Are you a Health Professional? Jump over to the doctors only platform. Click Here

Attention deficit hyperactivity disorder in children (child ADHD)

Print Friendly, PDF & Email

What is Attention Deficit Hyperactivity Disorder in Children (Child ADHD)

ADHDAttention deficit hyperactivity disorder (ADHD) is a behavioural syndrome related to abnormal brain functioning. ADHD is characterised by symptoms such as impulsivity, hyperactivity and/or inattention. While these symptoms are experienced by all people from time to time, they are severe and persistent in those with ADHD, and interfere with an individual’s normal functioning.

Children who suffer from ADHD often have difficulty functioning at school and in other social environments.

Caring for children with the condition can be disruptive to family life and often causes considerable stress for parents, siblings and others who live with them.

ADHD is most commonly diagnosed in children when they begin school.

Statistics on Attention Deficit Hyperactivity Disorder in Children (Child ADHD)

 Estimates of the percentage of children and adolescent who have ADHD 1.7% to 17.8%; however, most estimates lie between 5–10%. A recent study estimated that the global prevalence of ADHD is 5.3%. Boys are significantly more likely to be diagnosed with ADHD than girls – at least four out of every five cases of ADHD are diagnosed in boys. The incidence in different communities (e.g. Australia vs. United States) is thought to vary, however the variation might also be because different methods are used to diagnose ADHD.

Standard criteria outlined in the Diagnostic and Statistical Manual of Mental Disorders are now used to diagnose ADHD throughout Australia.

Recent research using these criteria revealed that almost 9% of American children have ADHD. However, less than half had been diagnosed by a health professional and less than a third were receiving appropriate treatment. Thus there are likely many undiagnosed cases of ADHD in the North American community.

In Australia, the National Survey of Mental Health and Wellbeing reported that 11% of children and adolescents fulfilled the criteria for ADHD. On a national basis, 0.5% of 4–17 year olds were prescribed stimulant medications to treat the condition between June 2006 and May 2007. The proportion of children prescribed stimulants varied between states (e.g. in NSW, 1.5% of 4–17 year olds were prescribed stimulants in the period). Similar to other countries, the vast majority of diagnosed ADHD cases in Australia are boys. In the 2006–07 period, 15,466 males were prescribed stimulant medication, compared to 3872 females, a ratio of about 4:1.

There has been an increase in the reported number of children with ADHD in the past decade, and the prescription of stimulant medication to treat the condition has also increased. For example, in Australia from 1984 to 2000, the number of scripts issued for stimulant medications to treat ADHD increased by an average of 31% per year. However the proportion of children prescribed stimulant medication remains below the proportion of children with ADHD and this apparent increase in the rate of reported cases of ADHD is due to increased awareness amongst health professionals and the public on the condition.

Risk Factors for Attention Deficit Hyperactivity Disorder in Children (Child ADHD)

The exact cause of ADHD is unknown, but several factors are associated with ADHD development.

Genetic factors

ADHDGenetic influence is possible, as ADHD is known to run in families. Family studies show that 10-35% of immediate family members of children with ADHD are likely to have the disorder, and the risk to siblings is 35%. Identical twins are more likely to both be affected than non-identical twins. It has been found that a number of genes for the substances which transport messages from the brain do not work properly in individuals with ADHD, and these genes are inherited genetically.

Not all individuals with the genetic predisposition to ADHD will develop the disorder. Environmental factors also influence who does and who does not develop ADHD.

Environmental and family factors

Exposure during pregnancy with cigarettes, alcohol and other substances (e.g. cocaine) may increase the risk of ADHD. Maternal stress during pregnancy also increases the risk of ADHD in children. Preschool children with higher levels of lead in their bodies are also at higher risk of developing ADHD.

Chaotic parenting may increase the risk of developing ADHD, but the relationship between ADHD and parenting may result from both negative aspects of the child influencing the parents’ behaviour, and of the parents influencing the child’s behaviour.The children of parents who are more demanding, aversive, negative, controlling, intrusive, disapproving, power assertive and less rewarding are at greater risk of ADHD.

Acquired brain injury can also increase the risk of ADHD.

