The prevalence of DSM-III-R "prodromal" symptoms of schizophrenia in non-psychotic psychiatric outpatients.
A cross-sectional point prevalence study of the DSM-III-R prodromal symptoms in non-psychotic (n = 501) consecutive outpatients from a catchment area with 260000 inhabitants is presented. The relationship between the three most psychosis-specific prodromal symptoms and the development of psychosis during the following 6 months was also explored. The prevalence of any prodromal symptom was 25%, the most prevalent being impairment of role functioning (14%), isolation and withdrawal (11%) and lack of initiative (8%). The most prevalent symptom in affective disorders was lack of initiative (14%); in personality disorders, it was impairment of role functioning (21%). The prevalences of the most psychosis-specific symptoms "peculiar behaviour", "magical thinking" and "unusual perceptual experiences" was 1-2%. At re-evaluation 6 months later, three of 20 patients (15%) with one or more such symptoms had become psychotic, two with schizoaffective disorder, one with affective psychosis. It was concluded that DSM-III prodromal symptoms are common among non-psychotic outpatients, but most such symptoms are non-specific for psychosis. Persistent peculiar behaviour, magical thinking and unusual perceptual experiences have a very low prevalence but may indicate an increased risk for psychosis. Such patients should be followed with that risk in mind.
Horneland
Marthe
M
Rogland Psychiatric Hospital, Psychiatric outpatient clinic Sandnes, Holbergsgaten 15, NO-4306 Sandnes, Norway. ma-horn@online.no
Vaglum
Per
P
Larsen
Tor Ketil
TK
D000293:Adolescent; D000328:Adult; D000368:Aged; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010045:Outpatients; D015995:Prevalence; D011379:Prognosis; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology; D012307:Risk Factors; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D013997:Time Factors