LONDON, Ontario, Oct. 28 (UPI) -- Canadian and Hungarian scientists say they've discovered DNA from suicide victims who suffered major depression shows an important chemical modification.
Dr. Michael Poulter of the University of Western Ontario led a team of researchers in comparing brain tissue from a group of people who suffered a major depressive disorder and committed suicide, with the brain tissue of people who had died from heart attacks and other causes.
The researchers said they found an increased rate of DNA methylation in the brains of suicide victims. Methylation is a chemical that inhibits DNA's functioning. The scientists said they determined the rate of DNA methylation in the brain tissue of suicide victims was nearly 10 times that of the control group.
The research team also found methylation inhibited a gene controlling the development of a neurotransmitter receptor with a major role in behavioral regulation.
Scientists say the findings suggest genetic and environmental factors might interact to produce specific and long-lasting modifications in brain circuits.
The study that included scientists from Carleton University, the University of Ottawa and McGill University in Canada, along with researchers at Semmelweis University in Hungary, appears in the journal Biological Psychiatry.
