Some Definitions

Compiled by Bruce Springer, MD

Tolerance: A state in which an increased dosage of a psychoactive substance is needed to produce a desired effect.

Abuse: The harmful use of a specific psychoactive substance. Abuse may take place without the full syndrome of addiction.

Dependence: A physiological state of adaptation to a specific psychoactive substance characterized by the emergence of a withdrawal syndrome during abstinence, which may be relieved in total or in part by re-administration of the substance.

Addiction: A disease process characterized by the continued use of a specific psychoactive substance despite physical, psychological, or social harm. This may or may not include tolerance and dependence, and is identified by certain other behaviors as:

1. The drug is used more than intended;
2. There is inability to control drug use;
3. Effort is expended to obtain the drug;
4. Important activities are replaced by drug use.

Prevalence: The number of people in a population with a specific disease divided by the total number of people in that population.

* Source: American Society of Addiction Medicine