title: Association Between Deliberate Self-harm and Violent Criminality.
abstract: Individuals who self-harm may have an increased risk of aggression toward others, but this association has been insufficiently investigated. More conclusive evidence may affect assessment, treatment interventions, and clinical guidelines.
  
  
  
  To investigate the association between nonfatal self-harm and violent crime.
  
  
  
  This population-based longitudinal cohort study, conducted from January 1, 1997, through December 31, 2013, studied all Swedish citizens born between 1982 and 1998 who were 15 years and older (N = 1 850 252). Individuals who emigrated from Sweden before the age of 15 years (n = 104 051) or immigrated to Sweden after the age of 13 years (ie, <2 years before the beginning of the follow-up; n = 22 009) were excluded. Data analysis was performed from April 21, 2016, to June 4, 2016.
  
  
  
  Receipt of self-harm-associated clinical care.
  
  
  
  Conviction of a violent crime according to the Swedish penal code.
  
  
  
  The study cohort consisted of 1 850 525 individuals (950 382 males and 900 143 females), and the mean (SD) follow-up time was 8.1 (4.7) years (range, 0-17.0 years; minimum age, 15 years; maximum age, 32 years). During a mean follow-up period of 8.1 years, 55 185 individuals (3.0%) received clinical care for self-harm. The crude hazard ratio was 4.9 (95% CI, 4.8-5.0) for violent crime conviction in exposed individuals compared with the unexposed group. Women who self-harm were at particularly high risk for expressing violent behaviors. After adjustment for relevant psychiatric comorbidities and socioeconomic status, an almost doubled hazard of violent offense remained (hazard ratio, 1.8; 95% CI, 1.8-1.9).
  
  
  
  Self-harm is associated with an increased risk of conviction for a violent offense in both sexes. The risk of violence, as well as the risk of suicide and self-harm, should be assessed among offending and self-harming individuals.
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Hanna
authors.initials: H
authors.lastname: Sahlin
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Ralf
authors.initials: R
authors.lastname: Kuja-Halkola
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Johan
authors.initials: J
authors.lastname: Bjureberg
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Paul
authors.initials: P
authors.lastname: Lichtenstein
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden2Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Molero
authors.affiliation: Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Mina
authors.initials: M
authors.lastname: Rydell
authors.affiliation: Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm.
authors.forename: Erik
authors.initials: E
authors.lastname: Hedman
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Runeson
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden4Department of Clinical Sciences, Psychiatry, Umeå University, Umeå, Sweden.
authors.forename: Jussi
authors.initials: J
authors.lastname: Jokinen
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden3Division of Psychology, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm.
authors.forename: Brjánn
authors.initials: B
authors.lastname: Ljótsson
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Clara
authors.initials: C
authors.lastname: Hellner
mesh_terms: D000293:Adolescent; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D003415:Crime / Q000523:psychology* / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D001523:Mental Disorders / Q000453:epidemiology / Q000523:psychology; D016016:Proportional Hazards Models; D012042:Registries; D012306:Risk; D016728:Self-Injurious Behavior / Q000453:epidemiology* / Q000523:psychology*; D012959:Socioeconomic Factors; D013223:Statistics as Topic; D013405:Suicide / Q000523:psychology / Q000706:statistics & numerical data; D013548:Sweden; D014754:Violence / Q000523:psychology* / Q000706:statistics & numerical data*; D055815:Young Adult