Arnold 1989

Methods	Cross‐over trial of omega‐6 PUFA, dexamphetamine and placebo
Participants	Inclusion criteria: children of normal intelligence aged between 6 and 12 years with a DSM III diagnosis of ADHD by a child psychiatrist, a score of at least 18 on the Conners hyperactivity index and a score of at least 24 on the first 6 items of David's Hyperkinetic Rating scale Median age: 9 years, gender: all 18 were boys, loss to follow‐up: unclear, 18 participants completed Exclusion criteria: psychoactive drug use in the preceding week or history of seizures Baseline scores: not stated Setting: Ohio, US
Interventions	Cross‐over trial of omega‐6 PUFA, d‐amphetamine and placebo for 1 month each.  All were given as 4 capsules twice daily for 1 month. Omega‐6 PUFA Efamol® capsules: contained 500 mg evening primrose oil which provides 350 mg linoleic acid and 40 mg gamma linolenic acid, 13 IU vitamin E as preservative Dextroamphetamine: a 10 or 15 mg time‐released capsule Placebo: paraffin oil
Outcomes	ADHD symptoms Teacher‐rated Conners total score and hyperactivity index at 2 and 4 weeks
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not stated
Allocation concealment (selection bias)	Unclear risk	Not stated
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Placebo was described as matched
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Behavioural ratings were blinded
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not stated
Selective reporting (reporting bias)	High risk	Unclear what other outcomes were used. A parent rating of the Conners scale appears to have been used but was not reported because it was "noncontributory".
Other bias	Unclear risk	Baseline characteristics of each group were not reported. Results for a Psychiatrists' Global Rating were reported but this scale was not described. Study funded by Efamol Research Institute.