Multi-Indicator Surveillance of Amphetamine-Type Stimulants (ATS) and Synthetic Cathinones in Italy: A Systematic Review of Seizure, Wastewater, and Toxicological Data

Synthetic stimulant drugs in Italy are evolving rapidly, with amphetamine-type stimulants (ATS) and synthetic cathinones (SC) representing a growing public health challenge. However, no previous study has integrated multiple surveillance indicators to assess the availability and consumption of these substances across Italy. This systematic review synthesized comprehensive evidence published between 2000 and 2023 from three monitoring indicators: drug seizures reports, wastewater-based epidemiology (WBE), and toxicological/clinical studies. Searches of Scopus, PubMed, and Google Scholar identified 969 records, of which 49 studies and reports met the inclusion criteria: 15 on drug seizures, 18 on WBE, and 16 on toxicological studies. Eligible articles were fully reviewed and summarized. Results indicated a diverse and evolving landscape, with increasing detection of synthetic cathinones and significant regional variation in ATS and SC consumption. In total, seven ATS and twenty-five SC were identified across all indicators. Amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 4-methylethcathinone (4-MEC), and methylenedioxypyrovalerone (MDPV) were consistently detected in seizure, wastewater, and toxicological data, indicating their availability and consumption in Italy. WBE studies showed marked spatial and temporal variability in stimulant consumption, while seizure and toxicological data highlighted the increasing diversification of synthetic cathinones in the Italian drug market. Key limitations include uneven geographical coverage and methodological heterogeneity among studies. The findings demonstrate the value of integrating WBE, forensic, and law enforcement indicators to strengthen surveillance of emerging stimulant drugs in Italy.