Background: This study was undertaken to examine the validity of different diagnostic definitions of hyperactivity in a Chinese population. Estimates of the prevalence of hyperactivity were made according to these different diagnostic definitions.
Method: In a two-stage epidemiological study of hyperactivity in Hong Kong, 3069 Chinese schoolboys were screened by questionnaires; and a stratified sample of 611 of them entered a second stage for more detailed diagnostic assessment.
Results: Children with hyperkinetic disorder (ICD-10) or ADDH (DSM-III) both displayed significant hyperactive symptoms, but with somewhat different external correlates; hyperkinetic disorder tended to show more neurodevelopmental impairments, ADDH more cognitive and educational difficulties. These findings raise the possibility of heterogeneity in the disorders present with hyperactivity. The DSM-III-R category of ADHD was more common, and those extra cases, that did not overlap with ADDH or hyperkinetic disorder, included children with no obvious behavioural, cognitive or neurodevelopmental impairments. Hence ADHD may be an over-inclusive category. Prevalence rates for hyperkinetic disorder, ADDH and ADHD were respectively 0.78%, 6.1% and 8.9%.
Conclusions: A disorder of hyperactivity does exist in the Chinese culture, displaying the same kinds of symptomatology and external correlates as in the West. The prevalence rates of hyperkinetic disorder and ADDH in Chinese schoolboys are on the low side when compared to those reported in Western studies.