What is ADHD?

I think I'm misunderstood a lot… People with ADHD are actually very clued up, people don't think they are but I understand stuff really quickly... I find if I'm strict with myself then I’m good, and routine is really good. If I'm out of a routine then it just goes downhill, everything just falls to pieces...It’s bizarre, as you don’t actually realise when you’re out of control… and then when a mate says "come on what's going on?" That's when you go uhhh, and it hits you like a ton of bricks...

Attention Deficit Hyperactivity Disorder (ADHD) is a highly heritable neurodevelopmental disorder that starts in early childhood. It is characterised by pervasive inattention, impulsivity and hyperactivity that is inappropriate to the developmental age and it negatively impacts directly on social and academic/occupational activities. People with ADHD often find it hard to sustain attention especially when doing boring tasks; they rush through tasks just to get them done (or fail to finish altogether); become easily distracted; lose or forget things; interrupt others and/or blurt things out; fidget and find it hard to relax; find it difficult to wait their turn and control their emotions. They experience these difficulties to a greater extent than their peers, and this often causes them problems at home, in educational and/or occupational activities, and in their interpersonal relationships. They often feel irritated and frustrated because they do not reach their potential. Their symptoms are present from childhood and have a heterogeneous progression. For some individuals symptoms remit with age (most commonly overt hyperactive and impulsive symptoms), while others experience persistent symptoms and associated impairment into adulthood [1,2]. As a life span condition, young people with ADHD often experience greater difficulty coping with the life-changes they will face as they mature, e.g. accepting responsibility, difficulty with exams, career decisions, leaving home, gaining employment, romantic relationships, dealing with interpersonal conflict, having children etc. Thus practitioners must consider the life stage of the presenting patient and their needs at that time.

How Common is ADHD?

I don't mean to be offensive, like I'll say to someone "wow, that shirt makes you look fat" but I won't think in my head that could hurt their feelings, when obviously a comment like that would hurt their feelings.

ADHD is reported in many cultures [3] and whilst there are a wide range of prevalence rates cited, most converge on a figure of 5% during childhood years [4]. The UK estimate is a rate of 3.6% in boys and 0.9% in girls [5]. Around 15% of those with childhood ADHD will still meet DSM-IV criteria for a full diagnosis at age 25, and around 50% will continue to experience some persistent symptoms [1]. As children, up to four times more boys than girls are diagnosed, whereas in adulthood women are just as likely to be diagnosed. This may be because younger boys present as more hyperactive, which means that they are more likely to be noticed as having a behavioural problem.

What Causes ADHD?

ADHD can run in families and genes play a significant role in brain development, with a number of different genes thought to be involved that may be linked to brain chemicals. However, there isn’t one single explanation; a range of environmental and psychosocial factors can interact with genetics to give large variation in symptoms [6].

  • Genetic factors
    Studies of families, twins and adopted children have shown that the heritability of ADHD is substantial in first degree relatives of individuals with ADHD [7]. A number of genes have been implicated such as those linked to the dopamine and serotonin systems in the brain [8]. However, no single gene has been identified.
  • Environmental factors
    Other factors that also affect brain development include smoking, drinking, and substance use during pregnancy, pre-term birth, low birth-weight, birth trauma, and maternal depression. These factors can interact with genetic/neurological factors to increase the risk of ADHD. [9]
  • Psychosocial factors
    The degree of nurture and stimulation that a child receives in early life may also have an impact, as can early social adversity such as deprived institutional care and disrupted family relationships [10]. However, the exact link between psychosocial factors and ADHD is not known. In the case of family relationships for example, it is hard to tell whether disrupted relationships lead to ADHD, or vice versa.

Diagnostic Classification of ADHD

The Diagnostic and Statistical Manual of Mental Disorders V (DSM-V) criteria defined by the American Psychiatric Association [11] are the most widely used and include three subtypes of ADHD: predominantly inattentive, predominantly hyperactive/impulsive, and combined presentation (see Box 1). The hyperkinetic disorder criterion of the World Health Organization [12] defines a subgroup of the DSM-IV category that represents a more restricted application of the diagnostic criteria. However, most practitioners prefer to follow the broader DSM-V criteria that allow for the coexistence of comorbid psychiatric disorders as this fits more closely with clinical practice. DSM-V criteria require onset of symptoms by age 12. For children, six (or more) symptoms must have persisted for at least six months. For older adolescents and adults (age 17 and older), at least five symptoms are required. Symptoms must have persisted for at least six months to a degree that is inconsistent with evelopmental level and must negatively impact directly on social and academic/occupational activities.

