Early course of schizophrenia in a representative Dutch incidence cohort.
OBJECTIVE
To describe the early course of psychotic disorders in general and to examine whether certain variables can predict the early course of schizophrenic disorders (DSM-IV: schizophrenia, schizophreniform or schizoaffective disorder).


METHODS
Follow-up and re-diagnosis of a highly representative Dutch incidence cohort (N=181), thirty months after first contact with a physician for a psychotic disorder. Poor course was defined as a continuous psychotic illness or a score of less than 39 on the Global Assessment of Functioning scale.


RESULTS
The follow-up rate was 92%. 125 Subjects were diagnosed with a schizophrenic disorder. Poor course was present in 70 of these subjects (56%). Univariable analysis showed that male sex, heavy cannabis use during the follow-up period (sometimes or often more than one joint a day) and long duration of dysfunctioning before psychosis onset (>1 month) were predictors of poor course, while age at onset, ethnicity, socioeconomic status and duration of untreated psychosis (trend, p=0.08) were not. The effect of cannabis was confounded by sex. Multivariable analysis showed that male sex was the sole significant and independent predictor of poor course and explained 13% of the variation. The odds ratio for males, adjusted for duration of pre-psychotic dysfunctioning and cannabis use during the follow-up period, was 3.0 (95% CI, 1.0-8.9). STRENGTHS AND LIMITATIONS: This is the first study to examine the influence of cannabis in an epidemiological, highly representative sample. A limitation was the sample size.


CONCLUSIONS
Male sex is an independent risk factor for an unfavorable early course in schizophrenia.
Selten
Jean-Paul
JP
Rudolf Magnus Institute of Neuroscience, Department of Psychiatry, University Medical Center Utrecht, Utrecht, the Netherlands. J.P.Selten@umcutrecht.nl
Veen
Natalie D
ND
Hoek
Hans W
HW
Laan
Winfried
W
Schols
Diede
D
van der Tweel
Ingeborg
I
Feller
Wilma
W
Kahn
René S
RS
D000293:Adolescent; D000328:Adult; D001714:Bipolar Disorder / Q000175:diagnosis / Q000453:epidemiology; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003865:Major Depressive Disorder / Q000175:diagnosis / Q000453:epidemiology; D054242:Emigrants and Immigrants; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology; D008875:Middle Aged; D009426:Netherlands; D017063:Outcome Assessment, Health Care; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000453:epidemiology; D012559:Schizophrenia / Q000175:diagnosis* / Q000453:epidemiology; D012565:Schizophrenic Psychology; D012737:Sex Factors; D012959:Socioeconomic Factors