What is delusional disorder?
Delusional disorder, previously called paranoid disorder, is a type of serious mental illness — called a “psychosis”— in which a person cannot tell what is real from what is imagined. The main feature of this disorder is the presence of delusions, which are unshakable beliefs in something untrue. People with delusional disorder experience non-bizarre delusions, which involve situations that could occur in real life, such as being followed, poisoned, deceived, conspired against, or loved from a distance. These delusions usually involve the misinterpretation of perceptions or experiences. In reality, however, the situations are either not true at all or highly exaggerated.
People with delusional disorder often can continue to socialize and function quite normally, apart from the subject of their delusion, and generally do not behave in an obviously odd or bizarre manner. This is unlike people with other psychotic disorders, who also might have delusions as a symptom of their disorder. In some cases, however, people with delusional disorder might become so preoccupied with their delusions that their lives are disrupted.
Although delusions might be a symptom of more common disorders, such as schizophrenia, delusional disorder itself is rather rare. Delusional disorder most often occurs in middle to late life.
What are the types of delusional disorder?
There are different types of delusional disorder based on the main theme of the delusions experienced. The types of delusional disorder include:
- Erotomanic. Someone with this type of delusional disorder believes that another person, often someone important or famous, is in love with him or her. The person might attempt to contact the object of the delusion, and stalking behavior is not uncommon.
- Grandiose. A person with this type of delusional disorder has an over-inflated sense of worth, power, knowledge, or identity. The person might believe he or she has a great talent or has made an important discovery.
- Jealous. A person with this type of delusional disorder believes that his or her spouse or sexual partner is unfaithful.
- Persecutory. People with this type of delusional disorder believe that they (or someone close to them) are being mistreated, or that someone is spying on them or planning to harm them. It is not uncommon for people with this type of delusional disorder to make repeated complaints to legal authorities.
- Somatic. A person with this type of delusional disorder believes that he or she has a physical defect or medical problem.
- Mixed. People with this type of delusional disorder have two or more of the types of delusions listed above.
Symptoms and Causes
What causes delusional disorder?
As with many other psychotic disorders, the exact cause of delusional disorder is not yet known. Researchers are, however, looking at the role of various genetic, biological, and environmental or psychological factors.
- Genetic. The fact that delusional disorder is more common in people who have family members with delusional disorder or schizophrenia suggests there might be a genetic factor involved. It is believed that, as with other mental disorders, a tendency to develop delusional disorder might be passed on from parents to their children.
- Biological. Researchers are studying how abnormalities of certain areas of the brain might be involved in the development of delusional disorders. An imbalance of certain chemicals in the brain, called neurotransmitters, also has been linked to the formation of delusional symptoms. Neurotransmitters are substances that help nerve cells in the brain send messages to each other. An imbalance in these chemicals can interfere with the transmission of messages, leading to symptoms.
- Environmental/psychological. Evidence suggests that delusional disorder can be triggered by stress. Alcohol and drug abuse also might contribute to the condition. People who tend to be isolated, such as immigrants or those with poor sight and hearing, appear to be more vulnerable to developing delusional disorder.
What are the symptoms of delusional disorder?
The presence of non-bizarre delusions is the most obvious symptom of this disorder. Other symptoms that might appear include:
- An irritable, angry, or low mood
- Hallucinations (seeing, hearing, or feeling things that are not really there) that are related to the delusion (For example, a person who believes he or she has an odor problem may smell a bad odor.)
Diagnosis and Tests
How is delusional disorder diagnosed?
If symptoms are present, your doctor will perform a complete medical history and physical examination. Although there are no laboratory tests to specifically diagnose delusional disorder, the doctor might use various diagnostic tests — such as X-rays or blood tests — to rule out physical illness as the cause of your symptoms.
If the doctor finds no physical reason for the symptoms, he or she might refer the person to a psychiatrist or psychologist, health care professionals who are specially trained to diagnose and treat mental illnesses. Psychiatrists and psychologists use specially designed interview and assessment tools to evaluate a person for a psychotic disorder. The doctor or therapist bases his or her diagnosis on the person’s report of symptoms, and his or her observation of the person’s attitude and behavior.
