The International Statistical Classification of Diseases and Related Health Problems, 10th Revision (ICD-10) medical classification system was published by the World Health Organization in 1992.1
ICD-10 refers to attention-deficit hyperactivity disorder (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).2
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“.1
Overview of the ICD-10 medical classification system for ADHD1
- The main symptoms of HKD are impaired attention and overactivity. Both are necessary for diagnosis.
- Impaired attention – manifested by a lack of persistent task involvement and a tendency to move from one activity to another without completion.
- Overactivity – characterised by restlessness, talkativeness, noisiness and fidgeting, particularly in situations requiring calm.
- Early onset – behavioural symptoms present prior to 6 years of age, and of long duration.
- Impairment must be present in two or more settings (e.g. home, classroom, clinic).
- Diagnosis of anxiety disorders, mood affective disorders, pervasive developmental disorders and schizophrenia must be excluded.
ICD-10 also lists symptoms characteristic of children with HKD, but not necessary or sufficient for diagnosis:1
- Disinhibition in social relationships
- Recklessness in dangerous situations
- Non-adherence to social norms (interrupting, intruding on others, prematurely answering questions, difficulty in waiting in turn).
Note that deficits in persistence and attention should be diagnosed only if they are excessive for the child’s age and IQ; and overactivity should be considered in the context of what is expected in the situation and by comparison with other children of the same age and IQ.1
Caution is recommended in children of pre-school age, and only extreme levels of hyperactivity should lead to a diagnosis in these individuals.1
Diagnosis of HKD may also be made in adult life using the same criteria; however, attention and activity must be judged with reference to developmentally appropriate norms.1
- 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.
- 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.