Delusionsare a false belief about something that is not true or not real.
This article discusses different types of delusions, as well as common themes of delusions.
Delusions interfere with a person’s day-to-day function.

PeopleImages / Getty Images
PeopleImages / Getty Images
What Is Delusional Disorder?
Delusional disorder is characterized by one or more firmly-held false beliefs that persist for a month or longer.
What Causes Delusional Disorder?
Delusional disorder is a rare condition and difficult to study.
Genetics may also contribute to the development of a delusional disorder.
An imbalance of chemicals or abnormalities in the brain can also play a part in delusions.
Does the Person Know They Are Experiencing a Delusion?
People with delusional disorder do not believe they are experiencing a delusion.
Types of delusions include persecutory,erotomanic, grandiose, jealous, somatic, and mixed/unspecific.
What AreHallucinations?
Hallucinationsoften occur with delusions.
These can be visual (seeing things that aren’t there) or auditory (hearing voices).
This can include another person, a machine, or an entire institution or organization.
Persecutory delusions are considered to be an extreme form ofparanoia.
People with erotomanic delusions often believe that their “crush” is sending secret messages to them.
Grandiose Delusions
People who have grandiose delusions believe that they are superior to other people.
These beliefs can give a person a sense of belonging and self-worth.
Grandiose delusions are commonaffecting about two-thirds of people with bipolar disorder and half of people with schizophrenia.
Examples of grandiose delusions include:
Grandiose delusions can lead to risky or dangerous behaviors.
This is different from the typical jealousy that many people experience.
Somatic Delusions
Somatic delusions are focused on the physical body.
A person with somatic delusions falsely believes that something is wrong with their body.
Mixed delusions means that the person has multiple types of delusions, but none are more common than another.
Unspecified delusions don’t clearly fit into a specific category.
Delusions are common with mental health diagnoses, but can also occur with medical conditions such as brain injury.
Types of delusions include persecutory, erotomanic, grandiose, jealous, somatic, mixed, and unspecified.
Delusions often revolve around a specific theme, such as love, guilt, religion, or infidelity.
Lancellotta E, Bortolotti L.Are clinical delusions adaptive?.Wiley Interdiscip Rev Cogn Sci.
2019;10(5):e1502.
doi:10.1002%2Fwcs.1502
Ahmed S, Venigalla H, Mekala HM, et al.Traumatic Brain Injury and Neuropsychiatric Complications.
Indian J Psychol Med.
[Updated 2023 Jul 10].
In: StatPearls [Internet].
Harvard Health Publishing.Delusional disorder.
Joseph SM, Siddiqui W.Delusional Disorder.
[Updated 2023 Mar 27].
In: StatPearls [Internet].
Freeman D, Garety P.Advances in understanding and treating persecutory delusions: A review.Soc Psychiatry Psychiatr Epidemiol.
2013;25(3):334-339.
American Psychological Association.APA dictionary of psychology: Somatic delusion.
Kiran C, Chaudhury S.Understanding delusions.Ind Psychiatry J.
2009;18(1):3-18. doi:10.4103%2F0972-6748.57851