Suppression of the HPA axis stress-response: implications for relapse

Abstract

This article presents the proceedings of a symposium held at the meeting of the International Society for Biomedical Research on Alcoholism (ISBRA) in Mannheim, Germany, in October 2004. This symposium explored the potential role of hypothalamic-pituitary-adrenal (HPA) axis dysregulation upon relapse. HPA axis stimulation induces the release of the glucocorticoid cortisol, a compound with profound effects upon behavior and emotion. Altered stress-responses of the HPA axis in abstinent alcohol-dependent subjects, therefore, may influence their affective and behavioral regulation, thus impacting their potential for relapse. Bryon Adinoff began the symposium with a review of HPA axis dysfunction in alcohol-dependent subjects, including recent studies from his lab demonstrating an attenuated glucocorticoid response to both endogenous and exogenous stimulation in one-month abstinent men. Klaus Junghanns presented his work demonstrating that a blunted ACTH or cortisol response to subjective stressors (social stressor or alcohol exposure) is predictive of a return to early drinking. The final two presenters examined the interaction between naltrexone and HPA responsiveness in alcohol-dependent or at-risk subjects, as naltrexone induces an increase in ACTH and cortisol. Falk Kiefer discussed the relationship between basal HPA axis responsivity and clinical outcome following treatment with naltrexone or acamprosate. Plasma ACTH significantly decreased over the course of the study in the placebo group, but not the medication groups [corrected] Lower basal concentrations of ACTH and cortisol were associated with quicker relapse in the placebo group only. Suchitra Krishnan-Sarin described her preliminary work, in which family-history positive (FH+) and family history negative (FH-) subjects were administered naltrexone, followed by an assessment of alcohol-induced craving. The cortisol response to alcohol was significantly and inversely related to craving in the FH+, but not the FH-, subjects. Alterations in HPA axis responsivity may therefore have a negative impact upon clinical outcome in alcohol-dependent subjects, and disinhibition of the axis with medication may have therapeutic potential.