The need for standardized, scientific criteria for describing drug-using behavior.
D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D008297:Male; D009042:Motivation; D012107:Research Design; D012651:Self Medication; D012660:Semantics; D019966:Substance-Related Disorders / Q000453:epidemiology*; D014481:United States