Delusional disorder is characterized by 1 or more firmly held false beliefs that persist for at least 1 month, without other symptoms of psychosis.
The false beliefs may be ordinary things that could occur (such as being deceived by a spouse) or things unlikely to occur (such as having internal organs removed without leaving a scar).
This disorder may develop in people with a paranoid personality disorder.
Doctors base the diagnosis on standard psychiatric diagnostic criteria and the person’s history after they rule out other possible causes.
People usually remain functional and employed.
A good doctor-patient relationship is essential to treatment.
Delusional disorder usually first affects people in middle age or older. It is less common than schizophrenia. Delusional disorder is distinguished from schizophrenia by the presence of delusions without any of the other prominent symptoms of psychosis (such as obvious hallucinations, disorganized speech, or disorganized behavior) or behavioral disturbances. To be diagnosed with delusional disorders, delusions must not be attributable to another medical condition or a substance (illicit drug or other substance that affects thinking or behavior).
Delusions may involve situations that could conceivably occur in real life, such as being followed, poisoned, infected, or loved at a distance. Less commonly, they may involve situations that are very unlikely to occur, such as having internal organs removed without leaving a scar. The difference between a delusion and a false or mistaken belief is that people continue to believe in a delusion no matter how much clear evidence contradicts it.
Symptoms of Delusional Disorder
A delusional disorder may develop in someone who already has paranoid personality disorder. Beginning in early adulthood, people with a paranoid personality disorder have a pervasive distrust and suspiciousness of others and their motives.
Early symptoms of delusional disorder may include the following:
Feeling exploited
Being preoccupied with the loyalty or trustworthiness of friends
Reading threatening meanings into benign remarks or events
Bearing grudges for a long time
Responding readily to perceived slights
In people with delusional disorder, behavior is not obviously bizarre or odd. They tend to function relatively well, except when their specific delusions cause problems. For example, they may have marital problems if they are incorrectly convinced their spouse is being unfaithful.
Types of delusional disorder
There are several subtypes of delusional disorder, with different symptoms:
Erotomanic: People believe that another person is in love with them. They often try to contact that person through telephone calls, emails, text messages, social media messaging, or letters. Some attempt surveillance, and stalking is common. Behavior related to the delusion may be illegal.
Grandiose: People are convinced that they have some great talent or have made some important discovery.
Jealous: People are convinced that a spouse or lover is unfaithful. This belief is based on incorrect inferences supported by dubious evidence. Under such circumstances, physical assault may be a significant danger.
Persecutory: People believe that they are being plotted against, spied on, maligned, or harassed. People may repeatedly file lawsuits or reports to the police or other government agencies. Rarely, people resort to violence in retaliation for imagined persecution.
Somatic: People are preoccupied with a bodily function or attribute, such as an imagined physical deformity or odor. The delusion can also take the form of an imagined medical disorder, such as having parasites.
Diagnosis of Delusional Disorder
A doctor’s evaluation, based on standard psychiatric diagnostic criteria
Physical examination and sometimes medical tests to exclude other disorders
After excluding other specific conditions that can cause delusions (such as a substance use disorder), a doctor bases the diagnosis largely on the person’s history and symptoms. A doctor also must assess how dangerous the person might be, particularly how likely the person is to act on the delusions.
Treatment of Delusional Disorder
Establishment of a good doctor-patient relationship
Sometimes antipsychotic medications
Treatment can be difficult because some people firmly believe their delusion and refuse to seek help. A good doctor-patient relationship helps. Once a relationship is established, doctors can encourage people who are resistant to being treated to participate in treatment.
Hospitalization may be needed if a doctor believes that people are dangerous.
Antipsychotic medications are helpful but are not always effective in reducing symptoms.
A long-term treatment goal is to shift the person’s focus away from the delusion to a more constructive and gratifying area, although this goal is frequently difficult to achieve.
Prognosis for Delusional Disorder
Delusional disorder does not usually cause severe impairment. However, people may become progressively more involved with their delusion.
Most people are able to remain employed, as long as their work does not involve people or events related to their delusions.
