Swedish Study Finds Low IQ Increases Risk for Suicide
Nine times more Swedish men with lower IQs attempt suicide compared to those with higher IQs, according to a recent study. In addition, the risk increases as intelligence decreases.
The researches studied over 1.1 million men in the military in Sweden for up to 24 years, beginning when they were 16 to 25 years old. Military service is required for all young men in Sweden, while the nationalized health services tracks their medical treatment, including hospitalizations for suicide attempts. Young Swedish recruits take an IQ test as part of the standard military induction process.
Among men in the lowest IQ group, one in 22 attempted suicide before the end of the study, compared with one in 200 in the highest IQ group. The average over all IQ groups was one suicide attempt per 60 recruits.
Even after adjusting for known suicide factors like education, socio-economic status, and even being overweight, men with lower IQs attempted suicide 3.5 times more often. Men with psychosis in all IQ groups were equally likely to commit suicide.
The findings represent a cross-section of Swedish society, applying to the young male population in general. However, the results may not apply to women, older men or to people in other countries.
The study, by Finn Rasmussen at the Karolinska Institute in Stockholm, was published online in the British Medical Journal. It was funded by Wellcome Trust in Glasgow.
Many people in accurately assume that “geniuses” or those with higher IQs are neurotic, depressed or suicidal, according to Karestan Koenen, Ph.D. with the Harvard School of Public Health. He cites Ernest Hemingway and Woody Allen as examples, but quickly points out that this perception is untrue. In fact, therapists should consider a patient’s IQ when assessing suicide risk.
Men in the lowest group had IQs of 73 or lower, while the highest group had IQs of 127 or higher. The Swedish IQ test differs from those used in the U.S. because it measures a basic knowledge of chemistry and physics, as well as vocabulary, visualization and logic. Higher scores on the Swedish test may be a more accurate measure of education than of innate ability.
The study did not show that low IQ causes suicide, only that the two are linked in young Swedish men. Researchers theorize that men with lower IQs are less likely to seek help, have fewer coping skills, or are less willing to address the underlying causes of suicidal thoughts. They speculate that the lower IQ may be due to a genetic factor linked to suicide, or to poverty, violence or childhood adversity that also predisposes the men to take their own lives.
By Joni Holderman, [email protected], contributing reporter for Mental Health News.