Challenges in measuring concurrency, agency and intentionality in polydrug research.

Polydrug use is of particular interest to researchers concerned with the drug use of youth and young adults because it is associated with progression to regular and addictive drug use. New research shows that polydrug use appears to be taking new forms as youth use multiple drugs concurrently in the same setting, sometimes to achieve specific desired effects. Existing approaches to measuring polydrug use are confusing and inconsistent. This paper calls for new ways of measuring polydrug use that capture concurrency in context to obtain more accurate assessments of drug mixing and its potential physical and social effects.