Prevalence and Contributing Factors of Illicit Drug Use Among Youth Aged 18-24 in South Korea

South Korea-despite its "drug-free" reputation-exhibits an increasing incidence of drug use, particularly among youths. In this age group, both environmental and individual factors influence illegal drug use. This study aimed to explore the prevalence of illicit drug use and examine the association between individual and environmental factors and drug use among Korean youths. We administered a cross-sectional survey among South Koreans aged 18-24 years through an online panel; the survey assessed participants' characteristics and drug use, as well as relevant individual and environmental factors. The synthetic minority oversampling technique addressed variable imbalance. Logistic regression models analyzed associations between factors and drug use, while Shapley values determined these factors' relative importance. The lifetime prevalence of drug use among the participating youths was 3.9%, with prescription drugs and inhalants being the most prevalent. Negative attitudes toward drugs, a high awareness of South Korea's drug problem, and knowledge of drug use's consequences were associated with lower drug use. High peer pressure, perceived peer drug use, and drug availability were associated with elevated drug use, as were younger age, sexual minority status, living abroad, poor health, and high stress. The high prevalence of prescription drug and inhalant use among South Korean youths suggests that the perception that the country is drug-free is inaccurate and emphasizes the need for targeted intervention strategies. Effective prevention measures should include community education regarding drug risks, early detection of at-risk individuals, and enhanced access to tailored treatment alternatives.