A 2015 pilot study on the Dax and Mont-de-Marsan (FERIATOX) fertilization sites on 27 patients showed that although several psychoactive substances have been identified in these patients (cocaine, ketamine, MDMA, cannabis, etc.) No DK was identified in this study. It is possible, however, that the profile of people who frequent ferias is different from that of music festivals, which explains the lack of identification of these substances in the FERIATOX study. To support this hypothesis, it seems important to renew this study on festive events of the type of music festival. The Garorock Festival (Marmande), held at the beginning of July, seems to be relevant for the study.