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Everitt BJ, Robbins TW. Neural systems of reinforcement for drug addiction: from actions to habits to compulsion. Nat Neurosci 8: 1481-1489

Department of Experimental Psychology and the MRC-Wellcome Behavioural and Clinical Neuroscience Institute, University of Cambridge, Downing Street, Cambridge CB2 3EB, UK.
Nature Neuroscience (Impact Factor: 14.98). 12/2005; 8(11):1481-9. DOI: 10.1038/nn1579
Source: PubMed

ABSTRACT Drug addiction is increasingly viewed as the endpoint of a series of transitions from initial drug use--when a drug is voluntarily taken because it has reinforcing, often hedonic, effects--through loss of control over this behavior, such that it becomes habitual and ultimately compulsive. Here we discuss evidence that these transitions depend on interactions between pavlovian and instrumental learning processes. We hypothesize that the change from voluntary drug use to more habitual and compulsive drug use represents a transition at the neural level from prefrontal cortical to striatal control over drug seeking and drug taking behavior as well as a progression from ventral to more dorsal domains of the striatum, involving its dopaminergic innervation. These neural transitions may themselves depend on the neuroplasticity in both cortical and striatal structures that is induced by chronic self-administration of drugs.

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    • "One could speculate that the approach bias may only be evident in early stages of cannabis abuse, predicting escalation of cannabis use rather than problem severity. This is in line with addiction models that suggest that motivational processes, like attentional and approach bias may play a role when substance use is still under voluntary control (Di Chiara, 2000; Everitt and Robbins, 2005). Yet, craving, but not cognitive control, predicted treatment progress, contradicting these same models. "
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