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, unshakable beliefs in something untrue or not based on reality. 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. If the delusions could not happen in reality (aliens, television broadcasting your thoughts) then a person might be considered delusional with bizarre-type delusions. People with delusional disorder often can continue to socialise and function 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 the middle to late life and is slightly more common in women than in men.
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 behaviour 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.
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 there) that are related to the delusion (For example, a person who believes he or she has an odour problem may smell a bad odour.)
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, 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. Abnormalities in the functioning of brain regions that control perception and thinking may be linked to the formation of delusional 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.
How Is Delusional Disorder Diagnosed?
If symptoms of delusional disorder are present, your doctor will likely perform a complete medical history and physical exam. Although there are no lab tests to specifically diagnose delusional disorder, the doctor might use various diagnostic tests, such as imaging studies or blood tests, to rule out physical illness as the cause of the 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 with 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 behaviour. The doctor or therapist then determines if the person’s symptoms point to a specific disorder. 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.
How Is Delusional Disorder Treated?
Treatment for delusional disorder most often includes medication and psychotherapy. Delusional disorder can be very difficult to treat in part because its sufferers often have poor insight and do not recognise that a psychiatric problem exists. Studies show that close to half of patients treated with antipsychotic medications show at least partial improvement. Antipsychotic medicines are the primary treatment for delusional disorder. Sometimes, psychotherapy can also be a helpful adjunct to medications as a way to help patients better manage and cope with the stresses related to their delusional beliefs and its impact on their lives. Psychotherapies that may be helpful in delusional disorder include the following:
- Individual psychotherapy: Can help the person recognise and correct the underlying thinking that has become distorted.
- Cognitive-behavioural therapy (CBT): Can help the person learn to recognise and change thought patterns and behaviours 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.
The primary medications used to attempt to treat delusional disorder are called antipsychotics. Drugs used include:
- Conventional antipsychotics: Also called neuroleptics, these have been used to treat mental disorders since the mid-1950s. They work by blocking dopamine receptors in the brain. Dopamine is a neurotransmitter believed to be involved in the development of delusions. Conventional antipsychotics include Thorazine, Loxapine, Prolixin, Haldol, Navane, Stelazine, Trilafon, and Mellaril.
- Atypical antipsychotics: These newer drugs appear to be effective in treating the symptoms of delusional disorder with fewer movement-related side effects than the older typical antipsychotics. They work by blocking dopamine and serotonin receptors in the brain. Serotonin is another neurotransmitter believed to be involved in delusional disorder. These drugs include Risperdal, Clozaril, Seroquel, Geodon, and Zyprexa.
- Other medications: Tranquillizers and antidepressants might also be used to treat anxiety or mood symptoms if they occur in combination with delusional disorder. Tranquillizers might be used if the person has a very high level of anxiety or problems sleeping. Antidepressants might be used to treat depression, which often occurs in people with delusional disorder
People with severe symptoms or who are at risk of hurting themselves or others might need to be hospitalised until the condition is stabilised.
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 who stalks or harasses the object of his or her delusion 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.
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 recognise that they are not well, or they may attribute their symptoms to other factors, such as the environment. They also might be too embarrassed or afraid to seek treatment. Without treatment, delusional disorder can be a life-long illness.
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.
Credit: Reviewed by Smitha Bhandari for WebMD.