Hoeppner 1997.

Study characteristics
Methods	Double‐blind, cross‐over trial with 2 interventions: HD‐MPH LLD‐MPH placebo 4 orders Placebo, LD‐MPH, HD‐MPH HD‐MPH, placebo, LD‐MPH Placebo, HD‐MPH, LD‐MPH LD‐MPH, placebo, HD‐MPH
Participants	Number of participants screened: 95 Number of participants included: 50 Number of participants followed up: 50 (39 boys, 11 girls) Number of withdrawals: none Diagnosis of ADHD: DSM‐III‐R Age: mean 9.6 years (range 6‐18.1) IQ: not stated MPH‐naive: not stated Ethnicity: not stated Country: USA Setting: outpatient clinic Comorbidity: not stated Comedication: not stated Other sociodemographics: none Inclusion criteria Meeting DSM‐III‐R ADHD, DSM‐III ADD or DSM‐III‐ADD/H criteria Score ≥ 1½ SD above the norm on the CPRS or the CTRS Exclusion criteria No information
Interventions	Participants were randomly assigned to different possible orders of HD‐MPH (0.3 mg/kg), LD‐MPH (0.15 mg/kg) and placebo (doses rounded up to the nearest 2.5 mg) Mean MPH dosage: not stated Administration schedule: twice/d, 8:00 am and 12:00 pm Duration of each medication condition: 1 week Washout before trial initiation: "received an appropriate wash‐out period" Medication‐free period between interventions: from lunchtime until next morning, 20 h Titration period: none Treatment compliance: not stated
Outcomes	ADHD symptoms CPRS, CTRS: completed daily
Notes	Sample calculation: no Ethics approval: no information Comments from trial authors Dependent measures in this trial often failed to detect significant dose‐response effects when analysed individually, and placebo effect were found for 4 of the 9 measures. Although ratings from the Conners' Parent and Teacher Rating Scales were sensitive to dose‐response effects, findings were not uniform across raters and did not correspond with cognitive response Small sample size Key conclusion of trial authors According to cognitive rank order ratings, linear and quadratic MPH response patterns were identified, with the best dose for each group significantly different from that obtained for all other conditions Exclusion of MPH non‐responders/children who have previously experienced AEs while taking MPH before randomisation: no Any withdrawals due to AEs: no Funding source: not declared Email correspondence with trial authors: March 2014. Emailed trial authors to request additional information but have received no reply
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No information
Allocation concealment (selection bias)	Low risk	Pharmacists randomly assigned participants to 1 of 4 trial sequences
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Placebo consisted of an opaque capsule filled with lactose; active drug consisted of the same lactose‐filled capsule, to which MPH was added
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Placebo consisted of an opaque capsule filled with lactose; active drug consisted of the same lactose‐filled capsule, to which MPH was added
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts Selection bias (e.g. titration after randomisation → exclusion): no
Selective reporting (reporting bias)	Low risk	No indication of reporting bias