Long-term exposure to the hormone cortisol may leave a lasting mark on the genome and influence how genes that control mood and behavior are expressed, a study led by Johns Hopkins researchers suggests. The finding, published in the September 2010 issue of Endocrinology, could eventually lead to new ways to explain and treat depression, bipolar disorder, and other mental illnesses.
Scientists and physicians have long been interested in the cause of depression, a sometimes debilitating disorder that affects about 16 percent of people at least once over the course of a lifetime. While studies have shown that many other mental illnesses are strongly heritable, studies have shown that the risk of depression is only about 40 percent genetic. Consequently, environmental factors are thought to play a major role in causing this disease.
Read moreChronic Stress May Cause Lasting Genetic Changes