How is ADHD Diagnosed?


The diagnostic criteria of ADHD listed below are defined in the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM5) produced by the American Psychiatric Association (APA).  Despite numerous hyped claims of imminent technological diagnostic breakthroughs, it remains the case that no biological marker is diagnostic for ADHD.[1]  Despite the lack of any diagnostic biological markers, many people, including some patients and parents, mistakenly believe ADHD is diagnosed using a series of 'scientific' tests. In reality the DSM5 behavioural criteria, listed below, remain the basis for diagnosing ADHD.

Modified extract from the the Diagnostic and Statistical Manual of Mental Disorders 5th Edition (DSM5)

ADHD Diagnostic Criteria.[1]

To meet the DSM5 diagnostic criteria a child should display either:

  • six of the behavioural criteria below at 1 (Predominantly Inattentive Subtype - sometimes referred to as passive ADHD or ADD)

  • six of the behavioural criteria below at 2 (Predominantly Hyperactive/Impulsive Subtype)

  • or six of both 1 and 2 (Combined Subtype)

for at least six months to an extent that is inconsistent with their age and significantly impairs their social and academic functioning. For adolescents 17+ and adults five are sufficient.

1. Inattention

  • often fails to give close attention to details or makes careless mistakes in schoolwork, work, or during other activities

  • often has difficulty sustaining attention in tasks or play activities

  • often does not seem to listen when spoken to directly

  • often does not follow through on instructions and fails to finish schoolwork, chores, or duties in the workplace

  • often has difficulty organizing tasks and activities

  • often avoids, dislikes or is reluctant to engage in tasks that require sustained mental effort (such as schoolwork or homework)

  • often loses things necessary for tasks or activities (e.g., toys, school assignments, pencils, books, or tools)

  • is often easily distracted by extraneous stimuli

  • is often forgetful in daily activities

2. Hyperactivity and Impulsivity 

  • often fidgets with hands or feet or squirms in seat

  • often leaves seat in classroom or in other situations in which remaining seated is expected

  • often runs about or climbs excessively in situations in which it is inappropriate

  • often unable to play or engage in leisure activities quietly

  • is often “on the go” or often acts as if “driven by a motor”

  • often talks excessively

  • often blurts out answers before questions have been completed

  • often has difficulty awaiting turn

  • often interrupts or intrudes on others (e.g., butts into conversations or games)

DSM5 also recognizes two additional categories of ADHD where children “do not meet the full criteria for ADHD”.

  • Other Specified ADHD – when clinician “chooses to communicate the specific reason that the presentation does not meet the criteria for ADHD”. 

  • Unspecified ADHD – when the clinician “chooses not to communicate the specific reason that the presentation does not -meet” these criteria.   

Editorial Comment: Part of the reason I (Dr Martin Whitely) am a critic of ADHD as a diagnosis entity is I that consider it is absurd that fidgeting, disliking homework, playing loudly, being on the go, and talking excessively, are regarded as evidence of a psychiatric or a neuro-developmental disorder. What do you think?


Clinicians don't need to observe ADHD type behaviours.  They diagnose children or adolescents with ADHD by relying on third party reports of children exhibiting the above behaviours.  Usually parents and teachers are asked to complete a questionnaire detailing if their child always, often, sometimes or never displays these behaviours.  How ‘often’ a child or adolescent ‘fidgets’ or ‘interrupts’ or ‘avoids homework’ or ‘fails to remain seated’ or is ‘distracted’ so that they exhibit ‘some impairment’ is not defined in DSM5. Except for those aged 17 and over being required to display less criteria (five instead of six), the diagnostic criteria are identical for pre-schoolers and adults

The most commonly used diagnostic questionnaire is the Connors rating scales which formats the 18 diagnostic ADHD criteria in a tick-box questionnaire format.  There are separate long and short versions (six in total) of the Connors rating scales for parents, teachers, and for adolescents (who rate their own behavior).  Long versions of the Connors ratings scales have between 60 and 90 questions, while short versions have less than 30 questions.[2]  Shortly before his death, Keith Connors who designed the ratings scales expressed his regret at the dumbing down of the ADHD diagnostic process writing, "in today’s ADHD world the detailed family and developmental history has been replaced by word of mouth from parents and teachers and quickie interviews, largely by untrained primary care or general pediatric pediatric practitioners."[3]

Many of the diagnostic criteria, in particular "making careless mistakes, not ‘seeming to’ listen, failing to finish school work, being disorganised, disliking schoolwork or homework, blurting out answers and leaving a seat when remaining seated is expected", are all evidence of a student’s failure to thrive or comply in a school environment.  Children is classes controlled by competent, engaging  teachers are obviously far less likely to misbehave and are therefore less likely tom qualify for a diagnosis.  

