The Skeptics' Guide to the Universe: How to Know What's Really Real in a World Increasingly Full of Fake

by Steven Novella

Those who deny the existence of mental illness play similar semantic games. They narrowly define illness as pathological disease, meaning that there has to be something objectively abnormal about cells, tissues, or organs. This description does apply to some diseases, but not all: There are disorders that are defined by the way some organ or system is functioning, but in the absence of clear pathology. Migraine headaches, for example, are a clear disorder without any diagnosable pathology. There are many brain disorders, because brain function depends upon more than just the health of brain cells. Healthy brain cells may still be organized and networked in such a way that their function is disordered. The brain is the organ of mood, thoughts, and behavior. Disordered brain function may therefore lead to a mood disorder or thought disorder. We call such entities mental illness.