About mental illness

Every year one in five people will experience some form of mental illness. A mental illness, also known as a mental disorder, affects how a person thinks, feels, behaves and interacts with others.

There are many conditions that are recognised as a mental illness. Some of the most common mental illnesses include:

Anxiety disorders

An anxiety disorder is a medical condition characterised by persistent and excessive worry, which does not subside when a stressful situation has passed. Anxiety can be ongoing and can exist for no particular reason at all. Whilst everybody feels anxious from time to time, feelings cannot be controlled by people with anxiety and it often makes it hard to cope with everyday life.

The most common anxiety disorders include: 

Mood disorders

Mood disorders, often referred to as affective disorders, involve persistent feelings of being overly sad or happy. People may experience unpredictable moods and fluctuations between being extremely happy and extremely sad, or may just feel down all of the time.

The most common mood disorders include:

Psychotic disorders

Psychotic disorders involve distorted awareness and thinking, or a loss of contact with reality, which can be in the form of hallucinations and/or delusions.  Many people with a psychotic disorder describe that they hear voices and cannot trust their own mind.

The most common psychotic disorders include: 

  • Psychosis
  • Schizophrenia
  • Bipolar I
  • Schizoaffective disorder (a combination of schizophrenia and an affective disorder)
  • Schizophreniform disorder (short term schizophrenia where social, school or work patterns may not be affected)

Personality disorders

People with personality disorders have extreme thoughts and behaviours and may find it difficult to cope with everyday life. They aren’t able to change their actions or thoughts and have trouble relating to situations and other people; often resulting in issues at work or school, in relationships and during social encounters.

The main types of personality disorders include:

  • Antisocial personality disorder
  • Avoidant personality disorder
  • Borderline personality disorder

    Other mental illnesses

    There are some mental illnesses that do not fit into a neat category, including attention deficit disorder, autism, and eating disorders. Click here for more information on other mental illnesses.