<unk> , also known as drug dependence, is a biopsychological situation where-by 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, which results in the experience of withdrawal, which necessitates the re-consumption of the drug. A drug addiction, a distinct concept from<unk> , is defined as compulsive, out-of-control drug use, despite negative consequences. An addictive drug is a drug which is both rewarding and reinforcing. ΔFosB, a gene transcription factor, is now known to be a critical component and common factor in the development of virtually all forms of behavioral and drug addictions, but not dependence. The International Classification of Diseases classifies<unk>  as a mental and behavioural disorder. Within the framework of the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV),<unk>  is redefined as a drug addiction, and can be diagnosed without the occurrence of a withdrawal syndrome. It was described accordingly: "When an individual persists in use of alcohol or other drugs despite problems related to use of the substance,<unk>  may be diagnosed. Compulsive and repetitive use may result in tolerance to the effect of the drug and withdrawal symptoms when use is reduced or stopped. This, along with Substance Abuse are considered Substance Use Disorders." In the DSM-5 (released in 2013), substance abuse and<unk>  have been merged into the category of substance use disorders and they no longer exist as individual diagnoses.
Substance dependence
Polysubstance dependence
Benzodiazepine dependence
Nicotine dependence
Amphetamine dependence
Substance Abuse
Addiction
Cocaine dependence