“Our study suggests that if people have a single genetic risk factor alone or a traumatic environment in very early childhood alone, they may not develop mental disorders like schizophrenia,” says Guo-li Ming, M.D., Ph.D., professor of neurology and member of the Institute for Cell Engineering at the Johns Hopkins University School of Medicine.

“But the findings also suggest that someone who carries the genetic risk factor and experiences certain kinds of stress early in life may be more likely to develop the disease.”