Having a short version of a certain gene may make people more susceptible to depression after stressful events, such as losing a job or a loved one. People only have to inherit one copy of the gene, from either parent, to become more vulnerable to depression, the researchers in Britain, New Zealand and the United States found.
Stress events, such as divorce or illness, are well-known triggers for depression--one of the five leading causes of disability in the world. "However, not all people who encounter a stressful life experience succumb to (depression)," the researchers wrote.
They evaluated the 5-HTT, or serotonin transporter gene, because the protein it controls is affected by well-known anti-depression drugs called selective serotonin reuptake inhibitors. Serotonin is a message-carrying chemical linked with mood. The 5-HTT gene, also known as the serotonin transporter gene, controls the recycling of the chemical messenger.