title: Linking substance use with symptoms of subclinical psychosis in a community cohort over 30 years.
abstract: OBJECTIVE
  The aim of the study was to examine the temporal associations between substance use and subclinical psychosis symptoms.
  
  
  METHODS
  Data from a prospective community study sampled within a single cohort over 30 years (1978-2008) were analysed with discrete-time hazard models.
  
  
  METHODS
  General population-based sample.
  
  
  METHODS
  At initial sampling in 1978 males (n = 292) were 19 and females (n = 299) were 20 years old.
  
  
  METHODS
  Two psychosis syndromes representing 'schizotypal signs' and 'schizophrenia nuclear symptoms' and various substance use variables including cannabis, alcohol, tobacco and multiple-drug use (i.e. cannabis combined with other drugs).
  
  
  RESULTS
  In bivariate analyses, schizotypal signs were predominantly associated with regular cannabis use in adolescence (OR = 2.29, 95% CI 1.32-3.97). Schizophrenia nuclear symptoms were mainly related to alcohol (OR = 1.84, 95% CI 1.00-3.38) and multiple-drug use (OR = 2.35, 95% CI 1.38-4.02) during adolescence. Multivariate analyses showed that, in particular, regular cannabis use during adolescence was associated with the occurrence of subsequent schizotypal symptoms over a 30-year period (OR = 2.60, 95% CI; 1.59-4.23), whereas multiple-drug use in adolescence was associated predominantly with schizophrenia nuclear symptoms (OR = 1.75, 95% CI 1.01-3.03). Alcohol misuse was only slightly associated with the onset of such symptoms.
  
  
  CONCLUSIONS
  A significant portion of the occurrence of subclinical psychosis symptoms in adulthood can be attributed to excessive cannabis and multiple-drug use during adolescence. This is in line with the hypothesis that long-term sensitization of dopaminergic brain receptors plays a role in developing psychotic symptoms.
authors.affiliation: Department of General and Social Psychiatry, Psychiatric University Hospital Zurich, Zurich, Switzerland. roessler@dgsp.uzh.ch
authors.forename: Wulf
authors.initials: W
authors.lastname: Rössler
authors.forename: Michael P
authors.initials: MP
authors.lastname: Hengartner
authors.forename: Jules
authors.initials: J
authors.lastname: Angst
authors.forename: Vladeta
authors.initials: V
authors.lastname: Ajdacic-Gross
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D011605:Psychoses, Substance-Induced / Q000209:etiology*; D012559:Schizophrenia / Q000209:etiology; D019966:Substance-Related Disorders / Q000150:complications*; D055815:Young Adult