Abstract
Cannabis is traditional plant that contains psychoactive substances. In the past, there were reports suggesting the utilisation of cannabis for various purposes, for instance, recreation, medicine, and textile. However, many countries, including Thailand, probihited the use of cannabis, and included it in the narcotic or addictive substabce list. So far, there have been a number of reports suggesting harmful effects of cannabis on health, especially, deleterious effects on brain function and increasing risk of the use of other substances.
Between 2015 and 2016, there were massive campaigns from both public and private agencies urging an amendment of the 1979 Narcotics Act in the way that withdraws cannabis from the narcotic drug list. This campaign is related to not only medicalisation, but also legalisation of cannabis. This report therefore sought to review the current situation regarding the use of cannabis for medical purposes in various aspects, such as benefits, caveats, as well as international experience in cannabis legalisation and challenges in the Thai healthcare system. It is hoped that results from this study will serve as grounds for future research, and can be useful to later policy decision. The main data collection technique is literature review on electronic databases, especially, Medline.
The findings show that most research on cannabis was confined in laboratory or animal studies. Though there were some clinical trials on humans, the majority of them still had limited number of participants, and compared clinical effects of cannabis with placebo. Regarding international experiences, the scope of cannabis medicalisation varies substantially; from extracting some substances in cannabis or using cannabis-like derivatives to produce second- or third-line drugs for treating patients with certain diseases, using herbal cannabis (by oral route or smoking) under supervision of physicians, to using cannabis in recreational activities. Some countries implemented decriminalisation measures. The openness of cannabis policies in many countries has some similar features, namely, (1) cannabis related laws were gradually amended over time rather than having a radical change, and (2) there were several measures implemented in parallel with the cannabis legalisation/medicalisation in order to prevent the use of cannabis in the way that deviates from original policy intentions.
Note that this review found that most information was retrieved from international literature. This observation reflected gaps in knowledge regarding medical use of cannabis in Thailand. Thus it is imperative to support domestic research on cannais in various angles, such as how to improve species of cannabis for better botanical use, how to extract medical substance from cannabis, and how to promote pharmacological studies on the effectiveness and efficacy of cannabis for treating certain diseases. This point should include research questions outside health service system arena, such as social science research and law studies. Some broader research questions should be taken into account, such as public opinions towards cannabis and the readiness and aprropriateness of existing laws in controlling cannabis. If the Thai government aims to implement policies vis-à-vis the utilisation of cannabis, it is imperative to distinguish medicalisation issue from legalisation issue while communicating with the wider publi. Moreover, the government should assess its capacity in regulating the use of cannabis before introducing cannabis-medicalisation/legalisation policies and the potential cost of treating patients with substance abuse.
