. Author manuscript; available in PMC: 2013 Aug 1.

Published in final edited form as: J Child Psychol Psychiatry. 2012 Feb 10;53(8):864–873. doi: 10.1111/j.1469-7610.2012.02527.x

Table 2.

Means and (standard deviation) of gender. age, IQ and TOWRE scores in ADHD probands, siblings of ADHD probands and unaffected controls.

		ADHD Probands (n=221)	ADHD siblings			Controls (n=245)	F / χ2	p
		ADHD Probands (n=221)	Affected (n=20)	Subthreshold (n=35)	Unaffected (n=201)	Controls (n=245)	F / χ2	p
Male %		89	55	60	45
Age		12.19 (2.58)	10.29 (2.77)	11.81 (3.24)	11.89 (2.97)	12.58 (2.33)	4.64	0.01
IQ		99.06 (14.66)	98.13 (15.66)	93.75 (14.46)	101.82 (13.39)	108.30 (13.78)	17.44	0.01
TOWRE		92.46 (16.73)	92.81 (16.92)	93.18 (15.94)	98.94 (14.94)	100.52 (14.63)	8.77	0.01
Centre %	a	0	0	0	0	0
	b	77	90	60	73	100
	c	23	10	40	27	0	85.18	0.01
	d	0	0	0	0	0

a= Netherlands

b=UK-London

c= UK-Southampton

d= Spain