Table 1. Age, gender and test scores of participants by group, N = 565.

Group	ADHD (n = 401)	ASD (n = 85)	Controls (n = 79)	P
Age: M ± SD	9.10 ± 3.58	5.31 ± 2.12	8.32 ± 2.53	<0.001a
Gender: % boys	79.6	80.0	77.2	0.883
Tests of Variable Attention: M ± SD	-3.78 ± 3.28	N/A	3.85 ± 1.67	<0.001
ADHD scaleb	42.43 ± 14.43	N/A	14.11	<0.001
CARS	N/A	40.71 ± 8.04	N/A	N/A

^apost-hoc analysis: ADHD children were significantly different from ASD children; ASD children were significantly different from controls.

^bAustralian Twin Behaviour Rating Scale (ATBRS)