Evidence of 2 Populations of Mephedrone Abusers by Hair Testing. Application to 4 Forensic Expertises

Background: New psychoactive substances are conquering the drug scene. Among these substances, cathinone derivatives have been observed since late in the years 2000. At that time, there was evidence of increasing use of the synthetic cathinone mephedrone, particularly amongst clubbers. Although the emergent drugs have an aura of safety, there is an increasing amount of experiences on their secondary effects. Mephedrone is known to induce psychosis. Method: Given the potential negative effects of mephedrone, the laboratory was asked to test for the drug in hair, a cumulative matrix that can document single, occasional or repetitive abuse of xenobiotics. Mephedrone was tested in hair by GC/MS, using a standard procedure developed for stimulants such as amphetamine or ecstasy. Results: In the head hair of 24 positive abusers, mephedrone was identified in the range 0.1 to 87 ng/mg, clearly determining 2 populations, one with co-administration of ecstasy and a second without ecstasy. In the first population, mephedrone concentrations were 0.1 to 5 ng/mg; in the second population, mephedrone concentrations were 3 to 87 ng/mg. These findings should help in the understanding the addiction of subjects. In 4 separate forensic cases, mephedrone was identified in hair of abusers, including a rape case (0.54 ng/mg), a fatal car crash (0.38 ng/mg), a fatal drowning (1.21 ng/mg), and a fatal overdose (6.99 ng/mg). Conclusion: Hair testing for new psychoactive substances appears as a good complement to standard urine analyses. This study confirms the increasing diffusion of new drugs among the forensic population of abusers.