Table 3.

Parameter Estimates for Mediation Models

Model	Estimate (Std. Err.)	p-value
Outcome: Total # of Mini-drinks
Predictor: Sedation
ba	−0.034 (0.060)	0.578
bb	1.735 (0.439)	<0.001
bc (direct effect)	−0.686 (0.272)	0.014
bc’	−0.661 (0.255)	0.012
Predictor: Stimulation†
ba	0.289 (0.056)	<0.001
bb	1.969 (0.537)	<0.001
bc (direct effect)	0.228 (0.348)	0.516
bc’	−0.280 (0.342)	0.416
Outcome: Latency to 1st Mini-drink
Predictor: Sedation
ba	−0.034 (0.060)	0.578
bb	−2.700 (1.086)	0.013
bc (direct effect)	1.780 (0.691)	0.010
bc’	1.823 (0.648)	0.005
Predictor: Stimulation
ba	0.289 (0.056)	<0.001
bb	−3.385 (1.378)	0.014
bc (direct effect)	−0.150 (0.677)	0.825
bc’	0.827 (0.747)	0.268
Outcome: Average BrAC
Predictor: Sedation
ba	−0.034 (0.060)	0.578
bb	0.018 (0.005)	<0.001
bc (direct effect)	−0.006 (0.002)	0.020
bc’	−0.005 (0.002)	0.011
Predictor: Stimulation†
ba	0.289 (0.056)	<0.001
bb	0.015 (0.005)	0.002
bc (direct effect)	0.008 (0.004)	0.028
bc’	0.004 (0.003)	0.184

Note: All estimates presented are unstandardized coefficients. The term b_c’ represents the effect of the predictor on the outcome while controlling for craving mediator. The term b_b represents the effect of the mediator when the predictor is in the models. For latency (seconds) to 1^st drink outcome, estimates derived from Accelerated Failure Time (AFT) models, whereas all other outcomes utilized mixed models. In all analyses, the following variables were controlled for: medication, randomization order for medication, OPRM1 status, gender, ethnicity, drinking days past 30 days, drinks per drinking day past 30 days, and alcohol metabolites (ALDH2 (rs671) and ADH1B (rs1229984). Significance status of these covariates is reported within the manuscript.

^†denotes significant mediated effect of craving