Depression, recognized as the leading cause of disability worldwide, affects nearly one in six people over their lifetimes. Despite decades of research, much remains unknown about the biological mechanisms underlying this debilitating condition. Professor Raz Yirmiya, a pioneering researcher in the field of inflammation and depression from the Department of Psychology at the Hebrew University of Jerusalem, has recently published a comprehensive review in Brain, Behavior, and Immunity , offering new insights that challenge long-held beliefs and open pathways toward personalized treatment .
Traditional theories of depression have focused on neurotransmitters like serotonin and norepinephrine, suggesting that a deficiency in these brain chemicals may lead to depressive symptoms . While widely accepted, these theories have failed to explain why a significant portion of patients do not respond to conventional antidepressants. Over the last 30 years, Professor Yirmiya's research, along with work from others, has pointed to a different culprit: chronic inflammation , both in the body and the brain.
"In many individuals, depression results from inflammatory processes ," explains Professor Yirmiya, who was one of the first researchers to draw connections between immune system dysfunction and depression in the 1990s. In his latest review, he carefully analyzed the 100 most-cited papers in the field, creating what he calls a "panoramic view" of the complex interactions between inflammat.