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 1) acute bri ef psychoses occur predominantly in females, 2) they often do not conf orm to the diagnoses of DSM-III-R, 3) they are temporally stable, and 4) nonacute brief psychoses do not share these distinctive features. M ethod: The data are from a follow-tip study of 221 first-admission pat ients with affective and nonaffective psychoses. Patients were given e xtensive assessments at initial evaluation, 6-month followup, and 24-m onth follow-up. The research team made consensus ratings of the presen ce of psychosis, DSM-III-R diagnosis, mode of onset of disorder, and c ourse of disorder. Brief psychoses were defined by a diagnosis of nona ffective psychosis at the initial evaluation and a rating of full remi ssion at 6-month follow-up; acute brief psychoses met the additional c riterion of acute onset as defined by ICD-10. Results: Twenty (9%) of the 221 psychoses were brief psychoses. Only seven (3%) were acute bri ef psychoses, but among these, six occurred in women, five were undiag nosable, and none had 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 em erged 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 psy choses such as schizophrenia.