Formal attempts to standardize the definitions of terms used to describe drug and alcohol disorders have not been entirely successful for a variety of reasons. Nevertheless, a common vocabulary is needed. The following are working definitions often employed by health care professionals who specialize in drug and alcohol disorders. More exacting, criteria-based definitions, which are more suitable for research purposes, can be found in the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R), of the American Psychiatric Association.
Psychoactive Substance Use
Drugs may be used in a socially accepted or medically sanctioned manner to modify or control mood or state of mind. Examples include having a drink with a friend or taking an antianxiety agent for an acute anxiety state in accordance with a physician's prescription.
Psychoactive Substance Abuse (Or Problematic Use)
The use of a substance to modify or control mood or state of mind in a manner that is illegal or harmful to oneself or others is considered problematic use, or abuse. Examples of the potential consequences of harmful use include accidents or injuries, blackouts, legal problems and sexual behavior that increases the risk for HIV infection.
Addiction
Addiction is characterized by the repeated, compulsive seeking or use of a substance despite adverse social, psychologic and/or physical consequences. A wide range of substances, both legal and illegal, can be abused addictively (see Common Substances of Abuse)3-14.
Addiction is often (but not always) accompanied by physical dependence, a withdrawal syndrome and tolerance. Physical dependence is defined as a physiologic state of adaptation to a substance, the absence of which produces symptoms and signs of withdrawal.
Withdrawal syndrome consists of a predictable group of signs and symptoms resulting from abrupt removal of, or a rapid decrease in the regular dosage of, a psychoactive substance; the syndrome is often characterized by overactivity of the physiologic functions that were suppressed by the drug and/or depression of the functions that were stimulated by the drug.
Tolerance is a state in which a drug produces a diminishing biologic or behavioral response; in other words, higher doses are needed to produce the same effect that the user experienced initially.
It is possible to be physically dependent on a drug without being addicted to it, and conversely, it is possible to be addicted without being physically dependent15. An example of physical dependence without addiction is the patient with cancer who becomes tolerant of and physically dependent on the opiates prescribed to control pain. Such a patient may undergo withdrawal with discontinuation of the usual dose but will not experience social, psychologic or physical harm from using the drug and would not seek out the drug if it were no longer needed for analgesia16. In comparison, addiction without physical dependence may be seen in a person who uses marijuana to such a degree that it interferes with psychosocial functioning but the person does not experience physical discomfort with discontinuation. Addiction is also still present in the newly detoxified heroin addict who no longer suffers from withdrawal or tolerance but nevertheless craves the opiate high and will invariably relapse to active heroin abuse without further treatment.
Factors contributing to the development of addiction include the reinforcing properties and availability of the drug, family and peer influences, sociocultural environment, personality and existing psychiatric disorders. Genetic heritage appears to influence susceptibility to alcohol addiction, and possibly addiction to tobacco and other drugs as well17.
Detoxification
Detoxification is the process by which an individual who is physically dependent on a substance is withdrawn from it, often by gradual administration of decreasing doses of the drug of dependence or of a cross-tolerant drug. The primary objective of detoxification is to relieve withdrawal symptoms while the patient adjusts to a drug-free state. It is not, in itself, a treatment for addiction, because it does not affect the long-term course of addiction.
Relapse
The return to drug use after a significant period of abstinence is termed relapse. It is a characteristic of addiction. Relapses may occur over a period of years, because continued recovery requires a series of profound behavioral, social, psychologic and physiologic changes.