Psychoactive Substances: Analytical Strategies for the Identification of Designer Drugs in Forensic and Clinical Contexts.

Introduction: Designer drugs, or novel psychoactive substances (NPS), are synthetic analogues of controlled drugs engineered to mimic their pharmacological effects while evading legal regulation. Their rapid emergence and global distribution pose major challenges to public health, law enforcement, and analytical laboratories due to their unpredictable effects and complex chemical variability. Methods: This review compiled and analyzed recent literature on the classification, pharmacology, abuse patterns, and analytical detection of designer drugs. Key instrumental techniques such as gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and nuclear magnetic resonance (NMR) were evaluated alongside novel sensor-based technologies. Relevant case studies were examined to highlight clinical and forensic implications. Findings: The major classes of designer drugs include synthetic cathinones, cannabinoids, benzodiazepines, phenidate derivatives, and dissociatives. Traditional analytical methods provide high sensitivity and selectivity but face challenges like matrix effects, derivatization needs, and limited on-site applicability. Emerging sensor technologies, including molecularly imprinted polymers and aptamer-based biosensors, offer rapid and portable alternatives for field testing. GC-MS and LC-MS/MS remain the gold standards for confirmatory testing, while innovative nano-enabled sensors show promise for real-time detection and point-of-care diagnostics. Conclusion: Continuous evolution of designer drugs necessitates adaptable analytical strategies. Integration of advanced sensor platforms with established chromatographic methods and strengthened inter-laboratory validation can enhance global surveillance and improve public health responses to NPS abuse.