Substance dependence also known as
drug dependence is an adaptive state that develops from repeated
drug administration, and which results in
withdrawal upon cessation of drug use. A
drug addiction, a distinct concept from substance dependence, 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 addiction and drug addictions, but not dependence.