Understanding ADHD

ADHD (Attention-Deficit/Hyperactivity Disorder) is a neurodevelopmental condition that affects how the brain manages attention, impulse control and activity levels. It isn’t a character flaw or something people simply grow out of – though it often looks different at 35 than it did at 8.

Clinically, ADHD has three presentations: predominantly inattentive (trouble focusing, organising, finishing tasks), predominantly hyperactive-impulsive (restlessness, impulsive decisions, interrupting), and combined, where both are present. UK diagnosis follows the NICE NG87 guideline, which requires symptoms to have been present since childhood, to show up in more than one setting, and to cause real, ongoing impairment – not just occasional distraction.

How common is it? More common than most people assume. In the NHS’s 2023/4 Adult Psychiatric Morbidity Survey, 13.9% of adults in England screened positive for ADHD traits on the same ASRS-6 screen used on this site – around 6.5 million people – though the survey itself is clear that screening positive isn’t the same as having a diagnosis, and that true prevalence is considerably lower. Screening rates were highest among 16–24 year-olds and higher among women than men.

Why so many adults are only finding out now: ADHD research and diagnostic practice have moved on substantially, and presentations without obvious hyperactivity — especially in women – were, for years, simply less likely to be recognised. Many people taking this screening are doing so after recognising the same patterns in themselves that led to someone else’s diagnosis.

What this page isn’t: a diagnosis, or a substitute for one. It’s background, so that if your free screening result suggests ADHD is worth exploring, you understand what that actually means before the next step.