Researchers at the Medical University of South Carolina have identified a stress-related gene that plays a significant role in driving anhedonia, a loss of interest in activities that are usually rewarding. This finding was published in eLife.
The team noted that many individuals can fully recover after extended periods of stress. Yet some people who experience chronic stress begin to show depressive symptoms over time.
Major depressive disorder often coincides with reduced activity in the frontal lobe of the brain. The NPAS4 gene, which influences this brain region, became the focus of the study. In stressed mice, NPAS4 is activated, which in turn changes the expression of other genes and dampens activity in this critical reward-processing area.
While the mice did not exhibit all features of depression, they did lose interest in activities they once enjoyed. NPAS4 did not appear to drive social avoidance or heightened anxiety in this model.
These findings could steer the development of treatments that target specific depressive symptoms rather than the whole disorder, potentially leading to more precise pharmacological approaches. [Citation: eLife study reported by USC researchers, 2024]