What topics does this cannabis study cover?

This study covers research on: Mental Health, Addiction.

Where was this research published?

Published in Addiction (Abingdon, England) on May 21, 2026.

Mental Health Addiction

Cannabis legalization in Thailand linked to 1,700+ excess teen hospitalizations

Change of substance-related hospitalisation in adolescents after cannabis legalisation in Thailand in 2022.

Addiction (Abingdon, England) • May 21, 2026 • Moderately Relevant

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AI Summary

Thailand's legalization of cannabis in June 2022 had unintended consequences for adolescent health. Within the first 68 weeks following legalization, researchers documented a dramatic 25.5-fold increase in weekly cannabis-related hospitalizations among teenagers aged 10-19 years, translating to 1,762 excess hospital admissions that would not have occurred under previous restrictions. This interrupted time-series analysis examined nationwide hospital data, making it one of the first real-world studies to track how cannabis legalization directly impacts youth health outcomes in a middle-income country.

The impact extended beyond cannabis alone. The study found statistically significant increases in hospitalization rates for stimulants, nicotine, volatile solvents, and hallucinogens, suggesting that cannabis legalization may have cascading effects on adolescent substance use patterns more broadly. Notably, alcohol, sedative, and cocaine-related hospitalizations showed no significant changes, indicating that the legalization's impact was selective and concentrated among other recreational substances.

These findings carry important implications for countries considering cannabis legalization. The data underscore that legislative changes affecting substance availability can have substantial public health consequences for vulnerable populations, particularly adolescents whose developing brains may be more susceptible to substance-related harms. The research suggests that legalization frameworks should incorporate robust preventive strategies, age-restricted access enforcement, and public health monitoring systems to mitigate risks to youth, even in jurisdictions where adult access is permitted.

📄 Original Abstract

On 9 June 2022, Thailand changed its cannabis legislation, expanding access to individuals aged >18 years. Evidence suggests that such changes could increase the risk of cannabis use and related harms, and could influence patterns of use of other substances among adolescents. This study measured the potential impact of these legislative changes on adolescent substance-related hospital admissions. An interrupted time-series study to assess the impact of cannabis legalisation on substance-related hospitalisations using anonymised admission records from the Thai Health Information Portal. Nationwide study in Thailand spanning from 1 October 2016 to 30 September 2023, with 9 June 2022 marking cannabis legalisation. Adolescents aged 10-19 years in Thailand. Based on International Classification of Diseases, 10th Revision diagnostic codes, hospitalisation records were classified as relevant or irrelevant to each of eight predefined substance categories: stimulants (excluding cocaine), alcohol, cannabis, sedatives (including opioids and narcotics), volatile solvents, nicotine, hallucinogens and cocaine. There were an additional 25.5 weekly cannabis-related hospitalisations (95% prediction interval = 23.5-27.2) compared with counterfactual predictions, resulting in 1762 excess cases over the 68-week post-legalisation period. Statistically significant excess admissions were also observed for stimulants, nicotine, volatile solvents and hallucinogens, corresponding to additional admissions of 9.1, 1.4, 0.5 and 0.5 per week, respectively (95% prediction intervals = 0.3-15.4, 0.4-2.1, 0.3-0.7 and 0.2-0.7, respectively). No statistically significant changes were observed for alcohol-, sedative- or cocaine-related hospitalisations. Cannabis legalisation in Thailand was followed by a marked rise in adolescent hospitalisations related to cannabis, alongside an increase in stimulant-, nicotine-, volatile solvent- and hallucinogen-related hospitalizations. These findings highlight the potential unintended consequences of cannabis legalisation in Thailand and underscore the need for preventive strategies to reduce adolescent exposure and related harm.

Paper Type

📄 Research

Publication

Journal: Addiction (Abingdon, England)
Published: May 21, 2026
PMID: 42167765
DOI: 10.1111/add.70484

Authors (8)

Sirada Puetpaiboon Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Songyos Rajborirug Department of Epidemiology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
Vorthunju Nakhonsri Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
Chumpol Ngamphiw Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
Peerapat Khunkham Medical Molecular Biotechnology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, Pathum Thani, Thailand.
+3 more authors