From the time anorexia nervosa was described medically in 1873 experts have assumed patients chose to restrict food because of psychological problems. Now neuroscience research reveals that we have fundamentally misunderstood AN, attributing to choice, psychological issues and character flaws, behaviors and attitudes that are actually caused by primitive nonconscious biological mechanisms triggered by serious weight loss in those with genetic vulnerability. Patients protesting, “I would eat if I could but I can’t” finally convinced the authors of the Diagnostic and Statistical Manual of Mental Disorders-5 (DSM-5) to remove the verb “refusal [to eat]” from the latest version. In other words, anorexia nervosa is due neither to “nervosa” (psychopathology) nor conscious choice, but to dozens of evolved biological changes that make them unable to eat normally.
In subsequent posts I will describe in more detail how and why these biological changes evolved.