Table II.

Descriptive Summary of Data for Study Variables

Variable	Mean (SD)	Range in sample	Proportion of Missing Data
Cognitive Variables:
Estimate of IQ (scaled scores)	9.73 (2.8)	2.0-17.5	1%
Letter Canc. Task: Time z- score	−.002 (1.1)	−8.6-2.3	4%
Letter Canc. Task: Total Errors z- score	23 (.89)	−3.0-2.8	4%
Number Canc. Task: Time z- score	−.02 (1.1)	−4.8-2.1	4%
Number Canc. Task: Total Errors z- score	.10 (.94)	−6.0-2.5	4%
Symbol Canc. Task: Time z- score	.08 (1.9)	−15.9-2.8	5%
Symbol Canc. Task: Total Errors z- score	.35 (.82)	−1.3-3.0	5%
Trails B Time Score z- score	−1.1 (1.9)	−15.9-1.66	6%
CPT Total Index Score	9.0 (6.6)	0-30	4%
CPT Commissions T-Score	47.8 (10.3)	19-75	4%
CPT Omissions T-Score	42.0 (8.6)	15-72	4%
WISC Attention (scaled scores)	9.5 (2.7)	1-18	2%
Connors Behavior Report T-Scores			4%
Oppositionality	53.9 (11.2)	31-90
Cognitions	53.8 (11.6)	41-90
Hyperactivity	56.0 (11.4)	42-90
ADHD	54.6 (10.7)	40-90
Psychological Variables
Anxiety	47.4 (18.4)	9-95	6%
Depressive Symptoms (T-score)	44.5 (9.6)	0-82	2%