Children from lower socioeconomic classes have higher rates of ADHD, and are more likely to be undertreated for their disorder. The increased rates of ADHD in poorer children is thought to relate to greater exposure to factors which increase the risk of ADHD (e.g. tobacco exposure during pregnancy, childhood lead exposure, complications of pregnancy and delivery). In addition, the negative impact of ADHD on social, academic and career outcomes may cause ADHD sufferers to cluster in lower socioeconomic groups.

Congenital factors

Studies have shown a possible link between the use of cigarettes and alcohol during pregnancy, and the risk of ADHD in offspring. Maternal substance abuse (e.g. cocaine, nicotine) may also cause ADHD-like symptoms.

Pregnancy and delivery complications (e.g. prematurity) have also been linked with increased rates of ADHD.

Brain structure factors

Some studies suggest that ADHD is caused by a compromised structure in areas of the brain that relate to inhibition and attention. There is also evidence that the brain size of children with ADHD is slightly smaller than in children without ADHD.

Neurophysiological factors

ADHD symptoms may be a result of cognitive deregulation, where the child’s behaviour results from insufficient forethought, planning and control, and leads to impulsive responses and higher error rates.

Children with ADHD may also respond more impulsively in order to complete tasks more quickly, and therefore avoid delays.

In a situation where the child is not in control (e.g. in a classroom where he/she is expected to behave in a certain way), the child could achieve control by either daydreaming (inattention) or by fidgeting (hyperactivity).

Dietary factors

ADHD has been linked to the intake of food additives, food colourings and refined sugar. These substances have been shown to exacerbate ADHD symptoms. Diets that exclude foods containing substances which worsen behavioural problems, such as the Australian-developed FAILSAFE diet, have been used as treatments for ADHD since the 1980s. While the association between diet and ADHD symptoms is clear, dietary interventions alone are not enough to treat the symptoms of ADHD, and are best used in combination with pharmacological and educational interventions.

Children with iron deficiency have more severe symptoms of ADHD than those without iron deficiency.

Symptoms of Attention Deficit Hyperactivity Disorder in Children (Child ADHD)

ADHDThe principal signs and symptoms of ADHD are:

  • Impulsivity: Children seem unable to curb their immediate reactions or think before they act.
  • Hyperactivity: Children always seem to be “on the go” or constantly in motion.
  • Inattention: Children have a hard time keeping their minds on any one thing and may quickly become bored with a task.

These symptoms appear early in a child’s life and will occur for many months. Often, impulsivity and hyperactivity precedes inattention, which may not emerge for a year or more. These symptoms appear at different settings (e.g. school, home, the play ground). People with ADHD may show some or all of the symptomatic behaviours. Hence, there are three subtypes of ADHD:

  • Predominantly hyperactive-impulsive type: Does not show significant inattention;
  • Predominantly inattentive type: Does not show significant hyperactive-impulsive behaviour;
  • Combined type: Displays both inattentive and hyperactive-impulsive behaviour.

In order for ADHD to be diagnosed, a specially trained health professional must conclude that the child meets the criteria outlined in the DSM-IV. These criteria state that the child must express a minimum of six out of nine symptoms of inattention, and/or a minimum of six out of nine symptoms of hyperactivity/impulsivity. In addition, these symptoms must:

  • Have persisted for at least six months;
  • Be present in two or more different settings;
  • Be present before the age of seven years;
  • Be severe, have a negative impact on the child’s functioning in social and other settings, and be inconsistent with the child’s development level (e.g. must not be normal behaviour for the child’s age);
  • Not be explained by other mental disorders (e.g. schizophrenia).


Some signs of inattention are when the patient often:

  • Has difficulty focusing on any one thing;
  • Gets bored with a task in only a few minutes;
  • Does not seem to listen when spoken to directly;
  • Is easily distracted by irrelevant sights and sounds;
  • Has difficulty focusing consciously (e.g. on an activity that they do not like) or learning something new;
  • Has difficulty organising tasks and activities;
  • Avoids or dislikes, or is reluctant to engage in, tasks that require sustained mental effort (e.g. schoolwork or homework);
  • Loses things necessary for tasks (e.g. toys, assignments, pencils, books, tools);
  • Is forgetful in daily activities.

