Affiliations : McGill, Canada
Journal reference: doi: 10.1097/j.pain.0000000000001386
Summary: Chronic pain affects around 8% of the population, and can be difficult to live with as it affects day to day activities. Chronic pain is also often comorbid with anxiety and mood disorders. In this study, the researchers found that CBD – the non addictive component of marijuana – can potentially be used to treat chronic pain and comorbid anxiety through two fascinating parallel mechanisms.
Chronic pain is a persistent pain which lasts longer than 12 weeks despite medication or treatment. It is often related to pre-existing medical conditions such as diabetes, arthritis, fibromyalgia, irritable bowel syndrome, back pain and nerve damage. It has a high incidence in the population with 20.4% of adults in the U.S.A. suffering from chronic pain, of which 8% suffer from high-impact chronic pain. This illness also has a high socioeconomic impact as it is one of the most common reasons that individuals seek medical care and it is a major cause for opioid dependence. It also leads to restrictions in mobility, daily activities, and a decrease in general quality of life. In addition, chronic pain is often comorbid with mood and/or anxiety disorders. It becomes apparent that the treatment of chronic pain should be an imminent public health concern.
Together with Dr. Gobbi’s lab at The Department of Psychiatry in McGill, we ran a study that demonstrated that a low but repeated dose of cannabidiol (CBD) can be used to treat chronic pain and comorbid anxiety. CBD is a non-addictive compound of marijuana that affects the brain and nervous system without getting users high. CBD has recently been shown to possess important therapeutic potential for treating a wide range of disorders such as pain, nausea, epilepsy, and psychosis. Using an animal model of chronic pain induced by nerve damage, our research team demonstrated that these effects could be expanded to treat chronic pain and anxiety. If this result is replicable in humans, a modest dose of CBD could result in a safe and effective drug treatment for patients who suffer from chronic pain and comorbid anxiety.
Our study further revealed that CBD alleviates chronic pain and anxiety through two different parallel mechanisms:
- The pain mechanism involves the stimulation of a particular subtype of receptors, called TRPV1 channels. These receptors are known to play a role in the modulation of pain.
- The anxiety mechanism involves CBD interactions with a subtype of receptors belonging to the serotonin receptor family, the 5HT1A, which are essential to the management of anxiety. Serotonin is informally called the “happy hormone” since it is a mood stabilizer that plays a fundamental role in wellbeing.
To date chronic pain and anxiety are mainly treated with opioids and benzodiazepines, both of which are very addictive medications and present high risks of overdose. Although the endocannabinoid system had already been widely explored for its potential therapeutic properties in chronic pain, the most studied target of the system was the cannabinoid receptor CB1 that has low affinity with CBD but rather binds to tetrahydrocannabinol (aka THC, marijuana’s most psychoactive compound) and induces marijuana’s euphoria and dependence.
As shown in our study, CBD could represent a secure alternative to THC and opioids in treating chronic pain (sciatica, low back pain, cancer related pain, and even menstrual pain). If administered moderately and repeatedly with the right dose determined on a case by case basis, it could alleviate pain and anxiety without the addictive and euphoric effects of drugs of abuse.
This is particularly relevant in countries such as Canada (where this study was carried out) where CBD has been legalized following passage of Canada’s Cannabis Act and is now allowed for recreational use nationwide.