A bizarre delusion consists of illusions of events that are impossible in real life. They can be non-understandable and supernatural in nature.

Bizarre Delusional Disorder

Delusional Jealousy Disorder, also known as Othello Syndrome, occurs when an individual wrongfully believes their sexual partner is unfaithful to them. This type of delusional disorder is found more often in males and can sometimes be associated with suicidal or homicidal ideations. 

Delusional Jealousy Disorder

An erotomaniac delusion, also known as Clérambault syndrome, occurs when an individual believes that another individual, especially one of a higher status, is in love with them. Individuals with this disorder can justify denials of these feelings as an affirmation of love. This disorder is commonly found in women. However, men with this delusion can be more aggressive.

Erotomaniac Delusional Disorder

 A Grandiose Delusion, also known as Megalomania, occurs when an individual believes in their inflated importance or greatness based on a false belief of special powers or greater knowledge. Individuals with these delusions oppose any attempts others make to convince them that they are wrong. 

Grandiose Delusional Disorder

An individual who experiences persecutory delusions thinks that someone is conspiring, attacking, or harassing them to cause harm. This is a common delusion, and individuals who experience it may feel anxious, irritable, and aggressive. 

Persecutory Delusional Disorder

Somatic delusional disorder, also known as monosymptomatic hypochondriacal psychosis, involves an individual feeling abnormalities inside their body, such as being infested with parasites, body dysmorphic delusion, and body odor or halitosis. An individual with this delusion can experience anxiety and nervousness. 

Somatic Delusional Disorder

This refers to a delusional disorder where two or more themes are present. For example- an individual can have a mix of grandiose and somatic delusional disorder and this mix of delusions would be listed in this category. 

Mixed Delusional Disorder

When individuals have a thought broadcasting delusion, they believe others can hear their thoughts.

Thought Broadcasting Delusional Disorder

In a thought insertion delusion, an individual believes that their thoughts are not their own, and instead, someone is putting other thoughts into their minds.

Thought Insertion Delusional Disorder

Sometimes, a delusion does not fit into any of the typical categories. These delusions are typically listed under ‘unspecified types.’ 

Unspecified Type Delusional Disorder

There are different types of Delusional Disorder, depending on  the specific delusion the individual is experiencing:

- Delusional jealousy
- Bizarre
- Erotomania
- Grandiose
- Persecutory
- Somatic
- Mixed
- Thought broadcasting
- Thought insertion
- Unspecified


University of Pittsburgh

Previously referred to as paranoid disorder, delusional disorder is characterized by an inability to recognize reality from false beliefs called delusions. It occurs more often in middle age or later in life. This disorder is diagnosed when someone holds one or more non-bizarre delusions as truth for a month or more. These delusions cannot be sourced from culture or other causes. Symptoms include irritability and hallucinations.  

Delusional Disorder

Joseph, S. M., &amp; Siddiqui, W. (2023, March 27). Delusional Disorder. National Library of Medicine . https://www.ncbi.nlm.nih.gov/books/NBK539855/ 

Delusional Disorder NCBI (updated)

Also called folie à deux, this occurs when one person in a relationship that has a delusion influences the other to develop that delusion. This can happen to groups too, referred to as folie à plusiers, and can be seen in cults. 

Shared psychotic disorder

Types of Delusional Disorder

Certain populations are more vulnerable to this psychotic disorder:
- People who are deaf or hard of hearing
- People who are visually impaired
- People who face language barriers 
- Elderly People

Population at Risk for Delusion Disorder

A study found an association between the HLA-A*03 gene, delusional disorder, and paranoid schizophrenia. It is found that this gene alone, in combination with other HLA genes or other closely linked non-HLA genes, may lead to vulnerability to delusional disorder and paranoid schizophrenia.   

Genetic Association between Delusional Disorder and Paranoid Schizophrenia

Psychotherapy is typically used to treat delusional disorder. The treatment focuses on exploring possible biological and psychological problems and decreasing symptoms by helping the individual work toward reality. A therapist first establishes a trustful bond with the individual by expressing sympathy and accepting their delusions, a supportive response the individual is often not accustomed to from others. Subsequently, the therapist helps increase the individual’s self-confidence, challenges the delusional thought process, and addresses any underlying psychological problems. Cognitive-behavioral therapy and other solution-oriented therapies are particularly useful during this stage of treatment.

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