Medical cannabis treatments have proved highly effective at managing many of the symptoms of multiple sclerosis (MS). Here, we take a look at which symptoms in particular are positively affected by use of cannabis or cannabis-based therapies.
Multiple Sclerosis (MS) is a condition mediated by dysfunction of the immune system, whereby an abnormal immune response is targeted at the central nervous system. It is a life-long condition that affects the spinal cord, the brain and the optic nerve. According to the American National MS Society, it is estimated that over 2 million people globally are affected. Cannabis treatment is considered a possibility for MS sufferers because it is anti-inflammatory, analgesic and anti-spasmodic.
1. Cannabis is anti-inflammatory
Inflammation of neural tissue is the primary characterisation of multiple sclerosis. MS is an autoimmune disease in which the body’s own immune cells attack the central nervous system, leading to inflammation of the myelin sheaths that enclose the neurons (nerves) in the brain and spinal column. This inflammation ultimately leads to the myelin sheaths becoming irreparably damaged, which in turn causes a range of neurological symptoms including loss of motor control, muscle weakness and spasms, unstable mood and fatigue.
Cannabis is well-known to reduce inflammation, and has been used as an anti-inflammatory for thousands of years by physicians and herbalists the world over. In recent years, the ability of cannabis to reduce MS-related inflammation has been thoroughly investigated, and has provided the basis for the world’s first market-approved pharmaceutical—Sativex, produced by the UK company GW Pharmaceutical.
Research has demonstrated that agonists of the CB1-receptor (such as THC or the endogenous partial agonist anandamide) exert a neuroprotective effect in individuals suffering from MS mediate neuroprotection during inflammatory insults. In one important study, mice bred to be deficient in CB1-receptors exhibited increased susceptibility to inflammation and neurodegeneration when infected with an animal model of MS known as experimental allergic encephalomyelitis.
2. Cannabis has analgesic properties
Pain is one of the most common and debilitating symptoms of MS, and is experienced by 30-90% of sufferers. MS-related pain occurs either directly as a result of inflammation of neural tissue, or as a result of muscle spasms and spasticity exerting pressure on the musculoskeletal system.
Cannabis has a proven ability to manage pain associated with MS. In a clinical trial conducted on humans in 2005, cannabis-based medicine was delivered in the form of a sublingual spray, with a 1:1 THC:CBD ratio. The trial demonstrated that the cannabis-based medicine was significantly more effective than placebo at reducing pain and sleep disturbances in MS sufferers.
Smoked cannabis has also been shown to be effective at reducing MS-related pain in several studies, including a patient survey of 112 MS sufferers from the US and UK in which the overwhelming majority reported a decrease in pain after smoking cannabis.
Cannabis reduces pain in MS sufferers by directly working to reduce immune response and resultant inflammation, and also reduces musculoskeletal pain caused by muscle spasms and spasticity. A scientific review published in 2007 indicated that a buccal spray containing both THC and CBD was more effective at managing MS-related pain than only CBD or only dronabinol (a synthetic form of THC).
3. THC and CBD are antispasmodic
Muscle spasms—sudden, involuntary contractions of a muscle or muscle group—are another common feature of MS. Spasticity is reported by 60-90% of patients. Spasms can cause a sharp, temporary sensation of pain that usually disappears after a short time. Muscle spasticity is an abnormal increase in muscle tone or stiffness. This can affect walking, balance and sometimes speech. Muscle spasticity is caused by damage to nerve pathways that control movement.
Cannabis has been demonstrated to both reduce the frequency of muscle spasms and the severity of muscle spasticity. In 2005, a randomised, double-blind, placebo-controlled, crossover study (considered the gold standard of clinical trials) found that cannabis (consisting of both THC and CBD) improved the mobility and the frequency of muscle spasms in 37 our of 50 subjects. A randomised controlled trial conducted in 2007 demonstrated that cannabis preparations containing THC and CBD were more effective than placebo at treating muscle spasticity, although this particular study did not reach statistical significance.
The effect of cannabis on muscle spasms and spasticity is likely due to its ability to reduce inflammation of the neurons and slow the overall progression of the disease. A study published in Nature in 2000 demonstrated that cannabinoid receptor agonists including THC and R(+)-WIN 55,212 (a synthetic agonist) ameliorated symptoms of spasticity and tremor, while antagonists of the cannabinoid receptors (particularly the CB1-receptor) exacerbated the symptoms.
4. Cannabis is antidepressant
Clinical depression is a common feature of multiple sclerosis, and is experienced by up to 50% of MS sufferers throughout the course of the illness. Depression in MS may occur due to damage to the nerves that help to regulate mood, or may be a side-effect of other medications used to control the progression of the disease. As well as major depression, MS can also lead to a range of associated symptoms of emotional dysfunction.
The ability of cannabis to treat depression is disputed, and there is substantial evidence on both sides. Several studies have indicated that THC, CBD, and CBC (cannabichromene) can exert an antidepressant-like effect. The endocannabinoid system is known to play an important role in mood regulation and subjective levels of happiness, and endocannabinoids such as anandamide are fundamental to the process. It is believed that certain genetic variations in the expression of CB1-receptors render some individuals more susceptible to the mood-elevating effects of cannabis.
Over 90% of the 112 MS sufferers from the US and UK in the previously-cited survey reported that use of cannabis ameliorated symptoms of depression. The relationship at work is complex, and subjective improvements in mood may be due to improvements in other symptoms that may cause emotional distress, including pain and spasticity, as well as by directly affecting neurons involving in mood regulation.
5. Cannabis may ease abdominal complaints
MS can lead to a range of gastrointestinal complaints including abdominal pain, constipation (experienced by around 40% of patients) and faecal incontinence (experienced by 7% of patients). These symptoms can be embarrassing, distressing and painful.
51-60% of the respondents of a patient survey reported that defecation urgency was reduced with use of cannabis, 44% reported that faecal incontinence was reduced, and 30% reported that constipation was eased. Cannabis has long been associated with gastrointestinal dysfunction including IBS and Crohn’s disease; it is believed that the effect of cannabinoids on the receptors (specifically the CB2-receptors) in the peripheral nervous system that controls gut function is responsible.
While cannabis may not have medical significance in terms of curing MS or targeting its direct cause, its effects may be extremely beneficial at managing symptoms. Even depression experienced by MS sufferers may be a side effect of other symptoms, and by reducing other symptoms, cannabis may elevate the quality of life for MS sufferers.
- Disclaimer:This article is not a substitute for professional medical advice, diagnosis, or treatment. Always consult with your doctor or other licensed medical professional. Do not delay seeking medical advice or disregard medical advice due to something you have read on this website.