Box 1: Classification of DSM-V ADHD Symptoms

Predominantly inattentive presentation

Six out of nine inattentive symptoms rated as 'often' (or five symptoms if age 17 and older)

Predominantly hyperactive-impulsive presentation

Six out of nine hyperactive/impulsive symptoms rated as 'often' (or five symptoms if age 17 and older)

Combined presentation

Six out of nine inattentive symptoms AND six out of nine hyperactive/impulsive symptoms rated as 'often' (or five symptoms respectively if age 17 and older)

How is ADHD Diagnosed?

Even though ADHD is a common childhood disorder, it is often undiagnosed or misdiagnosed. Early diagnosis and intervention (with multi-disciplinary management) is important to minimise negative outcomes in the longer term [13]. International guidelines are available to assist with the diagnosis, treatment and management of ADHD [14]. In the UK, these have been made by the National Institute for Health and Clinical Excellence (NICE) [6].

As for many conditions, a diagnosis begins with the observation of frequency and severity of characteristic symptoms. Screening questionnaires are often used to indicate the presence of self-rated symptoms. Wherever possible it is recommended that these are supplemented by ratings from an informant, such as a parent or teacher/tutor. For adults, assessments determine presence of symptoms in childhood as well as current symptoms, as meeting criteria for childhood ADHD is a prerequisite for making the diagnosis in adulthood.

When they diagnosed me and I finally could take the tablets, I realised after a while I was concentrating at school and I wasn't a bad kid like they thought. That's when I passed my eleven plus, because I could actually sit down and take an exam, which was really nice.

A diagnosis should never be made solely on the basis of screening questionnaires as false positive results can be obtained using screens, but they are useful for indicating whether a more comprehensive assessment is needed. This consists of a clinical interview with the individual and often with someone who knows them well. The interview assesses for presence of symptoms and associated impairment.

It is important to consider the presence of comorbid symptoms and/or differential diagnosis (see Module 2 and Module 3). If an individual meets criteria for ADHD but does not experience any functional problems or impairment from their symptoms, a diagnosis of ADHD cannot be made. When assessing ADHD in teenagers it is important to remember that symptom presentation may change with age (e.g. remission of hyperactive behaviours).

How is ADHD Treated?

Medication and psychological treatments are the most common interventions.


Around 1% of children in the UK are currently receiving medication for ADHD [15]. This usually includes stimulants such as the various formulations for methylphenidate including Ritalin, Concerta XL, Medikinet XL, Equasym XL or Lisdexamphetamine [Elvanase] . Non-stimulants such as atomoxetine (Strattera) are another option; the latter being the only medication licensed for adult use.

I went six months without medication, I tried to cope and I thought I was doing well, but when I look back now, I just feel so much clearer.

The aim of treatment is to reduce core ADHD symptoms and improve mood, irritability, and self confidence. It usually then creates flow on improvement in school work, behaviour, and social skills. NICE recommend that for adults and children with severe impairment, drug treatment should be the first-line intervention, with stimulants considered first due to their demonstrated effectiveness, followed by atomoxetine [6]. However, responses to medication treatment can vary. Medications are available in different formulations (e.g. short-acting stimulants last 3-5 hours, long-acting stimulants last up to 12 hours and atomoxetine provides 24 hour coverage) so it is important to work with clients to find the medication and dose that suits them. Fine tuning and careful dosage can make a great deal of difference.

As with all medications some people describe side effects, which may be physiological (e.g. stomach aches, headaches) and/or psychological (e.g. nervousness, feeling less sociable). The most common side effects are short term appetite loss, sleep difficulty or blunting personality.

Psychological Treatments

For young people with mild to moderate impairments, or those who do not want pharmacological treatment, NICE recommend CBT psychological treatments [6]. Psychological programmes are available for a range of ages from pre-school to adulthood. These programmes include a range of techniques most commonly based on a cognitive-behavioural paradigm that aim to develop skills in behavioural control, emotional control, organisation, time-management, attention and memory training, and social skills training.

For younger children programme activities are usually delivered 'indirectly' via parents or teachers; as children grow older and in the teenage years these move towards more 'direct' work with the individual themselves. A large body of research suggests that psychological treatments are effective in reducing ADHD symptoms, especially for children with mild to moderate problems and, when used in conjunction with medication, they may also increase effectiveness for children with more severe impairment and comorbid problems [16].

