The application of Moral Foundations Theory in Drug Studies - A Scoping review with narrative synthesis

Abstract

Objective This study aims to map and evaluate the application of Moral Foundations Theory (MFT) in drug-related research, identifying key insights, conceptual and methodological challenges, and future research directions.

Background Drug use presents a significant societal challenge, impacting individuals and communities. While evidence-based approaches in drug policy are increasing, the influence of morality on drug policy development, attitudes toward drug use and people who use drugs (PWUD) is often neglected. Moral Foundations Theory (MFT) provides a framework for understanding these moral motivations. Despite some studies applying MFT to drug research, the theory has faced critiques, and a comprehensive review of its application in this field is still lacking.

Methods A scoping review was conducted using Scopus, Web of Science, and APA PsycINFO, identifying 703 records. After screening and deduplication, 23 peer-reviewed studies were included. Extracted data included study characteristics, theoretical assumptions, measurement tools, policy framings, and use of moral foundations. Thematic synthesis and a custom rubric supported interpretive analysis.

Results This scoping review highlights that the Moral Foundations Theory (MFT) is mainly used in drug studies within Western contexts as a quantitative measurement. Measurement methods for MFT foundations varied widely, often focusing disproportionately on Purity while neglecting Liberty and finding Loyalty largely insignificant. Political ideology complicated the understanding of the complex relationships between morality, drug use, attitudes, and policies. Additionally, the moral "target," or the group receiving moral concern, was often unspecified, limiting interpretive depth. Still, MFT studies revealed that moral framing, perceived group membership, and narrative strategies significantly influenced attitudes toward drug use, people who use drugs (PWUD), and related policies.

Conclusion Moral Foundations Theory (MFT) sheds light on how morality influences drug use, attitudes, and policy; however, its application is often inconsistent and fragmented. Future research should consistently use all six foundational elements, specify the moral targets being analysed, and consider context-specific framing and ideological differences. These changes would strengthen MFT's role in shaping effective and ethical drug policy.