Abstract
PURPOSE: Throughout the world, illicit drug use continues to pose a significant risk to public health. The opioid crisis in North America, the diversion of the prescription drug tramadol throughout Africa, and the increasing supply of methamphetamines in East and South Asia all contribute to increasing risks to individual and societal health. Furthermore, the violation of human rights in efforts to enforce prohibitionist values poses significant threats to many individuals worldwide. With these evolving situations, it is imperative that researchers direct their attention to the various populations of illicit drug users. However, the inclusion of illicit drug users, often considered a vulnerable population, as participants in research studies presents several increased risks that must be addressed in study protocols. Researchers are required to provide "additional safeguards" to all study protocols involving illicit drug users, but there is often substantial variability and inconsistency in how these safeguards are applied. Additional safeguards can be timely, costly, and unduly burdensome for researchers, ethical review boards, and research participants. APPROACH: Through synthesis of the current literature, this article addresses the barriers to studying illicit drug users and the methods researchers can utilize to minimize risk. A case study is provided to illustrate the high level of scrutiny of study protocols involving the participation of illicit drug users and the effect of such scrutiny on recruitment of participants. The article concludes with a discussion of the effects of the current political climate on the recruitment of illicit drug users in research. CONCLUSIONS: Individuals who participate in criminal or illegal behaviors such as illicit drug use, prostitution, illegal entry into a country, and human trafficking are susceptible to multiple physical, mental, and social health risks, as well as criminal prosecution. The importance of research on the health of marginalized populations cannot be overstated. This work must continue, and at the same time, we must continue to protect these individuals to the best of our ability through diligent attention to sound research methods. CLINICAL RELEVANCE: The use of illicit drugs continues to pose a substantial threat to global health. Individuals who use illicit drugs are susceptible to multiple physical, mental, and social health risks, as well as criminal prosecution. It is imperative that researchers study these vulnerable populations in order to develop interventions to minimize individual and societal harm. There are several barriers to the study of illicit drug users that must be addressed through rigorous methodology and the addition of safeguards.