Borcherding 1990.

Methods	Single‐center, randomized, double‐blind, placebo‐controlled, cross‐over trial Country: United States Number of study sites: 1 Statistical methods: ITT (all randomized children/adolescents are included in the analysis, with any missing data imputed with the group mean value)
Participants	Sample size: 46 children/adolescents with an ADHD diagnosis according to DSM‐III criteria Dropouts: NR Psychiatric comorbid conditions: oppositional defiant disorder, conduct disorder, reading developmental disorder, arithmetic disorder, dysthymic disorder Age range: 6 years to 12 years Mean age (SD): 8.6 (1.7) years Sex: 46 (100%) males ADHD subtype: NR
Interventions	Three interventions (all 46 children/adolescents participated in each of the three interventions): Dextroamphetamine (short acting), weight‐based dosing increasing each week (children < 30 kg (66 lbs) received 10, 25, and 40 mg/day, twice a day; children/adolescents > 30 kg (66 lbs) received 15, 30, and 45 mg/day, twice a day), (n = 46) Methylphenidate hydrochloride, weight‐based dosing increasing each week (children < 30 kg (66 lbs) received 25, 40, and 70 mg/day, twice a day; children/adolescents > 30 kg (66 lbs) received 30, 50, and 90 mg/day, twice a day), (n = 46) Placebo (n = 46) Duration: 63 days (3 x 21‐day treatment periods)
Outcomes	Relevant outcomes: ADHD core symptom severity, assessed with Conners' Teacher Rating Scale ‐ Short Form* and Conners' Parent Rating Scale ‐ Long Form Clinical impression, assessed with Clinical Global Impressions ‐ Improvement scale Academic performance, assessed with: the Barnell Loft, Ltd, Developing Key Concepts in Math test Retention: proportion of participants who completed the trial Adverse events Other outcomes: Nervous habits/mannerisms, compulsive acts and obsessive thinking assessed with Children's Psychiatric Rating Scale Urine biochemistry Plasma biochemistry Renal clearance Cognitive ratings, assessed with Conners' Continuous Performance Test
Notes	ClinicalTrials.gov identifier: not available Authors' affiliation: National Institute of Mental Health Study funding: NR Outcomes were presented across four publications with varying sample sizes *Unpublished data on the ADHD symptoms as rated by the Conners' Teacher Rating Scale ‐ Short Form were sought on three separate occasions but were not obtained
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method of sequence generation not described
Allocation concealment (selection bias)	Unclear risk	Method of allocation concealment not described
Incomplete outcome data (attrition bias) All outcomes	High risk	This study has four associated publications, and all reports have varying numbers of participants. Upon communication with the corresponding author of these reports, it was confirmed that the numbers of participants vary in the four publications due to missing data and dropouts. Reasons for missing data not provided
Selective reporting (reporting bias)	Unclear risk	Study protocol not available and the possibility of reporting bias could not be assessed
Other bias	Unclear risk	No information on the validity of the primary outcome measure provided
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Blinding of participants and personnel not described
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of outcome assessment not described