Alice Park reports on a gene that may prove to trigger depression in some people, for TIME:
As powerful as genes are in exposing clues to diseases, not even the most passionate geneticist believes that complex conditions such as depression can be reduced to a tell-tale string of DNA.
But a new study confirms earlier evidence that a particular gene, involved in ferrying a brain chemical critical to mood known as serotonin, may play a role in triggering the mental disorder in some people.
Researchers led by Dr. Srijan Sen, a professor of psychiatry at University of Michigan, report in the Archives of General Psychiatry that individuals with a particular form of the serotonin transporter gene were more vulnerable to developing depression when faced with stressful life events such as having a serious medical illness or being a victim of childhood abuse. The form of the gene that these individuals inherit prevents the mood-regulating serotonin from being re-absorbed by nerve cells in the brain. Having such a low-functioning version of the transporter starting early in life appears to set these individuals up for developing depression later on, although the exact relationship between this gene, stress, and depression isn’t clear yet.
Sen’s results confirm those of a ground-breaking study in 2003, in which scientists for the first time confirmed the link between genes and environment in depression…
[continues at TIME]