Twelve-month treatment of heroin addicts with methadone or buprenorphine normalized plasma cortisol levels, and controlled withdrawal symptoms as well as craving. During treatment, the time course of plasma cortisol levels and craving was not strictly correlated: heroin craving was more elevated at 12 than at 3 months. The results suggest a correlation between hypercortisolism, withdrawal symptoms and heroin use and suppose a more complex role for craving and its components in drug-taking behaviour. The main goal of the pharmacological treatment of opioid-dependence should be addressed at the normalization of hypothalamic-pituitary-adrenocortical (HPA) axis more than at the control of craving.