Table 1.

Participant demographics

	Groups
	Males								Females
Measure	Cannabis use by age 16 (n = 207)						Comparison group (n = 538)	p	Cannabis use by age 16 (n = 158)						Comparison group (n = 678)	p
Age (M, SD)	14.50, 0.47						14.52, 0.39	0.54	14.51, 0.53						14.54, 0.42	0.33
Handedness (L, R)	25, 182						66, 472	0.94	18, 140						60, 618	0.32
PDS (M, SD)	2.65, 0.49						2.54, 0.55	0.01	3.22, 0.39						3.17, 0.44	0.13
Perceptual IQ (M, SD)	108.11, 13.55						108.18, 14.56	0.95	109.40, 13.49						107.77, 13.23	0.17
Verbal IQ (M, SD)	114.19, 13.267						112.07, 13.14	0.05	112.93, 12.29						109.22, 13.80	0.002
SES (M, SD)	18.52, 3.97						17.88, 3.82	0.05	18.26, 3.94						17.88, 3.68	0.26
Cannabis use levels	1	2	3	4	5	6			1	2	3	4	5	6
(N)	62	35	26	24	23	37			56	39	19	20	9	15

Note. PDS: Puberty Development Scale (Carskadon & Acebo, 1993); SES: Socioeconomic status.

Cannabis use levels from the ESPAD and measured on an ordinal scale (1 = 1–2x, 2 = 3–5x, 3 = 6–9x, 4 = 10–19x, 5 = 20–39x, 6 = 40x+). All measures (with the exception of cannabis use) were obtained at age 14. All demographics measures were also included as predictors in feature selection analyses.