The clinical neurobiology of drug craving

Abstract

Drug craving has re-emerged as a relevant and important construct in the pathophysiology of addiction with its inclusion in DSM-V as a key clinical symptom of addictive disorders. This renewed focus has been due in part to the recent neurobiological evidence on craving-related neural activation and clinical evidence supporting its association with drug use, relapse, and recovery processes. This review covers the neurobiology of drug craving and relapse risk with a primary focus on cocaine addiction and a secondary emphasis on alcohol addiction. A conceptualization of drug craving on the continuum of healthy desire and compulsive seeking, and the associated neurobiological adaptations associated with the development of an increased craving/wanting state is presented. Altered dopamine neurochemistry as well as disrupted prefrontal control and hyperactive striatal-limbic responses in experiencing drug cues, stress, drug intake and in basal relaxed states are identified as neurobiological signatures that predict drug craving and drug use. Thus, the clinical and neurobiological features of the craving/wanting state are presented with specific attention to alterations in these cortico-limbic-striatal and prefrontal self-control circuits that predict drug craving and relapse risk. The methodological challenges that need to be addressed to further develop the evolving conceptual approach to the neuroscience of drug craving is presented, with a focus on identification and validation of biomarkers associated with the craving state and treatment approaches that may be of benefit in reversing the neurobiological adaptations associated with drug craving to improve treatment outcomes in addiction.

FIGURE 1

A schematic diagram representing drug craving on a dimensional continuum with increasing levels of drug exposure and history is presented. Drug-related neuroadaptations in cortico-striatal limbic networks and neurochemical adaptations that may be examined for their contribution to the drug craving state are highlighted. VTA=ventral tegmental area; HP=hippocampus; CRF=corticotrophin releasing factor; VS=ventral striatum; DA=dopamine; PFC=prefrontal cortex; GABA= Gamma-aminobutyric acid ; Ecb=endocannabinoids.