When talking about the therapeutic effects of CBD, it’s often the cannabinoid’s pain reducing ability that is mentioned. As headaches are the most common source of pain in the general population, it would make sense then that CBD could be an interesting therapeutic target.
Cannabis – a long history of treating headaches
While the cannabis plant is mentioned as a treatment for headaches in ancient texts dating back thousands of years, its use only became commonplace in the west during the 19th century when it was prescribed by many doctors as a tincture. However, all that changed with prohibition in the 1930s, and since then for many the cannabis plant’s capacity to quell a headache has merely become a welcome side effect of its recreational use.
These days, aside from the multitude of anecdotal reports relating to medical cannabis and headaches, conclusive clinical evidence is lacking. But what scientists do know is that in many headache disorders such as migraines, the endocannabinoid system is intrinsically linked.
What is a migraine?
While headaches in general affect approximately 47% of the population, migraines alone cost the United States an estimated $13.3 billion annually in missed days at work and lower productivity.
They are characterised by a throbbing pain in the frontal area of the head that typically cause feelings of nausea, vomiting, and sensitivity to sound and light. For some sufferers, a migraine is often preceded by visual disturbances such as auras. Migrainers are three times more like to be women, and while generally beginning during childhood, they are most prevalent between the ages of 25 and 50.
What causes migraines is rather a mystery, but most credit dysfunctional brainstem centres, in particular the activation of the trigeminovascular system, a major pain pathway. There is also a neuro-inflammatory element with the production of the excitatory neurotransmitter glutamate and other inﬂammatory neuropeptides from the sensory nerve terminals. These irritate and further dilate blood vessels, inducing more release from the sensory neurons and an increase of pain impulses.
Drops in serotonin levels have also been noted during migraine attacks, which is why one of the preventative forms of treatment is tricylic antidepressants that regulate serotonin levels. Other common treatments are standard pain relievers like paracetamol or ibroprufen, as well as Triptans that constrict the blood vessels and block pain pathways in the brain.
Migraines and the Endocannabinoid System
One theory posited about a possible contributing cause of migraines is a dysregulation in the endocannabinoid system (ECS) – the body’s complex network of receptors and cannabis-like chemicals that act to modulate pain, the immune system, mood, sleep, appetite and memory. Scientists have observed several ECS mechanisms that may have an implication in migraine attacks. Anandamide (AEA) one of the prime endocannabinoids in the body, is both analgesic and has been found to potentiate the serotonin 5-HT1A receptors. Studies also suggest that endocannabinoids inhibit the trigeminovascular system.
But perhaps the clearest indication of endocannabinoid dysfunction contributing to migraines is a study carried out in 2007 at the University of Perugia and published in the Journal of Neuropsychopharmacology. Researchers measured endocannabinoid levels in the cerebrospinal fluid of patients with chronic migraines finding significantly lower amounts Anandamide, concluding that this “may reflect an impairment of the endocannabinoid system in these patients, which may contribute to chronic head pain.”
Are migraines a sign of Clinical Endocannabinoid Deficiency?
This link between lower levels of endocannabinoids in migraine patients has contributed to the formulation of what has been termed Clinical Endocannabinoid Deficiency, a theory developed by Neurologist and Cannabinoid Researcher Dr Ethan Russo. Based on the idea that many brain disorders are associated with a lack of certain neurotransmitters such as acetylcholine in the case of alzheimer’s and dopamine in Parkinson’s, Russo has suggested that “a comparable deﬁciency in endocannabinoid levels might manifest similarly in certain disorders that display predictable clinical features as sequelae of this deﬁciency.”
In an interview with project CBD he described how “If you don’t have enough endocannabinoids you have pain where there shouldn’t be pain. You would be sick, meaning nauseated. You would have a lowered seizure threshold. And just a whole litany of other problems.”
Russo says that this deficiency can be addressed by introducing plant cannabinoids, which act much like those found in the body by stimulating the endocannabinoid receptors. While CB1 agonists such as Marinol and Nabilone have been tested for migraines, Russo suggests that the ECS needs a “gentle nudge” rather than the “forceful shove” given by these synthetic variants. He suggests small doses of whole plant cannabis, which contain “additional synergistic and buffering components, such as CBD and cannabis terpenoids.”
CBD and migraines
Russo in particular singles out CBD (Cannabidiol) as bringing balance to the endocannabinoid system. In his interview with Martin Lee from Project CBD he says, “cannabidiol is an endocannabinoid modulator, in other words, when given chronically it actually increases the gain of the system…. So, if there’s too much activity in a system, homeostasis requires that it be brought back down. If there’s too little, it’s got to come up. And that’s what cannabidiol can do as a promoter of endocannabinoid tone.”
Scientists are still unsure exactly how CBD interacts with the endocannabinoid system because unlike the psychoactive cannabinoid THC, it doesn’t bind directly with any of the endocannabinoid receptors. Instead it activates many other non-endocannabinoid receptors, some of which are implicated in the development and treatment of migraines, such as the 5-HT1A serotonin and TRPV-1 receptors, the latter mediating pain perception.
One other possible explanation is CBD’s role as a fatty acid amide hydroxylase (FAAH) inhibitor. This enzyme breaks down anandamide in the body, so by inhibiting its production scientists theorize that it could lead to higher levels of the pain relieving endocannabinoid; something that would potentially be of benefit to migraine sufferers.
Certainly, some migraine patients are finding that CBD can help reduce the incidences of attacks. 42 year old Claire from the UK has had migraines and daily headaches for twenty years, for which she was prescribed Triptans with varying efficacy. She decided to try CBD oil, and while she’s less than a month into treatment, so far the results looks promising.
“I have had no headache for 3 weeks and taken zero medication in that time,” says Claire. “My head has felt ‘fuzzy’ on occasions but no where on the level of a migraine. I used to suffer from visual disturbances and numbness on one side of my body during a migraine attack. Although I am somewhat nervous about shouting about the benefits after 3 weeks, I am optimistic that this is going to work long term.”
Lack of clinical evidence
Right now there have been no gold standard, double blind, placebo clinical studies published to back up any anecdotal accounts suggesting CBD or indeed cannabis in general as effective treatments for headaches and migraines. Although one placebo-controlled study assessing the safety and efficacy of the synthetic THC medication Dronabinol for migraines has been conducted, the results are still pending.
Currently, the largest study to take place was done on a retrospective basis. Published in 2016 it found that out of 121 participants diagnosed with migraines and prescribed medical cannabis by a doctor, 103 saw the frequency of their migraines reduced by half. However, little was known about the varieties of medical cannabis used, with the authors highlighting that future studies “should be conducted to explore a cause-and-effect relationship and the use of different strains, formulations, and doses of marijuana to better understand the effects of medical marijuana on migraine headache treatment and prophylaxis.”
So much like the nature of migraines themselves, CBD for headaches and migraines remains scientifically underexplored, with further research required. That’s why we would love to hear about your own personal experience. Has taking CBD helped lessen the frequency and severity of your migraines or indeed any other types of headaches? Please share your experience in the comments section below.