Hyperactivity and impulsivity

Some signs of hyperactivity are when the patient often:

  • Feels restless, fidgets with hands or feet, or squirms while seated;
  • Runs, climbs, or leaves a seat in situations where sitting or quiet behaviour is expected;
  • Has difficulty playing or engaging in leisure activities quietly;
  • Is “on the go”, or acts as if “driven by a motor”.


Some signs of impulsivity are when the patient often:

  • Blurts out answers before question has been completed;
  • Has difficulty awaiting turns;
  • Interrupts or intrudes on others (e.g. “blurts into” conversations or games);
  • Has difficulty restraining emotions (e.g. anger).


ADHD often occurs in children who have another psychiatric condition, for example:

How is Attention Deficit Hyperactivity Disorder in Children (Child ADHD) Diagnosed?

ADHDThe diagnosis of ADHD must be made by a professional with training in ADHD (e.g. child psychiatrists and psychologists, developmental/behavioural paediatricians, behavioural neurologists). If a general practitioner suspects your child has ADHD, it is normal for the doctor to refer you to a specialist for assessment.

The diagnosis is based on very specific symptoms, which must be present in more than one setting (e.g. at home and at school), must have started before 7 years of age, and must have lasted for at least 6 months. The child should have a clinical evaluation if ADHD is suspected.

Evaluation may include:

  • Parent and teacher questionnaires;
  • Psychological evaluation of the child AND family, including IQ testing and psychological testing;
  • Complete developmental, mental, nutritional, physical and psychosocial examination.

These assessments are commonly conducted by:

  • Interviewing parents and teachers;
  • Asking parents and teachers to complete rating scales;
  • Observing a child’s behaviour;
  • Assessing the child’s performance at school.

A comprehensive assessment of a child with suspected ADHD should include questioning about:

  • History: Family, past and current medical, psychosocial;
  • Medical: Physical and neurological examination, and other appropriate investigations;
  • Development: To exclude other disorders (e.g. hearing and vision difficulties) as the cause of behavioural problems, and to make further specialist referrals when appropriate;
  • Behavioural: For example, a description of behaviour in various settings, especially home and school;
  • Educational: For example, a review of classroom observations and test results, including estimates of intellectual capabilities, strengths and weaknesses and measure of academic achievement, including language development.

Further investigations, such as brain imaging and neurophysiological tests, are generally not conducted as part of the routine assessment of ADHD.

Prognosis of Attention Deficit Hyperactivity Disorder in Children (Child ADHD)

ADHD usually begins before preschool age. Some parents may suspect it and seek help, but for most it goes unnoticed until the child experiences problems at school. Occasionally, teachers may be the first to recognise that the child has a problem, and point it out to the parents or school psychologist.

Once diagnosed, ADHD can be treated, and treatment involving medication and lifestyle interventions is usually successful in reducing the symptoms of the disorder. Many children outgrow ADHD in adolescence and early adulthood, but for some it may persist as adult ADHD.

Adult ADHD 

For more information on ADHD in adults, see Adult ADHD.



How is Attention Deficit Hyperactivity Disorder in Children (Child ADHD) Treated?

ADHDEach family and child with ADHD must have an individualised management plan formulated specifically for them. Treatment of ADHD is usually multimodal (i.e. involves several different treatments simultaneously) and typically involves medications, dietary modifications, psychotherapy and behavioural and social skills training.


Stimulant medications such as methylphenidate (e.g. Concerta, Ritalin) and dextroamphetamine (e.g. Dexedrine) are recommended as the first line treatment for children with ADHD. The use of these stimulant medications should be considered for most children with ADHD, as they are the single most effective treatment in reducing the symptoms of ADHD and allowing children to function normally in the classroom, at home and in other settings. While there are a number of side effects which can occur while children are taking stimulant medication (e.g. loss of appetite, difficulty sleeping and, less commonly, dizziness, stomach aches and headaches), the medicines are safe for short and long term use. In the long term, the only demonstrated side effect of stimulant medication use is a small reduction in height.

