Scientists at the Medical University of South Carolina have found that a stress-regulating gene plays an important role in depression causing anhedonia, a loss of interest in normally rewarding or enjoyable activities. Research published eLife.
Scientists noted that many people can fully recover after prolonged stress. However, some people who experience repetitive stress develop depressive symptoms.
People with major depressive disorder often experience decreased brain activity in the frontal lobe of the brain. Scientists focused on the NPAS4 gene, as it is involved in the functioning of this part of the brain. Biologists have found that exposure to stress in mice activates NPAS4. In response, it alters the activity of other genes and reduces the functioning of this important reward-related area of the brain.
The mice did not develop all the symptoms of depression, but only lost interest in previously enjoyable activities. NPAS4 was not involved in social avoidance or anxiety behavior.
The scientists’ discovery will help develop drugs that target specific symptoms of depression.