Donnelly 1989.

Methods	Single‐center, randomized, double‐blind, placebo‐controlled, cross‐over trial Country: United States Number of study sites: 1 Statistical methods: ITT
Participants	Sample size: 20 children/adolescents with an ADHD diagnosis according to DSM‐III criteria Dropouts: NR Psychiatric comorbid conditions: oppositional defiant disorder, conduct disorder, mental learning disorder, language disorder Age range: NR Mean age (SD): 8 (2) years Sex: 20 (100%) males ADHD subtype: NR
Interventions	Three interventions (all 20 children/adolescents participated in each of the three interventions): Dextroamphetamine (short acting), weight‐based dose, 0.5 mg/kg/day, twice a day, (n = 20) Fenfluramine hydrochloride, weight‐based dosing increasing each week (0.6 mg/kg/day, 1.3 mg/kg/day, 2.0 mg/kg/day), twice a day, (n = 20) Placebo (n = 20) Duration: 63 days (3 x 21‐day treatment periods)
Outcomes	Relevant outcomes: ADHD core symptom severity, assessed with Conners' Teacher Rating Scale ‐ Short Form Clinical impression, assessed with Clinical Global Impression scale* Adverse events Other outcomes: Vigiliance/attention and impulsivity, assessed with Conners' Continuous Performance Test Motor activity, assessed with activity monitor Biochemical and platelet measures (urine and plasma) Measures of prolactin
Notes	ClinicalTrials identifier: not available Authors' affiliation: university and National Institute of Mental Health Study funding: NR Donnelly 1986 is a pilot study of Donnelly 1989 and therefore have overlapping data *Unpublished data on the Clinical Global Impression scale sought on three separate occasions but not obtained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	Low risk	All recruited children/adolescents included in analyses. Only one dropout, with reasons 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