The overall goal of research at the Division of Biological Research on Drug Dependence is to increase the understanding of brain mechanisms of relevance for the aetiology of drug addiction and to develop strategies for relevant treatment. Studies of drug effects on brain circuits involved in reward and dependence are combined with attempts to develop peptidomimetics reducing the expression of opioid withdrawal, an important aspect in the treatment of opioid addiction. Studies are also aimed to find strategies to repair drug-induced brain damages, i.e. using growth factors counteracting apoptosis and stimulating neurogenesis. As animal models do not reflect all complexity of addiction current research also involves epigenetic adaptations and regulation of plastic neuropeptide genes in human brain. Novel mechanisms, by which neuropeptides cause neurodegeneration in human brain receive particular attention.