Metabolic Mechanisms of the Electrophysiological Biomarkers for Response to Methylphenidate Treatment in Children With ADHD

1. Patients with ADHD 1. Inclusion Criteria - Patients, aged 6 to 18 years, meet the DSM-5 diagnostic criteria for ADHD. - At baseline, patients have a Clinical Global Impressions-ADHD-Severity (CGI-ADHD-S) score greater than 4. - Patients have a Full IQ (FIQ) score greater than 80. 2. Exclusion Criteria - Patients have a major psychiatric disorder, such as autism spectrum disorder, schizophrenia, affective disorders, or substance use disorders. - Patients have a major disorder of central nervous system, such as epilepsy. - Patients have a major systemic disease, such as diabetes mellitus or cardiovascular diseases. - Patients have ever received any medication to treat the clinical symptoms of ADHD. 2. Neurotypical participants: 1. Inclusion Criteria - aged 6 to 18 years - All of the neurotypical participants have no psychiatric disorder in lifetime according to the diagnostic criteria of DSM-5. 2. Exclusion Criteria - participants have any disorder of central nervous system or major systemic disease - participants have ever taken any psychotropic drug, or who have FIQ scores less than 80, will be excluded from the present study. Always talk to your doctor about whether this trial is right for you.