Diagnosis & Tests

There is no simple test to determine whether you or your child has attention deficit hyperactivity disorder (ADHD). If you think that you or your child may have ADHD, see your GP.

Attention Deficit Hyperactivity Disorder (ADHD)

Diagnosing ADHD

ADHD is normally diagnosed between the ages of three to seven, although in some cases it may not be until much later. It is more commonly diagnosed in boys.

There are several criteria that must be met for a child to be diagnosed with ADHD. Adults are harder to diagnose because there is no definitive set of age-appropriate symptoms.

Visiting your GP

Your GP will ask:

  • About your symptoms and those of your child.
  • When these symptoms started.
  • Where the symptoms occur, for example at home or in school.
  • How the symptoms affect your (or your child’s) quality of life.
  • If there have been any recent changes, for example a death or divorce in the family.
  • If there is a family history of ADHD.
  • Any other problems, or symptoms of different health conditions.


Functional Impairment

Your GP will want to know if these symptoms are causing functional impairment. This means whether they are affecting day-to-day life. For example, a child may have functional impairment if:

  • They are unable to make or keep friends.
  • They are unable to wash or feed themselves.

Assessing Children

If you are a parent whose child may have ADHD, you may be offered parent training or an education programme to teach you to use behavioural techniques to help your child.

Read for more information about how ADHD is treated.

Alternatively, if your child’s symptoms are causing severe functional impairment, your GP will refer your child to another healthcare professional who will be able to diagnose ADHD.

Assessing Adults

For adults with ADHD symptoms, your GP will assess your symptoms and may refer you to a specialist if:

  • You were not diagnosed with ADHD as a child, but
  • Your symptoms began during childhood and have been ongoing since then
  • Your symptoms are not caused by another mental health condition
  • Your symptoms are causing moderate or severe functional impairment; for example, you are underachieving at work or find intimate relationships difficult.

You may also be referred to a specialist if you had ADHD as a child or young person and your symptoms are now causing moderate or severe functional impairment.


If your GP suspects that you or your child has ADHD, they may refer you to a specialist such as:

  • A child or adult psychiatrist (an expert in mental and emotional health).
  • A paediatrician (an expert in children's health).
  • The mental health services for children and young people.


Who you are referred to will depend on your age and what is available in your local area. Your specialist can make an accurate diagnosis after a detailed assessment that may include:

  • A physical examination, which will rule out other possible causes for the symptoms.
  • A series of interviews with you or your child.
  • Interviews or reports from other significant people, such as partners, parents and teachers.

Diagnosis in Children and Teenagers

To be diagnosed with ADHD, your child must also have:

  • Been displaying symptoms continuously for at least six months.
  • Started to show symptoms before the age of seven – although in some cases a diagnosis can still be made if symptoms do not start until after this age.
  • Been showing symptoms in at least two different settings – for example, at home and at school, to rule out the possibility that the behaviour is just a reaction to certain teachers or parental control.
  • Symptoms that make their lives considerably more difficult, on a social, academic or occupational level.
  • Symptoms that are not just part of a developmental disorder or difficult phase, and are not better accounted for by another condition.

Diagnosis in Adults

Diagnosing ADHD in adults is more difficult because there is no definitive list of symptoms that can be applied to an adult who may have the condition.

If your GP refers you to a specialist, they will ask about your present symptoms. However, under current diagnostic guidelines, a diagnosis of adult ADHD cannot be confirmed unless your symptoms have been present from childhood.

To help your specialist decide on your diagnosis, they may ask about your childhood and whether your symptoms were present then. If you find it difficult to remember, or you were not diagnosed with childhood ADHD, your specialist may wish to see your old school records or talk to your parents, teachers or anyone else who knew you well when you were a child.

For an adult to be diagnosed with ADHD, their symptoms should cause a moderate degree of impairment in different areas of their life. Examples of impairment could be:

  • Underachieving at work or in education.
  • Driving dangerously.
  • Difficulty carrying out daily activities, such as shopping.
  • Difficultly making or keeping friends.
  • Difficulty in relationships with partners.

If your problems are recent and did not occur regularly in the past, you are not considered as having adult ADHD.