Association of IQ scores and school achievement with suicide in a 40-year follow-up of a Swedish cohort

Acta Psychiatr Scand. 2008 Aug;118(2):99-105. doi: 10.1111/j.1600-0447.2008.01171.x. Epub 2008 Mar 10.


Objective: Few studies have investigated the association of childhood IQ and school achievement with suicide. The aim of this study was to investigate the association of childhood IQ with suicide in a cohort of Swedish women and men.

Method: 21 809 subjects born in 1948 and 1953 who completed IQ and school tests at age 13 years have been followed until 2003. Information on paternal education and in-patient care for psychosis was linked using the Swedish personal identification number.

Results: There were 180 suicides amongst subjects with measured IQ. High IQ was associated with reduced suicide risk among men (OR per unit increase in age-adjusted model 0.90, 95% CI 0.83-0.99), while there was no statistical evidence of an association in women (OR 1.04, 95% CI 0.90-1.20). Among men with a history of psychosis, high IQ was associated with an increased risk of suicide.

Conclusion: Low childhood IQ at age 13 years is associated with an increased risk of suicide in men but not in women; however, amongst those with psychosis, low IQ appears to be protective.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Cognition / physiology
  • Cohort Studies
  • Educational Status
  • Fathers / psychology
  • Fathers / statistics & numerical data
  • Female
  • Follow-Up Studies
  • Humans
  • Intelligence / physiology*
  • Intelligence Tests / statistics & numerical data*
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Odds Ratio
  • Psychotic Disorders / epidemiology
  • Psychotic Disorders / psychology
  • Sex Distribution
  • Socioeconomic Factors
  • Suicide / psychology*
  • Suicide / statistics & numerical data*
  • Sweden / epidemiology