DSM5 implicitly recognises that boring environments create bored students who misbehave.  It states: "Signs of the disorder may be minimal or absent when the person is receiving frequent rewards for appropriate behaviour, is under close supervision, is in a novel setting, is engaged in especially interesting activities, has consistent external stimulation (e.g., via electronic screens) or is in a one-to-one situation (e.g., the clinician’s office)”.[4]  Critics contend a diagnosis of ADHD shifts the focus away from what might be wrong with the school, or teacher and that ADHD type behaviours may be a normal response to a child or adolescent’s environment.[5]

As well as being a primary source of the information used by clinicians to diagnose ADHD, research indicates that, in the majority of cases, teachers are the first to suggest a student be referred for diagnosis.[6][7][8]  There is a high degree of variability in teacher responses to ADHD in regards participation in the diagnostic process, teaching practice and acceptance of the validity of the diagnosis.[9][10]  A child's chances of being diagnosed with ADHD are therefore highly dependent on who there teacher is.

Teacher attitude and practice is just one of many non-biological factors that have been shown to effect rates of ADHD diagnosis and medication use.  Variations in both parent and clinician attitudes and practice have a strong impact on a child’s chances of being diagnosed and ‘medicated’ (or 'drugged' depending on your perspective).  Arguably a diagnosis of ADHD says more about the adults in a child’s life (parents, teachers and doctors) than it does about the child.

Many other factors  including gender (with boys 3x more likely to be diagnosed as girls), ethnicity of students and teachers[11], divorce[12]low maternal education, lone parenthood and the receipt of social welfare[13], sexual abuse[14], sleep deprivation[15], perinatal issues[16], artificial food additives[17], mobile phone use[18], postcode and regulatory capture[19], have all been associated with an increased risk of an ADHD diagnosis.

American Psychiatric Association's DSM5 v World Health Organisation's ICD

The eighteen behavioural diagnostic criteria for ‘Hyperkinetic Disorder’ outlined in the International Clarification of Diseases 10 (ICD10), produced by the World Health Organization are virtually identical to those for ADHD.  There are, however, two subtle but important distinctions. First, for a diagnosis of hyperkinetic disorder under ICD10, a child or adolescent (under 17) is required to display at least six of nine of the inattentive and three of five of the hyperactive and one of four of the impulsive behaviours. For a DSM5 diagnosis of ADHD, six of nine of the inattentive behaviours or six of nine of the hyperactive/impulsive behaviours are sufficient.  Second, unlike the DSM5 definition of ADHD, ICD-10 states hyperkinetic disorder should not be diagnosed if another condition that may explain the behaviour is diagnosed.

The United Kingdom National Institute for Health and Care Excellence (NICE) ADHD guidelines describe children who meet the ICD10 diagnostic criteria for hyperkinetic disorder as having “severe ADHD “ and those who don’t  but  do meet the broader DSM5 criteria as having “moderate ADHD”.  NICE identifies that determining what constitutes severe, moderate, and “other ADHD” and wellness, are matters for clinical judgement, “taking into account the severity of impairment, pervasiveness, individual factors and familial and social context”.[20]  Critics contend the arbitrary distinction between the ICD10 and the subtypes of ADHD recognised in DSM5 and the degree of clinical discretion facilitates inconsistency in the application of these labels. Typically fewer children are diagnosed and medicated using the narrower ICD10 criteria.[21]


[1]  American Psychiatric Association (2013), Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition, (DSM5) pp. 59-66

[2]  ‘ADHD Connors Test’, The ADD/ADHD Support Site.  Available at (accessed 7 May 2013). 

