Table 1.

Demographics of study participants.

	HC	MA
No. of subjects	n = 89	n = 56
			F	df	P
Age (years)	31.7 (8.3)	33.8 (8.2)	2.4	111	0.15
Years education	14.8 (2.1)	12.6 (1.3)	4.4	107	0.04
Years maternal education	14.4 (2.7)	12.7 (2.7)	12.1	105	0.001
			χ2	df	P
% Married	20.2	5.4	8.0	3	0.05
% Unemployed	25.8	80.3	46.1	2	<0.001
Gender
% Male	50.6	62.5	2.0	1	0.16
Ethnicity			20.0	5	0.001
% White	66.3	53.6
% Black	12.4	1.8
% Hispanic	5.6	26.8
% Asian	10.1	3.6
% Native American	0.0	1.8
% Other	5.6	12.5
% Parole/probation	0.0	21.4	23.3	2	<0.001
Substance use
% Smokers	44.9	91.1	13.2	1	<0.001
Average years of MA use	NA	11.1 (7.2)
Average days of use/30 days	NA	20.4 (8.6)

Continuous variables are listed as mean of each group with adjacent standard deviation in parentheses. Demographic variables were analyzed by two-way analysis of variance comparisons (continuous variables) or Pearson’s χ² comparisons (categorical variables) to assess for statistical significances of differences in demographic profile information between study groups, as listed in Table 1. P values reaching statistical significance (<0.05) are shown in bold type. HC: healthy controls; MA: methamphetamine; NA: not applicable.