Mental Health: mental ill health

The mental ill health dimension relates to mental illnesses and mental health problems. 

Mental illness refers to a diagnosable illness defined through recognised classifications such as the WHO International Classification of Disease (ICD10) or the Diagnostic Statistical Manual Version IV produced by the American Psychiatric Association 1994. 

They have traditionally been divided in a variety of ways including distinguishing between:

• Organic (identifiable brain malfunction) versus functional (not due to structural abnormalities of the brain)
• Neurosis (severe forms of normal experiences such a low mood, anxiety) versus psychosis (severe distortion of a person's perception of reality)

Terminology however varies considerably across professions and cultures, and in different information sources, the definition may include or exclude different conditions.

The term mental health problem is often used to describe conditions seen as less serious, as distinct from severe and/or enduring mental illness.  Mental health problems interfere with a person’s cognitive, emotional or social abilities such that their daily living can be impacted, but to a lesser extent than a mental illness. Mental health problems are more common, are usually less severe and of shorter duration than mental illnesses but may develop into a mental illness. The distinction between mental health problems and mental illness is not clear-cut, but is usually made on the basis of severity and duration of the symptoms.