The abbreviation for attention deficit hyperactivity disorder.
See ATTENTION DEFICIT DISORDER (HYPERACTIVITY SYNDROME).
see attention-deficit/hyperactivity disorder.
(ADHD, attention deficit disorder, hyperkinetic disorder) a developmental disorder characterized by grossly excessive levels of activity and a marked impairment of the ability to attend and concentrate. The behaviour may be predominantly hyperactive-impulsive, predominantly inattentive, or combined. It is hypothesized that the majority of patients have a higher than normal number of dopamine transporter complexes, reducing the amount of freely available dopamine in the synaptic cleft. This leads to cognitive problems, including an inability to keep attention, to focus attention, and to perform organizational planning. Learning is impaired as a result, and behaviour can be disruptive and may be defiant or aggressive. ADHD is highly genetic. It is estimated to affect up to 5% of children; the prevalence is lower in adults because the number of dopamine transporter complexes in the brain naturally declines over time. Untreated, many children later develop *conduct disorder or *personality disorders. Treatment usually involves drugs (such as amphetamines and *methylphenidate) and behaviour therapy; the family needs advice and practical help.... attention-deficit/hyperactivity disorder