Table 1.

Demographic data

Variables	Control group	Cocaine users	Value	df	P value
Study I
Male/female participants, n, total	42/21, 63	59/21, 80	χ2 = 0.85*	1	0.36
Age, y	29.65 (8.95)	30.06 (9.00)	t = −0.27†	141	0.79
Education, y	10.51 (1.74)	10.07 (1.73)	t = 1.50†	141	0.14
Verbal IQ	105.22 (9.99)	102.74 (11.22)	t = 1.38†	141	0.17
Smoker/nonsmoker, n	46/17	64/16	χ2 = 0.97*	1	0.33
FTND sum score, 0–10‡	2.46 (2.20)	3.85 (2.43)	t = −3.10†	110	<0.01
BDI sum score, 0–63	4.06 (3.89)	9.36 (7.91)	t = −4.90†	141	<0.001
Social network size§	26.41 (13.19) (n = 60)	19.94 (12.05) (n = 72)	t = 2.94†	130	<0.01
Study II
Male/female participants, n, total	12/4, 16	12/4, 16	χ2 = 0.00*	1	1.00
Age, y	32.63 (8.33)	33.38 (9.12)	t = −0.24†	30	0.81
Education, y	11.25 (1.61)	11.00 (1.51)	t = 0.45†	30	0.65
Verbal IQ	106.63 (11.16)	104.56 (10.62)	t = 0.54†	30	0.60
Smoker/nonsmoker, n	9/7	11/5	χ2 = 0.53*	1	0.47
FTND sum score, 0–10‡	1.63 (1.85)	4.40 (3.63)	t = −1.96†	16	0.07
BDI sum score, 0–63	2.63 (2.53)	6.94 (8.63)	t = −1.92†	30	0.07
Social network size§	24.88 (14.39)	20.20 (13.43) (n = 15)	t = 0.93†	29	0.36

Significant P values are shown in bold. Means and SD of means are in parentheses.

^*χ² test (across all groups) for frequency data.

^†Independent t test.

^‡FTND was measured in smokers only.

^§Measured by the Social Network Questionnaire.