Proposal of a Conceptual Framework on Barriers to Addiction Prevention and Their Potential Contribution to Prevention Failure.

Prevention science has generated substantial evidence on interventions aimed at preventing substance use and other addictive behaviours. However, less attention has been paid to the conditions that hinder their design, implementation, sustainability, and equitable benefit. To propose a conceptual definition of barriers to prevention, establish criteria for identifying them, and develop a theoretical taxonomy of their main categories, incorporating a gender perspective and examining their specificity across preventive actions. Barriers to prevention should not be understood solely as operational obstacles to programme implementation, but as ecological factors, conditions, or processes that interfere with essential preventive functions and reduce the distribution of preventive protection. When barriers are structural or disproportionately affect specific groups or territories, reductions in coverage, accessibility, acceptability, continuity, equity, or preventive benefit may contribute to maintaining or amplifying prevention failure. We therefore propose a six-category taxonomy and a two dimensional identification model based on the joint presence of functional interference and observable consequences. The framework also considers how barriers may vary according to prevention form, preventive function, intervention package or strategy, mode of delivery, and setting. A more precise conceptualization of barriers to prevention may strengthen theory, improve implementation research, and support public policies that are more sensitive to equity, gender, and the regulation of risk-promoting environments.