title: The population impact of severe mental illness on violent crime.
abstract: OBJECTIVE
  This study aimed to determine the population impact of patients with severe mental illness on violent crime.
  
  
  METHODS
  Sweden possesses high-quality national registers for all hospital admissions and criminal convictions. All individuals discharged from the hospital with ICD diagnoses of schizophrenia and other psychoses (N=98,082) were linked to the crime register to determine the population-attributable risk of patients with severe mental illness to violent crime. The attributable risk was calculated by gender, three age bands (15-24, 25-39, and 40 years and over), and offense type.
  
  
  RESULTS
  Over a 13-year period, there were 45 violent crimes committed per 1,000 inhabitants. Of these, 2.4 were attributable to patients with severe mental illness. This corresponds to a population-attributable risk fraction of 5.2%. This attributable risk fraction was higher in women than men across all age bands. In women ages 25-39, it was 14.0%, and in women over 40, it was 19.0%. The attributable risk fractions were lowest in those ages 15-24 (2.3% for male patients and 2.9% for female patients).
  
  
  CONCLUSIONS
  The population impact of patients with severe mental illness on violent crime, estimated by calculating the population-attributable risk, varies by gender and age. Overall, the population-attributable risk fraction of patients was 5%, suggesting that patients with severe mental illness commit one in 20 violent crimes.
authors.affiliation: Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford OX3 7JX, UK. seena.fazel@psych.ox.ac.uk
authors.forename: Seena
authors.initials: S
authors.lastname: Fazel
authors.forename: Martin
authors.initials: M
authors.lastname: Grann
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D015331:Cohort Studies; D003415:Crime / Q000706:statistics & numerical data*; D005260:Female; D005555:Forensic Psychiatry / Q000706:statistics & numerical data; D006753:Hospital Records / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis / Q000453:epidemiology* / Q000523:psychology; D010351:Patient Discharge / Q000706:statistics & numerical data; D011618:Psychotic Disorders / Q000453:epidemiology / Q000523:psychology; D012042:Registries / Q000706:statistics & numerical data*; D012307:Risk Factors; D012559:Schizophrenia / Q000453:epidemiology; D012565:Schizophrenic Psychology; D017678:Sex Distribution; D012737:Sex Factors; D013548:Sweden / Q000453:epidemiology; D014754:Violence / Q000706:statistics & numerical data*