“There’s a fundamental biological difference between males and females in how they respond to stress at the cellular level, in both mice and people,” John Cirrito, Ph.D., an author of the study and associate professor of neurology, said in a statement. “We don’t think that stress is the sole factor driving the sex difference in Alzheimer’s disease. There are many other differences between men and women—in hormones, lifestyle, [and] other diseases they have—that undoubtedly contribute in some way. But that stress is driving one aspect of this sex difference I think is very likely.”