Cortisol response in the stress condition was significantly predictive of time to alcohol relapse (χ2=6.12; P=.01; HR=1.10, 95% CI, 1.02-1.18), but not time to heavy drinking relapse. Cortisol to corticotropin ratio was a significant predictor of alcohol relapse, particularly in the neutral, relaxing condition (time to alcohol relapse: χ2=7.38; P=.007; HR=2.12; 95% CI, 1.23-3.63; time to heavy drinking: χ2=10.4; P=.001; HR=2.55; 95% CI, 1.29-4.1), but also in the stress condition (time to alcohol relapse: χ2=5.74; P=.02; HR=1.65; 95% CI, 1.10-2.49; time to heavy drinking: χ2=4.04; P=.05; HR=1.52; 95% CI,1.02-2.42) and at baseline levels for time to alcohol relapse only (χ2=4.49; P=.04; HR=1.68; 95% CI, 1.04-2.71). In each case, higher cortisol levels and cortisol to corticotropin ratios were predictive of shorter time to alcohol relapse and shorter time to heavy drinking, with higher adrenal sensitivity during the neutral condition conferring a 2- to 2.5-fold greater risk of relapse for both time to alcohol relapse and time to heavy drinking (Figure 6). Corticotropin or cortisol responses at baseline or corticotropin responses during any condition were not predictive of alcohol relapse.
