title: Quetiapine in patients with comorbid schizophrenia-spectrum and substance use disorders: an open-label trial.
abstract: BACKGROUND
  Preliminary evidence suggests that clozapine relieves the craving for psychoactive substances in schizophrenia patients. Quetiapine shares crucial pharmacological properties with clozapine. Promising results have been described with quetiapine therapy in patients with psychosis and substance use disorder.
  
  
  METHODS
  Based on Diagnostic and Statistical Manual of Mental Disorders - fourth edition (DSM-IV) criteria, patients were diagnosed with comorbid schizophrenia-spectrum and substance use disorders. Patients were switched to quetiapine for a 12-week open-label trial. Craving, quantities used, days of consumption, and severity of substance abuse were assessed every 3 weeks. Alcohol and Drug Use Scales were administered on baseline and end-point. Psychiatric symptoms, depressive symptoms, extrapyramidal symptoms, and cognition were also assessed at baseline, week 6 and week 12.
  
  
  RESULTS
  Twenty-four schizophrenia-spectrum patients were included in the last observation carried forward (LOCF) analyses, responding to one or more of the following substance use disorders: cannabis (15 patients), alcohol (10 patients), and other psychoactive substances (nine patients). Overall, severity of substance abuse improved during the study. Less weekly days were spent on drugs of abuse. A decrease in the weekly Canadian dollars spent on psychoactive substances was also observed. Cognition, psychiatric, depressive, and extrapyramidal symptoms also significantly improved (p < 0.05).
  
  
  CONCLUSIONS
  In this open-label, uncontrolled trial, significant improvements were noted in substance abuse, psychiatric symptoms, extrapyramidal symptoms, and cognition during quetiapine therapy. The study suffered from three main limitations: (1) the open-label design of the study; (2) the patients' poor compliance; and (3) the small sample size involved. Controlled studies on the use of quetiapine in dual diagnosis schizophrenia are warranted to confirm that the effects are drug-related.
authors.affiliation: Centre de recherche Fernand-Seguin, Hôpital Louis-H. Lafontaine, Montreal, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Potvin
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Stip
authors.forename: Olivier
authors.initials: O
authors.lastname: Lipp
authors.forename: Robert
authors.initials: R
authors.lastname: Elie
authors.forename: Adham
authors.initials: A
authors.lastname: Mancini-Marië
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Demers
authors.forename: Marc-André
authors.initials: MA
authors.lastname: Roy
authors.forename: Roch-Hugo
authors.initials: RH
authors.lastname: Bouchard
authors.forename: Alain
authors.initials: A
authors.lastname: Gendron
mesh_terms: D000328:Adult; D000437:Alcoholism / Q000150:complications / Q000188:drug therapy; D003071:Cognition / Q000187:drug effects; D003987:Dibenzothiazepines / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D002189:Marijuana Abuse / Q000150:complications / Q000188:drug therapy; D000069348:Quetiapine Fumarate; D012559:Schizophrenia / Q000150:complications / Q000188:drug therapy*; D012565:Schizophrenic Psychology; D012720:Severity of Illness Index; D019966:Substance-Related Disorders / Q000150:complications / Q000188:drug therapy* / Q000523:psychology
chemical_list: D003987:Dibenzothiazepines; D000069348:Quetiapine Fumarate