Delusional Disorder
Key points
- Delusional disorder (sometimes called paranoid disorder) is one of the psychotic disorders.
- The main symptom is a persistent delusion or delusions (a fixed belief) of something that is not happening but is plausible in real life.
- Since delusional disorder is rare, other major illnesses, such as schizophrenia, mood disorder or a medical problem should be considered whenever delusional ideas arise.
- Some have a persistent delusion that waxes and wanes in its intensity and significance.
What Is It?
Delusional disorder (sometimes called paranoid disorder) is one of the psychotic disorders. Psychosis has a variety of definitions, but it can be understood in simple terms as a gross impairment in the ability to recognize reality. Examples of psychotic symptoms are delusions (false beliefs) and hallucinations (false perceptions). Psychosis can be a part of many mental disorders including schizophrenia, mood disorders such as depression and some medical conditions.
The key feature of delusional disorder is the presence of one or more delusions, sometimes with a theme of persecution. People with this diagnosis do not have prominent mood disturbances nor do they typically have hallucinations. They do not exhibit strange forms of emotional expression, such as sometimes is seen in schizophrenia.
Delusions are false beliefs based on an incorrect interpretation of reality. The person holds the belief firmly, despite clear evidence or proof to the contrary. A religious or cultural belief that is also accepted by other members of the person's community (an idea that is an article of faith) is not a delusion. Delusional ideas have a wide variety of themes in addition to persecution. Delusions can have jealous themes or relate to body function (somatic delusions). Ideas can be erotic or grandiose. Delusions usually involve circumstances that could occur in reality. Bizarre ideas such as being controlled by an outside force or having thoughts inserted into one's head usually are not a feature of this illness.
Often, since people with delusional disorder are aware that their beliefs are unique, they do not talk about them. In these cases, the disorder can be detected only by observing unusual behavior that is a consequence of the belief.
Delusions, like all psychotic symptoms, can be a part of many different psychiatric disorders. The term delusional disorder is used when the problem is limited to delusional ideas or when delusions are by far the most prominent feature of the illness.
When hallucinations occur, they are part of the delusional belief. For example, someone who has the delusion that internal organs are rotting may hallucinate smells or sensations related to that delusion.
When functioning is impaired, it is a direct result of the delusion. The person may be capable of performing work, but may never leave the house because of a fear of being harmed. The lifetime risk of delusional disorder is less than one in 1,000. The cause of delusional disorder is not known.
Symptoms
The main symptom is a persistent delusion or delusions (a fixed belief) of something that is not happening but is plausible in real life. Types include:
- Erotomanic — delusion of a special, loving relationship with another person, usually someone famous or of higher standing
Written and revised by
Gerald Hurowitz, M.D.
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