Table 2.

Hierarchical regression of past 3-month alcohol use.

	Standardized b †	p	R 2	Δ R2	Δ F
Quantity
Step 1		<0.001	0.21	0.21	8.75
Age	0.06	0.45
Years Alcohol	0.38	<0.001
Years Tobacco	−0.16	0.06
Years Marijuana	0.23	0.02
Years Other Drugs	−0.05	0.59
Step 2		0.74 ‡	0.22	0.01	0.42
Accumbens	0.03	0.71
OFC	−0.07	0.38
Accumbens × OFC	−0.04	0.64
Frequency
Step 1		<0.001	0.15	0.15	5.83
Age	−0.06	0.42
Years Alcohol	0.31	<0.001
Years Tobacco	−0.10	0.25
Years Marijuana	0.16	0.10
Years Other Drugs	0.02	0.88
Step 2		0.03 ‡	0.20	0.05	2.96
Accumbens	0.18	0.03
OFC	−0.20	0.02
Accumbens × OFC	0.09	0.25

^† Betas for all predictors are taken from the final model (including Step 2); ^‡ p _Δ.