In recent years medicine has increasingly recognized a connection between mind and body and how the interaction between the two can affect our health. But in its effort to avoid a problematic separation between mind and body, medicine has been led astray. Due to misunderstanding what in philosophy is called mind-body dualism, trained medical doctors end up over-diagnosing conditions as psychosomatic, automatically construing medically unexplained symptoms as psychiatric problems. This is a philosophical error that ends up putting the health of patients at risk, argues Diane O’Leary.