Table 1.

Demographic information for males and females in each group in the sample of young adults (Study 2).

	Drug-Naive Controls (DNC)				Heavy drinkers (HD)				Cannabis users (CU)
	Females (n = 20)		Males (n = 25)		Females (n = 16)		Males (n = 23)		Females (n = 9)		Males (n = 11)
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Age (years)	19.9	1.2	20.0	1.1	20.0	1.2	19.7	1.2	20.1	1.2	20.5	1.2
% Daily smokers	0.0		0.0		0.0		13.0		11.1		27.3
% Right handed	90.0		100.0		81.3		78.3		77.8		90.9
AUDIT score#	3.1	2.9	2.9	3.0	9.5	3.3	9.1	2.6	9.3	4.6	11.4	4.6
Lifetime standard drinks (log units)†	1.4	1.2	1.5	0.9	2.7	0.5	2.6	0.4	2.8	0.5	3.0	0.4
Lifetime standard drinks (mean and CI)†	25.2	(7.8–81.4)	31.6	(14.2–70.0)	470.4	(254.4–869.8)	391.0	(267.6–571.3)	624.6	(314.4–1240.8)	1, 029.2	(581.9–1,820.1)
Age of onset of regular drinking	18.5	1.6	18.0	1.7	17.5	1.6	17.3	1.3	16.3	1.2	16.6	1.0
Duration of regular drinking	1.4	1.5	2.0	1.7	2.5	1.6	2.4	1.4	3.8	1.7	3.9	1.1
DUDIT-E score	0.7	1.3	0.6	0.8	1.4	1.5	2.2	2.1	6.7	2.0	7.5	3.8
DUDIT-E range	0–4		0–2		0–4		0–9		3–9		3–15
Age first regular cannabis use*									17.0	1.2	17.4	1.2
Duration regular cannabis use, years*									2.1	1.5	2.6	1.1
Frequency of cannabis use (days/month), last 6 months, median and range*									4.2	(1.8–18.2)	12.9	(2.0–30.0)

^#AUDIT scores are useful only for internal comparison between groups, due to the alteration to Question 3 as described in the text.

^†Due to non-normal distributions, lifetime standard drinks were converted to log scores prior to statistical analysis; the mean and SD reported are in log units, while the numbers in brackets below give the inverse log of the mean, and the confidence interval calculated for that mean, in units of standard drinks.

^*n = 7 females, 10 males; data were not recorded for the first three cannabis user participants.