New Link Between Genes, Stress … and Depression

(Ivanhoe Newswire) -- Numerous studies have shown that the brain molecule neuropeptide Y (NPY) helps to restore calm after stressful events. A team of University of Michigan-led researchers has now found that people whose genes predispose them to produce lower levels of NPY are more responsive to negative stimuli in key brain circuits related to emotion – and are therefore less resilient in the face of stress and may be at higher risk for developing a major depressive disorder.

The scientists hope the research will eventually help with early diagnosis and intervention for depression and other psychiatric illnesses, and in the development of therapies that can be tailored to individuals based on their genetic profiles.

"This is what we mean when we talk about 'personalized medicine,' " the study's lead author, Brian Mickey, M.D., Ph.D., an assistant professor in the Department of Psychiatry at the University of Michigan Medical School and researcher at the U-M Molecular and Behavioral Neurosciences Institute was quoted as saying. "These are genetic features that can be measured in any person. We hope they can guide us toward assessing an individual's risk for developing depression and anxiety."

Using three separate approaches, researchers found that individuals with the genotype that produces lower amounts of NPY had measurably stronger brain responses to negative stimuli and psychological responses to physical pain. They were also overrepresented in a population diagnosed with a major depressive disorder.

Using three separate approaches, each with a varying number of research subjects ranging from 58 to 152, U-M researchers and their partners studied the link between NPY gene expression and emotional processing.

Subjects with low-expression NPY genotypes were overrepresented in the group with depression.

"We're not just associating a particular gene with a particular illness," the authors were quoted as saying.  "We're expanding the understanding of the physiology of depression."

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SOURCE: Archives of General Psychiatry, February 7, 2011