Research links stress to depression

By Staff Writer

According to new research published in the journal Neuron, complex molecular mechanisms that are associated with chronic stress may help scientists find new treatments for depression.

For the study, Dr. Watanabe, coauthor Dr. Shusaku Uchida and their colleagues surveyed two different mouse strains that showed separate behavioral responses to chronic stress. They looked for genetic mechanisms that are associated with vulnerability in stressful events.

The authors found that vulnerable mice exhibited depression-like behaviors when exposed to chronic mild stress, while resilient mice did not. The vulnerable mice had a lower level of gene expression for glial cell-derived neurotrophic factor (Gdnf), which is important for the regulation of brain plasticity and has been linked to depression.

The reduced level of Gdnf expression was reversed by treatment with antidepressants.

The researchers concluded that people who are exposed to stressful events may not show signs of depression, but some individuals are predisposed to major depression when exposed to psychological stress.

According to research conducted by PBS, major depression affects approximately 15 million American adults or about 8 percent of the U.S. population age 18 and older in a given year.