[3]  Frances A, Keith Connors, Father of ADHD, Regrets Its Current Misuse Setting things straight on the ADHD diagnosis Posted Mar 28, 2016 (accessed 30 March 2019)

[4]  American Psychiatric Association (2013), Diagnostic and Statistical Manual of Mental Disorders. Fifth Edition, (DSM5) pp. 61

[5]  Linda J. Graham, ‘Drugs, labels and (p)ill-fitting boxes: ADHD and children who are hard to teach’, in Discourse: Studies in the Cultural Politics of Education, Vol. 29, No. 1, March 2008, p. 94.

[6]  Linda Graham, ‘The Politics of ADHD’, in Proceedings of the Australian Association for Research in Education (AARE) Annual Conference, Adelaide, November 2006, p. 14.

[7]  Phillips, C. B. (2006). Medicine goes to school: Teachers as sickness brokers for ADHD. Plos Medicine, 3(4), e182–e182.

[8]  Sax, L., & Kautz, K. J. (2003). Who first suggest the diagnosis of attention-deficit/hyperactivity disorder? Annals of Family Medicine, 1(3), 171. doi:10.1370/afm.3

[9]  Jody ShermanCarmen Rasmussen & Lola Baydala The impact of teacher factors on achievement and behavioural outcomes of children with Attention Deficit/Hyperactivity Disorder (ADHD): a review of the literature Pages 347-360 | Received 30 Jan 2007, Published online: 15 Nov 2008

[10]  Teachers' Knowledge of ADHD, Treatments for ADHD, and Treatment Acceptability: An Initial Investigation Vereb, Rebecca L; DiPerna, James C. School Psychology Review; Bethesda 33.3  (2004): 421-428

[11]  Schneider H, Eisenberg D. Who receives a diagnosis of attention-deficit/ hyperactivity disorder in the United States elementary school population? Pediatrics. 2006;117(4):e601-9.

[12]  Hjern A, Weitoft GR, Lindblad F. Social adversity predicts ADHD-medication in school children--a national cohort study. Acta Paediatr. 2010;99(6):920-4.

[13]  Russell G, Ford T, Rosenberg R, Kelly S. The association of attention deficit hyperactivity disorder with socioeconomic disadvantage: alternative explanations and evidence. J Child Psychol Psychiatry. 2014;55(5):436-45.

[14]  Weinstein D, Staffelbach D, Biaggio M. Attention-deficit hyperactivity disorder and posttraumatic stress disorder: differential diagnosis in childhood sexual abuse. Clin Psychol Rev. 2000;20(3):359-78.

[15]  Thakkar VG. Diagnosing the Wrong Deficit. New York Times. 2013 27 April.

[16]  Schmitt J, Romanos M. Prenatal and perinatal risk factors for attention-deficit/hyperactivity disorder. Arch Pediatr Adolesc Med. 2012;166(11):1074-5.

[17]  McCann D, Barrett A, Cooper A, Crumpler D, Dalen L, Grimshaw K, et al. Food additives and hyperactive behaviour in 3-year-old and 8/9-year-old children in the community: a randomised, double-blinded, placebo-controlled trial. Lancet. 2007;370(9598):1560-7.

[18]  Byun YH, Ha M, Kwon HJ, Hong YC, Leem JH, Sakong J, et al. Mobile phone use, blood lead levels, and attention deficit hyperactivity symptoms in children: a longitudinal study. PLoS One. 2013;8(3):e59742.

[19]  Whitely MP. Attention Deficit Hyperactivity Disorder Policy, Practice and Regulatory Capture in Australia 1992–2012 [PhD]. Perth, WA: Curtin University; 2014.

[20]  Attention Deficit Hyperactivity disorder: diagnosis and management, Clinical guideline [CG72] Published date: September 2008 Last updated: February 2016

[21]  Based on the narrower criteria of ICD‑10, hyperkinetic disorder is estimated to occur in about 1–2% of children and young people in the UK. Using the broader criteria of DSM‑IV, ADHD is thought to affect about 3–9% of school‑age children and young people in the UK, and about 2% of adults worldwide.