These medical terms are applicable to all abused substances, including those substances intended to be helpful, such as prescribed and over-the-counter medications.

Substance: Drug, chemical or biologic entity that is self-administered.

Habituation: Pattern of repeated drug use in the absence of an actual physical need for the drug. There is no desire for increased use. There may be withdrawal manifestations.

Misuse: Drug used for the purposes other than those for which it is intended. Common among people, especially the elderly, who self-medicate for variety of reasons.

Abuse: Drug use patterns that lie outside the limits acceptable by society and that have a negative impact on psychologic, physiologic, and social functioning of an individual. Drug abuse may be combined with misuse.

Dependence: Reliance on a substance that has reached the level that absence of it will cause an impairment in function. There are two types of dependences:

Psychologic dependence: Compulsive need to experience pleasureable repsponse from the substance. Physical dependence: Altered physiologic state from prolonged substance use; regular use is necessary to prevent withdrawal.

Tolerance: Decreased effect of a substance that results from repeated exposure. It is possible to develop cross-tolerance to other substances in the same category.

Withdrawal: Constellation of physiologic and psychologic responses that occur when there is abrupt cessation or reduced intake of a substance on which an individual is dependent or when the effect is counteracted by a specific antagonist.

Addiction: Compulsive substance use that exists for both physical and psychologic reasons.

Dual: Simultaneous dependence on substances that have similar effects, such as barbiturates and alcohol.

Mixed: Dependence on more than one substance not necessarily similar in effect, such as alcohol and cocaine.

Craving: Subjective need for a substance, usually experienced after decreased use or abstinence.

Loss of control: Inability to quit after just one drink or substance use (one drink, one drunk). Substance takes control of a persons life.

Abstinence: Refrain from substance use.

Sobriety: Complete abstinence practiced within a balanced, healthy lifestyle.

Detoxification: Process of removing the substance and its effect from the individuals body.

Relapse: Process of readdiction during sobriety.

Binge: Consumptions of large quantities of a substance on occasion to the point of excess.