Substance abuseSubstance abuse, also known as drug abuse, is the use of a drug in amounts or by methods that are harmful to the individual or others. It is a form of substance-related disorder. Differing definitions of drug abuse are used in public health, medical, and criminal justice contexts. In some cases, criminal or anti-social behavior occurs when the person is under the influence of a drug, and long-term personality changes in individuals may also occur.
Substance use disorderSubstance use disorder (SUD) is the persistent use of drugs (including alcohol) despite substantial harm and adverse consequences as a result of their use. The National Institute of Mental Health (NIMH) states that “Substance use disorder (SUD) is a treatable mental disorder that affects a person's brain and behavior, leading to their inability to control their use of substances like legal or illegal drugs, alcohol, or medications. Symptoms can be moderate to severe, with addiction being the most severe form of SUD”.
Substance dependenceSubstance dependence, also known as drug dependence, is a biopsychological situation whereby an individual's functionality is dependent on the necessitated re-consumption of a psychoactive substance because of an adaptive state that has developed within the individual from psychoactive substance consumption that results in the experience of withdrawal and that necessitates the re-consumption of the drug. A drug addiction, a distinct concept from substance dependence, is defined as compulsive, out-of-control drug use, despite negative consequences.
