Scientists have tirelessly searched through the genetic makeup of people with metal illnesses trying to find a common variation(s) that could account for conditions such as schizophrenia and bipolar disorder. However this has been inconclusive so researchers have turned to epigenetics, the study of how experience and environment effect the expression of certain genes. Epigenetic marks regulate when and how much protein is made with out actually altering the DNA itself. It is believed that these “marks” can affect behavior, and thus may interfere with metal health. This idea was tested in a study with rats. Researchers proved that affectionate mothering alters the expression of genes, allowing them to dampen their physiological response to stress, which was then passed on to the next generation. This is thought to be similar in humans and these markers develop as an animal adapts to its environment. Epigenetic research led scientists to prove that offspring of parents who experienced famine are at a higher risk for developing schizophrenia. Additionally, some people who have autism, epigenetic markers had silenced the gene which helps produce the hormone oxytocin which helps the brain’s social circuit. And therefore a brain that lacks this hormone would most likely struggle in social situations. Thomas Lehner of genomics research at the National Institute of Mental Health says that studies and research have shown that epigenetic modifications impact behavior and he also believes that these effects can be reversed. By studying genes at the “epi” level, researchers are hoping to find patterns that were hidden at the gene level. Finding and targeting these patterns can lead to more effective treatment of and management of certain mental illnesses. There are many projects and studies at some of the most prestigious institutes, such as Tufts and Johns Hopkins, that are focused on the study of things at the epigenetic level.