Prevalence of attention deficit hyperactivity disorder in primary school children in Taiwan.

Chinese versions of Conners' Teacher's Rating Scale (CTRS) and the Werry-Weiss-Peters Activity Scale (WWPAS) were applied to 4,290 randomly selected primary school children in Kaohsiung. Using relative operational characteristic analysis to determine the best cut-off points, the validity of the WWPAS and CTRS for estimating the prevalence of attention deficit hyperactivity disorder (ADHD) was established. It was found that CTRS had satisfactory results, but the WWPAS did not have an optimal cut-off score. Using CTRS as a screening tool, the estimated overall prevalence rate of ADHD among Kaohsiung primary school children was found to be 9.9%, while the rate in boys (14.9%) was 3.3 times higher than in girls (4.5%). The assumption that hyperactivity is uncommon among Chinese children was proven to be unreliable.