Prevalence of Stimulant, Hallucinogen, and Dissociative Substances Detected in Biological Samples of NPS-Intoxicated Patients in Italy.

A number of new psychoactive substances (NPS) have been released in the last decade, and the list of NPS continues to grow. This paper reports a retrospective evaluation of the toxicological analyses in 1,445 suspected intoxication cases by psychostimulant, hallucinogen, and dissociative NPS occurring in hospitals across Italy from 2011 to 2019. The objectives of the study were to contribute to the monitoring of the NPS diffusion based on analytically confirmed intoxications, and to evaluate the importance of the clinical toxicological laboratory in the diagnosis of NPS intoxication. For at least one NPS of the considered classes, 246 patients (17.0%) tested positive. Forty-four different NPS were detected and a consistent turnover was observed during the nine-year period, especially regarding cathinones. Among the positive cases, 47.2% tested positive for dissociative NPS, with particular regard to ketamine. Hallucinogens (30.9%) was the second most frequent NPS involved. Stimulants were found in 20% of the positive cases with a considerable presence of cathinones. Findings confirm the dynamism of the NPS phenomenon, underline the importance of awareness of this new public health threat among health care professionals, and highlight the need for analytical confirmation for the identification of the drugs in forensic contexts.