The amount of medication a child will be prescribed will depend on a number of factors, including the child’s age, the severity of their symptoms and their response to the medication. For more information about medication doses, a health professional should be consulted.

Dietary modifications

Food additives, as well as chemicals which occur naturally in many foods, can exacerbate the symptoms of ADHD in many children. Diets such as the Australian-developed FAILSAFE diet can be recommended as part of multimodal treatment; however, the effectiveness of such diets are limited because patients may find it difficult to keep to the diet.


Psychotherapy may not help the symptoms or the underlying cause of ADHD, but it does help the people with ADHD to like and accept themselves despite their disorder.

Behavioural therapy

Cognitive behavioural therapy helps people develop more effective ways to work on immediate issues. Rather than helping patients to understand their feelings and actions, behavioural therapy helps to directly change their thinking and coping, which may then lead to changes in behaviour.

Social skills training

Social skills training can also help children learn new behaviours. In social skills training, the therapist discusses and models appropriate behaviours important in developing and maintaining social relationships (e.g. waiting for a turn, sharing toys, asking for help, responding to teasing), then gives the patient a chance to practice.

Support groups

Support groups help parents connect with other people who have similar problems and concerns with their ADHD children.

Parenting support

The parents or guardians of children with ADHD may require psycho-social support or support to develop parenting strategies which minimise disruptive behaviour.


Biofeedback (also known as neurofeedback) is a therapy which involves monitoring the seemingly involuntary behaviours of a child and feeding this information back to the child. In doing so, the child becomes more aware of their behaviour and is  therefore in a position to consciously change it. Biofeedback has been successfully applied to the treatment of ADHD patients.

New and emerging therapies

Future goals of ADHD therapy, similarly to all diseases with genetic factors, is the development of individualised pharamcogenetic treatments. Pharmacogenetics is a new concept in the development of disease treatments. The basic idea is that different people may have different genetic mutations that contribute to a disease and hence they have a slightly different form of the disease. Pharmacogenetics is designing different drugs to suit the gene affected in an individual. The advantage of individualising treatment like this is potentially better management of symptoms, decreasing side effects and will also pave the way to identifying individuals that are likely to be refractory to certain ADHD medications, hence avoiding unnecessary medicating.

More information

For more information on the symptoms of ADHD and its medications, and some useful tools and animations, see
Childhood ADHD.


