Details

Autor(en) / Beteiligte

• Volkow, Nora D
• Wang, Gene-Jack
• Fowler, Joanna S
• Tomasi, Dardo
• Telang, Frank
• Baler, Ruben

Titel

Addiction: Decreased reward sensitivity and increased expectation sensitivity conspire to overwhelm the brain's control circuit

Ist Teil von

• BioEssays, 2010-09, Vol.32 (9), p.748-755

Ort / Verlag

Weinheim: Wiley-VCH Verlag

Erscheinungsjahr

2010

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• Based on brain imaging findings, we present a model according to which addiction emerges as an imbalance in the information processing and integration among various brain circuits and functions. The dysfunctions reflect (a) decreased sensitivity of reward circuits, (b) enhanced sensitivity of memory circuits to conditioned expectations to drugs and drug cues, stress reactivity, and (c) negative mood, and a weakened control circuit. Although initial experimentation with a drug of abuse is largely a voluntary behavior, continued drug use can eventually impair neuronal circuits in the brain that are involved in free will, turning drug use into an automatic compulsive behavior. The ability of addictive drugs to co-opt neurotransmitter signals between neurons (including dopamine, glutamate, and GABA) modifies the function of different neuronal circuits, which begin to falter at different stages of an addiction trajectory. Upon exposure to the drug, drug cues or stress this results in unrestrained hyperactivation of the motivation/drive circuit that results in the compulsive drug intake that characterizes addiction.