Association Between Deliberate Self-harm and Violent Criminality

JAMA Psychiatry. 2017 Jun 1;74(6):615-621. doi: 10.1001/jamapsychiatry.2017.0338.

Abstract

Importance: 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.

Objective: To investigate the association between nonfatal self-harm and violent crime.

Design, setting, and participants: 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.

Exposures: Receipt of self-harm-associated clinical care.

Main outcomes and measures: Conviction of a violent crime according to the Swedish penal code.

Results: 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).

Conclusions and relevance: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Age of Onset
  • Child
  • Child, Preschool
  • Cohort Studies
  • Comorbidity
  • Crime / psychology*
  • Crime / statistics & numerical data*
  • Female
  • Humans
  • Incidence
  • Infant
  • Longitudinal Studies
  • Male
  • Mental Disorders / epidemiology
  • Mental Disorders / psychology
  • Proportional Hazards Models
  • Registries
  • Risk
  • Self-Injurious Behavior / epidemiology*
  • Self-Injurious Behavior / psychology*
  • Socioeconomic Factors
  • Statistics as Topic
  • Suicide / psychology
  • Suicide / statistics & numerical data
  • Sweden
  • Violence / psychology*
  • Violence / statistics & numerical data*
  • Young Adult