A gene associated with an increased susceptibility to depression and mental illness causes changes in the structure of the brain. American scientists report this in an article published in the journal Biological Psychiatry. The researchers focused on carriers of one of two known variants of the serotonin transporter gene called SERT-1. Previous studies have found that people with a shortened version of this gene are more likely to experience depression and mental disorders. During autopsies of the bodies of 49 deceased carriers of this gene, scientists discovered that the posterior part of the thalamus of the brain, which is the site of localization of negative emotions, was enlarged by 20% and contained 20% more nerve cells, MedNews reports. According to one of the participants in the research project, professor of psychiatry Dwight Herman, scientists also found a decrease in the size of certain parts of the brain in carriers of a shortened version of SERT. The protein, the structure of which is encoded by this gene, promotes the reuptake of serotonin, which is produced by brain cells and takes part in the transmission of nerve impulses between them. Modern antidepressants - serotonin reuptake inhibitors - block this process, which is directly related to sudden changes in activity and mood in mentally unstable people. According to Dwight Herman, about 17% of the US population carry two copies of the short version of SERT, which is associated with an increased tendency to depression. “The brains of people with depression are wired differently, and for treatment to be effective, we must learn to identify these people as early as possible, before the changes become irreversible,” the researcher notes..