psychiatric disorders
Delusional Disorder
Introduction
Delusional disorder is characterized by firmly held false beliefs (delusions) that persist for at least 1 month, without other symptoms of psychosis. Delusions are distinguished from mistaken beliefs in that delusional beliefs remain unchanged in the face of clear, reasonable evidence to the contrary; this distinction is sometimes difficult to make when the beliefs are more plausible (eg, that a spouse is unfaithful). Delusional disorder is distinguished from schizophrenia by the presence of delusions without any other Symptoms and Signs (eg, hallucinations, disorganized speech or behavior, negative symptoms). The delusions may be Nonbizarre: They involve situations that could occur, such as being followed, poisoned, infected, loved at a distance, or deceived by one’s spouse or lover. Bizarre: They involve implausible situations such as believing that someone removed their internal organs without leaving a scar. In contrast to Schizophrenia , delusional disorder is relatively uncommon. Onset is generally involutional, occurring in middle or late adult life. Psychosocial functioning is not as impaired as it is in schizophrenia, and impairments usually arise directly from the delusional belief. When delusional disorder occurs in older patients, it is sometimes called paraphrenia. It may coexist with mild Dementia . The physician must be careful to distinguish delusions from (See also Introduction to Schizophrenia and Related Disorders .) 