ORIGINAL ARTICLE — Science Daily reports on a study published in the October 15 issue of Biological Psychiatry, “compared the brain tissues of those who had major depressive disorder and committed suicide to those from a control group who died suddenly, from heart attacks and other causes.”
[The researchers] found the genome in people who have committed suicide as a result of major depression was being chemically modified by a process that is normally involved in regulating cell development. As [Dr. Michael Poulter, one of the researchers] explains, “We have about 40,000 genes in every cell and the only reason a skin cell becomes a skin cell as opposed to a heart cell is because only a fraction of the genes are being expressed, and the other genes not being expressed are shut down by this genetic process of DNA methylation.” The rate of methylation in the suicide brains was found to be nearly ten times that of the control group, and the gene being shut down was a neurotransmitter receptor that plays a major role in regulating behavior.
John H. Krystal, M.D., Editor of Biological Psychiatry and affiliated with both Yale University School of Medicine and the VA Connecticut Healthcare System, comments, “This is exciting new evidence that genetic and environmental factors may interact to produce specific and long-lasting modifications in brain circuits. Further, these modifications may shape the course of one’s life in extremely important ways, including increasing the risk for major depressive disorder and perhaps suicide.”