Persistent attention-deficit/hyperactivity disorder (ADHD) in children and adolescents may be associated with a gene mutation that encodes a subunit on a brain receptor, findings from a longitudinal Italian study suggest. A 5-year follow-up study of more than 400 children revealed a polymorphism in the N-methyl-D-aspartate (NMDA) receptor 2B subunit gene (Grin2b) that not only predicted persistent ADHD but was also linked to reductions in anterior cingulate volumes in the brain. The findings were presented here at the European Psychiatry Association (EPA) 24th Congress.