Table 1.

Descriptive data of the sample distribution according to COMT genotype.

	val/val	met+	χ2	df	P
N	61	94	–	–	–
Sex (%female)	59.00	59.60	<0.01	1	0.95
	Mean (SD)	Mean (SD)	t	df	P
Age (years)	9.61 (1.20)	9.81 (1.10)	−1.08	153	0.28
Raven (z-score)	0.43 (0.75)	0.52 (0.70)	−0.82	153	0.41