Gene Variant Plus Stress Increase Depression Risk

A study has found that among people who experience stressful events over five years, 43% of those with a short version of the serotonin transporter gene develop depression, compared to only 17% of those with a long version of the gene. The findings were reported in the July 18, 2003, issue of Science.

Researchers followed 847 Caucasian New Zealanders, born in the early 1970s, from birth into adulthood. They found that 17% carried two copies of the stress-sensitive short version, 31% carried two copies of the protective long version, and 51% carried one copy of each version. After charting stressful life events from ages 21-26, such as homelessness, disabling injuries, debt, relationship problems, and abuse, they found that 17% of participants had a diagnosis of a major depression in the past year, and 3% had either attempted or thought about suicide. Carriers of the short version represented only 10% of the participants. Such events failed to predict a diagnosis of depression among those with two copies of the long variant.

Since the most widely prescribed class of antidepressants act by blocking the serotonin transporter gene, it has been a prime suspect in mood and anxiety disorders. However, eight previous studies did not detect its link to depression.

"We found the connection only because we looked at the study members' stress history,” noted Dr. Terrie Moffitt, of King's College London (UK), who conducted the research along with colleagues from King's College and the University of Wisconsin (Madison, USA).





Related Links:
King's College London
U. of Wisconsin