Addiction—The state of being both physically and psychologically dependent on a substance.
Dependence—A state in which a person requires a steady concentration of a particular substance to avoid experiencing withdrawal symptoms.
Detoxification—A process whereby an addict is withdrawn from a substance.
Intoxication—The desired mental, physical, or emotional state produced by a substance.
Street drug—A substance purchased from a drug dealer; may be a legal substance, sold illicitly (without a prescription, and not for medical use), or it may be a substance which is illegal to possess.
Tolerance—A phenomenon whereby a drug user becomes physically accustomed to a particular dose of a substance, and requires increasing dosages in order to obtain the same effects.
Withdrawal—Those side effects experienced by a person who has become physically dependent on a substance, upon decreasing the substance's dosage or discontinuing its use.
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