ADHD - Attention Deficit Hyperactivity Disorder

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Attention Deficit Hyperactivity Disorder, more commonly referred to by the acronym ADHD, is a spectrum condition involving a triad of behaviour difficulties: hyperactivity, impulsivity and inattention. Though there is some evidence of all three characteristics in those with ADHD most people are predominantly hyperactive and impulsive, while others are principally inattentive.

ADHD diagram

The characteristics of ADHD are distributed throughout the population and vary in severity. Only where this causes significant impairment (at least a moderate degree of psychological, social and/or educational or occupational impairment) will they meet the criteria for a diagnosis of ADHD. Diagnosis is usually based on the presence of symptoms before the individual is 7 years old though it may be later before a formal diagnosis is made. Diagnosis can only be made by a health professional such as a paediatrician specialising in behaviour and/or childhood development.

How does ADHD present in children and young people?

Inattention - the following are frequently seen:

Hyperactivity - the following are frequently seen:

Impulsivity- the following are frequently seen:

Sensory Differences

There is growing evidence that many ADHD individuals have differences in the way they process sensory information. For example, ADHD children who struggle with sitting tend to sense less from their vestibular and proprioceptive systems and need frequent little movements to ‘boost the signal’. These children often enjoy and seek very physical games and sports.

ADHD individuals may also have increased sensitivity to sound, sight and touch, which are the main sensory channels for interacting with the world around them. A consequence of this is that they are easily distracted by novel stimulus such as movement. In busy environments like a classroom this may lead to sensory overload for some individuals.

ADHD children may also be more likely to pick their skin, bite nails, chew clothing etc as a way of coping with sensory needs. There is more information on the page about sensory needs.

Working Memory

Poor working memory is associated with ADHD. This can make it hard to hold on to explanations and instructions. ADHD individuals are often easily distracted and this causes them to lose information they are storing in their short term memory. This leads to confusion and failure when doing tasks involving a number of steps. There is more information on our page about working memory. There is some emerging evidence that meditation exercises can improve concentration and focus in learning.

Prevalence and Gender

ADHD is a common behavioural diagnosis with studies varying between 5% to 11% of all children. In terms of gender studies report a ratio of about 6 boys diagnosed for every girl with ADHD. However, many believe that girls are unrepresented in the data due to differences in the presentation of ADHD between the genders. Gender plays an important part in shaping our social, emotional and psychological behaviour. It should therefore not be surprising that most girls with ADHD present differently to boys with ADHD. Diagnostic criteria for ADHD tends to be based on male presentation and symptoms and this may account for the under representation of girls.

Girls also may be more likely to be of the inattentive type of ADHD and therefore be less problematic than the stereotypical idea of a hyperactive boy. Whereas boys tend to externalise their difficulties and get noticed; girls tend to internalise stresses and difficulties and hide them. This may put them at increased risk of developing self-harming behaviours and other mental health issues. Girls can also be much better at masking their difficulties and may for example hide attention difficulties in the classroom by relying on friends for support.

See also ADHD in Girls

Causes of ADHD

ADHD is believed to be largely an inherited condition that runs in families. This may account for about two-thirds of incidences of ADHD. However, genes may be influenced by environmental factors and so the risks of a child developing the condition may be more complex than purely inheriting certain genes from their parents. ADHD also occurs where there is no obvious family history. Certain environmental factors have been associated with ADHD. These include smoking during pregnancy which may double the chances of developing ADHD. Other tetratogens such as alcohol or drug use may also increase risk of developing ADHD or controversially; they may cause conditions such as Fetal Alcohol Spectrum Disorder, which are often incorrectly diagnosed as ADHD. Other enviromental pollutants such as lead are also implicated in being a potential cause of ADHD. Other biological factors include prematurity, low birth weight and bottle feeding.

Apart from the biological influences described above an increased risk of ADHD is associated with a number of socio-economic factors. These include poverty, single parenthood, young mothers, history of anti-social behaviour in fathers, poor maternal education, social care involvement and maternal depression.


Diagnosis in children can be only made by a medical professional qualified in paediatric development. This is usually a specialist consultant doctor. Diagnosis is based on observed behaviours. Questionnaires are often used to collate the observations of parents and any other professionals involved the child such as teachers at the school or nursery. There are internationally agreed criteria for diagnosing ADHD and evidence from observations will be used to determine whether this is the correct diagnosis. Diagnosis can be made at any age though there is an expectation that symptoms have been present from before the age of seven. Because ADHD has a strong genetic link it is not uncommon now for parents to be told that they have ADHD when taking their child for diagnosis.


Parenting a child with ADHD can be very challenging and many parents benefit from parenting training in behaviour management strategies.

Parents may find joining a local parenting support group beneficial as they can share challenges, advice and strategies.

Teachers should make necessary adaptions to their practice to support the individual needs of a student with ADHD. This may include giving them access to fidget toys, sensory cushions, movement breaks to support hyperactivity and using task boards and additional visual scaffolding of tasks to help inattention. Strategies for supporting a student with weak working memory are often effective in supporting those with ADHD.

Medication - The symptoms of ADHD can often be managed by medication. Most are pychostimulants and they can be effective in up to three quarter of children with ADHD. Children on medication generally show improved academic performance and fewer social and behaviour difficulties. However, some children experience side effects such as appetite suppression and sleep difficulties though these are often minimised by use of slow release tablets and consistent use. Sometimes further medication to reduce the impact of side effects is prescribed. For example, melatonin for sleep difficulites.


Many children with ADHD experience literacy difficulties and there is evidence to suggest a genetic link between ADHD and dyslexia. There is also good evidence that ADHD children are more likely to experience dyscalculia.

ADHD is also associated with an increased risk of depression, anxiety, self-harm and suicide.


A presentation slide video is also available

What is ADHD slide presentation

An introductory guide to ADHD and how it presents in children.


ADHD Institute (2016) Aeitiology Available at: (Accessed 16.01.16)
ADHD Institute (2016) Epidemiology Available at: (Accessed 16.01.16)
Blum, K et al (2008) Attention-deficit-hyperactivity disorder and reward deficiency syndrome Neuropsychiatric Disease and Treatment 2008:4(5) 893–917 (Accessed 16.01.16)
CHADD (Children and Adults with Attention-Deficit/Hyperactivity Disorder) (2015) About ADHD Available at: (Accessed 16.01.16)
Germanò, E., Gagliano, A. & Curatolo, P. (2008) Comorbidity of ADHD and Dyslexia Developmental Neuropsychology Vol. 35, Iss. 5, 2010 Available at (Accessed 30.04.16)
Miller, L., Nielsen, D. & Schoen, S. (2012) Attention deficit hyperactivity disorder and sensory modulation disorder: A comparison of behavior and physiology Research in Developmental Disabilities 33 (2012), pp.804-818 Available at (Accessed 16.01.16)
Shimizu, V., Bueno, O. & Miranda, M. (2014) Sensory processing abilities of children with ADHD Braz. J. Phys. Ther. vol.18 no.4 São Carlos July/Aug. 2014 Epub July 25, 2014

You may also be interested in the following pages:


Sensory Needs

Working Memory