Illegal drug use implies costs for society. Estimating these costs is a methodological challenge, given the difficulty of quantifying the degree of causality between drugs and their negative consequences. A further problem is assigning a monetary value to items that do not have market value.
Social cost estimates are potentially a valuable source of informing policy makers on the impact of prevention, treatment and law enforcement strategies. The present study aims at meeting this challenging area of health policy. It is designed to provide methodological guidance on how to calculate the social cost of drug abuse, mainly through a "cost-of-illness" approach. A case study of the methodology used to calculate the social cost of both licit and illicit drug in France is given as practical example at the end of the document.