Impact of substance use on conversion to psychosis in youth at clinical high risk of psychosis.
Elevated rates of substance use (alcohol, tobacco, cannabis) have been reported in people at clinical high risk (CHR) of developing psychosis and there is some evidence that substance use may be higher in those who convert to a psychosis compared to non-converters. However little is known about the predictive value of substance use on risk of conversion to psychosis in those at CHR of psychosis. In the current study, 170 people at CHR of psychosis were assessed at baseline on severity of alcohol, tobacco and cannabis using the Alcohol and Drug Use Scale. Participants were recruited across three sites over a four year period as part of the Enhancing the Prospective Prediction of Psychosis (PREDICT) study. Predictors of conversion to psychosis were examined using Cox proportional hazards models. Results revealed that low use of alcohol, but neither cannabis use nor tobacco use at baseline, contributed to the prediction of psychosis in the CHR sample. Prediction algorithms incorporating combinations of additional baseline variables known to be associated with psychotic conversion may result in increased predictive power compared with substance use alone.
Hotchkiss Brain Institute, Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada.
Lisa
L
Buchy
Department of Psychiatry, University of North Carolina, Chapel Hill, NC, United States.
Diana
D
Perkins
Department of Psychiatry, Yale University, New Haven, CT, United States.
Scott W
SW
Woods
Hotchkiss Brain Institute, Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada.
Lu
L
Liu
Hotchkiss Brain Institute, Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada. Electronic address: jmadding@ucalgary.ca.
Jean
J
Addington
D000293:Adolescent; D000328:Adult; D019973:Alcohol-Related Disorders / Q000150:complications; D000465:Algorithms; D002648:Child; D018450:Disease Progression; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D002189:Marijuana Abuse / Q000150:complications; D062706:Prodromal Symptoms; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011618:Psychotic Disorders / Q000150:complications* / Q000175:diagnosis*; D012306:Risk; D019966:Substance-Related Disorders / Q000150:complications*; D014029:Tobacco Use Disorder / Q000150:complications; D055815:Young Adult
Alcohol; Cannabis; Prodrome; Psychosis; Substance use; Tobacco