ADHD

Attention-deficit/hyperactivity disorder: the three presentations, what brain research shows about attention and reward, why it often continues into adulthood, common myths, and how stimulant medication and other treatments help.

What it is

Attention-deficit/hyperactivity disorder (ADHD) is diagnosed when persistent patterns of inattention and/or hyperactivity-impulsivity, beginning in childhood, impair functioning in more than one setting. There are three presentations: predominantly inattentive (difficulty sustaining attention, disorganisation, forgetfulness, losing things), predominantly hyperactive-impulsive (fidgeting, restlessness, interrupting, acting without thinking) and combined. Worldwide estimates suggest roughly 5% of children and around 2.5% of adults meet criteria. Boys are diagnosed more often; girls more often have the inattentive presentation and may be missed.

Not just childhood

ADHD often continues into adulthood, though hyperactivity tends to become inner restlessness. Adults may struggle with organisation, time management, procrastination and emotional regulation. Many people are first diagnosed as adults.

The brain

ADHD is highly heritable (around 70–80% in twin studies). Brain research shows group-level differences rather than a diagnostic marker: altered functioning of fronto-striatal networks supporting attention, inhibition and working memory; differences in reward processing, with stronger preference for immediate rewards; and altered regulation of the default mode network, which may intrude during tasks. A 2007 study led by Philip Shaw found that cortical thickness peaked about three years later on average in children with ADHD, suggesting delayed maturation in some regions. Dopamine and noradrenaline signalling are involved.

Myths

ADHD is not caused by sugar, bad parenting or too much screen time (though environments can make symptoms better or worse). It isn't a lack of intelligence or effort. People with ADHD can often hyperfocus on things they find interesting — the difficulty is in regulating attention, not having none.

Treatment

Stimulant medications — methylphenidate and amphetamines — increase dopamine and noradrenaline signalling and are among the most effective treatments in psychiatry for reducing core symptoms in many people. Non-stimulants (such as atomoxetine and guanfacine) are alternatives. Behavioural parent training is recommended for young children; CBT, coaching and practical strategies help adults. School and workplace accommodations — clear structure, breaks, reminders — also matter.