Kim 2015a.

Methods	A cohort study of methylphenidate use for 12 weeks
Participants	Number of participants screened: not stated Number of participants included: 86 Number of participants followed up: 37 Number of withdrawals: 49 Diagnosis of ADHD: DSM‐IV (subtype: inattentive, hyperactive‐impulsive or both) Age: mean 8 IQ: > 70 Sex: 34 males, 3 females Methylphenidate‐naïve: 2‐month washout period prior to study Ethnicity: not stated Country: Korea Comorbidity: none Comedication: none Sociodemographics: none Inclusion criteria Patients diagnosed at the Korea University Medical Centre between August 2007‐December 2010 attending outpatient clinic Showing signs and symptoms of either inattention or hyperactivity‐impulsivity or both according to DSM‐IV‐TR criteria for ADHD Exclusion criteria Medical problems requiring special attention such as cardiovascular disorders, learning disabilities and mental retardation Other psychiatric comorbidities
Interventions	Methylphenidate type: immediate release or extended release Mean methylphenidate dosage: 22.23 (SD 8.93) mg/0.70 (SD 0.20) mg/kg Administration schedule: not stated Duration of intervention: 12 weeks Treatment compliance: 43% completed 12 week programme
Outcomes	Non‐serious adverse events: All participants were evaluated for adverse events during each visit, and an interview with their care providers was conducted
Notes	Sample calculation: no Ethics approval: study approved by Institutional Review Board of Guro Hospital, Korea University Medical Center Funding/vested interests: financial support from Jun Sang‐Bae Child and Adolescent Psychiatry Research Grant from the Korean Foundation of Neuropsychiatric Research Key conclusions of the study authors: HF and RMSSD suggested that parasympathetic dominance in ADHD can be changed by methylphenidate treatment Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: not stated Supplemental information requested twice from the study authors in May and June 2016 with no reply