The 4th International Symposium on Drug-Related Studies – 2026, organized by the National Dangerous Drugs Control Board (NDDCB) of Sri Lanka, will be held in November 2026 under the theme “One Nation, One Response: Advancing Collective Action and Scientific Evidence to Address Drug Challenges.” As Sri Lanka’s national focal point for drug prevention, control, treatment, and rehabilitation, the NDDCB remains committed to promoting research, innovation, and evidence-based policymaking to address the evolving complexities of drug-related challenges. The symposium serves as a premier platform for researchers, policymakers, practitioners, law enforcement professionals, healthcare experts, and community stakeholders to exchange knowledge, share best practices, and strengthen collaborative responses to drug-related issues.