Ketamine Use and Driving in Northeastern France

"In the present study, the overall percentage of drivers who tested positive for ketamine in a roadside oral fluid test was 2.6%. This percentage was higher than that described by Gish et al. in samples collected at a music festival in southwest France (1.4% in 2017 and 0.4% in 2019) [17], but also higher than the prevalence previously reported in the driver population of other countries [18, 19, 20, 21] where the highest prevalence was found in Australia in 2012 (1.5%) [18]. While the nature of the musical event may partly explain the difference observed in our study (rave party) with that of Gish et al. (rock festival), regional disparities in illicit drug use may exist. The percentage of ketamine positivity observed in our study during the last 7 months of 2020 was of the same order as those previously described, but cannot be compared to earlier data from our region since ketamine in oral fluid samples was unfortunately not tested in our laboratory before May 2020. However, we report a significant increase in ketamine use in 2021 compared to 2020, which is consistent with the study led by the French Addictovigilance Network, where the number of ketamine users with a substance use disorder in the OPPIDUM programme increased 2.5‐fold between 2012 and 2021 [9]. In this study, we also observed a higher number of ketamine‐positive cases in the summer and autumn. This observation is consistent with the evolution of ketamine use from a confidential one, at high doses in free parties and in the party scene in the 2000s, to a large one, in a ‘techno and electro’ festive context during festivals, in bars or in clubs [22, 23, 24]. It is now more common to consume ketamine in trace amounts, as consumers are no longer looking for hallucinogenic properties, but rather for a more moderate stimulant effect. The higher consumption of ketamine during the summer period reported in the present study is consistent with those reported in Toulouse (southwestern France) since 2017, in relation to a diffusion of this substance from alternative parties to electronic parties. Indeed, the latter are more frequent in the summer period and the larger number of participants in outdoor events is also a source of increased diversity and availability of substances [25]. In addition to summer and autumn, a marginal use of ketamine in winter was observed in our region during a rave party in January 2023. The same situation was observed in Toulouse during techno‐house and industrial techno parties in 2018, underlining the trivialized consumption of ketamine by techno partygoers. In this study, we cannot exclude the possibility that drivers attending supervised events, such as music festivals, which require prior authorization from the prefecture and are associated with more pronounced and systematic control, were included, thus introducing a possible bias. On the contrary, it should be noted that the use of the DrugWipe®5S as a roadside screening test in accordance with French regulations did not allow for the direct detection of ketamine [11]. This may have introduced a potential underestimation and selection bias among drivers tested for drug use, but this may be limited as 95.4% of the ketamine‐positive drivers identified in this study were polydrug users, mainly using COC, THC and AMP. Interestingly, this problem could be easily overcome by using some rapid oral fluid tests such as DrugWipe® 6S, Ora‐Check®, SalivaScreen®, OratectXP®, which are able to detect ketamine at cut‐offs of 5 to 50 ng/mL for ketamine and 30 to 75 ng/mL for norketamine [26, 27]. Finally, among the ketamine users, we do not exclude the possibility of having included depressed persons using the antidepressant esketamine. Indeed, the dextrorotatory isomer of ketamine (s‐ketamine) cannot be differentiated from ketamine by our non‐chiral chromatography method, whereas major depression has been reported to favour drug of abuse consumption [28]. However, the study by Baudot et al. showed that only a small number of patients are treated with esketamine in France [29], limiting the bias introduced by our analytical method."