Types of Delusions

Medically Reviewed by Zilpah Sheikh, MD on May 07, 2024
5 min read

Delusions are beliefs that aren't based on reality, culture, religion, or social identity. The people affected by them can’t be convinced by facts or reason that their delusional belief is untrue.

Delusions can be a symptom of mental illness, including psychotic disorders such as schizophrenia, or they can be the only mental health disorder a person has. When that’s the case, it’s called delusional disorder. With delusional disorder, the person has an untrue idea, experience, or memory and believes that the delusion is especially important or meaningful.

The most common types of delusions include:

Grandiose delusions. This is when a person believes that they have a great talent, have made a great discovery, or are an extremely important person. They may also believe they have a great amount of power or knowledge or are in close communication with a deity. 

Delusional jealousy. A person with this type of delusion believes that their sexual partner is unfaithful, even when it's impossible.

Paranoid or persecutory delusions. This is when a person believes that they are being conspired against, attacked, harassed, harmed, or obstructed in their pursuit of some goal.

Somatic delusions. This is when a person believes that they have something wrong with a part of their body, a part of their body is missing, or that they can feel strange things in their body. 

Reference delusions. This is when a person believes that they can pick up on other people's thoughts or that another person's actions are directed against them. They may also believe that they are receiving special messages from the TV or radio.

Other types of delusions include:

Bizarre delusions. This happens when a person believes in a phenomenon that is impossible, not understandable, or unrelated to normal life.

Erotomaniac delusions. The affected person believes that another person, usually someone famous or of high status, is in love with them.

Misidentification syndrome. In this case, a person believes that someone they know has been replaced by someone else who looks exactly like them.

Mixed delusions. These arise when a person has delusions that don't follow one theme but seem to have two or more themes.

Here are some ways that delusions may show themselves:

  • People with grandiose delusions may believe that they have a special destiny, are more important than other people, are immortal, or have supernatural powers.
  • People with delusional jealousy may believe that their partner is cheating on them even when they have no evidence to suggest infidelity or when it's impossible. For instance, if the partner of a person with delusions is their primary caretaker and hasn't been away from their partner for enough time to have cheated on them.
  • People with paranoid delusions may believe that powerful people are spying on them or that everyone is talking behind their back.
  • People with somatic delusions may believe that they have parasites infecting all their internal organs or that insects have burrowed into their skin.
  • People with reference delusions may believe that news stories are about them or that car license plates have a meaningful message specifically for them.

Types of delusions in schizophrenia

Schizophrenia is a mental health disorder that's characterized by psychosis. Psychosis is a cluster of symptoms that show the person has lost contact with reality. These symptoms include delusions, hallucinations, disorganized thinking and speech, and bizarre and inappropriate behavior. People with schizophrenia may have one or more or even all of these symptoms.

Most people with schizophrenia have delusions, and they tend to be bizarre. This means that their delusions are unbelievable, fantastic, or incredible and clearly not based on ordinary experiences.

Bipolar disorder and depression

Bipolar disorder is a mental health disorder that causes changes in mood, energy, activity levels, and concentration. Mood changes usually go from being elated, irritable, or energized (known as mania) to being sad, indifferent, or hopeless (known as depression). 

About 50%-66% of people with bipolar disorder have psychosis at some point in their illness. Delusions are more common than hallucinations in this disorder. Delusions are much more common during manic episodes than during depressive episodes. The most common kinds of delusions in people with bipolar disorder tend to be grandiose, persecutory, and referential delusions.

Psychosis with unipolar depression is rare. However, some people with depression will develop psychosis. This is known as "major depressive disorder with psychotic features" or "psychotic depression". The types of delusions that these people have are often related to their depressed feelings, such as hearing voices that criticize them or tell them that they don't deserve to live.

Obsessive-compulsive disorder (OCD)

OCD is a mental health disorder that causes repeated unwanted thoughts, ideas, or sensations (called obsessions). To help get rid of the thoughts, people with OCD may feel driven to do something repeatedly (called compulsions), such as wash their hands or count things.

Their obsessions aren't delusions. Most people with OCD realize that their obsessions and compulsions don't make sense. People with delusions don't realize that they believe things that aren't true. 


Delirium is a mental health condition that causes confused thinking and a lack of awareness of surroundings. It can be caused by severe, long-term illness, some medicines, infection, surgery, or withdrawal from alcohol.

Delusions are part of the group of symptoms that define delirium.

Other conditions that can cause delusions

Aside from schizophrenia, bipolar disorder, and delirium, people with the following disorders may also have delusions:

  • Schizoaffective disorder
  • Delusional disorder
  • Schizophreniform disorder
  • Shared psychotic disorder
  • Brief psychotic disorder
  • Substance-induced psychotic disorder
  • Major neurocognitive disorder
  • Dementia

Delusions happen when a person believes in things that other people don't believe, even when they are part of the same culture, religion, or social group.

In contrast, hallucinations are when a person hears, sees, feels, smells, or tastes things that other people can't. For instance, a common hallucination is to hear voices. Hallucinations are very real to the person having them, even though other people can't experience those same things.

Both are similar in that they are perceptions or beliefs that aren't true, real, or verifiable. They are different in that hallucinations come from some sort of sensory perception, while delusions are beliefs that don't arise from a person's sense perception.

Delusions are beliefs that aren't true and aren't shared by other people around you or in your culture, religion, or social identity. The people who have them can’t be convinced by facts or reason that their delusional belief isn't true. People with schizophrenia or other psychotic disorders, bipolar disorder, delirium, or dementia may have delusions. There are several main types of delusions, including grandiose delusions, delusional jealousy, and paranoid delusions.