Understanding the nature of addiction depends on understanding several related concepts. The following discussion explains and clarifies those concepts.

Abuse and Misuse

In everyday English, abuse is understood to mean practices that are in some way improper or cruel, as in the term "child abuse." As applied to drugs, however, the term is difficult to define and carries different meanings in different situations. Some drugs, such as morphine, have medical purposes. If they are used for other reasons, or in unnecessarily large quantities, then the term "drug abuse" is applied. Other substances, such as alcohol, are legal but do not serve