Our understanding of schizophrenia has increased greatly in recent years, as studies of large groups of people have identified a multitude of genetic variants that increase a person’s risk of the disease. But each of those individual risk factors accounts for “only a very minor amount of the overall risk,” said Alex Nord, a professor of neurobiology, physiology and behavior in the College of Biological Sciences; psychiatry and behavioral sciences; and a core faculty member at the Center for Neuroscience.