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About mental illness

Page last updated: 2010

How do I recognise if someone may have a mental illness?

While symptoms vary, and each person with mental illness is different, all people with mental illness will experience some of the symptoms listed below.

Symptoms on their own, or as isolated events are not necessarily a sign of mental illness, however persistent, multiple or severe symptoms may require a mental health assessment.

Possible symptoms

There are a range of symptoms which may indicate mental illness. These include:
  • Changes in thinking or perceiving including:
    • Anxiety - being overly fearful about things that may never happen
    • Depression - sadness and lack of interest in life that lasts for more than a couple of weeks
    • Confused or disorganised thinking - sometimes it is difficult to understand or make sense of what the person is saying.
  • Changes in mood including:
    • Sadness coming out of nowhere that cannot be explained
    • Extreme excitement or happiness
    • Mixtures of moods from very happy to very sad
    • Pessimism, seeing the world as grey and lifeless
    • Feeling hopeless
    • Loss of interest in once pleasurable activities
    • Thinking or talking about suicide or other forms of self harm Top of page
  • Changes in behaviour including:
    • Sitting and doing nothing
    • Friendlessness, abnormal self-involvement
    • Dropping out of activities, decline in work, academic or athletic performance
    • Anger and hostility that is out of character
    • Indifference, even in highly important situations
    • Inability to express joy
    • Inappropriate laughter
    • Inability to concentrate or cope with minor problems
    • Irrational statements
    • Peculiar use of words or language structure
    • Excessive fears or suspiciousness
    • Drug or alcohol abuse
    • Forgetfulness and loss of valuable possessions
    • Attempts to escape through frequent changes of address
    • Bizarre behaviour (strange posturing)
    • Unusual sensitivity to noises, light, clothing
  • Physical changes including:
    • Being very active or not active at all or a combination of both
    • Poor hygiene or personal care
    • Unusual eating habits/patterns
    • Unexplained weight gain or loss
    • Sleeping too much or being unable to sleep Top of page
  • Hallucinations - problems with any of the senses (sight, sound, touch smell and taste). Most often they are auditory hallucinations or voices that the person can hear that are not real to anyone else. They are often very distressing to the person as the voices may say upsetting things and other people deny hearing them.
  • Delusions - psychotic symptoms of particular types of mental illness, such as schizophrenia. They are firmly held beliefs that are not held by other members of the person's social group. Persons who experience delusions may offer bizarre explanations for experiences or circumstances. For example, they may believe they are being spied upon, followed, poisoned or that they possess great unrecognised talent.
Sometimes, particularly if this is the first time your family member or friend has been unwell, it may not be possible to make a clear diagnosis or to determine what is causing the symptoms. Each person is unique and the symptoms they have will be unique to them. There is no reliable way to predict what the course of an illness may be. Symptoms may change from year to year. Also one person's symptoms may be very different from those of another, although the diagnosis may be the same.

Often symptoms of mental illness run in cycles and may vary in severity. The length of time an episode of mental illness may last also varies. Some people are affected for a few weeks or months, while for others, the illness may last many years or for a lifetime.

In some cases of apparent mental illness, physical illnesses can be found to be the cause. Possible physical illness always needs to be investigated when mental illness is suspected. Top of page

Note: This guide is for informational purposes only. It is not meant to be used as a diagnostic tool. It is very important that you seek a professional evaluation if you have concerns about yourself or another person.

If you are concerned about a family member or friend you should contact your GP or local mental health service.