Large-Scale Swedish Study Reveals Female Relatives’ Suicidal History Significantly Impacts Suicide Risk for Women Beyond Genetic Factors

A Swedish study found that sisters and mother-daughter pairs share a unique suicide attempt risk that cannot be explained by genetic factors alone.

By: AXL Media

Published: Mar 12, 2026, 11:25 AM EDT

Source: Information for this report was sourced from BMJ Group

The Complexity of Sex Differences in Suicidal Behavior

New research drawing on decades of Swedish population data has shed light on the intricate interplay between genetics and environment in suicidal behavior. While it is well-documented that men die by suicide more frequently than women, women attempt suicide approximately twice as often as their male counterparts. This study, which tracked over three million individuals born between 1963 and 1998, aimed to determine if these sex-specific patterns were driven by biology or social surroundings. The findings suggest that while the "blueprints" for risk are partially inherited, the shared experiences within a family—particularly among women—are powerful drivers of suicidal intent.

Familial Clustering and the Power of Same-Sex Influence

The researchers identified a distinct pattern of "familial clustering," where the risk of a suicide attempt was significantly higher among relatives of those who had previously attempted to take their own lives. This clustering was most pronounced among first-degree relatives and notably stronger in same-sex pairs. For women, the presence of a mother or sister who had attempted suicide increased their own risk by nearly four times. This indicates that the suicidal intentions of female first-degree relatives may exert a unique influence on women, suggesting that social modeling or shared sex-specific life stressors within the home are major contributing factors.

Genetic Heritability Versus Environmental Impact

To isolate the impact of nature versus nurture, the team analyzed over two million sibling and half-sibling pairs. The results confirmed that approximately 42% of the risk for suicide attempts is heritable, a figure that remained consistent across both men and women. However, because this genetic risk did not differ between the sexes, it cannot account for why women attempt suicide at higher rates. Instead, a small but statistically significant portion of the risk was attributed to shared environmental factors. This reinforces the theory that non-genetic elements—such as neurobiological, hormonal, and environmental interactions—underlie the specific vulnerabilities observed in women.