Is withdrawal-induced anxiety in alcoholism based on β-endorphin deficiency?

Abstract

Associations between several psychopathological alterations and lowered beta-endorphin(beta E) plasma levels have already been stated in former studies. However, whereas single measures during static conditions generally failed in linking beta E levels with psychopathology, dynamic changes of beta E in particular have been shown to be associated with spells of anxiety and depression. During alcohol withdrawal, a decreased secretion of beta E with a delayed normalization has been reported, but up to now only few data became available regarding the interaction of plasma beta E and psychopathological parameters. The aim of our study was to test the hypothesis whether beta E during acute alcohol withdrawal is associated with anxiety, depression, and craving. We observed self-rated anxiety, depression, and craving during alcohol withdrawal and assessed beta E levels (RIA) in a consecutive sample of 60 alcoholics on day 1 and day 14 after onset of withdrawal, and in 30 healthy volunteers. To control for mutual interactions of beta E and the pituitary-adrenocortical hormone secretion, plasma corticotropin (ACTH) and cortisol were also determined. In accordance with prior studies, beta E was significantly lowered on day 1 and day 14 of alcohol withdrawal relative to controls. Plasma levels of ACTH correlated significantly with beta E in alcoholics at both time points and in controls, without differing significantly between the groups. Self-rated anxiety, depression, and alcohol craving decreased significantly between day 1 and day 14. Levels of beta E were inversely correlated with anxiety day 1 (r=-0.58) and day 14 (r=-0.71). Partial correlation coefficients controlling for ACTH plasma levels revealed that this correlation was largely independent from ACTH. In addition, a significant inverse relationship was found between beta E and craving on day 14 (r=-0.28). No association appeared between beta E and depression. Our results give first evidence that lowered beta E during alcohol withdrawal may contribute to anxiety as a common disturbance during this state.