Gorman 2006.

Study characteristics
Methods	Participants with ADHD took part in a randomly ordered, double‐blind, cross‐over clinical drug trial comprising 21 consecutive days of: MPH placebo
Participants	Number of participants screened: not stated Number of participants included: 43 Number of participants followed up: 41 (21 boys, 20 girls) Number of withdrawals: 2 Diagnosis of ADHD: DSM‐IV (combined (n = 22), hyperactive‐impulsive (n = 0), inattentive (n = 19)) Age: mean 9.08 years (range 6.26‐12.55) IQ: mean 107.66 MPH‐naive: 37 (out of 41, 90%) Ethnicity: white (92.67%) Country: USA Setting: outpatient clinic Comorbidity: > 2 anxiety disorders (12.16%), lifetime affective disorder (2.46%), ODD or CD (49.28%) Comedication: 0% Other sociodemographics: mean 50.43 (range 22‐66) (Hollingsworth socioeconomic status) Inclusion criteria 6‐12 years of age Diagnosis of ADHD according to DSM‐IV, and based on a combination of the Parent Interview for Child Symptoms‐4 and a semi structured interview IQ > 80 Normal or corrected vision and hearing No current use of medicine Exclusion criteria Physical disabilities; history of neurological disorder, chronic medical illness, bipolar disorder, schizophrenia or pervasive developmental disorder; and an episode of major depressive disorder within at least 6 months
Interventions	Participants were randomly assigned to 1 dose of MPH and placebo Mean MPH dosage: final daily dose 33.12 mg ± 1.36 (SE), range 25‐50 mg/d (0.94 ± 0.02 mg/kg) Administration schedule: twice/d Duration of each medication condition: 21 days Washout before trial initiation: not stated Medication‐free period between interventions: from lunch to the following morning Titration period: 0.25 mg/kg twice/d (breakfast and lunch) on days 1‐2; 0.25 mg/kg twice/d, plus 0.125 mg/kg at 4:00 pm on days 3‐7; 0.3 mg/kg twice/d and 0.15 mg/kg at 4:00 pm on days 8 to 14; and 0.4 mg/kg twice/d, and 0.2 mg/kg at 4:00 pm on days 15‐21. All dosages were administered to the nearest 2.5 mg Titration: took place after randomisation Treatment compliance: not stated. 4 participants with ADHD had undergone previous trials of stimulant therapy ranging from 2 weeks to 7 months
Outcomes	ADHD symptoms IOWA CTRS and IOWA CPRS: at the end of each treatment period (around day 21) Serious AEs 5 participants with ‘serious side effects’ were referred to, but no further information was given Non‐serious AEs Barkley and Murphy Side Effects Rating Scale, rated by an investigator, at the end of each treatment Weight, in street clothes and without shoes on a professional scale, at the end of each treatment period
Notes	Sample calculation: not described Ethics approval: yes Comment from trial authors "The unusually high proportion of girls reflects increasing sensitivity by clinicians to the identification of girls with ADHD as well as the awareness of our referring sources that we were trialling sex differences in ADHD" Key conclusions of trial authors ADHD subtypes benefited comparably from MPH treatment with respect to inattention Children with ADHD‐combined subtype underwent greater reductions in hyperactivity/impulsivity, but children with ADHD‐inattentive subtype also benefited in this respect Only children with ADHD DSM‐IV combined displayed a reduction in externalising problems under MPH. ADHD subtypes reacted comparably with stimulant treatment with respect to arithmetic performance, valence of teacher and parent comments and task‐incompatible behaviours ‐ all measures that do not distinguish between inattention, hyperactivity/impulsivity or oppositionality Somatic effects of treatment were comparable for subtypes Comment from review authors Chang et al. 2001 (in Gorman 2006) is a PhD thesis; the other 2 articles are based on data from this. We have not had access to the full thesis Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH before randomisation: no Any withdrawals due to AEs: not stated Funding source: NIMH Email correspondence with trial authors: January 2014. We obtained supplemental information from trial authors. Trial authors do not have the files anymore; therefore we are not able to obtain all of the data requested
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Answer from trial author: "Table of random numbers were used to make the allocation process, such that numbers ending in an even digit corresponded to one order and those ending in an odd digit to another" (Krogh 2014c [pers comm]
Allocation concealment (selection bias)	Low risk	Answer from trial author: "Table of random numbers were used to make the allocation process, such that numbers ending in an even digit corresponded to one order and those ending in an odd digit to another" (Krogh 2014c [pers comm]
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo capsules, identical in appearance and taste to those containing MPH, and administered on the same schedule
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Second author blinded. Placebo capsules, identical in appearance and taste to those containing MPH, and administered on the same schedule
Incomplete outcome data (attrition bias) All outcomes	Low risk	When parents reported serious side effects (n = 5), their children’s dosages were reduced, or planned increments were omitted. However, trial authors noted "eliminating participants who could not tolerate their assigned dosage might potentially skew the sample" Selection bias (e.g. titration after randomisation → exclusion of MPH non‐responders or placebo responders): no
Selective reporting (reporting bias)	High risk	Answer from trial author: "Event related potentials and performance measures on a cognitive task were not reported (I didn't attempt to publish the ERP data because the analyses I conducted did not yield significant results) ‐ And since we do not look at this outcome, we see it as low" (Krogh 2014c [pers comm])