Clinicians describe a persistent pattern of inattention and/or hyperactivity-impulsivity that gets in the way of life. In the DSM-5-TR the adult threshold is five symptoms in a domain, rather than the six used for children, because the outward picture often quiets with age while the difficulty does not. ICD-11 (code 6A05) describes the same condition, with inattentive, hyperactive-impulsive, and combined patterns, beginning in childhood and causing impairment.
The three presentations
Predominantly inattentive. Detail slips, tasks stall, conversations fade, organisation collapses, and things go missing. A person can look calm, capable, and “away with it”. This pattern is a common reason adults, and especially women, are missed for years.
Predominantly hyperactive-impulsive. In adults the running and climbing of childhood often becomes an inner restlessness: fidgeting, leaving the seat, talking over people, impatience, decisions made a beat too early.
Combined. Both clusters are present at the level the criteria require. Many adults who eventually seek help recognise themselves here, once the inattentive half is named rather than blamed.
What else the criteria require
- Several symptoms were present before the age of 12.
- Symptoms show up in more than one setting — not only at a hated job, and not only at home.
- There is clear interference with functioning: work, study, relationships, or daily life.
- The picture is not better explained by another condition alone.
That last point is why a questionnaire cannot finish the job. Anxiety, depression, autism, trauma, sleep disorders, substance use, thyroid disease, and the aftermath of head injury can all look similar. They can also sit alongside ADHD. Telling them apart needs a clinician, usually with a developmental history and, where possible, someone who knew the person as a child.
Why adults still arrive late
Many adults built workarounds: a frightening memory for deadlines that are tomorrow, a partner who holds the admin, a job that is novel enough to grip them. The World Federation of ADHD consensus statement (Faraone and colleagues, 2021) is clear that ADHD is a valid disorder with well-described risks, and that it is also treatable. Research reviews commonly place it in the region of 2 to 3 percent of adults. A large share were never assessed as children.
What this screen will not do
This site does not decide a clinical presentation, does not weigh other explanations, and does not recommend treatment. A result is information you can take to a doctor. It is not a diagnosis.