• About 45 per cent of Australian adults will be affected by mental illness at some time in life. Three per cent will be seriously affected.
  • Depression and anxiety disorders are the most common mental illnesses.
  • With treatment and support, the majority of people with mental illness will recover well.
One in five Australians experience a mental illness very year. Episodes of mental illness can come and go throughout a person’s life. Some people experience their mental illness only once and then fully recover. Unfortunately, only about half of those affected by mental illness receive treatment.

Types of mental illness

Mental illness is a general term that refers to a group of illnesses that affect the brain, in the same way that heart disease refers to a group of illnesses that affect the heart.

Mental illnesses can be separated into two main categories, being:
  • depression and anxiety disorders – for example, persistent feelings of depression, sadness, tension or fear that are so disturbing they affect the person’s ability to cope with day-to-day activities. Conditions that can cause these feelings include: anxiety disorders (for example, phobias and obsessive compulsive disorder), eating disorders and depression.
  • psychotic illness – for example, schizophrenia. Psychosis affects the brain and causes changes in a person’s thinking, emotions and behaviour. People who experience an acute psychotic episode lose contact with reality and may develop delusions or hallucinations.

One in five adults are affected by mental illness

Almost half of all Australian adults (45 per cent) are affected by mental illness at some time in their life. Some are affected by more than one condition. The most common forms of mental illness are:
  • Depression – around 15 per cent of adults are affected by depression at some point in their life.
  • Anxiety disorders – around 26 per cent of adults are affected by anxiety disorders at some point in their life.
The remainder of people with mental illness are affected by substance use disorders, psychotic illnesses (for example, schizophrenia) and by other conditions.

Some people are severely affected

Around three per cent of adults are severely affected by mental illness. The more severely disabling ‘low prevalence’ mental illnesses include:
  • Schizophrenia – this disorder affects approximately one per cent of Australians at some point in their life.
  • Bipolar disorder – this condition affects up to two per cent of Australians at some time during their life.
  • Other forms of psychosis – include drug-induced psychosis.
  • Some chronic forms of depression.

Mental illness and families

Most people with mental illness do not have family members with the illness. For some mental disorders, there does not seem to be a link at all. Although a predisposition to schizophrenia and bipolar disorder can be inherited, this is only one of several factors that contribute to the development of the illness.

These 'triggering' factors may include:
  • stressful life events
  • drug misuse
  • hormonal changes.
However, the causes are still not fully understood. Families of those affected need support too.

Increased risk of suicide

Up to one in ten people affected by mental illness commit suicide, compared to an average of one in a hundred for the whole population. Effective, ongoing treatment is essential to minimise the risk of suicide.

Recovery for people with mental illness

Provided they receive appropriate ongoing support and treatment, most people with mental illness recover well and are able to lead fulfilling lives in the community.

With appropriate support and treatment, the most likely outcomes for specific conditions are:
  • Anxiety disorders – the majority of people will improve over time.
  • Bipolar disorder – about 80 per cent of people will improve.
  • Schizophrenia – about 60 per cent of people with schizophrenia will improve and can live independently with support. About 20 per cent of those diagnosed with schizophrenia will have an episode or two, and then never experience symptoms again. For another 20 per cent, symptoms are more persistent, treatments are less effective and greater support services are needed.

Where to get help


More information

Mental health services topics

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

Last updated: July 2015

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