Attention Deficit Hyperactivity Disorder in Children (Child ADHD) References

  1. Froehlich TE, Lanphear BP, Epstein JN, et al. Prevalence, recognition, and treatment of attention-deficit/hyperactivity disorder in a national sample of US children. Arch Pediatr Adolesc Med. 2007;161(9):857-64. Abstract | Full text
  2. Attention deficit hyperactivity disorder (ADHD): NIH Publication No. 08-3572 [online]. Bethesda, MD: National Institutes of Health; 3 April 2008 [cited 24 December 2008]. Available from: URL link
  3. Medication management for attention deficit hyperactivity disorder: A brief guide for parents and non health professionals [online]. Sydney, NSW: Royal Australasian College of Physicians; 10 July 2006 [cited 24 December 2008]. Available from: URL link
  4. Attention deficit and hyperkinetic disorders in children and young people: A national clinical guidline [online]. Edinburgh, UK: Scottish Intercollegiate Guidelines Network; 29 June 2001 [cited 24 December 2008]. Available from: URL link
  5. Criteria for diagnosis and management of attention deficit hyperactivity disorder in children and adolescents [online]. North Sydney, NSW: New South Wales Government Health; 1 February 2008 [cited 24 December 2008]. Available from: URL link
  6. Polanczyk G, de Lima MS, Horta BL, et al. The worldwide prevalence of ADHD: A systematic review and metaregression analysis. Am J Psychiatry. 2007;164(6):942-8. Abstract | Full text
  7. Sawyer MG, Kosky RJ, Graetz BW, et al. The National Survey of Mental Health and Wellbeing: The child and adolescent component. Aust NZ J Psychiatry. 2000;34(2):214-20. Abstract
  8. Attention deficit hyperactivity disorder in children and adults in New South Wales 2007: Final report of the special review [online]. Sydney, NSW: Clinical Excellence Commission; 2 May 2008 [cited 24 December 2008]. Available from: URL link
  9. Buckmaster L. Research brief no. 2 200405: Medication for attention/deficit hyperactivity disorder (ADHD): An analysis by Federal Electorate (200103) [online]. Canberra, ACT: Australian Parliamentary Library; 16 November 2004 [cited 21 September 2009]. Available from: URL link
  10. Faraone SV, Perlis RH, Doyle AE, et al. Molecular genetics of attention deficit/hyperactivity disorder. Biol Psychiatry. 2005;57(11):1313-23. Abstract
  11. Wallis D, Russell HF, Muenke M. Review: Genetics of attention deficit/hyperactivity disorder. J Pediatr Psychol. 2008;33(10):1085-99. Abstract | Full text
  12. Larsson H, Lichtenstein P, Larsson JO. Genetic contributions to the development of ADHD subtypes from childhood to adolescence. J Am Acad Child Adolesc Psychiatry. 2006;45(8):973-81. Abstract
  13. Lowe N, Kirley A, Hawi Z, et al. Joint analysis of the DRD5 marker concludes association with attention-deficit/hyperactivity disorder confined to the predominantly inattentive and combined subtypes. Am J Hum Genet. 2004;74(2):348-56. Abstract | Full text
  14. Smalley SL, McCracken J, McGough J. Refining the ADHD phenotype using affected sibling pair families. Am J Med Genet. 2001;105(1):31-3. Abstract
  15. Gerring JP, Brady KD, Chen A, et al. Premorbid prevalence of ADHD and development of secondary ADHD after closed head injury. J Am Acad Child Adolesc Psychiatry. 1998;37(6):647-54. Abstract
  16. Sowell ER, Thompson PM, Welcome SE, et al. Cortical abnormalities in children and adolescents with attention-deficit hyperactivity disorder. Lancet. 2003;362(9397):1699-707. Abstract
  17. Swain A, Soutter V, Loblay R, Truswell AS. Salicylates, oligoantigenic diets and behaviour. Lancet. 1985;326(8445):41-2. Abstract
  18. Konofal E, Lecendreux M, Arnulf I, Mouren M. Iron deficiency in children with attention-deficit/hyperactivity disorder. Arch Pediatr Adolesc Med. 2004;158(12):1113-5. Abstract | Full text
  19. Brown TE. Executive functions and attention deficit hyperactivity disorder: Implications of two conflicting views. Int J Disabil Develop Edu. 2006;53(1):35-46. Abstract
  20. Pliszka S. Practice parameter for the assessment and treatment of children and adolescents with attention-deficit/hyperactivity disorder. J Am Acad Child Adolesc Psychiatry. 2007;46(7):894-921. Abstract | Full text
  21. Faraone SV. Advances in the genetics and neurobiology of attention deficit hyperactivity disorder. Biol Psychiatry. 2006;60(10):1025-7. Abstract
  22. Kieling C, Goncalves RR, Tannock R, Castellanos FX. Neurobiology of attention deficit hyperactivity disorder. Child Adolesc Psychiatr Clin N Am. 2008;17(2):285-307. Abstract
  23. Burks HF. Burks’ Behavior Rating Scale: Manual. Los Angeles: Western Psychological Services; 1996. Publisher
  24. Conners CK, Sitarenios G, Parker JDA, Epstein JN. The revised Conners’ Parent Rating Scale (CPRS-R): Factor structure, reliability and criterion validity. J Abnorm Child Psychol. 1998;26(4):257-68. Abstract
  25. Lubar JF, Swartwood MO, Swartwood JN, O’Donnell PH. Evaluation of the effectiveness of EEG neurofeedback training for ADHD in a clinical setting as measured by changes in T.O.V.A. scores, behavioral ratings, and WISC-R performance. Biofeedback Self Regul. 1995;20(1):83-99. Abstract
Print Friendly, PDF & Email


Posted On: 29 April, 2004
Modified On: 15 May, 2018
Reviewed On: 13 October, 2009


Created by: myVMC