Early Warning System for New Psychoactive Substances surveillance in the Community of Madrid, Spain
N Mata-Pariente, F Sánchez-Arenas, E Chong-Chong, AM Ruiz-Tornero, F Domínguez-Berjón, A Arce-Arnáez, C Tortosa-Laso, A Martín-Martínez, A Caballero-Bermejo,Abstract
Background
The global use of new psychoactive substances (NPS) has increased over recent decades, posing significant public health challenges. In this context, the Community of Madrid (CM) implemented an Early Warning System for NPS (EWS-NPS) surveillance in hospital emergency departments (ED) to monitor NPS use, enabling early detection and timely public health responses.
Methods
A multidisciplinary working group, led by the General Directorate of Public Health and comprising professionals from the Institute of Legal Medicine (ILM) and the Hospital Care Directorate, was established to implement the project. A technical protocol was developed to define case notification procedures for suspected NPS-related acute intoxications in hospital ED, including the collection of biological samples and their submission to the ILM laboratory. A pilot study was conducted in 4 public hospitals in the CM, covering 22% of the region’s 7,2 million inhabitants. A descriptive analysis was performed using data from the 2025–2026 period.
Results
The EWS-NPS was launched in March 2025. Since then, 52 cases were analyzed. NPS were detected in 20 cases (38,5%), involving 13 different NPS. The most frequently identified NPS were ketamine, MAB-CHMINACA (cannabinoid), 3-CMC and α-PVP (cathinones), 2C-B (phenethylamine) and GHB. Most patients with confirmed NPS detection were male (85,0%), with a mean age of 28 years and a high prevalence of polydrug use, involving other psychoactive substances, primarily cocaine, MDMA and methamphetamine. More than half of patients (60,0%) had a history of mental health disorders.
Conclusions
Preliminary results indicate a high proportion of NPS detections among patients attending ED with suspected NPS intoxication. Most patients are young adult men with concurrent polydrug use. The EWS-NPS is a valuable tool for monitoring emerging drug trends and supporting the development of targeted preventive strategies to address this growing public health concern.
Key messages
• An early warning system for new psychoactive substances in hospital emergency departments is a valuable tool for monitoring emerging drug use.
• It enables the design of targeted preventive strategies.