Variable Level Placebo
(n = 26) 		20 mg
(n = 26) 		30 mg
(n = 26) 		40 mg
(n = 26) 		Total
(n = 104)
Sex, N (%) Male 8 (30.8) 8 (30.8) 8 (30.8) 8 (30.8) 32 (30.8)
Female 18 (69.2) 18 (69.2) 18 (69.2) 18 (69.2) 72 (69.2)
Age, years Mean (SD) 24.62 (4.97) 26.81 (6.52) 25.62 (6.17) 26.65 (6.28) 25.92 (5.99)
Median 24 25.5 23 24 24
Q1; Q3 21; 26.75 22; 30 21; 29 22.25; 30 21; 29
Min 18 18 18 18 18
Max 38 39 39 39 39
Smoking, N (%) No 24 (92.3) 24 (92.3) 22 (84.6) 24 (92.3) 94 (90.4)
Yes 2 (7.7) 2 (7.7) 4 (15.4) 2 (7.7) 10 (9.6)

N = number; Q1 = first quartile; Q3 = third quartile; SD = standard deviation.