There can be little question that we need better treatments for mental disorders. The recent Global Burden of Disease Study1 demonstrates how neuropsychiatric disorders are a leading source of medical disability in the United States, increasing since 1990 despite a concomitant increase in pharmacologic treatments.2 Although there have been many commercially successful medications for anxiety, depression, and psychosis, few compounds have shown truly new mechanisms of action, and even fewer represent true breakthroughs in efficacy.3 For many of our most serious clinical challenges, such as anorexia nervosa, posttraumatic stress disorder, the core symptoms of autism, and the cognitive deficits of schizophrenia, to name a few, we lack effective medications altogether.