Acute blockade of CB1 receptor leads to reinstatement of MDMA-induced conditioned place preference

► MDMA-induce CPP can be reinstate after extinction by a priming dose. ► The role of the cannabinoid system on the reinforcing effects of MDMA is not clear. ► No study has evaluated its role on the reinstatement of MDMA drug-seeking behavior. ► CB1 agonist WIN55212-2 and CB1 inverse agonist/antagonist SR141716A were used. ► The acute blockade of the endocannabinoid system reinstates MDMA-induced CPP. ► WIN 55212-2 increases the effect of a non-effective priming dose of MDMA.