A gene called MKP-1 appears to play an important role in the development of depression, and could be a target for a new class of anti-depressants, according to researchers from Yale University. Ronald S. Duman, senior author of the study and professor of psychiatry and pharmacology at Yale, said that the gene could be a primary cause or contributing factor to abnormalities that lead to depression. The exact causes of depression remain a mystery to scientists, and symptoms vary greatly among individuals. Most researchers and clinicians believe that there are many different physiological processes involved in major depressive disorder, which would explain why people respond differently to anti-depressants. While many people respond well to these medications, up to 40 percent of depressed individuals do not respond to medications that are currently available, and these medications can take weeks to months to work. For the study, the researchers performed whole genome scans on tissue samples from 21 deceased people who had been diagnosed with depression. They compared the gene expression levels to those of 18 non-depressed individuals, and found that one gene—called MKP-1—was increased two-fold in the brain tissue of the depressed people. They also found that the gene inactivates a molecular pathway that plays a crucial role in the survival and function of neurons, and this change has been associated with depression and other disorders in previous studies. The researchers also found that when the gene is inactivated in mice, the mice became more resilient to stress. However, when the gene is activated, the mice exhibited symptoms of depression. These findings suggest that MKP-1 could be a target for developing a new class of anti-depressants. Source: Science Daily, Genetic Trigger of Depression Identified: Potential Target for Novel Class of Therapeutic Agents, October 18, 2010