ADHD  Inclusion Criteria:  Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition The diagnosis of each child had to be made by a child psychiatrist in a structured interview that employed the Kiddie Epidemiologic Version of the Schedule for Affective Disorders and Schizophrenia (K-SADS-E)  Exclusion Criteria:  History of neuropsychiatric diseases Any known major physical illnesses Taken any medication to treat ADHD  Health  Inclusion Criteria:  Age- and gender-matched children without ADHD  Exclusion Criteria:  History of neuropsychiatric diseases Any known major physical illnesses