Medical cannabis has served as a therapeutic agent for over 5,000 years. Scientists are just beginning to understand its full potential in modern medicine. The healthcare systems worldwide now recognise medical cannabis as a valuable treatment option for chronic pain and neurological conditions. Scientific evidence continues to support its therapeutic benefits across various medical conditions, despite some viewing it as a controversial treatment choice. As I wrote in this piece, you'll learn about medical cannabis's mechanisms, proven benefits, and safety considerations that shape this evolving treatment option.
The Science Behind Medical Cannabis
The cannabis plant has more than 100 different chemicals known as cannabinoids. Each one affects the body in its own way [1]. Let's look at how these compounds work with our body's natural systems to create therapeutic benefits.
Understanding Cannabinoids and the Endocannabinoid System
The endocannabinoid system is a complex network that helps regulate nerve signals throughout our body [2]. This system is vital in controlling many body processes. It manages our stress response, how we feel pain, our memories, and our behaviour patterns throughout life [3].
The system has two main receptors: CB1 and CB2. You'll find CB1 receptors mostly in the brain and body tissues. The CB2 receptors are mainly in the spleen, thymus, and immune cells [2].
Key Active Compounds: THC and CBD
Scientists have studied two cannabinoids more than any others: delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Here's what makes them different:
| Characteristics | THC | CBD |
| Psychoactive Effects | Yes | No |
| Receptor Binding | Strong CB1 affinity | Weak CB1/CB2 affinity |
| Main Benefits | Pain, nausea, appetite | Anxiety, epilepsy, inflammation |
Mechanisms of Therapeutic Action
Cannabinoids use several different paths to create their therapeutic effects. THC binds strongly to CB1 receptors, which helps relieve pain and creates psychoactive effects [3]. CBD works differently and uses various pathways such as:
- Interaction with serotonergic systems
- Modulation of inflammatory responses
- Influence on pain signaling pathways
- Regulation of neurological activity
Medical cannabis helps control vomiting in chemotherapy patients effectively. It can also reduce pain moderately in people with nerve damage, cancer, and multiple sclerosis [1]. More than 75% of medical cannabis users take it daily [3], which shows its value in managing chronic conditions.
Evidence-Based Medical Applications
Let's look at clinical applications where medical cannabis has shown the most promising results through scientific research and patient outcomes.
Treatment of Chronic Pain Conditions
Chronic pain makes people seek medical cannabis more than any other condition, affecting about 1 in 5 Americans [4]. Research shows that medical cannabis works well for pain management. Studies report that chronic pain patients reduced their opioid use by 64% [4]. Cannabis-based treatments work especially well for:
- Chronic non-cancer pain
- Neuropathic pain
- Medication-rebound headaches
- Allodynia
Neurological and Mental Health Applications
Medical cannabis shows real promise in treating neurological and mental health conditions. Two-thirds of patients say pain relief is their biggest benefit [4]. The results look particularly encouraging for:
| Condition | Key Benefits |
| PTSD | Reduced symptom severity, improved sleep |
| Anxiety | Decreased medication dependence |
| Depression | Mood improvement, better sleep quality |
Cancer-Related Symptom Management
Medical cannabis plays a vital role in managing cancer symptoms. Research shows that cannabinoids help fight chemotherapy-induced nausea and vomiting effectively [5]. Between 20% and 40% of cancer patients find relief from various symptoms [6] such as:
- Nausea and vomiting
- Cancer-related pain
- Sleep disorders
- Anxiety and stress
It's worth mentioning that while cannabis helps with symptoms, some studies point to possible interactions with immunotherapy treatments [6]. Medical supervision remains essential when adding medical cannabis to cancer treatment plans.
Clinical Research and Effectiveness
The medical cannabis research landscape stands at a crucial point today. Clinical evidence grows faster than ever, yet researchers still face major hurdles when they conduct complete studies.
Current State of Scientific Evidence
Medical cannabis use jumped 4.5-fold between 2016 and 2020 [7]. The scientific evidence supporting its clinical uses hasn't kept up with this growth. Research shows that all but one of these oncologists lack confidence about cannabis knowledge, yet 40% still guide their patients [6]. Patients who use medical cannabis report better results in all functional areas. Their quality of life measures improved by 6.60 to 18.31 points [7].
