There are various approaches for categorizing or classifying illicit drug use. For example, criminal justice systems often make little distinction among levels or types of use. In contrast, epidemiologists commonly distinguish between use and abuse. Clinicians generally go a step further by distinguishing among drug use, misuse, abuse, and dependence. The American Society of Addiction Medicine and related groups make a further distinction between dependence, addiction, and pseudo-addiction. These various approaches to the classification of use are discussed below.