A Gene Is Found Innocent

A meta-analysis in the Journal of the American Medical Association says that the "addition of the serotonin transporter genotype did not improve the prediction of risk of depression beyond that associated with exposure to negative life events" — contrary to what a 2003 study found. The group of researchers, led by NIMH's Kathleen Ries Merikangas, analyzed data from 14 studies published between 2003 and March 2009 to determine whether people with a certain variant of the serotonin transporter gene interacted with stressful life events to increase the risk of depression. Merikangas tells the Wall Street Journal Health Blog that this gene and environment interaction "is somewhat of an oversimplification of the very complicated pathways that lead to both clinical depression and depression that is a human emotion." Columbia's Myrna Weissman tells the New York Times that the meta-analysis is "an excellent review paper" though she adds that "it ignored extensive evidence from humans and animals linking excessive sensitivity to stress" to the serotonin transporter gene.