A new wave of scientific research challenges some of the most common beliefs about using cannabis to treat health problems such as pain, insomnia, and mental health symptoms like paranoia, highlighting important lessons for Thai readers at a time when medical marijuana access is rapidly expanding in Thailand and across Asia.
The use of cannabis as medicine has surged since Thailand became the first Southeast Asian country to decriminalize cannabis plants in 2022—a move initially aimed to stimulate medical innovation and boost the economy through wellness tourism. But as ever more Thais purchase cannabis products online and at street dispensaries, fresh global research underscores that the effectiveness—and risks—of cannabis for many health problems are far from settled, with strong implications for the Thai public, patients, and caregivers (Washington Post, Medical News Today).
According to a detailed review published in the U.S. in 2025 (JAMA Network Open), evidence supporting cannabis for chronic pain relief remains limited. While some studies suggest that cannabinoids, the active compounds in cannabis, may provide moderate relief for certain conditions such as neuropathic pain, fibromyalgia, and complex cancer-related symptoms (PMC), meta-analyses consistently show only marginal benefit relative to placebo. In the case of insomnia and sleep disturbance, findings are even more cautious: Though cannabis can sometimes shorten the time to fall asleep for experienced users, it has not demonstrated substantial or consistent improvements in sleep quality or duration. Notably, for people suffering from insomnia due to medical conditions such as obstructive sleep apnea, research indicates little to no long-term benefit (Sleep Foundation).
The issue becomes even more complicated when it comes to mental health effects and the risk of paranoia. Cannabinoids can, in some patients, alleviate anxiety and nausea; however, for others—particularly adolescents, those with underlying mental health vulnerabilities, or individuals taking high-potency cannabis—scientists identify a significant risk of paranoia, psychosis, and disordered thinking (National Geographic). A recent Johns Hopkins University study in 2025 even discovered that a terpene called d-limonene found in cannabis might help counteract anxiety and paranoia, further showing the wide variability of cannabis’ mental effects (Curaleaf Clinic). As one Thai clinical faculty member at a prominent medical university noted, “Cannabis is complex; for some, it brings relief, but for others, especially younger people or those with certain genes, it can trigger severe psychological side effects.”
Thailand’s sweeping decriminalization has seen thousands of cafes, wellness centers, and online sellers entering the market, creating a consumer “green rush.” But this public enthusiasm outpaces the science. As summarized in the Wikipedia entry on medical cannabis, clinical trials to date have been hampered by legal restrictions, leading to an overall lack of high-quality, long-term studies—especially on oral, edible, and topical forms that are rapidly gaining popularity among Thai consumers. Short-term use, the data show, increases the risk of both minor effects (such as dizziness and drowsiness) and more serious consequences like hallucinations, cognitive impairment, and addiction. Long-term risks remain poorly defined but may include memory problems and elevated psychiatric disorder risk, especially among youth.
One of the most notable studies relevant to Thai readers is a 2023 clinical trial examining patients with fibromyalgia, a chronic pain disorder. The study compared cannabis alone, opioid painkillers (such as oxycodone), and a combination treatment. Results showed some synergistic benefit from using cannabis in combination with lower opioids, but cannabis alone failed to deliver significant pain reduction beyond placebo for most participants (PubMed). This finding aligns with a 2022 trial that looked at a natural compound blend of melatonin and cannabis extract (CBD) for insomnia. While some short-term improvement in sleep onset was observed, overall benefits were modest, and a substantial number of participants reported fatigue, grogginess, and cognitive side effects (PubMed).
Crucially, cannabis is not a universal remedy—even for its most popular health uses. The U.S. National Academies of Sciences, Engineering, and Medicine concluded that there is only conclusive or substantial evidence for cannabis’ ability to reduce chronic pain in adults, chemotherapy-induced nausea, and spasticity in multiple sclerosis, while evidence for use in insomnia, anxiety, PTSD, Tourette’s syndrome, and depression remains insufficient, mixed, or absent (Psychology Today).
What complicates the situation for Thailand is the diverse range of administration methods—capsules, lozenges, sprays, patches, edibles, vaporized oils, and inhaled forms are all readily available throughout the kingdom. The effects, onset time, and health risks can vary dramatically depending on the method and potency. For instance, non-inhaled products (such as edibles, which are popular in Thai health cafes) have a slower onset but longer duration, often leading to accidental overconsumption, particularly among new users unfamiliar with dosing (Wikipedia).
Additionally, Thailand’s Buddhist culture, with its focus on moderation and mindfulness in medicine, raises unique questions about the appropriate use of cannabis for wellness. Historically, cannabis was used in Thai traditional medicine centuries ago, often as a topical ingredient or in herbal compresses for pain relief, but never for recreational intoxication. Today’s market, however, includes potent modern hybrid strains and high-dose extracts far more powerful than the herbal remedies of the past (Medical News Today).
Psychiatric experts urge caution: In clinical practice, physicians at major Thai hospitals have started seeing an uptick in cannabis-related emergency room visits, primarily involving acute anxiety, paranoia, hallucinations, and, in rare cases, psychosis—most often among teenagers or adults using high-THC products from unregulated sources. As a senior Thai psychiatrist explained, “The science shows cannabis can be part of a medical plan for some diseases, but there is no magic bullet. For children, teens, pregnant women, or those with any mental health concerns, it is best to avoid it.”
Looking forward, global research is shifting towards more nuanced approaches. Scientists are investigating minor cannabinoids (such as CBG, CBN, and CBDV) for their therapeutic potential, as well as the precise “entourage effect” where cannabis compounds interact in complex ways. Regulation is also ramping up: The Thai Food and Drug Administration is working to implement clearer labeling, potency limits, and public health warnings, while researchers call for Thailand to invest in its own high-quality clinical trials tailored to the local population and cultural context (Washington Post).
For Thai readers weighing the risks and rewards of medical cannabis, the key takeaway from the latest science is caution. Those considering cannabis for pain or insomnia should do so only under the supervision of a licensed physician experienced in cannabinoid medicine and should avoid self-medicating, particularly with high-THC or unregulated products. For patients with mental health histories, young people, and pregnant or breastfeeding women, all major medical bodies recommend avoiding cannabis altogether.
As the cannabis landscape in Thailand continues to grow—and as policymakers weigh the lessons from Europe and the Americas—public education and patient safety must remain at the forefront. The history of Thai medicine shows respect for tradition and evidence; integrating cannabis into health care should follow the same principles, with careful, ongoing review of the science and respect for the individual and collective wellbeing.
For practical decision-making, Thais should:
- Consult certified healthcare professionals before starting any cannabis-based treatment
- Start with the lowest effective dose and monitor for side effects
- Avoid inhaled and high-potency THC products, particularly for vulnerable groups
- Stay informed on new research through official Thai public health channels
- Report adverse effects to health authorities to support national safety monitoring programmes
As new international scientific findings emerge, Thai society—guided by the principles of moderation and evidence—can ensure safe, responsible, and culturally sensitive cannabis use for health and wellness.