Public health surveillance of new psychoactive substances: recent developments.

PURPOSE OF REVIEW: New psychoactive substances (NPS) continue to emerge globally and present a threat to public health. This article summarizes the most recent literature on approaches for monitoring NPS use and adverse events related to use.

RECENT FINDINGS: A variety of approaches have recently been employed for surveillance of NPS use and associated harms, including the use of toxicology testing of patients in emergency departments, surveys of sentinel populations, drug checking and syringe services programs, wastewater-based epidemiology, and retrospective analyses of clinical samples and toxicology reports. These studies cover a range of time periods and NPS examined across numerous countries.

SUMMARY: Areas of particular interest for future research include the use of data from drug checking services to inform surveillance efforts of the illicit drug supply and the development of methods for wastewater-based monitoring of NPS. Studies that combine self-report data with toxicology testing in particular are important for capturing unintentional or unknown exposure to NPS including fentanyls and drugs like xylazine. Given the limitations associated with individual indicators of drug use and associated harms, the harmonization of multiple data sources can help present a more complete picture of both trends involving NPS to better inform public health responses.