Our results underscore the need for greater understanding of how the drugs used to treat ADHD, which increase cortical DA neurotransmission and are typically given in school age children [74], and schizophrenia, which block DA neurotransmission (DRD2) and are often given in adolescence, [75] may alter these normal developmental trajectories. This evidence concerns the gene DRD2 and attention deficit-hyperactivity disorder.