title: Substance use in a large sample of patients with schizophrenia or related disorders and co-morbid obsessive-compulsive symptoms.
abstract: OBJECTIVE
  The aim of this study was to examine the relationship between obsessive-compulsive symptoms (OCS) and substance use in patients with a non-affective psychotic disorder.
  
  
  METHODS
  The data were derived from the Genetic Risk and Outcome of Psychosis study. Using the Yale-Brown Obsessive Compulsive Scale, three groups of in- and outpatients with non-affective psychotic disorder (76.6% male, mean age 27.7 years, mean duration of illness 4.5 years) were distinguished: patients without OCS (N = 777), patients with mild OCS (N = 143) and patients with more severe OCS (N = 85). These three groups were compared using various substance use variables, including quantitative substance use variables and severity of substance use [Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) misuse disorders].
  
  
  RESULTS
  We found no statistically significant differences in smoking and other substance use variables between the three patients groups according to the severity of OCS.
  
  
  CONCLUSIONS
  Our large study sample and detailed comparison of substance use rates strongly adds to the evidence that schizophrenia patients with OCS do not differ in prevalence of substance use compared to patients without OCS. This suggests that in clinical practice, enquiring into (problematic) substance use is relevant in both schizophrenia patients with co-morbid OCS and patients without OCS.
authors.affiliation: Department of Psychiatry, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: Nienke
authors.initials: N
authors.lastname: Dekker
authors.forename: Marije
authors.initials: M
authors.lastname: Swets
mesh_terms: D000293:Adolescent; D000328:Adult; D001530:Belgium / Q000453:epidemiology; D015897:Comorbidity; D017831:Diagnosis, Dual (Psychiatry); D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009771:Obsessive-Compulsive Disorder / Q000453:epidemiology*; D015995:Prevalence; D011569:Psychiatric Status Rating Scales; D012559:Schizophrenia / Q000453:epidemiology*; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000453:epidemiology*
keywords: Obsessive–compulsive; psychosis; schizophrenia; substance use