Final answer:
Addiction is a chronic disorder characterized by the compulsive use of a substance and is prone to relapse. It often leads to drug dependence, which can have physical and psychological symptoms, and involves an increasing tolerance to the drug's effects.
Step-by-step explanation:
Addiction is a chronic disorder that is prone to relapse, even after significant periods of recovery. Drug addiction refers to the compulsive use of a substance such as a psychoactive drug despite negative consequences that such use may entail. Drug dependence is a condition that may develop as a result of ongoing addiction, where stopping use of the substance produces physical and/or psychological symptoms.
The DSM-5 classifies drug use disorders as addictive disorders. It involves a compulsive pattern of drug use that may comprise both physical and psychological dependence, with tolerance often developing over time, leading to the need for greater quantities of the drug to attain the same effect. Psychological dependence mainly refers to an emotional need for the drug, often a method to relieve psychological distress, which may manifest as a strong drug craving.