Table 2.

Bivariate Pearson’s Correlations of Study Variables

	1	2	3	4	5	6	7	8	9	10	11	12
1. Tobacco use age 17	1
2. Tobacco use age 22	0.44**	1
3. Alcohol use age 17	0.26**	0.19**	1
4. Alcohol use age 22	−0.02	0.20**	0.30**	1
5. Cannabis use age 17	0.32**	0.30**	0.46**	0.22**	1
6. Cannabis use age 22	0.10*	0.31**	0.29**	0.28**	0.37**	1
7. Friends’ use age 17	0.13*	0.06	0.12**	0.06	0.10*	0.00	1
8. Friends’ use age 22	−0.01	0.04	0.12**	0.15**	0.12*	0.09*	0.01	1
9. Onset illicit drugs	0.12**	0.23**	0.13**	0.20**	0.11*	0.20*	−0.04	0.21*	1
10. Abuse/dependence tendency	0.15**	0.28**	0.25**	0.10*	0.19**	0.28**	−0.02	0.15*	0.41**	1
11. Income	−0.07	−0.17**	0.13**	0.28**	−0.06	0.10*	−0.03	0.17**	0.10*	−0.03	1
12. Sex	0.05	−0.06	0.06	−0.17**	0.04	−0.06	0.05	−0.06	−0.07	−0.11*	0.03	1
13. Treatment condition	−0.02	−0.03	0.00	0.03	0.01	−0.08*	0.01	−0.03	−0.03	0.02	0.00	0.02

^*p < 0.05

^**p < 0.01