Abstract
Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common childhood-onset neurodevelopmental disorders, characterized by three core symptom clusters: inattention, hyperactivity, and impulsivity, which impair cognitive, academic, behavioral, emotional, and social functioning. Prevalence ranges from 9–15% among school-age children, with a male-to-female ratio of 4:1 for the predominantly hyperactive type and 2:1 for the predominantly inattentive type; in Vietnam, reported rates range from 2.68% to 4%. ADHD frequently co-occurs with oppositional defiant disorder, conduct disorder, anxiety, depression, learning disorders, developmental coordination disorder, autism spectrum disorder, and sleep disorders. The pathogenesis remains incompletely understood but involves genetic dysregulation of catecholamine metabolism, with heritability studies showing up to 92% concordance in monozygotic twins; environmental factors play a secondary role. Diagnosis follows DSM-5 criteria, requiring symptoms present before age 12, across multiple settings, for at least 6 months, causing functional impairment beyond developmental norms. First-line pharmacological treatment includes stimulants (methylphenidate, dextroamphetamine) and atomoxetine, with antidepressants and clonidine as second- and third-line options; behavioral and educational interventions are essential adjuncts. Prognosis shows that 40–70% of affected children continue to have symptoms into adolescence, and about 50% into adulthood, with increased long-term risk of antisocial personality disorder, substance use, depression, and anxiety.
