Abstract. 7 8 Substantial evidence shows that the hypophyseal-pituitary-adrenal 9 (HPA) axis and corticosteroids are involved in the process of addiction to 10 a variety of agents, and the adrenal cortex has key role. In general, 11 plasma concentrations of cortisol (or corticosterone in rats or mice) rise 12 on drug withdrawal in a manner that suggests correlation with the 13 behavioural and symptomatic sequelae both in man and in experimental 14 animals. Corticosteroid levels fall back to normal values in resumption of 15 drug intake. 16 The possible interactions between brain corticotrophin releasing 17 hormone (CRH) and proopiomelanocortin (POMC) products and the 18 systemic HPA, and additionally with the local CRH-POMC system in the 19 adrenal gland itself, are complex. Nevertheless, the evidence 20 increasingly suggests that all may be interlinked and that CRH in the 2
