Epidemiologists have found that drug use in and of itself is a limited way of describing and measuring drug consumption and related problems. As a result, they often distinguish between drug use and drug abuse. “Drug use” is used to refer to experimentation or low frequency, typically irregular, use of illicit drugs. It can be considered somewhat analogous to the term “alcohol use.” In contrast, “drug abuse” refers to regular and/or compulsive use of illicit drugs. The purpose of the two terms is to distinguish people on the basis of whether their illicit drug use has or has not become a significant feature of their lifestyle and whether it is likely to have a psychopathological character.