Kim 2014b.

Methods	A naturalistic cohort study of methylphenidate use for 8 weeks
Participants	Number of participants screened: not stated Number of participants included: 75 Number of participants followed up: 57 Number of withdrawals: 18 Diagnosis of ADHD: DSM‐IV (subtype: combined (48%), hyperactive‐impulsive (12%), inattentive (24%), not specified (16%)) Age: mean 9.7 (SD 2.8), range 6‐16 years old IQ: not stated Sex: 61 males, 14 females Methylphenidate‐naïve: not stated Ethnicity: not stated Country: Korea Comorbidity: 4 had oppositional defiant disorder, 5 had conduct disorder, 6 had anxiety disorder, 6 had learning disorder, 10 had depressive disorder, and 10 had mild to moderate intellectual disabilities Comedication: not stated Sociodemographics: yearly household income > USD 4000 = 23 (30.7%), USD 2000‐4000 = 20 (26.7%),< USD 2000 = 12 (16.0%), unknown = 20 (26.7%) Inclusion criteria: Children and adolescents aged 6‐16 with a DSM‐IV diagnosis of ADHD, with no baseline physical or laboratory abnormalities; were able to comply with the study visitation schedule and express a voluntary wish to withdraw from the trial
Interventions	Methylphenidate type: osmotic release oral system (OROS) Mean methylphenidate dosage: 36.3 (SD 15.5) mg/day Administration schedule: not stated Duration of intervention: not stated Treatment compliance: not stated
Outcomes	Non‐serious adverse events: Children who withdrew from the study because of adverse events
Notes	Sample calculation: no Ethics approval: not stated Funding/vested interests: the authors declare that they have no conflict of interest, and the organisation that sponsored the research had no part in the writing of the manuscript Key conclusions of the study authors: methylphenidate treatment for ADHD was associated with both symptom alleviation in children with ADHD and improvement in parental depressive mood and quality of life, suggesting that the effects of treatment could go beyond symptom improvement in ADHD Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: no