A study published today in AJP in Advance, the online advance edition of The American Journal of Psychiatry, the official journal of the American Psychiatric Association, reveals for the first time shape differences in the brains of children with ADHD, which could help pinpoint the specific neural circuits involved in the disorder. Researchers from the Kennedy Krieger Institute in Baltimore, Md. and the Johns Hopkins Center for Imaging Science used a powerful new analysis tool, large deformation diffeomorphic mapping (LDDMM), which allowed them to expand on previous volume studies and examine the precise shape of the basal ganglia, a part of the brain critical for controlling behavior and movement. The study found boys with the disorder showed significant shape differences and decreases in overall volume of the basal ganglia compared to their typically developing peers. However, no shape or volume differences were revealed in girls with ADHD, adding to a body of evidence suggesting sex strongly influences the disorder’s expression.