Table 3.

Demographic Information: Healthy Control (HC) versus Early Cannabis Onset versus Late Cannabis Onset.

Demographic Variables	HC n = 16	Early Onset n = 14	Late Onset n = 14	ANOVA (2-tailed)a
				F	p (ηp2)
Sex	6M, 10F	13 M, 1F	10 M, 4F	–	–
Handedness	16R, 0L	13R, 1L	14R, 0L	–	–
Age	22.94 ± 3.96	23.14 ± 7.07	22.79 ± 3.77	0.02	.98 (< .01)
IQ: WASIb	123.55 ± 6.85	116.00 ± 12.99	119.43 ± 6.11	2.01	.15 (.10)
Alcohol Use (days out of last 30)b	4.97 ± 4.50	5.82 ± 2.31	7.21 ± 5.94	0.81	.45 (.04)
Cannabis Use Variables
Age of Cannabis Onsetc	–	14.00 ± 1.04	17.36 ± 1.08	70.21	< .01 (.73)
Cannabis Use Episodes/Weekc	–	11.88 ± 4.56	17.65 ± 16.66	1.56	.22 (.06)
Cannabis Grams Used/Weekc	–	4.43 ± 2.66	6.05 ± 8.77	0.44	.51 (.02)
Duration of Cannabis Use (yr)c	–	9.57 ± 7.98	5.29 ± 3.58	3.36	.08 (.12)
Urinary THC/Creatinine Ratiod	–	408.43 ± 594.23	564.75 ± 754.35	0.35	.56 (.01)
CUDIT-R Scorec	–	15.14 ± 4.59	16.00 ± 6.08	0.18	.68 (.01)
MWC (16-item)c	–	7.71 ± 4.14	6.93 ± 3.25	0.31	.58 (.01)
Impulsiveness: BIS
Attentione	13.00 ± 3.58 * , *	16.79 ± 3.17 *	16.50 ± 3.18 *	4.87	.01 (.21)
Motore	20.73 ± 4.92	23.00 ± 4.49	23.29 ± 3.79	1.22	.31 (.06)
Non-Planninge	18.46 ± 5.17 * , **	26.36 ± 4.27 *	23.21 ± 5.37 **	7.91	< .01 (.31)
Totale	52.18 ± 12.85 * , *	66.14 ± 7.83 *	63.00 ± 10.50 *	5.94	.01 (.25)

Abbreviations: Analysis of Variance (ANOVA); Barratt Impulsiveness Scale (BIS); Cannabis Use Disorder Identification Test-Revised (CUDIT-R); Marijuana Withdrawal Checklist (MWC); Tetrahydrocannabinol (THC); Wechsler Abbreviated Scale of Intelligence (WASI).

Notes:

Bold numbers are significant at p ≤ .05 (2-tailed).

Italicized numbers are significant at p ≤ .10 (2-tailed).

^*Scheffé Post Hoc Analyses indicated significant differences between pairs at p ≤ .10 (2-tailed).

^**Scheffé Post Hoc Analyses indicated significant differences between pairs at p ≤ .05 (2-tailed).

^aDegrees of Freedom (df) = 2,41 unless otherwise noted.

^bdf = 2,35.

^cdf = 1,26.

^ddf = 1,24.

^edf = 2,36.