Neural systems of reinforcement for drug addiction: From actions to habits to compulsion

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.

Download full-text


Available from: Barry John Everitt, Apr 10, 2014
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Cannabis use disorders (CUDs) are the most prevalent substance use disorders among adolescents in treatment. Yet, little is known about the neuropsychological mechanisms underlying adolescent CUDs. Studies in adult cannabis users suggest a significant role for cognitive control and cannabis-oriented motivational processes, such as attentional bias, approach bias, and craving in CUDs. The current 6-month prospective study investigated the relationships between attentional bias, approach bias, craving, cognitive control, and cannabis use in adolescent patients in treatment for a primary or secondary CUD. Moreover, we investigated if these motivational processes and cognitive control could predict treatment progression after 6 months. Adolescents with a CUD had an attentional but no approach bias towards cannabis. In contrast to adult findings on the role of attentional bias, approach bias and cognitive control, only cannabis craving significantly correlated with current cannabis use and predicted cannabis use-related problems and abstinence from cannabis 6 months later. These findings identify craving as a predictor of treatment outcome, thereby supporting an important role for craving in the course of adolescent cannabis use and dependence. This prospective study is among the first to investigate neuropsychological mechanisms underlying adolescent CUDs, warranting future longitudinal studies. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
    Developmental Cognitive Neuroscience 04/2015; 22. DOI:10.1016/j.dcn.2015.04.001 · 3.71 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Exposure to drugs of abuse can result in profound structural modifications on neurons in circuits involved in addiction that may contribute to drug dependence, withdrawal and related processes. Structural alterations on medium spiny neurons (MSNs) of the nucleus accumbens (NAc) have been observed following exposure to and withdrawal from a variety of drugs; however, relatively little is known about the effects of alcohol exposure and withdrawal on structural alterations of NAc MSNs. In the present study male rats were chronically exposed to vaporized ethanol for 10 days and underwent 1 or 7 days of withdrawal after which the brains were processed for Golgi-Cox staining and analysis of dendritic length, branching and spine density. MSNs of the NAc shell and core underwent different patterns of changes following ethanol exposure and withdrawal. At 1 day of withdrawal there were modest reductions in the dendritic length and branching of MSNs in both the core and the shell compared to control animals exposed only to air. At 7 days of withdrawal the length and branching of shell MSNs was reduced, whereas the length and branching of core MSNs were increased relative to the shell. The density of mature spines was increased in the core at 1 day of withdrawal, whereas the density of less mature spines was increased in both regions at 7 days of withdrawal. Collectively, these observations indicate that MSNs of the NAc core and shell undergo distinct patterns of structural modifications following ethanol exposure and withdrawal suggesting that modifications in dendritic structure in these regions may contribute differentially to ethanol withdrawal.
    Brain research 01/2015; 1594:125-135. DOI:10.1016/j.brainres.2014.10.036 · 2.83 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Anecdotal evidence suggests that problematic use of social media has become prevalent among a large proportion of users and led to significant behavioral and psychological problems. Nevertheless, theory-driven investigation into this issue is still relatively scarce, and the few existing studies tend to adopt only a conceptual or descriptive approach. This study uses a theory-guided approach and seeks to clarify the development of psychological dependence in the context of social media, with a particular focus on microblogging. Building on the theory of rational addiction, this study hypothesizes that dependence is initially developed from habit. Furthermore, the study draws on the cognitive-affective-behavioral modeling paradigm to hypothesize that maladaptive cognition and affect tend to distort habit into psychological dependence. We conduct a longitudinal empirical test to validate the underlying mechanism of social media dependence as theorized in our study. The study concludes with a discussion of theoretical and practical implications.
    Decision Support Systems 01/2015; 69:40-49. DOI:10.1016/j.dss.2014.11.002 · 2.04 Impact Factor