The rationale of this proposal is based upon the high prevalence (7.5% in Taiwan (Gau et al., 2004b)), the magnitude of the short- and long-term impact on individuals, family, and society, the responsibility of attention-deficit hyperactivity disorder ADHD to treatments with CNS stimulants and Atomoxetine. Although numerous studies have shown that methylphenidate demonstrates significant effect on improving neuropsychological functioning including inhibition of executive function (e.g., Aron et al., 2003; Kempton et al., 1999; Konrad et al., 2004) and motor control measures (e.g., Moll et al., 2000), there has been no study examining the effect of Atomoxetine on the improvement of response inhibition or other neuropsychological functioning among children with ADHD. As several clinical trials have shown the efficacy of Atomoxetine in improving the core symptoms of ADHD (e.g., Eiland and Guest, 2004; Michelson et al., 2002) and Atomoxetine has been approved by FDA as first line medication for child and adult ADHD in 2002, we anticipate that Atomoxetine will demonstrate significant efficacy on treating ADHD by improvement of neuropsychological measures.

The objectives of this study are:

1. To examine the efficacy of atomoxetine on executive functioning measures including the Continuous Performance Test (CPT) and the executive function measures of the Cambridge Automated Neuropsychological Test Automated Battery (CANTAB).
2. To examine the efficacy of atomoxetine on other neuropsychological measures including the Wisconsin Card Sorting Test (WCST), and the attention, memory, and paired learning tests of the CANTAB.
3. To validate the ADHD using psychopathological, neuropsychological, functional brain imaging, behavioral, and social correlates.

This study is an open label, non randomized, clinical trial with daily dose of atomoxetine 1.2 mg/kg for subjects with ADHD. Thirty drug-naïve children with DSM-IV ADHD and 30 normal children matched in sex, age, and IQ will be recruited. All of the participants will be assessed by the CPT, WSCT, CANTAB, and several measures covering domains of ADHD symptoms and social functioning. Subjects with ADHD will be reassessed using the neuropsychological tests and other measures on Week 4 (Visit 2) 3 days, Week 12 (Visit 2) 3 days of treatment with atomoxetine 1.2 mg/kg.

The sample will consist of 30 subjects with ADHD, aged 10 to 15, and 30 subjects without ADHD, who are matched in age, sex, and IQ as cases. We anticipate that this study will provide enough evidence to support the efficacy of Atomoxetine not only on the symptoms improvement but also neuropsychological measures and fMRI studies among children with ADHD.