Prevalence, incidence, and stimulant use of attention-deficit hyperactivity disorder in Taiwan, 1996-2005: a national population-based study.

Purpose: We used National Health Insurance (NHI) database to examine the prevalence, incidence, and stimulant use of attention-deficit hyperactivity disorder (ADHD) diagnosis in Taiwan.

Methods: The National Health Research Institute provided a database of 10,00,000 random subjects for study. A population-based random sample of 372,642 patients aged younger than 18 was obtained as a dynamic cohort. Those study subjects who had at least one service claim from 1996 to 2005, with a principal diagnosis of ADHD, were identified.

Results: The cumulative prevalence of ADHD diagnosis increased from 0.06 to 1.64 % from 1996 to 2005. The annual incidence of ADHD diagnosis increased from 0.02 to 0.34 % from 1997 to 2005. The highest incidence rates of ADHD diagnosis for both males and females were in the 6- to 11-year age group. Higher incidence was detected in males (HR 3.76, 95 % CI 3.48-4.07), those who lived in northern region (HR 1.35, 95 % CI 1.07-1.71) and urban area (HR 1.53, 95 % CI 1.40-1.66). The percentage of stimulant use in children with ADHD diagnosis increased from 39.6 to 54.0 % from 1997 to 2005.

Conclusions: Our findings suggest increases in the prevalence and incidence rates of ADHD diagnosis in Taiwan, which was in line with those studies of Western countries. However, the prevalence of ADHD diagnosis in the NHI program was still much lower than in the community studies. The percentage of stimulant use in children with ADHD diagnosis also has an increasing trend, which warrants further study.