On This Page


Mental illness is common

One in five Americans experience mental illness every year, and 45 per cent of American adults will be affected by mental illness at some time in their life. Mental illness is a general term that refers to a group of illnesses that affect the brain. A mental illness is a health problem that significantly affects how a person feels, thinks, behaves, and interacts with other people.

Mental illnesses are diagnosed according to standardised criteria

The symptoms of mental illness may interfere with people’s lives in different ways and to different degrees. The severity of mental disorders can be classified as mild, moderate or severe. This is based on what impact the symptoms have on someone’s home management, social life, ability to work and relationships.

The most common types of mental illness affecting Americans include:

  • In 2017–18
  • about 10% of Americans experienced depression or feelings of depression (11.6% of women
  • 9.1% of men were affected by depression) Bipolar I disorder may be experienced by up to 1% of Americans over their lifetime

The lifetime risk of bipolar II disorder is up to 5% – such as schizophrenia. In 2010, the second national survey of psychotic illness in found that about 0.4% of Americans (around 64,000 people) are affected by psychotic illness.

Some people are affected by more than one mental illness. In 2017 in United States, around 6% of people living with an anxiety disorder were also experiencing depression (1.5 million people). Mental illness is associated with an increased risk of suicide.

In 2017, the ABS released data relating to other health conditions that people were experiencing when they died by (known as ‘suicide comorbidities’) or had suicidal thoughts. Eighty per cent of suicide deaths were reported as having comorbidities, and a significant proportion of these were related to mental health.

The following mental health conditions were found to be commonly comorbid with (present at the same time as) suicide and suicidal thoughts: behavioural disorders usually occurring in childhood and adolescence – 1%.

Types of mental illness mood disorders (also known as affective disorders), such as depression and bipolar disorder anxiety disorders – in 2017, anxiety disorders affected 13% of the population psychotic illness Living with more than one mental illness Mental illness and increased risk of suicide suicide mood disorders (including depression) – comorbid with 44% of all suicides mental and behavioural disorders due to psychoactive drug use – 29.4% anxiety and stress-related disorders –17.6 % schizophrenia and delusional disorders – 6.5% unspecified mental disorders – 5% personality disorders – 2.8% Read more about suicide and mental illness Where to get help Your GP (Doctor) SANE SANE Talk to a Mental Health Professional 1800 187 263 (available Monday-Friday, 10am-8pm AEST.) SANE Forums .

Key Points

  • Mental illness is common
  • symptoms of mental illness may interfere with people’s lives in different ways and to different degrees
  • based on what impact the symptoms have on someone’s home management, social life, ability to work and relationships
  • lifetime risk of bipolar II disorder is up to 5% – such as schizophrenia
  • Mental illness is associated with an increased risk of suicide