Delusional disorder is a psychotic disorder separate from schizophrenia, in which a person firmly holds false beliefs, despite clear evidence or proof to the contrary. Delusions, like all psychotic symptoms, can occur as part of many different psychiatric disorders. However, the term delusional disorder is used when delusion(s) are present persistently for at least one month, the disturbance is not attributable to substances, a medical condition or other mental disorder, and when functioning in day to day life is not markedly impaired.

The delusions may involve plausible, but highly improbable circumstances, like believing your neighbor is plotting to kill you. People with delusions may engage in litigious or antagonistic behavior in an effort to protect themselves from perceived threats. A religious or cultural belief that is accepted by other members of the person's community is not a delusion.


Diagnosing Delusional Disorders

People with delusional disorder tend to function relatively well, except when their delusions cause problems. Some people may become progressively more involved with their delusion.

There are several subtypes of delusional disorder, including:

  • Erotomanic: The belief that another person is in love with you, particularly someone famous or of high regard. This is often associated with stalking behavior.
  • Grandiose: The belief that you have a great talent, or have invented, or discovered something important.
  • Jealous: The belief that a spouse or lover is unfaithful.
  • Persecutory: The belief that you are being plotted against, spied on, maligned, or harassed.
  • Somatic: The belief that you have physical ailment or defect.

A diagnosis of delusional disorder is typically made after other specific conditions that can cause delusions, such as substance abuse, has been ruled out. A doctor bases the diagnosis largely on the person’s history and symptoms. The doctor also must assess how dangerous the person might be, particularly how likely the person is to act on the delusions.


How We Treat Delusional Disorder

Treatment can be difficult and some people continue to firmly believe their delusion(s), even refusing to seek or accept help. At NewYork-Presbyterian, we have psychiatrists, social workers, psychologists, and other licensed mental health workers experienced in helping patients and their loved ones deal with delusional disorder. Medications are frequently used to treat this disorder. Cognitive behavioral therapy for psychosis may help the person learn how to challenge their beliefs. Skills training and psychotherapies may help shift the person’s focus away from the delusion to ways they can be more successful in reaching their occupational, educational, and interpersonal goals.


Appointments & Referrals

For more than 15 years, U.S. News & World Report has ranked NewYork-Presbyterian Hospital among the top five hospitals for psychiatry in the United States. This high distinction is based on the our reputation as leaders in the diagnosis and treatment of psychiatric conditions. As leaders in the field, we are dedicated to providing high-quality care to patients with the most challenging disorders in our communities, clinics, inpatient units, and hospital day programs. 

If you think you or a loved one might benefit from the psychiatric services offered, get in touch with us. Please note, if this is an emergency, please dial 9-1-1.

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At NewYork-Presbyterian, we treat a diverse patient population with conditions ranging from the most common to the rarest and most complex. Clinicians in private practice or at other hospitals are welcome to refer their patient to NewYork-Presbyterian. Please call 888-694-5700 to arrange a referral.

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