How ADHD is assessed in children: what to expect
Written by the Brighters team · Clinically reviewed by Kannika Bharath Iyengar, Clinical Lead & Assessment Specialist
6 min read · Published 22 October 2026 · Last reviewed 23 October 2026
Your child can't sit through dinner. The teacher says he is always looking out of the window, or that she blurts out answers and can't wait her turn. Someone suggests, "Get him tested for ADHD." But what does that actually involve? There is no single test for ADHD. It is assessed by putting together what is seen at home, at school and with the child. This guide explains what clinicians look for and what the process usually looks like, so that you know what to expect.
What ADHD is, and what it is not
ADHD (attention-deficit/hyperactivity disorder) is a pattern of inattention, high activity and impulsive behaviour that goes beyond what is expected for a child's age and gets in the way of everyday life. All children are sometimes restless, distracted or impulsive, so having these moments does not mean a child has ADHD. What separates ADHD is how long the pattern lasts, how many places it shows up, and how much it gets in the way.
What clinicians look for
Clinicians use the criteria in the DSM-5-TR, the manual used to diagnose mental health and developmental conditions. In short:
- For children up to age 16: six or more symptoms of inattention, or six or more symptoms of hyperactivity and impulsivity (or both). From age 17, five are needed.
- The symptoms have lasted at least six months and are out of step with what is expected at that age.
- Several symptoms were present before age 12.
- The symptoms show up in two or more settings, such as home, school and with friends.
- They clearly get in the way of school or social life.
- They are not better explained by another condition, such as anxiety or depression.
Your child does not have to be hyperactive to meet these criteria. A child who mostly struggles to focus, finish things and stay organised can have ADHD with very little hyperactivity. These are often the quiet daydreamers who get missed.
Why parents, teachers and your child all matter
The American Academy of Pediatrics guideline says that children aged 4 to 18 who have problems with school or behaviour, together with inattention, hyperactivity or impulsivity, should be evaluated using reports from parents, school staff and others involved in their care, along with information from the child.
This is because ADHD has to show in more than one setting. A teacher sees how your child copes in a classroom, with other children and with demands that do not exist at home. You see what happens at home, over years. Neither view alone is enough, and when the two differ, that difference is useful to the clinician too.
Rating scales and the clinical interview
Clinicians use structured rating scales, so that everyone describes the same behaviours in the same way. On a rating scale, a parent or teacher says how often a child does each thing, such as finding it hard to wait for a turn or often losing things. The Vanderbilt scales are one widely used set, with separate versions for parents and teachers.
The scores show whether the pattern fits the ADHD criteria, but they never decide anything on their own. The clinician also talks with you about your child's development, health, sleep, school and daily life, and spends time with your child.
Checking for other explanations
Attention and behaviour problems have many possible causes. A careful assessment always asks whether something else explains the picture, or exists alongside ADHD. Clinicians think about emotional difficulties like anxiety, other developmental or learning difficulties, and physical factors like poor sleep, hearing or vision. If another condition seems likely, they may suggest a further assessment.
How the ADHD assessment works at Brighters
Brighters' ADHD assessment is for children aged 6 and over. It combines the Vanderbilt parent and teacher rating scales with the INDT-ADHD clinician interview, led by a psychologist over video. All the assessments your child needs take about 90 to 120 minutes in total, and our what to expect page walks through a session.
You fill in your scales beforehand and ask your child's teacher to fill in theirs, so the live time is spent talking rather than on forms. The report describes your child's strengths and support needs in plain language and gives practical recommendations for home and school. Decisions about treatment are for you and your child's doctor.
How to prepare
- Ask your child's teacher whether they can complete a rating scale, and keep recent school reports handy.
- Think of typical examples at home and at school, not just the best or worst days.
- Note when the behaviour began and whether it has changed.
- Mention anything about sleep, health, hearing, vision, or big changes in your child's life.
Frequently asked questions
Can a teacher's report alone show that a child has ADHD?
No. Because ADHD must show in more than one setting, clinicians need both home and school information, along with the child's history and an interview.
What if my child only struggles at school?
The criteria need symptoms in two or more settings. If a child struggles only in class, clinicians look for other reasons, such as learning difficulties, anxiety, or a poor fit with the classroom.
Does my child have to be hyperactive to have ADHD?
No. The criteria can be met through inattention symptoms alone. Many children with ADHD are quiet daydreamers rather than active ones.
At what age can ADHD be assessed?
The American Academy of Pediatrics guideline covers ages 4 to 18. Brighters' assessment is for children aged 6 and over.
This article is general information for parents. It is not medical advice or a diagnosis, and it does not replace an assessment by a qualified professional. If you are worried about your child, speak to your child’s doctor.