Castellheim A, et al. - Researchers here focused on investigating the role of general anesthetics as a risk factor for possible neurodevelopmental disorders (NDDs) in humans. Analysis of the Swedish databases Child and Adolescent Twins Study in Sweden (CATSS) and National Patient Register (NPR) indicated that exposure to anesthesia was associated with higher scores of Attention-Deficit/Hyperactivity Disorder (ADHD) in monozygotic (MZ) twins discordant for anesthesia, even when adjusting for congenital abnormalities. Finding hereby indicated a slight association of traits of ADHD with anesthesia in a genetically sensitive design.