The authoritative medical journal The Lancet published in October 2015 the answer to a question that has been on the minds of people all over the world: Does anesthesia affect the mental development of infants and children? If so, which is better: general anesthesia or local anesthesia? This multi-country, multi-center study from 28 hospitals in 7 countries around the world answered this question well. In this international evaluator-blinded, randomized, controlled, equivalence trial, researchers enrolled infants born at more than 26 gestational weeks and less than 60 gestational weeks of gestation.