Chazan 2011.

Methods	An open clinical trial of methylphenidate use for 6 months
Participants	Number of participants screened: 189 Number of participants included: 130 Number of participants followed up: 125 Number of withdrawals: 5 Diagnosis of ADHD: DSM‐IV (subtype: combined (63.1%), hyperactive‐impulsive (7.7%), inattentive (23.1%)) Age: mean 9.8 (2.8) years (range 5‐17) IQ: mean 92.34 (12.61) Sex: 96 males, 34 females Methylphenidate‐naïve: 86.9% Ethnicity: white: 77.7% Country: Brazil Comorbidity: ODD (46.9%); CD (13.1%); any mood disorder (13.1%); any anxiety disorder (40.8%) Comedication: yes Sociodemographics: classes: A + B (55%); C + D (45%) Inclusion criteria Age between 5 and 17 years ADHD diagnosis according to DSM‐IV Primary indication of treatment with methylphenidate Exclusion criteria Refusal or contraindication for methylphenidate use Estimated IQ < 70
Interventions	Methylphenidate type: immediate release and extended release Mean methylphenidate dosage: 0.48 mg/kg/day (SD 0.22) Administration schedule: not stated Duration of intervention: 6 months Treatment compliance: 76.4% adherence
Outcomes	Barkley side effects rating scale
Notes	Sample calculation: no Ethics approval: yes Funding: this work was supported by research grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Brazil; Edital MCT/CNPq 02/2006‐Universal, 478202/2006‐7) and Hospital de Clínicas de Porto Alegre Vested interests/authors' affiliations: Prof Rohde has served as a speaker and/or consultant for Eli‐Lilly, Janssen‐Cilag, and Novartis for the last 3 years. Currently, his only industry‐related activity is taking part in the advisory board/speakers' bureau for Eli Lilly, Novartis, and Shire (USD 10,000 per year and reflecting 5% of his gross income per year). The ADHD and Juvenile Bipolar Disorder Outpatient Programs chaired by him received unrestricted educational and research support from the following pharmaceutical companies in the last 3 years: Abbott, Bristol‐Myers Squibb, Eli‐Lilly, Janssen‐Cilag, Novartis, and Shire. Prof Polanczyk has served as a speaker for Novartis. Drs Chazan, Borowski, Pianca, and Ludwig report no conflict of interest Key conclusions of the study authors: our results suggest that ADHD combined subtype, maternal ADHD symptoms, and social adversities are independent negative predictors of methylphenidate response in children and adolescents with ADHD. Our study provides evidence for the involvement of clinical characteristics, maternal psychopathology, and environmental stressors in the response to methylphenidate Exclusion of methylphenidate non‐responders/children who have previously experienced adverse events on methylphenidate: not stated