Korean treatment-seeking sample shows distinct cannabis use profile

BACKGROUND: Although substance use disorders are increasingly recognized in the Republic of Korea (South Korea), empirical data on the prevalence and characteristics of drug use among treatment-seeking populations remain limited. This study examined the rate and temporal patterns of major psychoactive substance use-specifically sedatives/hypnotics/tranquilizers (sedatives), amphetamines, and marijuana/cannabis (cannabis)-across three timeframes and explored the associated sociodemographic and clinical factors. METHODS: Data were obtained from 540 adults with a history of substance use, recruited from medical and rehabilitation institutions as part of the 2021 Survey of Drug Abusers in Korea. Sociodemographic and clinical factors-including Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5)-based substance use disorder (SUD) diagnosis, self-recognition of addiction, depression, anxiety, and Addiction Severity Index (ASI) scores-were assessed. Group comparisons were conducted using χ² and t-tests. Multivariable logistic regression identified factors associated with sedative, amphetamine, and cannabis use across past 30-day, past-year, and lifetime periods. Multiple linear regression examined associations between each substance and ASI composite domains. Statistical significance was set at P < 0.05. RESULTS: Among the 540 individuals with a history of substance use, the lifetime rate of use was highest for amphetamines (71.9%), followed by cannabis (52.8%) and sedatives (38.1%). Sedative use remained relatively consistent across timeframes (30-day: 21.9%; 1-year: 28.9%; lifetime: 38.1%), suggesting patterns of chronic or concurrent use. Across all three substance groups, participants exhibited poorer mental health, including elevated levels of depression, anxiety, or psychiatric severity. Amphetamine and sedative users were more likely to be female, older, and of lower socioeconomic and educational status, with greater impairment in psychiatric, family, and social functioning, as well as higher self-recognition of addiction. In contrast, cannabis users were predominantly younger males with higher socioeconomic status but elevated anxiety levels. Institutional affiliation also differed by substance type: cannabis users were more frequently associated with rehabilitation centers, whereas amphetamine users were more often treated in medical institutions. CONCLUSION: Findings highlight the coexistence of shared psychosocial vulnerabilities and substance-specific risk profiles in Korea. Integrated, multidimensional interventions-linking psychiatric care, social support, and economic protection-are needed for amphetamine and sedative users. For younger cannabis users, early intervention and relapse prevention are essential. Strengthening coordination between medical and rehabilitation systems under Korea's Judicial-Treatment-Rehabilitation Linkage Model may reduce stigma and enhance recovery-oriented care for individuals with SUD.