Table 1. Descriptive Statistics of the Subjects Enrolled in the Study.

	Occasional			Regular			p-value
	Median	MAD	Range	Median	MAD	Range
Age	25	2	19–29	23	1.5	20–28	0.06
Education (post-compulsory, years)	6	2	4–9	6	2	2–15	0.9
Frequency of use last week (times/day)	0.14	0.1	0–1	2.5	0.5	1–7	<10−5
Frequency of use last 3 weeks (times/week)	1	0.63	0–2.5	20	5.5	5–60	<10−5
Frequency of use last 3 months (times/month)	3.5	1.5	1–10	62.5	22.5	20–250	<10−5
Years of usage	7.5	2.5	3.5–15	6.5	2.5	2–13	0.13
Age at onset	17	2	9–22.5	15.5	1.7	12–20	0.8
Alcohol (drinks/week)	5	2	1–10	10	5	0–80a	0.02

We report median values, median absolute deviation (MAD), range and significance of the between groups' comparison by mean of Wilcoxon-signed rank test. The years of usage and the age of onset refer to any cannabis use, and the alcohol consumption refers to drinks of 10 g ethanol.

^aOnly one subject declared a weekly alcohol consumption of 80 drinks/week (outlier), all the other subjects ranged between 0 and 20.