What Conditions Has Medical Cannabis Been Studied to Treat?
Cannabis has recently gained a lot of support in the US, with 33 states now legalizing medical cannabis. So how effective are the therapeutic effects of medical cannabis and what conditions has it been studied to treat?
Cannabis
To understand the therapeutic mechanisms of cannabis we have to understand its two main active compounds, the cannabinoids tetrahydrocannabinol (THC) and cannabidiol (CBD).
THC and CBD are part of the endocannabinoid system and can induce a range of effects on the body. THC is known for its high-inducing effects and acts out its functions by activating the G-protein coupled cannabinoid receptors CB1 and CB2. CBD, on the other hand, does not result in a high and instead induces its effects by activating some non-cannabinoid receptors and modulating receptor pathways.
Both THC and CBD have demonstrated an ability to treat a range of symptoms and conditions, although it's important to remember that cannabis’ potential therapeutic effects cannot be guaranteed for everyone.
So which medical conditions can cannabis help with?
Pain
One of the main attractions of cannabis as a therapeutic treatment is its reputation as a powerful pain reliever. In fact, 46% of the 356 patients in one survey of cancer patients who reported taking cannabis did so to treat their cancer-related pain. The research seems to be consistent with cannabis’ analgesic reputation, with one study showing the activation of the CB1 and CB2 cannabinoid receptors resulted in analgesic (pain-relieving) effects that were comparable to the effects of morphine in a tumor pain model.
THC might facilitate this pain-relief through its ability to modulate opioid release when binding to the CB1 receptor, hyperpolarizing the pre-synaptic terminal and closing calcium channels that hold back inhibitory and excitatory neurotransmitters at their synapses that can modulate opioid release.
Anxiety and Depression
Cannabis has also shown potential as a treatment for mood disorders such as anxiety and depression, with both THC and CBD individually demonstrating significant antidepressant-like effects.
THC activates cannabinoid receptors and it is thought that this activation may reduce levels of the stress hormone cortisol. This activation has been found to play a key role in blocking the neuroendocrine stress response, inhibiting the stress-cascade which initiates the production of cortisol.
CBD, on the other hand, is thought to induce its anti-depressant and anti-anxiety effects by increasing serotonin levels in the brain. Serotonin is closely linked to healthier mental functioning and CBD has demonstrated an ability to increase serotonin levels by activating the 5-HT1A serotonin receptor.
Reduce Symptoms Of Serious Disease
In a 2018 report, the World Health Organization (WHO) stated that CBD offered potential as a treatment for the symptoms of serious degenerative diseases including Alzheimer’s Disease, Parkinson’s Disease, and Multiple Sclerosis. This could occur through a number of mechanisms including CBD’s neuroprotective and anti-inflammatory effects.
Anti-Tumor Potential
While cancer and cannabis research is still in its preliminary stages, research has shown that cannabis has anti-tumor properties, with cannabis-induced CB1 receptor activation in one study showing an ability to slow cell growth in prostate cancer cultures. Another study using animal models showed that CB2 activation led to a significant reduction in specific glioma cancer cells.