Altered association of plasmatic oxytocin with affective stress response in alcohol use disorder

Oxytocin has been proposed to play a role in the development and maintenance of alcohol use disorder (AUD) through its interactions with stress pathways. Empirical evidence that indicates altered associations between endogenous oxytocin and stress reactivity in AUD is currently lacking. In this study, we investigated baseline plasmatic oxytocin concentrations of early-abstinent patients with AUD (N = 40) and matched healthy control participants (N = 37), who completed the Trier Social Stress Test (TSST) as well as a control task on two separate visits. We measured salivary cortisol and pulse rate as indicators of a physiological stress response, and anxiety ratings as an indicator of an affective stress response at multiple time points. Baseline oxytocin levels did not significantly differ between the groups. However, our results suggest an altered association of oxytocin and affective stress responses in participants with AUD: while participants with AUD showed a positive relationship between plasmatic oxytocin levels and stress-induced anxiety increase, the opposite relationship was found in control participants. We did not find evidence for an association of oxytocin with physiological stress responses. The present findings suggest that oxytocin may not possess the same anxiolytic properties in individuals with AUD under stress conditions as it does in healthy subjects. This is an important consideration for future hypotheses on the use of exogenous oxytocin in the treatment of AUD.