Neuroimagen y adicción Icorrelatos neuroanatómicos y funcionales de la administración aguda, el craving y el consumo crónicode psicoestimulantes

Abstract

In recent years there is an increasing interest in the study of the neurobiological correlates of psychostimulant use, including cocaine and MDMA. The application of neuroimaging techniques to this field has allowed us to examine "in vivo" the acute effects of psychostimulant drugs administration, the neural correlates of the intense urge for using these drugs (craving), and the morphological and functional alterations associated with chronic psychostimulants use. The aims of this review are: (1) To succinctly explain the main neuroimaging techniques applied in drug abuse research. (2) To outline the most updated neuroimaging findings in the study of the neural correlates of cocaine and MDMA use; here, we will consider (i) acute administration of the drug, (ii) experimentally-induced craving, and (iii) chronic effects of prolonged drug use. (3) To discuss the relevance of these findings for a better comprehension of addictive disorders and their treatment. The findings reviewed indicate that cocaine and ecstasy use induce common alterations in selected brain regions including the frontal cortex, the limbic system and the basal ganglia; predominantly lateralized in the right hemisphere. Acute drug administration is associated with hyperactivation of these regions, which also occurs during craving, whereas hypoactivation and structural damage is observed after chronic use. The putative role of these brain regions is consistent with the neuropsychological deficits observed in chronic drug users, including blunted motivation for natural reinforcers, and alterations in memory, executive functions and decision-making.