Ongoing Clinical Trials
Many clinical trials now explore medical cannabis applications. The average daily THC dose in these studies has risen from 6.5mg to 25.8mg. CBD doses remain steady at around 72.2mg [7]. Research teams now focus on:
- Pain management and ways to reduce opioid use
- Neurological conditions like epilepsy
- Cancer-related symptom control
- Mental health treatments
Research Limitations and Challenges
Researchers face big obstacles as they try to advance medical cannabis studies. The administrative barriers include:
| Challenge Type | Effect |
| Regulatory Barriers |
Complex registration processes and Schedule I classification [8] |
| Research Design | Problems with blinded, controlled studies [8] |
| Product Access | Limited options and strength in research-grade cannabis [8] |
NIH funding for cannabis research grew from $111.30 million in 2015 to $189.00 million in 2019 [8]. This money still falls short of the work to be done. Therapeutic cannabis research saw its funding rise from $21.00 million to $46.50 million during this time [8].
The biggest problem lies in the gap between research products and real-life applications. To name just one example, NIDA's highest THC content reaches only 12.4%, while commercial products often contain much higher levels [9].
Safety Profile and Risk Assessment
A complete safety assessment of medical cannabis shows both immediate and long-term effects that healthcare providers and patients need to review carefully.
Short-term Side Effects
Medical cannabis produces several immediate effects. Research shows that changes in alertness are common side effects, with drowsiness reported most often [10]. Much of users experience gastrointestinal distress that shows up as decreased appetite and diarrhea [10].
Clinical observations reveal these additional effects:
- Altered sensory perception and time awareness
- Raised heart rate (lasting up to three hours post-use) [11]
- Changes in blood pressure
- Potential cognitive impairment
Long-term Health Considerations
The largest longitudinal study identified several substantial long-term health effects. Regular cannabis use during adolescence or young adulthood can affect brain development, especially when you have areas related to attention, memory, and learning [11]. Studies show frequent users experience a 5.5-point decline in IQ from childhood [12].
| System Affected | Long-term Effect |
| Respiratory | Increased risk of bronchitis and lung inflammation [13] |
| Cognitive | Potential effects on memory and processing speed [12] |
| Cardiovascular | Higher risk of arrhythmias and vascular diseases [11] |
Drug Interactions and Contraindications
Research identified 399 potential drug interactions with cannabis, including 28 major and 371 moderate interactions [14]. The main concerns include:
- Warfarin: Cannabis can substantially increase bleeding risk [15]
- CNS Depressants: Increased risk of sedation and drowsiness [10]
- CYP3A4 Medications: Cannabis affects how these drugs metabolise [16]
CBD inhibits CYP2C19, which can triple certain medication levels like clobazam [16]. Patients taking multiple medications need careful monitoring since cannabis affects liver enzyme activity and drug metabolism [10].
Conclusion
Medical cannabis is a vital therapeutic option that offers promising benefits alongside potential risks that need to be thought through. Research shows cannabis gives positive results for chronic pain, neurological conditions, and cancer symptom management. Patient response varies based on their condition.
Scientific evidence about medical cannabis is expanding, despite research challenges. We now better understand how cannabinoids work with the body's endocannabinoid system. This knowledge helps explain the therapeutic effects and risks.
Patient safety is our most important priority, especially when it comes to drug interactions and long-term health impacts. Medical cannabis needs qualified medical supervision and careful monitoring. We have a long way to go, but we can build on this progress. Our ongoing research and evolving regulations will help us learn about better treatment approaches that minimise risks.
References
[1] - https://www.webmd.com/a-to-z-guides/medical-marijuana-faq
[2] - https://pmc.ncbi.nlm.nih.gov/articles/PMC8221009/
[3] - https://psychiatryonline.org/doi/10.1176/appi.ajp.2021.21111138
[4] - https://www.ncbi.nlm.nih.gov/books/NBK574562/
[5] - https://www.ncbi.nlm.nih.gov/books/NBK425767/
[6] - https://www.cancer.gov/news-events/cancer-currents-blog/2024/medical-cannabis-oncologists-patients-communication
[7] - https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2804653
[8] - https://pmc.ncbi.nlm.nih.gov/articles/PMC8783595/
[9] - https://news.unm.edu/news/how-the-federal-government-limits-valid-scientific-research-on-cannabis-sativa
[10] - https://www.fda.gov/consumers/consumer-updates/what-you-need-know-and-what-were-working-find-out-about-products-containing-cannabis-or-cannabis
[11] - https://my.clevelandclinic.org/health/articles/4392-marijuana-cannabis
[12] - https://www.health.harvard.edu/blog/cognitive-effects-of-long-term-cannabis-use-in-midlife-202206142760
[13] - https://nida.nih.gov/research-topics/cannabis-marijuana
[14] - https://www.drugs.com/drug-interactions/cannabis.html
[15] - https://www.webmd.com/vitamins/ai/ingredientmono-947/cannabis
[16] - https://www.webmd.com/a-to-z-guides/medical-marijuana-faq
