Researcher perspectives on including people who use drugs in clinical research.

People who use drugs are commonly excluded from clinical research despite being disproportionately impacted by numerous health conditions. Recent work indicates that community-recruited individuals report low support of research inclusion for persons reporting substance use. This study conducted a mixed-method assessment of researchers' attitudes on including persons reporting substance use in clinical research. Respondents (N = 168; 58% female; 58% psychologists) recruited via scientific society listservs and Twitter completed a survey containing two hypothetical research vignettes. Quantitative items evaluated respondents' endorsement of research participation by healthy adults, people who use drugs, and vulnerable populations. Qualitative items included open-ended questions asking reasons why people who use drugs should and should not participate in research. Respondents reported significantly lower support for research participation by people who use drugs compared to healthy adults ( <.001). Open-ended responses concerning the inclusion of people who use drugs included themes relevant to the Belmont Principles (e.g., capacity to consent) and data quality (e.g., "bad data," poor compliance). Although lower support for research participation by people who use drugs was observed compared to healthy adults, the magnitude of this difference was smaller than reported for prior community-recruited respondents. These findings emphasize salient factors that may serve as both protections for and barriers to inclusion of people who use drugs in research. Initiatives including adoption of person-first language, addressing stereotyping of people who use drugs, and emphasizing the benefits of including these populations in clinical research should be explored to reduce bias while retaining needed protections.