Relapse

Relapse, in relation to drug misuse, is resuming the use of a drug or a chemical substance after one or more periods of abstinence. The term is a landmark feature of both substance dependence and substance abuse, which are learned behaviors, and is maintained by neuronal adaptations that mediate learning and processing of various motivational stimuli. An important aspect of drug use is the propensity for repeated use and dependence, tendencies that are influenced by the nature of the drug itself and thus vary from substance to substance. Those substances that are cleared from the body most quickly, those with the highest pharmacological efficacy, and those that induce the highest tolerance elicit the most severe tendencies in users. Drug dependence can lead to increased tolerance to the substance in question, cravings, and withdrawal if the drug use ceases.