This Selected issue provides an exploratory European overview of costs associated with treatment for drug dependence. The cost of drug treatment in Europe is looked at from two main angles in this report. First, an overview is presented of the main sources of funding for drug treatment and the financing mechanisms that are employed in a number of European countries. This is followed by a focused analysis of the unit costs of the four main drug treatment modalities (detoxification, psychosocial inpatient, psychosocial outpatient and opioid substitution treatment). A summary of the contents is available.