Heavy metal has been reported that it can cause attention deficit and behavioral disturbance. The investigators hypothesis is that heavy metal is associated with children with attention deficit/hyperactivity disorder(ADHD).

Inclusion Criteria:

• 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/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 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 or homicidal ideation
• Subjects with mental retardation
• Subjects with Tourette's syndrome requiring drug therapy.
• 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 have been administrated alpha-2 adrenergic receptor agonist,antidepressant, antipsychotic, benzodiazepines, modafinil, anticonvulsant within recent 2 months.
• Subjects who dyed their hair within 8 weeks

Subjects must meet DSM-IV criteria for ADHD based-on the K-Schedule for affective disorder and schizophrenia(K-SADS-PL-K) interview