This study will evaluate clinical efficacy and safety of treatment with YY-162 in children with ADHD.

This is Double-Blind, two arms, multi-center, Interventional, 8 weeks study starting with YY-162(Combination of Ginkgo extract and Ginseng extract)in children with ADHD. Assessment of efficacy and safety will be performed at the baseline, weeks 2, 4 and 8. At the first visit, a full psychiatric history, demographic date and physical examination will be undertaken. Throughout the study, the following procedures, documentations and evaluations will performed; K-ARS, IOWA conner's rating scale, CGI-S/I, ATA, Children's color trails test and stroop test, intelligence test(from KEDI-WISC)and adverse event reporting.

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.