Table 3.

Sample means by substance and race.

			95% Confidence Level
	Mean	Std. Error	Lower Bound	Higher Bound
Tobacco Use
Irritability
Non/less frequent	1.53	.12	1.29	1.76
Heavy	1.98	.18	1.62	2.34
Marijuana Use
Craving marijuana
Non/less frequent	1.28	.15	.99	1.57
Heavy	1.69	.13	1.42	1.95
Strange/wild dreams
Non/less frequent	1.31	.15	1.02	1.61
Heavy	1.77	.14	1.50	2.04
Black
Withdrawal Discomfort Score
No	26.88	1.12	24.65	29.11
Yes	18.47	2.99	12.53	24.41
Depressed mood
No	2.24	.14	1.97	2.52
Yes	1.23	.37	.49	1.96
Sleep difficulty
No	2.50	.14	2.22	2.78
Yes	1.68	.38	.92	2.43
Nervousness/anxiety
No	2.14	.13	1.89	2.39
Yes	1.29	.34	.62	1.96
Strange/wild dreams
No	1.66	.11	1.44	1.87
Yes	1.04	.29	.48	1.69