The effect of banning MDPV on the incidence of MDPV-positive findings among users of illegal drugs and on court decisions in traffic cases in Finland.

In this study, we sought to determine what impact the banning of 3, 4- methylenedioxypyrovalerone (MDPV) had on the incidence of MDPV-positive findings and on user profiles in driving under the influence of drugs (DUID) and postmortem (PM) investigations in Finland. All MDPV-positive cases and a selection of corresponding court cases between 2009 and 2012 were examined. The median serum concentration of MDPV in DUID cases was 0.030 mg/L and in PM blood 0.12 mg/L. The number of MDPV-positive cases decreased both in DUID and PM investigations after the drug was banned. The decrease in the mean monthly numbers of MDPV-positive DUID cases was 51.1%. In court cases, MDPV was rarely mentioned until banned and frequently mentioned thereafter. Of the convicted, 37% were without a fixed abode, 98% had other charges besides that of DUID, and 13% appeared in the study material more than once. In MDPV-positive PM cases, the proportion of suicides was very high (24%). Research on new psychoactive substances is required not only to support banning decisions but more importantly to be able to provide a scientific assessment of the risks of these new substances to the public and potential users.