Health conditions


Delusions are beliefs that are not based on reality, and which other people within the person’s culture or religion do not share. Delusions are held with strong conviction despite what other people might say, or evidence to the contrary.

It is sometimes difficult to tell the difference between delusions and strongly held ideas. Unusual ideas and beliefs with delusional themes are held by many people in the community without mental illness.

Some people however, become very preoccupied with these strong beliefs.  If these cause distress and interference with daytime activities or relationships with other people, it is a sign of poor mental health, suggesting it may be helpful to seek professional help.

There are many different types of delusions, including:

  • Grandiose delusions, where a person believes they are exceptionally talented or rich, or holding much influence over others. 
  • Paranoid delusions, where a person believes that others wish to cause them harm, or that they are persecuted by others.
  • Delusional jealously, where a person believes their partner is unfaithful, even if the circumstances make the belief impossible.
  • Misidentification syndrome, where the person believes that a family member or friend has been replaced by an impostor who looks exactly like them
  • Bizarre delusions refer to situations or circumstances that are physically impossible.
  • Somatic delusions, where a person believes that their body (or parts of their body) is distorted, diseased or missing.
  • Delusions of reference refer to the belief that special messages are being sent, for example via the TV or radio, and that information in the environment has personal relevance.

Delusions and diagnosis

Delusions can be one of many symptoms of mental or medical problems. Delusions occur in a range of conditions including schizophrenia or schizoaffective disorder, mood disorders, personality disorders, some medical conditions and neurodegenerative disorders such as dementia and Parkinson’s.

Delusions may come about during an episode of psychosis, when the person is trying to make sense of symptoms such as hallucinations (‘hearing voices’) and unusual thoughts. For example, hearing voices talking about them may contribute to paranoid delusions whereby the person believes he is being followed and persecuted by people who wish him/her harm.

Practical advice for family and friends

Delusions can be really confusing for families, friends and other carers, and knowing how to respond can be challenging.

Appropriate ways to manage delusions include the following:

  • Understand that delusions are like real perceptions and can be very puzzling and frightening.
  • Showing love and support will help the person to feel safe expressing their concerns to you.
  • Encourage the person to describe their experiences. These may account for feelings and emotions.
  • Help the person manage their anxiety, stress and other emotions which can be a trigger.
  • Promote healthy behaviours such as eating well, exercise, staying away from alcohol and drugs.
  • Encourage people to attend community managed organisation and support groups.

Where to get help

  • See your GP. They will probably refer you to psychiatric services for an assessment, and so that you get the best possible treatment and care.
  • Ring Healthdirect Australia on 1800 022 222.
  • Ring RuralLink for Rural and remote areas 1800 552 002.
  • Contact the Mental Health Emergency Response Line (external site)
    • Perth metro callers Ph: 1300 555 788
    • Peel callers ph: 1800 676 822


Clinical Research Centre

This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.