What Is a Delusion?

What Is a Delusion?

Verywell / Alison Czinkota

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What Is a Delusion?

Delusions are defined as fixed, false beliefs that conflict with reality. Despite contrary evidence, a person in a delusional state can’t let go of these convictions.

Delusions are often reinforced by the misinterpretation of events. Many delusions also involve some level of paranoia. For example, someone might contend that the government is controlling our every move via radio waves despite evidence to the contrary.

Delusions are often part of psychotic disorders. They may occur along with hallucinations, which involve perceiving something that isn’t really there, like hearing voices or feeling bugs crawling on your skin.


Delusions are characterized by an unshakable belief in things that are not true, and often, there is a continued belief in the delusion despite contrary evidence. Not all delusions are the same. Some might involve non-bizarre beliefs that could theoretically occur in real life. Others may be bizarre, fantastical, or impossible. 

The nature of the delusional symptoms may play a central role in the diagnosis. Delusional disorder, for example, is characterized by non-bizarre delusions that often involve the misinterpretation of an experience or perception. In schizophrenia, the delusions may be bizarre and not rooted in reality.

Types of Delusions

There are several different types of delusions that characterize the diagnosis of delusional disorders. The type of disorder is determined by the theme of the delusions that are experienced.


In this type of delusion, individuals believe that a person—usually with a higher social standing—is in love with them. An example of this type of delusion would be someone who believes an actress loves them and that they are communicating with them via secret hand gestures during their TV show.


In grandiose delusions, individuals believe they have extraordinary talent, fame, wealth, or power despite the lack of evidence. An instance of this type of delusion would be someone who believes God gave them the power to save the universe and every day they complete certain tasks that will help the planet continue on.


Individuals with persecutory delusions believe they are being spied on, drugged, followed, slandered, cheated on, or somehow mistreated. An example might include someone who believes their boss is drugging the employees by adding a substance to the water cooler that makes people work harder. 


With this type of delusion, individuals might believe their partners are unfaithful. For instance, someone with this type of delusion might believe their partner is meeting their lover every time they use the restroom in public settings—they also think that they are sending their lover secret messages through other people (like the cashier in a grocery store).


Individuals with somatic delusions believe that they are experiencing physical sensations or bodily dysfunctions under the skin, or that they're suffering from a general medical condition or defect. For instance, someone who believes there are parasites living inside their body may be suffering from somatic delusions.

Mixed or Unspecified

When delusions don’t fall into a single category and no single theme dominates, the delusions are considered “mixed.” Mental health professionals may refer to the disorder as “unspecified" when delusions don’t fall into a specific category or the delusion type can’t be clearly determined.


Researchers aren’t exactly sure what causes delusional states. It appears a variety of genetic, biological, psychological, and environmental factors are at play.

Psychotic disorders seem to run in families, so researchers suspect there is a genetic component to delusions. Children born to a parent with schizophrenia, for example, may be at a higher risk of developing delusions.

Abnormalities in the brain may also play a role. An imbalance of neurotransmitters (chemical messengers in the brain) may increase the likelihood that an individual will develop delusions.

Trauma and stress also can trigger delusions. Meanwhile, individuals who tend to be isolated appear more vulnerable to developing a delusional disorder as well.

Sometimes, people share delusions. This experience is most common in individuals who reside together and have little contact with the outside world.

Related Conditions

Delusions may be symptoms of mental health problems or brain disorders. The following are some conditions that may involve delusions:

  • Brief psychotic disorder: People experience hallucinations, delusions, or disorganized speech that may be triggered by a stressful event. Symptoms of this disorder persist for one month or less.
  • Delusional disorder: People experience "non-bizarre" types of delusions and can usually act normally and don't have markedly impaired functioning. With only an estimated 0.2% of the population meeting the criteria, this disorder is considered a relatively rare mental illness.
  • Dementia: Although estimates vary, roughly one-third of individuals with dementia may experience delusions. Often, the delusions involve paranoia, such as thinking family members or caretakers are stealing from them.
  • Mood disorders: Sometimes, individuals with mood disorders like depression or bipolar disorder may experience delusions.
  • Parkinson’s disease: The prevalence varies widely but many patients with advanced Parkinson’s disease experience hallucinations and delusions.
  • Postpartum psychosis: Hormonal shifts after giving birth may trigger postpartum psychosis in some women. Some research indicates it's also linked to bipolar disorder.
  • Schizoaffective disorder: This disorder involves symptoms of schizophrenia as well as a mood issue, like depression or mania.
  • Schizophrenia: The disorder involves “positive symptoms,” such as hallucinations or delusions. It also involves “negative symptoms,” such as flat affect, reduced feelings of pleasure in everyday life, difficulty beginning and sustaining activities, and reduced speaking.
  • Schizophreniform disorder: This disorder involves symptoms similar to schizophrenia but for less than six months.
  • Substance/medication-induced psychotic disorder: Drug or alcohol intoxication or withdrawal may cause some individuals to experience delusions. Symptoms are usually brief and tend to resolve once the drug is cleared, though psychosis triggered by amphetamines, cocaine, or PCP may persist for weeks.


If a person is experiencing delusional symptoms, their doctor will begin by taking a medical history and performing a physical exam. Lab tests may also be ordered to rule out any physical illnesses that might be causing the symptoms.

If there is no medical condition causing the symptoms, a doctor may refer the individual to a psychiatrist for further evaluation. Mental health professionals may use a variety of psychological assessments to learn more about the person's symptoms. A diagnosis may then be made based on the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5)


It’s important for anyone experiencing delusions to seek professional help. This can be especially challenging, however, since people experiencing delusions often don't think of their beliefs as a problem because, by definition, the person experiencing delusions believes their experience to be fact. Consequently, it is often concerned loved ones who must bring the issue to the attention of a healthcare professional.

In some cases, psychiatric hospitalization is required to help people with delusions become stabilized—especially if they become a danger to themselves or others.

Treatment for delusions often includes a combination of medication and therapy.


Medications may include:

  • Typical, or first-generation antipsychotics: These medications are used to block dopamine receptors in the brain. Dopamine is a neurotransmitter that is believed to be involved in the development of delusions.
  • Atypical antipsychotics: These medications are used to block dopamine and also serotonin receptors in the brain. This leads to a different side effect profile than the first-generation antipsychotics.
  • Tranquilizers: Sometimes these medications are used to address anxiety, agitation, or sleep issues common in people with delusional disorders.
  • Antidepressants: These medications may be used to treat depression if someone with a delusion is experiencing a mood issue.


Therapy may include cognitive behavioral therapy (CBT), which helps an individual learn to recognize and change unhelpful thoughts and behaviors. Family therapy is often part of the treatment as well. Through therapy, family members can learn how to support someone who is experiencing delusions.


Managing the environment also can help someone with delusions. For example, if someone believes the government is spying on them through the TV, it may be best for that person to avoid watching television. Or, if a person believes they are being followed when they go into the community alone, it may be best to have someone go with them when they go out.

If you or a loved one are struggling with delusions, contact the Substance Abuse and Mental Health Services Administration (SAMHSA) National Helpline at 1-800-662-4357 for information on support and treatment facilities in your area.

For more mental health resources, see our National Helpline Database.

A Word From Verywell

Most disorders that involve delusions aren’t curable, but they are treatable. In fact, some people are able to live healthy, productive lives with few symptoms. But some do struggle to work, maintain healthy relationships, and participate in activities associated with daily living. Ask a healthcare professional to provide help and support for you or your loved one.

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Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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