Raz 2009a.

Study characteristics
Methods	Design: parallel trial Comparison: omega‐3/omega‐6 PUFA vs placebo
Participants	Inclusion criteria: 1. children aged 7 to 13 years; 2. with a written diagnosis of ADHD from a child psychiatrist, neurologist, paediatrician, or clinical psychologist Exclusion criteria: 1. use of ADHD medication in the past month; 2. use of EFA supplements in the past 3 months; 3. presence of pervasive developmental disorder, seizure disorder, schizophrenia, major depression, or bipolar disorder Number of participants: 63 Mean age: 10.5 years Gender: 38 boys and 25 girls at follow‐up ADHD subtypes: combined = 44; inattentive = 29; hyperactive = 27 Using ADHD drugs at baseline: 0% Baseline scores: parent‐rated DSM‐IV attention subscale: PUFA = 4.05, placebo = 4.43; parent‐rated DSM‐IV hyperactivity‐impulsivity subscale: PUFA = 3.29, placebo = 3.14; teacher‐rated Conners ADHD: PUFA = 3.85, placebo = 3.71 Setting: Bar‐Ilan University, Tel‐Hashomer Israel and Hillel‐Yaffe Medical Center, Hadera, Israel, 2007 Funding: not stated
Interventions	Intervention (32 participants): omega‐3/omega‐6 PUFA for 7 weeks; an oral soft gel capsule containing 240 mg of linoleic acid, 60 mg of alpha‐linolenic acid, 95 mg of mineral oil, and 5 mg of alpha‐tocopherol, given twice daily Control (31 participants): placebo for 7 weeks; 500 mg of ascorbic acid as an oral tablet twice daily
Outcomes	ADHD symptoms at 7 weeks Parent‐rated DSM‐IV attention and hyperactivity‐impulsivity subscales Teacher‐rated Conners scale Side effects: nausea
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Comment: The method of randomisation was not described except that participants were matched for gender and age and then randomised within each pair.
Allocation concealment (selection bias)	Unclear risk	Comment: assignment of treatments was based on study number
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: The authors described the trial as double‐blind. However, active and control interventions were different i.e. soft gel capsules and tablets respectively.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Comment: The researchers, teachers, parents and children were all directly involved in data collection, and all were blinded to treatment allocation until the end of the study.
Incomplete outcome data (attrition bias) All outcomes	High risk	Comment: data reported for 63/78 enrolled participants who remained in the trial at 7 weeks, loss to follow‐up: 15/78
Selective reporting (reporting bias)	High risk	Comment: The authors stated that the Conners subscales were "found to be unreliable" (p169), but not how this was demonstrated. These data were not reported.
Other bias	Low risk	Comment: There were no statistically significant differences between groups in stimulant use, co‐morbidities, inattention, hyperactivity/impulsivity, EFA deficiency score or blood biochemistry.