The doctor or therapist then determines if the person’s symptoms point to a specific disorder as outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which is published by the American Psychiatric Association and is the standard reference book for recognized mental illnesses. According to the DSM-5, a diagnosis of delusional disorder is made if a person has non-bizarre delusions for at least one month and does not have the characteristic symptoms of other psychotic disorders, such as schizophrenia.
Management and Treatment
How is delusional disorder treated?
Treatment for delusional disorder most often includes medication and psychotherapy (a type of counseling); however, delusional disorder is highly resistant to treatment with medication alone. People with severe symptoms or who are at risk of hurting themselves or others might need to be in the hospital until the condition is stabilized.
Psychotherapy is the primary treatment for delusional disorder. It provides a safe environment for patients to discuss their symptoms while encouraging healthier and more functional attitudes and behaviors.
Psychosocial treatments. Various psychosocial treatments can help with the behavioral and psychological problems associated with delusional disorder. Through therapy, patients also can learn to control their symptoms, identify early warning signs of relapse, and develop a relapse prevention plan. Psychosocial therapies include the following:
- Individual psychotherapy can help the person recognize and correct the underlying thinking that has become distorted.
- Cognitive-behavioral therapy (CBT) helps the person learn to recognize and change thought patterns and behaviors that lead to troublesome feelings.
- Family therapy can help families deal more effectively with a loved one who has delusional disorder, enabling them to contribute to a better outcome for the person.
Medications: The primary medications used to attempt to treat delusional disorder are called anti-psychotics. Medications include the following:
- Conventional antipsychotics, also called neuroleptics, have been used to treat mental disorders since the mid-1950s. These medicines work by blocking dopamine receptors in the brain. Dopamine is a neurotransmitter believed to be involved in the development of delusions. Conventional antipsychotics include chlorpromazine (Thorazine®), fluphenazine (Prolixin®), haloperidol (Haldol®), thiothixene (Navane®), trifluoperazine (Stelazine®), perphenazine (Trilafon®) and thioridazine (Mellaril®).
- Newer medications — called atypical antipsychotic drugs — appear to be more effective in treating the symptoms of delusional disorder. These medications work by blocking dopamine and serotonin receptors in the brain. Serotonin is another neurotransmitter believed to be involved in delusional disorder. These drugs include risperidone (Risperdal®), clozapine (Clozaril®), quetiapine (Seroquel®), ziprasidone (Geodon®) and olanzapine (Zyprexa®).
- Other medications that might be used to treat delusional disorder include tranquilizers and antidepressants. Tranquilizers might be used if the person has a very high level of anxiety and/or problems sleeping. Antidepressants might be used to treat depression, which often occurs in people with delusional disorder.
Can delusional disorder be prevented?
There is 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.
Outlook / Prognosis
What is the outlook for people with delusional disorder?
The outlook for people with delusional disorder varies depending on the person, the type of delusional disorder, and the person’s life circumstances, including the availability of support and a willingness to stick with treatment.
Delusional disorder is typically a chronic (ongoing) condition, but when properly treated, many people with this disorder can find relief from their symptoms. Some people recover completely and others experience episodes of delusional beliefs with periods of remission (lack of symptoms).
Unfortunately, many people with this disorder do not seek help. It often is difficult for people with a mental disorder to recognize that they are not well. They also might be too embarrassed or afraid to seek treatment. Without treatment, delusional disorder can be a life-long illness.
What are the complications of delusional disorder?
People with delusional disorder might become depressed, often as the result of difficulties associated with the delusions. Acting on the delusions also can lead to violence or legal problems; for example, a person with an erotomanic delusion may stalk or harass the object of his or her delusion, which could lead to arrest. Further, people with this disorder can eventually become alienated from others, especially if their delusions interfere with or damage their relationships.