Salivary cortisol measurements during a medically assisted alcohol withdrawal

Previous studies using plasma cortisol estimations have suggested that hypothalmo-pituitary-axis (HPA) activation occurs in alcohol-dependent patients during alcohol withdrawal. The present study set out to confirm this finding using salivary cortisol assays, which are a better indicator of plasma free cortisol, the fraction which exerts its physiological effects. Nine alcohol dependent patients provided four saliva samples (at 10 a.m., 2 p.m., 6 p.m. and 10 p.m.) on days 1, 3 and 7 of a medically assisted alcohol withdrawal (corresponding to 1, 3 and 7 days following the last drink, respectively).Withdrawal symptom severity, craving and mood disturbance were also measured. A group of non-alcohol-dependent individuals, without psychiatric or medical disorder, gave four samples at the same times on one day only. Mean daily cortisol levels in our alcohol-dependent population, as calculated by the area under the curve (AUC), decreased significantly over time (mean AUC (nmol/l/hour) on day 1 = 149, on day 7 = 85.7, p = 0.009) and were significantly higher than controls on each day (mean AUC in controls = 28.3, p = 0.001). The cortisol response showed a similar temporal trend to withdrawal symptom severity and mood disturbance. This is consistent with previous studies measuring plasma cortisol in alcohol withdrawal. However, the magnitude of the effect in our study was greater, and in contrast to some previous studies, levels were far from normal by day 7. The comparatively low cortisol response in our one mildly dependent patient suggests that there may be a relationship between dependence severity and the size of the cortisol response to withdrawal. Salivary cortisol sampling could prove to be a useful prognostic tool, with implications for subsequent withdrawal symptom severity, mood disturbances, risk of relapse and alcohol-related cognitive decline. There are implications for developing new treatments for alcohol withdrawal but more studies are needed.