An uncontrollable craving, seeking, and use of a substance such as alcohol or another drug. Dependence is such an issue with addiction that stopping is very difficult and causes severe physical and mental reactions.

See: Computer addiction.

An uncontrollable craving, seeking, and use of a substance, such as a drug or alcohol.

Surrender and devotion to the regular use of a medicinal or pleasurable substance for the sake of relief, comfort, stimulation, or exhilaration which it affords; often with craving when the drug is ab [..]

 A condition in which the body requires a drug in order to function without physical and psychological reactions to its absence; often the outcome of tolerance and dependence.

c. 1600, "tendency," of habits, pursuits, etc.; 1640s as "state of being self-addicted," from Latin addictionem (nominative addictio) "an awarding, a devoting," noun of a [..]

A chronic, relapsing disease characterized by compulsive drug seeking and use, despite serious adverse consequences, and by long-lasting changes in the brain.

According to DSM-IV (American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th ed., Washington, D.C., 1994):

The condition of being addicted, or unable to live without, a particular habit, substance or pursuit.

being abnormally tolerant to and dependent on something that is psychologically or physically habit-forming (especially alcohol or narcotic drugs) an abnormally strong craving (Roman law) a formal awa [..]

a place of being physically or psychologically dependent upon substances such as drugs and alcohol. Commonly referred to as substance abuse. Diagnostic criteria consists of tolerance, withdrawal, losi [..]

addiction (pop)

Any time a person continues to exhibit harmful or obsessive behavior, we can say that they are addicted. There are many, many types of addictions, from gambling, to sex, to drugs and alcohol.

Psychological or physiological dependence on a drug. With true addictions, severe symptoms appear when the addicted person stops taking the drug on which he is dependent.

compulsive physiological need for a habit-forming drug (as heroin)

See dependence.

Addiction refers to the chronic or habitual use of any chemical substance to alter states of body or mind for other than medically warranted purposes. Common addictions are to tobacco products, drugs, [..]

(n) an abnormally strong craving(n) being abnormally tolerant to and dependent on something that is psychologically or physically habit-forming (especially alcohol or narcotic drugs)(n) (Roman law) a [..]

Loss of control over indulging in a substance or performing an action or behavior, and continued craving for it despite negative consequences.

An addiction is an urge to do something that is hard to control or stop. If you use cigarettes, alcohol, or drugs like marijuana (weed), cocaine, and heroin, you could become addicted to them. They ca [..]

Repeated use of a psychoactive substance or substances, to the extent that the user (referred to as an addict) is periodically or chronically intoxicated, shows a compulsion to take the preferred substance (or substances), has great difficulty in voluntarily ceasing or modifying substance use, and exhibits determination to obtain psychoactive subst [..]

Strong dependence, both physiological and emotional, upon Heroin.

Strong dependence, both physiological and emotional, upon Morphine.

Uncontrollable craving, seeking, and use of a substance such as a drug or alcohol.

Research on addiction had already yielded a wide range of interesting and important findings when economists first arrived on the scene. The economic ...

<psychiatry> Pattern of compulsive drug use characterised by a continued craving for an opioid and the need to use the opioid for effects other than pain relief. (Psychological dependence). The state of being given up to some habit, especially strong dependence on a drug. (16 Dec 1997)

Addiction is a chronic, progressive but treatable disorder in which someone becomes dependent on a substance or behavior that’s psychologically or physically dangerous and habit-forming. Addiction cau [..]

(medicine) A state that is characterized by compulsive drug use or compulsive engagement in rewarding behavior, despite negative consequences.Angres DH, Bettinardi-Angres K (October 2008). "The [..]

a state or condition of existence characterized by habitually engaging in a highly specific and routine activity reiteratively and compulsively, irrespective of aversive or deadly consequences; the ad [..]

Physical dependence upon a drug, characterized by withdrawal symptoms in the absence of the drug.