Study reverses thinking on genetic links to stress, depression

A recent study published in PLOS One indicates that only about half of scientific discoveries will be replicated and stand the test of time. So perhaps it shouldn't come as a surprise that new research led by Washington University School of Medicine in St. Louis shows that an influential 2003 study about the interaction of genes, environment and depression may have missed the mark. Since its publication in Science, that original paper has been cited by other researchers more than 4,000 times, and some 100 other studies have been published about links between a serotonin-related gene, stressful life events and depression risk. It indicated that people with a particular variant of the serotonin transporter gene were not as well-equipped to deal with stressful life events and, when encountering significant stress, were more likely to develop depression. Such conclusions were widely accepted, mainly because antidepressant drugs called selective serotonin reuptake inhibitors (SSRIs) help relieve depression for a significant percentage of clinically depressed individuals, so many researchers thought it logical that differences in a gene affecting serotonin might be linked to depression risk. But in this new study, the Washington University researchers looked again at data from the many studies that delved into the issue since the original publication in 2003, analyzing information from more than 40,000 people, and found that the previously reported connection between the serotonin gene, depression and stress wasn't evident. The new results are published April 4 in the journal Molecular Psychiatry.