. Author manuscript; available in PMC: 2016 Apr 22.

Published in final edited form as: J Child Adolesc Subst Abuse. 2015 Dec 31;25(2):159–179. doi: 10.1080/1067828X.2014.969856

Table 1.

Demographic characteristics of participants.

	ADHD N = 77 M (SD)	Non-ADHD N = 62 M (SD)	χ ^2/p
Average age at Wave 1^a	7.27 (1.14)	7.50 (1.04)	.23
Average age at Wave 2^b	9.49 (1.26)	9.69 (1.25)	.35
% Male	78%	61%	.04^*
% Caucasian	46%	52%	.43
Full-scale IQ	104.85 (13.40)	112.09 (16.16)	.01^*
Total number of inattention symptoms	6.95 (1.86)	1.76 (1.89)	<.001^*
Total number of hyperactivity/impulsivity symptoms	5.26 (2.70)	1.32 (1.70)	<.001^*
Total number of ADHD symptoms	12.21 (3.04)	3.08 (2.95)	<.001^*
Total number of ODD symptoms	3.16 (2.35)	1.02 (1.64)	<.001^*
% ODD diagnosis	44%	13%	<.001^*
Total number of CD symptoms	.61 (.83)	.24 (.50)	<.01^*
MMBEQ: Positive-social	18.58 (8.19)	20.58 (8.09)	.15
MMBEQ: Negative arousal	13.13 (5.37)	11.85 (4.14)	.13
MMBEQ: Sedated/impaired	11.99 (4.40)	11.84 (3.44)	.83
MMBEQ: Wild/crazy	14.66 (4.11)	13.90 (3.93)	.27

Note. ADHD D Attention Deficit/Hyperactivity Disorder, ODD D Oppositional Defiant Disorder, CD D Conduct Disorder, MMBEQ D Memory Model-Based Expectancy Questionnaire.

Age distribution at Wave 1: age 6 D 39, 28%; age 7 D 37, 27%; age 8 D 35, 25%; age 9 D 28, 20%.

Age distribution at Wave 2: age 8 D 31, 22%; age 9 D 42, 30%; age 10 D 30, 22%; age 11 D 26, 19%; age 12 D 9, 7%; age 13 D 1, <1%.

p < .05.