Having a lower IQ has been linked in studies with smoking and heart disease, but a new study shows there may also be an association for men between scoring low on IQ tests in early adulthood and suicide attempts.
Researchers examined data on 1.1 million Swedish men who had their IQs tested in early adulthood. In that group were 17,736 men who had been hospitalized at least once for a suicide attempt during a follow-up of about 24 years.
They found a link between lower IQ scores and a higher risk of attempted suicide -- the lower the IQ, the more likely the men were to try to kill themselves. Men in the lowest IQ group were almost nine times as likely to have a suicide attempt as those in the highest group. The association held even after the researchers adjusted for age and socioeconomic status.
Having a lower IQ might put someone at a disadvantage in several ways, according to the study authors: Lower IQ tends to be linked with a lower socioeconomic level, which can bring with it social and financial hardships. Lower IQ is also tied to less healthful habits such as binge drinking. And IQ may also be a factor in how people deal with life's stresses and traumas. Some studies have shown that more intelligent people may deal better with pressure and might be better problem solvers.
"Suicide, either attempted or actual, is a serious problem, particularly amongst young adults, but we have a relatively poor understanding of what leads a person to take such drastic action," said study co-author Elise Whitley of the University of Glasgow, in a news release. "If we can better understand the association between IQ and suicide, this will provide valuable insight into why some people make such a tragic decision. Such knowledge would help inform public health strategies and provide help and support for vulnerable groups."
The study was released this week in the British Medical Journal.