The switch from one substance-of-abuse to another: illicit drug substitution behaviors in a sample of high-risk drug users

Abstract Background: Substitution can be defined as the consciously motivated choice to use one drug, either licit or illicit, instead of another, due to perceptions of cost, availability, safety, legality, substance characteristics, and substance attributions. Substitution represents a potential risk to drug users, mainly when substitutes are of higher potency and toxicity. This study offers a basic conceptualization of illicit substitution behavior and describes substitution patterns among users of two highly prevalent drugs of abuse—heroin and cannabis. Methods: Here, 592