. Author manuscript; available in PMC: 2017 Jul 1.

Published in final edited form as: Biol Psychiatry Cogn Neurosci Neuroimaging. 2016 Apr 13;1(4):353–363. doi: 10.1016/j.bpsc.2016.03.008

Table 1.

Participant characteristics.

	Controls (C) N=122		ADHD (A) N=169		Test Statistic		Subthreshold N=64		Siblings N=89
Demographic (Mean, SD)
Age, years	17.04	2.98	17.89	3.07	t(289)=2.36^*	A>C	18.37	3.32	17.63	4.12
IQ ^a	106.6	13.9	96.08	15.1	t(289)=−6.08^**	A<C	100.7	12.9	102.1	14.9
Medication use, years	-	-	2.41	3.12	-	-	1.95	3.13	0.002	0.01
Motion ^b	0.125	0.09	0.140	0.10	t(289)=1.35	-	0.129	0.09	0.113	0.09
Demographic (Number, %)
Sex, male	54	44.3	123	72.8	X²(1)=24.18^**	A>C	38	59.4	35	39.3
Scan location, Nijmegen	48	39.3	92	54.4	X²(1)=6.65^*	A>C	36	56.3	46	51.7
ODD ^c	-	-	46	27.2	-	-	8	12.5	2	2.25
CD ^d	-	-	6	3.80	-	-	-	-	-	-
Clinical (Mean, SD)
Hyperactive/impulsive symptoms ^e	46.45	5.24	69.59	14.2	t(289)=17.19^**	A>C	54.70	11.70	47.71	6.46
Inattentive symptoms ^e	46.12	5.72	66.09	10.9	t(289)=18.49^**	A>C	54.07	8.57	46.81	6.16

Estimated IQ based on Wechsler Intelligence Scale for Children or Wechsler Adult Intelligence Scale–III Vocabulary and block design (52, 53).

Motion as measured by frame-wise displacement (40)

Oppositional Defiant Disorder (ODD)

Conduct Disorder (CD)

Conners Parent Rating Scale questionnaire, standardized T-score (38). Range min. 40 to max. 90 (≥63 is clinical threshold). The test statistics only compare the ADHD and control group given that only these groups were included in the categorical analysis. The dimensional analyses included all participants listed in this table independent of diagnostic label

p<.05

^**

p < .001.