Delusional disorder is a type of mental health condition in which a person can’t tell what’s real from what’s imagined. There are many types, including persecutory, jealous and grandiose types. It's treatable with psychotherapy and medication.
Delusional disorder is a type of psychotic disorder. Its main symptom is the presence of one or more delusions.
A delusion is an unshakable belief in something that’s untrue. The belief isn’t a part of the person’s culture or subculture, and almost everyone else knows this belief to be false.
People with delusional disorder often experience non-bizarre delusions. Non-bizarre delusions involve situations that could possibly occur in real life, such as being followed, deceived or loved from a distance. These delusions usually involve the misinterpretation of perceptions or experiences. In reality, these situations are either untrue or are highly exaggerated.
Non-bizarre delusions are different from bizarre delusions, which include beliefs that are impossible in our reality, such as believing someone has removed an organ from your body without any physical evidence of the procedure.
People with delusional disorder often continue to socialize and function well, apart from the subject of their delusion. Generally, they don’t behave in an odd or unusual manner. This is unlike people with other psychotic disorders, who might also have delusions as a symptom. In some cases, however, people with delusional disorder might become so preoccupied with their delusions that their lives are disrupted.
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There are different types of delusional disorder, which are determined based on the main theme of the delusions the person experiences. The types of delusional disorder include:
Schizophrenia is a spectrum (or range) of conditions that involve psychotic symptoms, which include:
Delusional disorder is different from schizophrenia because there aren’t any other psychotic symptoms other than delusions.
In addition, in contrast to schizophrenia, delusional disorder is relatively rare, and daily functioning isn’t as impaired as it is in schizophrenia.
Delusional disorder most often occurs in middle to late life, with the average age of onset being 40 years.
The persecutory and jealous types of delusional disorder are more common in people assigned male at birth (AMAB), and the erotomanic type is more common in people assigned female at birth (AFAB).
People who tend to be socially isolated are more likely to develop delusional disorder. These populations include:
Although delusions might be a symptom of more common disorders, such as schizophrenia, delusional disorder itself is rather rare. Approximately 0.05% to 0.1% of the adult population has delusional disorder.
The most common type of delusional disorder is the persecutory type — when someone believes others are out to harm them despite evidence to the contrary.
The presence of delusions is the most obvious sign of delusional disorder, which vary based on the type.
Another characteristic of this condition is that the person often lacks self-awareness that their delusions are problematic. They’re unable to accept that their delusions are irrational or inaccurate, even if they recognize that other people would describe their delusions this way.
Anger and violent behavior may be present if someone is experiencing persecutory, jealous or erotomanic delusions.
Early symptoms of delusional disorder may include:
As with many other psychotic disorders, researchers don’t yet know the exact cause of delusional disorder. Researchers are, however, looking at the role of various factors that may contribute to the development of the condition, including:
Healthcare providers — mainly mental health professionals — diagnose delusional disorder when a person has one or more delusions for one month or more that can’t be explained by any other condition. The person must also not have the characteristic symptoms of other psychotic disorders, such as schizophrenia.
If someone is experiencing signs and symptoms of delusional disorder, a healthcare provider will perform a complete medical history and physical examination. Although there aren’t any laboratory tests to diagnose delusional disorder, their healthcare provider might use various diagnostic tests — such as imaging tests, a urine drug screen and blood tests — to rule out any physical conditions, medications or substances that could be causing the symptoms.
If their healthcare provider finds no physical reason for the symptoms, a consultation with a psychiatrist or psychologist will likely be made. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a psychotic disorder. They’ll ask questions about the delusions and assess the person’s mental status.
The psychiatrist or psychologist may also interview family members and friends so they can provide further details about the person’s delusions and a timeline of the symptoms.
As other mental health conditions can cause delusions, mental health professionals carefully assess the person for other symptoms. Delusional disorder can be misdiagnosed as any of the following conditions:
Treatment for delusional disorder most often includes psychotherapy (talk therapy) and medication, but delusional disorder is highly resistant to treatment with medication alone.
People with delusional disorder often don’t seek treatment for the condition on their own because most people with delusional disorder don’t realize their delusions are problematic or incorrect. It’s more likely they’ll seek help due to other mental health conditions such as depression or anxiety.
People with severe symptoms or who are at risk of hurting themselves or others might need to be admitted to the hospital until the condition is stabilized.
Psychotherapy is a term for a variety of treatment techniques that aim to help people identify and change troubling emotions, thoughts and behaviors. Working with a mental health professional, such as a psychologist or psychiatrist, can provide support, education and guidance to the person and their family.
Through therapy, people with delusional disorder can learn to manage their symptoms, identify early warning signs of relapse and develop relapse prevention plans. Types of psychotherapy include:
The primary medications used to help treat delusional disorder are called antipsychotics (neuroleptics). Medications include the following:
Other medications that healthcare providers might prescribe to treat delusional disorder include anxiolytics and antidepressants. Anxiolytics might help if the person has a very high level of anxiety and/or problems sleeping. Antidepressants can help treat depression, which often occurs in people with delusional disorder.
There’s no known way to prevent delusional disorder. However, early diagnosis and treatment can help decrease the disruption to the person’s life, family and friendships.
The prognosis (outlook) for people with delusional disorder varies depending on a few factors, including:
Delusional disorder doesn’t usually significantly affect a person’s daily functioning, but the severity of the delusion may gradually get worse. Most people with delusional disorder can remain employed as long as their work doesn’t involve things related to their delusions.
The prognosis of delusional disorder is better if the person sticks to their treatment plan. Almost 50% of people have a full recovery, more than 20% of people report a decrease in symptoms and less than 20% of people report minimal to no change in symptoms.
Unfortunately, many people with this condition don’t seek help. It’s often difficult for people with mental health conditions to recognize they’re not well. They also might be too embarrassed or afraid to seek treatment. Without treatment, delusional disorder can be a life-long condition.
If left untreated, delusional disorder might lead to:
If you know someone with delusional disorder, you can help by providing support and encouragement for them to seek help and treatment.
People with delusional disorder who feel pressured or repeatedly criticized by others will likely experience stress, which may worsen their symptoms. Because of this, a positive approach may be more helpful and effective.
The friends and family members of people with delusional disorder often experience stress, depression, grief and isolation. It’s important to take care of your mental health and seek help if you’re experiencing these symptoms.
A note from Cleveland Clinic
It’s important to remember that delusional disorder is a mental health condition. As with all mental health conditions, seeking help as soon as symptoms appear can help decrease the disruptions to life. Mental health professionals can offer treatment plans that can help manage thoughts and behaviors.
Last reviewed by a Cleveland Clinic medical professional on 05/22/2022.
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