because of the disability often associated with mental illness, many people depend on governments for assistance that extends beyond specialist mental health treatment. They require an array of community services including housing, community and domiciliary care, income support, and employment and training opportunities. The National Mental Health Report 2007 most recently analysed these costs and estimated that outlays by government on mainstream support for people with mental illness substantially exceed the costs of specialist mental health care (figure 5).

In addition to outlays by government, mental illness impacts on the broader economy by reducing workforce participation and impairing the productivity of those who are in employment. Estimates of the annual costs of the productivity losses attributable to mental illness range from $10 to $15 billion.
Top of page

Figure 2: Prevalence of selected mental illnesses by age group


Text equivalent below for figure 2: prevalence of selected mental illnesses by age group

Notes: Ages 16–85 based on supplementary analysis of data collected in the Australian Bureau of Statistics (ABS) 2007 National Survey of Mental Health and Wellbeing. Prevalence estimates exclude counts of persons with drug and alcohol disorders for whom there is no other co-existing mental illness (3% of adults). Prevalence data for ages 4–17 are based on the 1998 child & adolescent component of the first National Survey of Mental Health and Wellbeing.

Sources: Australian Bureau of Statistics (2008). National Survey of Mental Health and Wellbeing 2007: Summary of results. ABS Cat. No 4326.0. Australian Bureau of Statistics: Canberra.

* Sawyer, MB et al. (2000). The mental health of young people in Australia. Commonwealth Department of Health and Aged Care: Canberra.

Text version of figure 2

Prevalence of selected mental illnesses by age group:
  • 4-17 * - 14%
  • 16-24 - 18%
  • 25-34 - 21%
  • 35-44 - 21%
  • 45-54 - 20%
  • 55-64 - 13%
  • 65-74 - 8%
  • 75-85 - 5%
Top of page

Figure 3: Age of onset for the most common mental illnesses (anxiety and affective disorders)


Text equivalent below for Figure 3: Age of onset for the most common mental illnesses (anxiety and affective disorders)

Notes: Based on supplementary analysis of data collected in the ABS 2007 National Survey of Mental Health and Wellbeing.

Sources: Australian Bureau of Statistics (2008). National Survey of Mental Health and Wellbeing 2007: Summary of results. ABS Cat. No 4326.0. Australian Bureau of Statistics: Canberra.

Text version of Figure 3

Graph showing that 64% of people with anxiety and affective disorders have onset by age 21 years.
Top of page

Figure 4: Burden of mental illnesses relative to other disorders, in terms of years lost as a result of disability


Text equivalent below for figure 4: Burden of mental illnesses relative to other disorders, in terms of years lost as a result of disability

Source: Begg S et al. (2007).The burden of disease and injury in Australia 2003. PHE 82. Australian Institute of Health and Welfare: Canberra.

Text version of figure 4

Burden of mental illnesses relative to other disorders, in terms of years lost as a result of disability:
  • Other - 25%
  • Mental - 24%
  • Neurological - 19%
  • Chronic respiratory - 9%
  • Diabetes - 8%
  • Cardiovascular - 8%
  • Musculoskeletal - 7%
Top of page

Figure 5: Comparing the direct and 'indirect' cost to governments of mental illness, 2004–05


Text equivalent below for figure 5: Comparing the direct and 'indirect' cost to governments of mental illness, 2004–05

Source: Department of Health and Ageing (2007). National Mental Health Report 2007. Commonwealth of Australia: Canberra.

Text version of figure 5

Current costs ($ millions):
  • State and territory mental health costs - 2,376
  • Australian Government mental health-specific costs - 1,381
  • Other Australian Government support costs - 4,327
Top of page