In the largest study of its kind researchers have found a link between IQ scores and attempted suicide in men. The study was published this week in the British Medical Journal.

The team analyzed medical records of over one million men dating back nearly a quarter century. Of the one million, nearly 18,000 were admitted at least once for attempted suicide. After adjusting for age and socioeconomic status the scientists found that men with low IQ were increasingly more likely to be suicidal than those with higher IQ scores.

Researchers suggest that the association of an unhealthy lifestyle (that is, binge drinking) with lower IQ may influence suicidal ideation. But they also point to other studies that link lower IQ with poor problem-solving ability and this in turn can impact one’s resilience to stress in crisis situations. Another factor may be exposure to violence during childhood. Violence, either experienced directly or merely witnessed, has been shown to have a negative impact on IQ, as well as future suicide risk.

One caveat: This study is based on medical records of Swedish men between 16 and 57 years, so the results cannot be attributed to other cultures, women or even other age groups.

—Christie Nicholson