Decision-making deficits are at the centre of the definitions of addiction disorder. These deficits would be only the expression of a motivational bias because of which the patient is feeling the sensation of ‘craving’ and chooses to consume the substance of dependence in an automatic and compulsive way. The action of this substance on the mesolimbic dopaminergic reward system implies long-lasting modifications of the neural networks implied in the decision-making process, mainly the orbito-frontal cortex, the dorsolateral prefrontal cortex, the anterior cingular gyrus and the limbic system. Indeed, the addict’s decisional balance could be biased in favour of the consumption of the substance because of dysfunctional emotional (impaired salience attribution) and cognitive systems (impaired response inhibition).