Childhood adversity might lead to DNA changes that increase the risk for psychiatric disorders, U.S. researchers said. Dr. Audrey Tyrka of Butler Hospital, an associate professor at Brown University in Providence, R.I., said multiple studies have established the association between childhood adversity, including parental loss and childhood maltreatment, and risk for psychiatric disorders such as depression and anxiety. \"We need to understand the biology of this effect in order to develop better treatment and prevention programs,\" Tyrka said in a statement. \"Our research group turned to the field of epigenetics to determine how environmental conditions in childhood can influence the biological stress response.\" Epigenetics is the study of changes to the genome that do not alter the DNA sequence, but influence whether genes will be expressed, or \"turned on,\" versus whether they will be silenced, Tyrka said. Researchers looked at 99 healthy adults, some who had a history of parental loss or childhood maltreatment. DNA was extracted using a blood sample, and then analyzed to identify epigenetic changes to the glucocorticoid receptor. The study, published in the journal PLoS ONE, found among adults with a history of childhood adversity -- maltreatment or parental loss -- there had been changes in the way the gene behaved. \"Our results suggest that exposure to stressful experiences during childhood may actually alter the programming of an individual\'s genome,\" Tyrka said. \"This concept may have broad public health implications, because it linked childhood trauma with poor health outcomes.\"