Attention deficit hyperactivity disorder (ADHD) is characterized by inattention, hyperactivity, and impulsivity. Approximately 50% to 70% of children who had ADHD continue to meet its criteria in adolescence, but the problems stemming from adolescent ADHD can be more serious—including an increased risk of substance use, delinquency, academic failure, serious social impairment, and legal problems. Problems in school more than double when students with ADHD move from elementary school to middle and high school.