Article Text

Increased extrapyramidal symptoms in patients with schizophrenia and a comorbid substance use disorder
  1. S Potvin1,2,
  2. T Pampoulova1,2,
  3. A Mancini-Marië1,2,
  4. O Lipp2,
  5. R-H Bouchard3,
  6. E Stip1,2
  1. 1Centre de Recherche Fernand-Seguin, Hôpital Louis-H Lafontaine, Montreal, Canada
  2. 2Hôpital Louis-H Lafontaine, University of Montreal, Montreal, Canada
  3. 3Centre de Recherche, Université Laval Robert-Giffard, Quebec, Canada
  1. Correspondence to:
 Dr E Stip
 Centre de recherche Fernand-Seguin; 7331, rue Hochelaga, Montreal, Quebec, Canada H1N 3V2; emmanuel.stip{at}


Few data have been gathered about the impact of psychoactive substances on extrapyramidal symptoms (EPS) in schizophrenia, and so far, inconsistent results have been reported. We studied 41 outpatients with schizophrenia (based on DSM-IV criteria), who were divided into two groups: with (n = 17) and without (n = 24) a substance use disorder (alcohol, cannabis, and/or cocaine). Both groups were matched for sociodemographic data and psychiatric symptoms (Positive and Negative Syndrome Scale). EPS were evaluated with the Extrapyramidal Symptoms Rating Scale and the Barnes Akathisia Scale, and all patients were stable on either quetiapine or clozapine. Patients receiving anticholinergic drugs were excluded. Analyses of variance were conducted on both groups and showed that schizophrenia patients with a comorbid substance use disorder (especially cocaine) displayed more EPS compared with non-abusing patients.

  • DD, dual diagnosis
  • EPS, extrapyramidal symptoms in schizophrenia
  • ESRS, Extrapyramidal Symptoms Rating Scale
  • PANSS, Positive and Negative Syndrome Scale
  • PAS, psychoactive substances
  • SCID-IV, Structured Clinical Interview for DSM-IV
  • SCZ, schizophrenia only
  • cocaine
  • comorbidity
  • extrapyramidal symptoms
  • schizophrenia
  • substance use disorders

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  • Competing interests: None declared.

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