Epidemiology, diagnosis, and course of brief psychoses

Objective: This study investigated acute and nonacute brief psychoses. On the basis of previous work, the authors proposed that D acute brief psychoses occur predominantly in females, 2) they often do not conform to the diagnoses of DSM-III-R, 3) they are temporally stable, and 4) nonacute brief psychoses do not share these distinctive features. Method: The data are from a follow- up study of 221 first-admission patients with affective and nonaffective psychoses. Patients were given extensive assessments at initial evaluation, 6-month follow-up, and 24-month follow-up. The research team made consensus ratings of the presence of psychosis, DSM-III-R diagnosis, mode of onset of disorder, and course of disorder. Brief psychoses were defined by a diagnosis of nonaffective psychosis at the initial evaluation and a rating of full remission at 6-month follow-up; acute brief psychoses met the additional criterion of acute onset as defined by ICD-10. Results: Twenty (9%) of the 221 psychoses were brief psychoses. Only seven (3%) were acute brief psychoses, but among these, six occurred in women, five were undiagnosable, and none bad evolved into an affective disorder or a chronic disorder by the time of the 24-month follow-up. The 13 nonacute brief psychoses did not exhibit distinctive features, and five of them later evolved into chronic disorders. Conclusions: Acute brief psychoses emerged as a highly distinctive and temporally stable form of psychosis that may merit a separate diagnostic classification. The more numerous nonacute brief psychoses may represent mild forms of nonaffective psychoses such as schizophrenia.