In the United States, brief psychotic disorder may account for 9% of cases of first-onset psychosis. Psychotic disturbances that meet Criteria A and C, but not Criterion B, for brief psychotic disorder (i.e., duration of active symptoms is 1—6 months as opposed to remis- sion within 1 month) are more common in developing countries than in developed coun- tries. Brief psychotic disorder is twofold more common in females than in males.
Brief psychotic disorder may appear in adolescence or early adulthood, and onset can oc- cur across the lifespan, with the average age at onset being the mid 305. By definition, a diagnosis of brief psychotic disorder requires a full remission of all symptoms and an eventual full return to the premorbid level of functioning Within 1 month of the onset of the disturbance. In some individuals, the duration of psychotic symptoms may be quite brief (e.g., a few days).
Temperamental. Preexisting personality disorders and traits (e.g., schizotypal person- ality disorder; borderline personality disorder; or traits in the psychoticism domain, such as perceptual dysregulation, and the negative affectivity domain, such as suspiciousness) may predispose the individual to the development of the disorder.
It is important to distinguish symptoms of brief psychotic disorder from culturally sanc- tioned response patterns. For example, in some religious ceremonies, an individual may report hearing voices, but these do not generally persist and are not perceived as abnormal by most members of the individual’s community. In addition, cultural and religious back- ground must be taken into account when considering whether beliefs are delusional.
Functionai Consequences of Brief Psychotic Disorder
Despite high rates of relapse, for most individuals, outcome is excellent in terms of social functioning and symptomatology.
Other medical conditions. A variety of medical disorders can manifest with psychotic symptoms of short duration. Psychotic disorder due to another medical condition or a de— lirium is diagnosed when there is evidence from the history, physical examination, or lab- oratory tests that the delusions or hallucinations are the direct physiological consequence of a specific medical condition (e.g., Cushing’s syndrome, brain tumor) (see “Psychotic
Disorder Due to Another Medical Condition” later in this chapter).
Substance-related disorders. Substance/medication-induced psychotic disorder, sub- stance-induced delirium, and substance intoxication are distinguished from brief psychotic disorder by the fact that a substance (e.g., a drug of abuse, a medication, exposure to a toxin) is judged to be etiologically related to the psychotic symptoms (see ”Substance /Medication-
Induced Psychotic Disorder” later in this chapter). Laboratory tests, such as a urine drug screen or a blood alcohol level, may be helpful in making this determination, as may a care- ful history of substance use with attention to temporal relationships between substance in- take and onset of the symptoms and to the nature of the substance being used.
Depressive and bipolar disorders. The diagnosis of brief psychotic disorder cannot be made if the psychotic symptoms are better explained by a mood episode (i.e., the psychotic symptoms occur exclusively during a full major depressive, manic, or mixed episode).
Other psychotic disorders. If the psychotic symptoms persist for 1 month or longer, the diagnosis is either schizophreniform disorder, delusional disorder, depressive disorder with psychotic features, bipolar disorder with psychotic features, or other specified or un- specified schizophrenia spectrum and other psychotic disorder, depending on the other symptoms in the presentation. The differential diagnosis between brief psychotic disorder and schizophreniform disorder is difficult when the psychotic symptoms have remitted be- fore 1 month in response to successful treatment with medication. Careful attention should be given to the possibility that a recurrent disorder (e.g., bipolar disorder, recurrent acute ex- acerbations of schizophrenia) may be responsible for any recurring psychotic episodes.