1. Comparison 1: valproate versus placebo: aggression, observer‐reported (skewed data).

Study	Outcome	n(Exp)	Mean(Exp)	SD(Exp)	n(Cntrl)	Mean(Cntrl)	SD(Cntrl)	Statistic	Notes
Hellings 2005 20 mg/kg/day	OAS total score, at 8 wks (mean of wks 6, 7 & 8)	16	5.86	3.84	14	5.72	4.62	P = 0.96 (2‐sided Wilcoxon rank sum test)	Favours neither condition
Stanford 2005 750 mg/day	OAS aggression score, at 2 wks	7	2.02	1.95	8	4.38	1.86	F1,13 = 16.92 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.57; power = 0.97); treatment OAS aggression score significantly lower compared with the placebo group. Significant main effect by time (3 interventions of which valproate was one; baseline, 2, 4, 6 wks); F3,75 = 3.41;P = 0.02; partial eta2 = 0.12; power = 0.78).	Favours valproate Completer analysis (see note 1)
Stanford 2005 750 mg/day	OAS aggression score, at 4 wks	7	2.80	2.30	8	4.49	2.14	F1,13 = 16.92 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.57; power = 0.97); treatment OAS aggression score significantly lower compared with the placebo group Significant main effect by time (3 interventions of which valproate was one; baseline, 2, 4, 6 wks); F3,75 = 3.41;P = 0.02; partial eta2 = 0.12; power = 0.78)	Favours valproate Completer analysis (see note 1)
Stanford 2005 750 mg/day	OAS aggression score, at 6 wks	7	0.62	1.99	8	5.40	1.86	F1,13 = 16.92 (repeated measures ANOVA; P = 0.001; partial eta2 = 0.57; power = 0.97); treatment OAS aggression score significantly lower compared with the placebo group Significant main effect by time (three interventions of which valproate was one; baseline, 2, 4, 6 wks); F3,75 = 3.41; P = 0.02; partial eta2 = 0.12; power = 0.78).	Favours valproate Completer analysis (see note 1)

1. Data extracted from graph provided in study paper and confirmed by inspection of original Excel file supplied by lead author (email to J. Dennis 22 January 2009)

OAS = Overt Aggression Scale; wks = weeks