The publication of “Psilocybin-Induced Altered States of Consciousness: Tolerability, Assessment, and Prediction” by Erich Studerus reviews the newest research into the psychological and physiological effects of the classic psychedelic psilocybin and its use for consciousness research in healthy human subjects. The book could not be more timely, it coincidences with the new interest into the mechanism of action of psychedelic drugs and their potential value for emotion regulation in affective disorders.