Scholarly works systematically evaluating problems associated with the use of psychoactive substances are relatively recent (Edwards 1991; Edwards and Babor 2012; Babor et al 2017). The search for patterns and generalizations based on accumulated scientific evidence on drug use and public policy only began to develop in the 1970s (Edwards 2002). New epidemiological research tools, technological innovations, institutional growth, education programs, funding opportunities, specialized journals, professional societies, public recognition, and political support were all influential at this stage of development (Babor 2002). The emergence of the interdisciplinary ‘addiction field’, merging psychological, biomedical, and social perspectives, together with different nonacademic sources, illustrates the ambition to move the study of drugs ‘from faith to science’ (Heather et al 1992).

As the field consolidated, different disciplinary subgroups and research areas started to emerge, including those concentrated on policy, health, and harm. Drawing from the contributions of scholars, practitioners, activists, and decision-makers, a cumulative scientific base created new opportunities for the analysis and implementation of drug policy. As Babor and colleagues (2010) note, direct evidence allowed the study of the implications of various reforms in comparison with places and times where no intervention was accomplished. Drug policy reforms in countries like the Netherlands, Italy, Spain, the Czech Republic, Belgium, Germany, and Portugal, along with other subnational jurisdictions such as South Australia, Alaska, and Amsterdam, informed the new works dedicated to evaluate the effects of shifting from criminalization to other forms of noncriminal penalties.