In adolescence, psychological treatment may be particularly relevant to support young people who must develop greater responsibility for self-organisation and time-management of their studies. Additionally, it is during these years that many other associated problems may arise or become more marked such as mood and anxiety disorders, conduct problems, social relationship problems, and low self-esteem. See Box 2 for key findings about non-pharmacological interventions for ADHD [16].

Box 2: Key findings from a review of non-pharmacological interventions [15]
  • As children mature, the mode of intervention (e.g. pharmacological, psychosocial) will shift to reflect the developmental needs and circumstance of the individual.
  • As children mature the agent of implementation (e.g. parent, teacher) will also shift according to the developmental needs and circumstance of the individual
  • More Randomised Controlled Trials are needed to provide conclusive evidence for treatment efficacy.
  • Parent training is recommended for preschoolers and young school-age children, who may additionally benefit from classroom interventions.
  • Multimodal interventions are recommended for middle school/adolescent children.
  • CBT interventions are recommended for adults (either group or individual).


All interventions should include a psychoeducational component as knowledge and understanding about ADHD is crucial for dispelling lay beliefs, and will alleviate anxiety for the individual about the nature and progression of the ADHD condition. This can be effectively achieved through the provision of written information that can be disseminated to families, friends, teachers and employers. This should include information and web links about ADHD resources and support groups. Further information is available from professional/practice guidelines such as those issued by the British Association for Psychopharmacology [17], the European Network Adult ADHD [18], and NICE [6].

It is very important that teenagers who continue to have persistent symptoms and impairments maintain engagement with health services. However as teenagers become adults, they become more autonomous and responsible for their own care and they may have a period of not wishing to accept treatment or not attending appointments (this is not uncommon in other health areas).

Leaving school or further education seems to be an important marker as by the age of 21 most individuals with ADHD will disengage from services [19]. One way to maintain contact is to provide young adults with ADHD, and their families, information and advice about the longer-term problems and needs of young people with ADHD, and provide information about the transition process from child to adult ADHD services (see Module 8).

Key Points from Module 1

Box 3: Key points from Module 1 - Introduction to ADHD
  • ADHD is characterised by symptoms of inattention, impulsivity and hyperactivity that are associated with significant levels of academic, occupational and social impairment.
  • ADHD is reported in many cultures and 5% of children are estimated to have ADHD, with a 4:1 male female ratio.
  • Around two-thirds of those with childhood ADHD will experience persisting symptoms and impairments at age 25.
  • ADHD is caused by a combination of genetic, psychosocial and environmental factors – there is no single cause.
  • International guidelines are available to assist with the diagnosis, treatment and management of ADHD
  • ADHD can be treated effectively with medication and psychological treatments. These should be complemented by psychoeducation including written information about the nature and progression of ADHD, available treatments, service provision, and service-user support groups.


[1] Faraone, S., Biederman, J., & Mick, E. (2006). The age-dependent decline of attention deficit hyperactivity disorder: A meta-analysis of follow-up studies. Psychological Medicine, 36(2), 159-165.

[2] Young, S., & Gudjonsson, G. (2008). Growing out of Attention-Deficit/Hyperactivity Disorder: the relationship between functioning and symptoms, Journal of Attention Disorders, 12(2), 162-169.

[3] Hodgkins, P., Arnold, L.G., Shaw, M., Caci, H., Kahle, J., Woods, A.G., Young, S. (2012) A systematic review of long-term outcomes in ADHD: global publication trends. Frontiers in Psychiatry, 2, 84. http://dx.doi.org/10.3389/fpsyt.2011.00084

[4] Polanczyk, G., de Lima, M.S., Horta, B.L., Biederman, J., & Rohde, L.A. (2007). The Worldwide Prevalence of ADHD: A Systematic Review and Metaregression Analysis. American Journal of Psychiatry, 164, 942-948.

[5] Ford, T., Goodman, R., & Meltzer, H. (2003). The British Child and Adolescent Mental Health Survey 1999: the prevalence of DSM-IV disorders. Journal of the American Academy of Child and Adolescent Psychiatry, 42(10), 1203-1211.

[6] National Institute for Clinical Excellence. (2009). Attention deficit hyperactivity disorder: Diagnosis and management of ADHD in children, young people and adults. NICE clinical guideline 72. London.

