Efficacy and Safety Study of Combination of Ginkgo Extract and Ginseng Extract in Children With ADHD(Attention Deficit Hyperactivity Disorder)

Inclusion Criteria: * Mele and female subjects aged from 6 to 15 * Subjects must meet DSM-IV criteria for ADHD based-on the K-Schedule for affective disorder and schizophrenia(K-SADS-PL-K)interview * Subjects signed a written consent form voluntarily * Patient's assent to participate in the study and written informed consent form signed by one of the parents, parent surrogates or legal guardian. * Subjects who can keep visit schedule and whose parent/parent surrogates or legal guardian can willingly complete assessments defined in the study protocol. * Subjects/parents, parent surrogates or legal guardian who can understand the participation of the study and voluntarily withdraw from the study at any time. Exclusion Criteria: * Subjects who have difficulty swallowing tablet. * Subjects who have known allergy to plant extracts. * Subjects who meet DSM-IV diagnostic criteria for current major depressive disorder or anxiety disorder requiring drug therapy. * Subjects who have any history of bipolar disorder, psychotic disorder, and substance use disorder, have been diagnosed with a pervasive developmental disorder, organic brain disease and seizure disorder. * Subjects who have significant suicidal ideation. * Subjects with mental retardation. * Subjects with Tourette's syndrome requiring drug therapy. * Subjects who have been administrated Methylphenidate or Atomoxetine within recent 3 months and Ginkgo extract or Ginseng extract within recent 1 month. * Subjects who currently have a significant medical conditions(e.g. diseases of cardiovascular, hepatic, renal, respiratory, glaucoma) * Subjects who have abnormalities in the ECG or show clinically significant abnormalities of laboratory results including serum chemistries and hematology. * subjects who are currently taking alpha-2 adrenergic receptor agonist, antidepressant, antipsychotic, benzodiazepines, modafinil, anticonvulsant. * subjects who receive psychosocial treatment during the drug trial. * Subjects who are not able to swallow the study drug.