1.3.2 Diagnosing ADHD with ICD-10 and ICD-11
ICD-10 does not formally recognise ADHD and instead includes diagnostic criteria for hyperkinetic disorder (HKD). For a diagnosis of HKD to be made an individual must display symptoms of both impaired attention and overactivity, which includes impulsivity. The symptoms must also be present before 6 years of age. As with DSM-5 they must be found in two settings, and other conditions that could cause the same symptoms must first be ruled out.
From this brief description, which presentation type of ADHD, according to DSM-5, does HKD resemble?
It is like the combined presentation type because there are symptoms of inattention and hyperactivity/impulsivity.
The lack of recognition of ADHD in the ICD-10 has proved controversial over the years and ICD-11 (preview released in 2018 and due to be adopted in 2022) will now include ADHD as a formal diagnostic category that is very similar to that given in DSM-5. However, rather than requiring some symptoms be present before the age of 12, the broader term of ‘early to mid-childhood’ is given.
ICD-11 also adopts the distinct subtypes of ADHD found in DSM-5 but adds a further two: ‘other specified presentation’ and ‘presentation unspecified’. At the time of writing, the detail of what these two categories are likely to include is unclear.
What is the possible impact of the change in ICD-11 on reported prevalence? Explain your answer.
In countries using ICD-10, only the combined presentation of ADHD was formally recognised, and this was under the banner of HKD, so we may expect to see an increase in reported prevalence as ADHD is now reported separately and all categories are included.
Irrespective of which diagnostic system (DSM or ICD) is used, the symptoms of ADHD can vary over time. For example, symptoms of hyperactivity typically reduce with age (Faraone et al., 2006). This means that the specific presentation type may not remain the same for an individual and it may be necessary to re-assess their symptoms at regular intervals.