[7] Steinhausen, H.C. (2009). The heterogeneity of causes and courses of attention-deficit⁄ hyperactivity disorder. Acta Psychiatrica Scandinavica, 120(5), 392–399.

[8] Stergiakouli, E., & Thapar, A. (2010). Fitting the pieces together: current research on the genetic basis of attention-deficit/hyperactivity disorder (ADHD). Journal of Neuropsychiatric Disease and Treatment, 6, 551-560.

[9] Thapar, A., Cooper, M., Jefferies, R. & Stergiakouli, E. (2012). What causes attention deficit hyperactivity disorder? Archives of Disease in Childhood, 97(3), 260-265.

[10] Rutter, M. (2005). Environmentally mediated risks for psychopathology: research strategies and findings. Journal of Child Psychology and Psychiatry 44(1), 3–18.

[11] American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition. American Psychiatric Association, Washington, DC, USA.

[12] World Health Organization. (1993). The ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research. World Health Organization, Geneva, Switzerland.

[13] Shaw, M., Hodgkins, P., Caci, H., Young, S., Kahle, J., Woods, A., Arnold, L.G. (2012). A Systematic Review and Analysis of Long-term Outcomes in Attention Deficit Hyperactivity Disorder: Effects of Treatment and Non-treatment. BMC Medicine, 10; 99, http://dx.doi.org/10.1186/1741-7015-10-99

[14] Sexias, M., Weiss, M. & Mϋller, U. (2012). Systematic review of national and international guidelines on attention deficit hyperactivity disorder. Journal of Psychopharmacology, 26(6):753-765.

[15] Wong, I.C., Asherson, P., Bilbow, A., Clifford, S., Coghill, D., DeSoysa, R., Taylor, E. (2009). Cessation of attention deficit hyperactivity disorder drugs in the young (CADDY)-a pharmacoepidemiological and qualitative study. Health Technology Assessment (Winchester, England), 13(50), iii-iv, ix-xi, 1-120.

[16] Young, S. & Amarasinghe, J.A. (2010). Practitioner Review: Non-pharmacological treatments for ADHD: A lifespan approach. Journal of Child Psychology and Psychiatry, 51(2), 116-133.

[17] Nutt, D.J., Fone, K., Asherson, P., Bramble, D., Hill, P., Matthews, K., Young, S. (2007). Evidence-based guidelines for management of attention-deficit/hyperactivity disorder in adolescents in transition to adult services and in adults: recommendations from the British Association for Psychopharmacology. Journal of Psychopharmacology, 21(1), 10-41.

[18] Kooij, S.J.J., Bejerot, S., Blackwell, A., Caci, H., Casas-Brugué, M., Carpentier, P.J., Asherson, P. (2010). European consensus statement on diagnosis and treatment of adult ADHD: The European Network Adult ADHD. BMC Psychiatry, 10:67. http://dx.doi.org/10.1186/1471-244X-10-67

[19] McCarthy, S., Asherson, P., Coghill, D., Hollis, C., Murray, M., Potts, L., Wong, I.C.K. (2009). Attention-deficit hyperactivity disorder: treatment discontinuation in adolescents and young adults. British Journal of Psychiatry, 194(3), 273-277.

Further Reading and Useful Resources

Asherson, P. (2005). Clinical assessment and treatment of attention deficit hyperactivity disorder in adults. Expert Review of Neurotherapeutics, 5(4), 525-539.

Young, S., Murphy, C.M., & Coghill, D. (2011). Avoiding the 'twilight zone': Guidance and recommendations on ADHD and the transition between child and adult services. BMC Psychiatry. 11:174, http://dx.doi.org/10.1186/1471-244X-11-174

Young, S. & Bramham, J. (2012). Cognitive Behavioural Therapy for ADHD Adolescents and Adults: A Psychological Guide to Practice, Second Edition. Chichester: John Wiley & Sons.

Young, S. (2013). The 'RAPID' cognitive behavioral therapy program for inattentive children: preliminary findings. Journal of Attention Disorders, 17(6), 519-526.

Young, S., Fitzgerald, M., & Postma, M.J. (2013). ADHD: making the invisible visible An Expert White Paper on attention-deficit hyperactivity disorder (ADHD): policy solutions to address the societal impact, costs and long term outcomes, in support of affected individuals, http://www.europeanbraincouncil.org/pdfs/ADHD%20White%20Paper_15Apr13.pdf