Age-specific suicide mortality following non-fatal self-harm: national cohort study in Sweden

Psychol Med. 2015 Jun;45(8):1699-707. doi: 10.1017/S0033291714002827. Epub 2014 Nov 26.


Background: Possible age-related differences in risk of completed suicide following non-fatal self-harm remain unexplored. We examined associations between self-harm and completed suicide across age groups of self-harming patients, and whether these associations varied by violent index method, presence of mental disorder, and repeated self-harm.

Method: The design was a cohort study with linked national registers in Sweden. The study population comprised individuals aged ⩾10 years hospitalized during 1990-1999 due to non-fatal self-harm (n = 53 843; 58% females) who were followed for 9-19 years. We computed hazard ratios (HRs) across age groups (age at index self-harm episode), with time to completed suicide as outcome.

Results: The 1-year HR for suicide among younger males (10-19 years) was 14.6 [95% confidence interval (CI) 4.1-51.9] for violent method and 8.4 (95% CI 1.8-40.0) for mental disorder. By contrast, none of the three potential risk factors increased the 1-year risks in the youngest females. Among patients aged ⩾20 years, the 1-year HR for violent method was 4.6 (95% CI 3.8-5.4) for males and 10.4 (95% CI 8.3-13.0) for females. HRs for repeated self-harm during years 2-9 of follow-up were higher in 10- to 19-year-olds (males: HR 4.0, 95% CI 2.0-7.8; females: HR 3.7, 95% CI 2.1-6.5). The ⩾20 years age groups had higher HRs than the youngest, particularly for females and especially within 1 year.

Conclusions: Violent method and mental disorder increase the 1-year suicide risk in young male self-harm patients. Further, violent method increases suicide risk within 1 year in all age and gender groups except the youngest females. Repeated self-harm may increase the long-term risk more in young patients. These aspects should be accounted for in clinical suicide risk assessment.

Keywords: risk factors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Age Distribution
  • Child
  • Cohort Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Incidence
  • Male
  • Risk Assessment
  • Risk Factors
  • Self-Injurious Behavior / epidemiology*
  • Sex Distribution
  • Suicide / statistics & numerical data*
  • Sweden / epidemiology
  • Young Adult