Gene More Than Doubles Risk of Depression Following Life Stresses
Among people who suffered multiple stressful life events over 5 years, 43 percent with one version of a gene developed depression , compared to only 17 percent with another version of the gene, say researchers funded, in part, by the National Institute of Mental Health (NIMH). Those with the "short", or stress-sensitive version of the serotonin transporter gene were also at higher risk for depression if they had been abused as children. Yet, no matter how many stressful life events they endured, people with the "long", or protective version, experienced no more depression than people who were totally spared from stressful life events. The short variant appears to confer vulnerability to stresses, such as loss of a job, breaking-up with a partner, death of a loved one, or a prolonged illness, report Drs. Avshalom Caspi, Terrie Moffitt, University of Wisconsin and King's College London, and colleagues, in the July 18, 2003 Science.
The serotonin transporter gene codes for the protein in neurons, brain cells, that recycles the chemical messenger after it's been secreted into the synapse, the gulf between cells. Since the most widely prescribed class of antidepressants act by blocking this transporter protein, the gene has been a prime suspect in mood and anxiety disorders. Yet, its link to depression eluded detection in eight previous studies.