Signs of ADHD and how diagnosis works
6 min read · Last reviewed Wed Jul 08 2026 00:00:00 GMT+0000 (Coordinated Universal Time)
Signs by age
ADHD signs shift as children grow, which is part of why diagnosis can take time.
Pre-school (3-5 years): constant motion, difficulty with quiet activities, frequent tantrums relative to peers, impulsive behaviour around hazards.
Primary school (5-11 years): trouble staying seated, difficulty finishing schoolwork, frequent careless mistakes, blurting out answers, losing belongings, struggling with multi-step instructions.
Secondary school and beyond: less visible hyperactivity (more often internal restlessness), disorganisation with deadlines and belongings, procrastination, difficulty regulating emotions, and for some, anxiety or low mood that has built up from years of struggling without support.
What clinicians look for
Under UK guidance (NICE NG87), a diagnosis generally requires:
- Symptoms present in more than one setting (e.g. both home and school)
- Symptoms present before age 12
- Symptoms causing real difficulty with daily functioning — not just a parent's or teacher's preference for calmer behaviour
- Symptoms not better explained by another condition
What the diagnosis pathway actually looks like
- Start with your GP. They can refer to a community paediatrician or CAMHS (Child and Adolescent Mental Health Services).
- Information gathering. Expect questionnaires for parents and teachers (e.g. Conners or SNAP-IV scales), covering behaviour across settings.
- Specialist assessment. A paediatrician or psychiatrist reviews the history, may observe or interview your child, and rules out other explanations (sleep problems, anxiety, hearing issues, learning difficulties).
- Outcome. This might be a diagnosis, a recommendation for further assessment (e.g. for autism, which frequently co-occurs), or a "not at this time" with suggested strategies to try first.
Be prepared for a wait. NHS waiting times for ADHD assessment vary hugely by area and can run from several months to over a year. Many families use supportive strategies at home and at school while waiting — you don't need a diagnosis to start.
What to bring to an appointment
- Specific, dated examples rather than general impressions
- School reports or teacher comments, if available
- A note of what you've already tried and what happened
When to talk to your clinician
If you're unsure whether to pursue assessment, it's reasonable to ask your GP for their view based on what you've already observed — you don't need to be certain before asking the question.