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. The findings were published Feb. 7 in the Archives of General Psychiatry.
“This is what we mean when we talk about ‘personalized medicine,’ ” says 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. “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.”
The findings also help fill in new areas on the genetic “map” of depression, says the study’s senior author Jon-Kar Zubieta, M.D., Ph.D., a professor of psychiatry and radiology and research professor at the Molecular and Behavioral Neurosciences Institute.
“We’ve identified a biomarker – in this case genetic variation – that is linked with increased risk of major depression,” Zubieta says. “This appears to be another mechanism, independent of previous targets in depression research, such as serotonin, dopamine and norepinephrine.”
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.
Source: University of Michigan Health System