To the Editor: The study by Dr Fazel and colleagues1 linked treatment for schizophrenia, conviction for violent offenses, and a history of substance misuse. The authors found that 27.6% of a sample of patients with schizophrenia and a coexisting substance use disorder committed a violent offense, compared with 8.5% of a control group of patients with schizophrenia without a substance use disorder and 5.1% of a general population control group. They concluded that schizophrenia alone has a modest association with violent offending on the basis of the small difference in the rate of conviction for violent offenses between the population control group and the non–substance-using schizophrenia group.
Smith G, Large M, Nielssen O. Substance Abuse and Violent Crime in Patients With Schizophrenia. JAMA. 2009;302(11):1168-1169. doi:10.1001/jama.2009.1331