ADHD · attention-deficit/hyperactivity disorder
A neurodevelopmental condition defined by a persistent pattern of inattention and/or hyperactivity-impulsivity that starts in childhood and impairs daily functioning. It is among the most heritable psychiatric conditions and among the most responsive to medication.
Diagnosis
At least 6 symptoms of inattention or of hyperactivity-impulsivity (5 from age 17), lasting 6+ months, several present before age 12, appearing in two or more settings, and causing real impairment. Presentations: predominantly inattentive, predominantly hyperactive-impulsive, or combined.APA, DSM-5-TR (2022)
How common
About 5–7% of children worldwide, with similar rates across regions once diagnostic methods are matched. Roughly 2.5% of adults have persistent ADHD; about 6.8% have symptomatic adult ADHD regardless of childhood onset.Polanczyk et al., Am J Psychiatry 2007 · Thomas et al., Pediatrics 2015 · Song et al., J Glob Health 2021
Causes
Twin studies put heritability near 74%, spread across many common gene variants of small effect. Environmental contributors include very preterm birth, low birth weight and prenatal exposures. Poor parenting and sugar are not supported causes.Faraone & Larsson, Mol Psychiatry 2019 · Demontis et al., Nat Genet 2019
Course
Symptoms usually fluctuate rather than simply fade. In a long follow-up of children with ADHD, about 9% showed sustained recovery into adulthood; most cycled between periods of remission and recurrence.Sibley et al., Am J Psychiatry 2022
Treatment
Stimulants have the strongest short-term evidence: methylphenidate is the first choice for children and adolescents, amphetamines for adults. Non-stimulants (atomoxetine, guanfacine, viloxazine) work less strongly. Behavioral parent training is first-line for preschoolers.Cortese et al., Lancet Psychiatry 2018 · AAP guideline, Pediatrics 2019
Risks
ADHD roughly doubles mortality risk, driven mostly by accidents. Within the same people, periods on medication coincide with fewer injuries, crashes and criminal convictions.Dalsgaard et al., Lancet 2015 · Lichtenstein et al., NEJM 2012 · Faraone et al., World Federation consensus 2021