Table 2.

Distribution of ADHD, ODD, CD, and Internalizing Symptoms in the Eyes-open Sample

Group differences
	TD	ADHD	t-value	p-value
ADHD measures
DISC ADHD symptoms (0–23)	3.87 ± 3.94 (69)	16.26 ± 4.20 (50)	−16.19	<0.001*
CBCL ADHD subscale t-score	51.28 ± 2.52 (75)	65.49 ± 7.09 (51)	−13.74	<0.001*
SNAP-IV total (0–20)	1.77 ± 2.4 (74)	11.72 ± 4.27 (50)	−14.97	<0.001*
Conners – Teacher Form
Inattentive t-score	49.39 ± 10.47 (18)	61.25 ± 11.77 (16)	−3.09	0.004*
Hyperactivity t-score	56.19 ± 16.72 (16)	74.69 ± 12.97 (16)	−3.50	0.002*
TRF ADHD subscale t-score	53.00 ± 4.33 (12)	58.85 ± 11.91 (6)	−1.16	0.29
Additional externalizing disorders
DISC ODD symptoms	5.32 ± 3.4 (68)	5.94 ± 2.84 (48)	−1.06	0.29
DISC CD symptoms	0.64 ± 1.32 (67)	1.17 ± 1.76 (50)	−1.78	0.08
Internalizing disorders
CBCL internalizing subscale t-score	45.78 ± 10.06 (74)	55.67 ± 9.8 (51)	−5.48	<0.001*
DISC GAD symptoms	1.57 ± 1.72 (68)	1.34 ± 2.02 (50)	0.66	0.51
DISC depression symptoms	2.75 ± 2.4 (68)	3.22 ± 2.77 (50)	−0.96	0.34

Note. Values are means ± SD, with the number of participants with scores for each measure in parentheses. As expected, the ADHD group had significantly more ADHD symptoms compared with the typically developing control group, with the exception of the Teacher Report Form (TRF), which was completed in a small number of total cases. There was a significant difference in internalizing subscale t-scores on the CBCL, and this measure was included in the regression models as a covariate. DISC, Diagnostic Structured Interview Schedule – young child version; CBCL, Child Behavior Checklist; SNAP-IV, Swanson Nolan and Pelham checklist; ODD, Oppositional Defiant Disorder; CD, Conduct Disorder; GAD, Generalized Anxiety Disorder.

^*p<0.05