When evaluating patients for ADHD, it is typical to use multiple stages of assessment prior to formal diagnosis:1-3
- Clinical assessment
- Assessment tools and rating scales
- Clinical interviews with patients and parents/teachers for children and adolescents or partners for adults with ADHD.
Following assessment, the National Institute for Health and Care Excellence (NICE) guidelines state that a diagnosis of ADHD should only be made by a specialist psychiatrist, paediatrician or other appropriately qualified healthcare professional with training and expertise in the diagnosis of ADHD based upon a full clinical and psychosocial assessment, a full developmental and psychiatric history and observer reports of the individual’s mental state. For a diagnosis of ADHD, symptoms of hyperactivity-impulsivity and/or inattention should meet the diagnostic criteria in the Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM-5TM) for ADHD; and the International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) for HKD.1
There are two main classification systems for diagnosing ADHD:
International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10)
The ICD-10 medical classification system refers to ADHD as hyperkinetic disorder (HKD), a term widely used in Europe and included in European clinical guidelines developed with the European Network for Hyperkinetic Disorders (EUNETHYDIS).4,5 This classification system defines HKD as a persistent and severe impairment of psychological development, characterised by “early onset; a combination of overactive, poorly modulated behaviour with marked inattention and lack of persistent task involvement; and pervasiveness over situations and persistence over time of these behavioural characteristics”.5
The American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders – 5th Edition (DSM-5TM)
The DSM-5TM medical classification system for ADHD is published by the American Psychiatric Association, and is used in the US and the rest of the world. This classification system defines ADHD as “a persistent pattern of inattention and/or hyperactivity-impulsivity that interferes with functioning or development”.6
The DSM-5™ replaced the previous version (DSM-IV) in 2013.6,7 The National Institute for Health and Care Excellence (NICE) guidelines1 and other clinical guidelines2,3,8 refer to the DSM-5TM; however, some clinical trials initiated before the new edition also refer to DSM-IV.
Regardless of which set of medical classification systems is used, the features of ADHD described are similar, with both diagnostic criteria describing ADHD as a pattern of inattention and/or hyperactivity-impulsivity (combined, predominantly inattentive or predominantly hyperactive-impulsive presentations).6
These medical classification systems should be used in conjunction with a range of rating scales, which often measure the impact of ADHD upon more specific areas of functioning or quality of life.1-3,8
- NICE guideline 2018. Attention deficit hyperactivity disorder: diagnosis and management. Available at: https://www.nice.org.uk/guidance/ng87. Accessed February 2019.
- Canadian ADHD Resource Alliance (CADDRA). Canadian ADHD Practice Guidelines. Fourth Edition. Toronto, ON; CADDRA, 2018.
- Banaschewski T, Hohmann S, Millenet S. Aufmerksamkeitsdefizit-/Hyperaktivitätsstörung (ADHS) im Kindes-, Jugend- und Erwachsenenalter. DGKJP, DGPPN and DGSPJ German guidelines. 2018.
- Taylor E, Döpfner M, Sergeant J, et al. European clinical guidelines for hyperkinetic disorder — first upgrade. Eur Child Adolesc Psychiatry 2004; 13(Suppl 1): I/7-I/30.
- World Health Organization. The ICD-10 Classification of Mental and Behavioural Disorders. Available at: www.who.int/entity/classifications/icd/en/bluebook.pdf. Last updated 1993; 1: 1-263. Accessed February 2019.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. 2013.
- American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Washington, DC; American Psychiatric Association, 2004.
- Guías de Práctica Clínica en el SNS. Grupo de trabajo de la Guía de Práctica Clínica sobre las Intervenciones Terapéuticas en el Trastorno por Déficit de Atención con Hiperactividad (TDAH). 2017.