Pain is a huge global health problem. Worldwide, it is estimated that about 1 in 5, or 1.5 billion people experience pain, whilst 1 in 10 adults are diagnosed with chronic pain each year (1). Chronic pain can seriously impact quality of life and is associated with depression, an inability to work, disrupted social relationships and suicidal thoughts.
Use of opioids to treat debilitating chronic pain has skyrocketed in the Global North over the past decades, bringing with it a growing concern over increasing numbers of opioid dependents. The search for alternative effective treatments for chronic pain that carry less risks, and for treatments that might help pain patients taper down their use of opioids, has thrown cannabis into the spotlight.
Cannabis and Pain Relief
Cannabis is well known for its analgesic properties among cannabis users, although there is still little consensus over the efficacy of cannabinoids for chronic pain among the scientific community.
We know that the endocannabinoid system plays a crucial role in the transmission of pain signals. Activation of cannabinoid receptors (CB1) can block neurotransmitter release, preventing the activation of pain signalling. CB2 receptor activation is associated with quelling the immune system’s response, thus reducing inflammatory pain (2). Because of its activation of both CB1 and CB2 receptors, science has had its sights set on THC as the pain reliever. More recently, anecdotal evidence for the role of CBD and other cannabinoids in pain relief is growing, but their mechanisms of action are less clear.
A scientific review published in 2015 that included 31 studies containing 4535 patients between them, reported that 28 of the studies showed significant reduction in pain outcomes (3). Another study looking at cannabis use among fibromyalgia patients reported that each of the 26 participants benefited from using cannabis and 50% of participants ceased the use of all other pain medications (4). However, a study published in The Lancet in 2018 reported that cannabis use did not reduce chronic non-cancer pain in patients who were prescribed opioids (5).
Conventional Methods of Chronic Pain Management
Typical methods of pain management include exercise, physiotherapy, meditation and painkillers such as paracetamol and ibuprofen, depending on the condition. However, if these prove ineffective, opioids are often suggested.
Opioids and Risks
Risks associated with prolonged opioid use include adverse effects of the immune, respiratory and gastrointestinal systems, not to mention of course the potential for addiction, depression and overdose. Because of these risks, and concerns related to long term efficacy and safety, the administration of opioids for chronic non-cancer pain continues to be controversial and hotly debated. By contrast, cannabis doesn’t share the more acute risks associated with opioid use and has been proposed as a safer alternative.
Unfortunately, due to limited high quality studies regarding medical cannabis for chronic non-cancer pain, drawing conclusions regarding the efficacy of cannabis is problematic. Many have small participant numbers, short duration, the exclusion of patients with complex comorbidities, and common forms of chronic non-cancer pain (eg, back and neck pain, arthritis) are not included. Added to that, as was the case with the previously cited Lancet article, the quality and dosage of the cannabis are often not standardised.
In order to better inform the current debate, more research on the use of cannabis for the treatment of chronic pain is clearly needed, especially given that chronic pain is the most cited condition for medical cannabis use in the US and other jurisdictions where medicinal cannabis use is legally permitted.
Cannabis vs opioids
Abuse of prescription opioids is a widespread public health crisis, particularly in the US, where it has been declared a public health emergency. Although the current phase of the US opioid epidemic is primarily driven by illicit fentanyl and analogs, prescription opioids contribute to more than 35% of the overall overdose mortality (6).
As cannabis has no known lethal dose and far less severe adverse effects there is a strong incentive to investigate its potential as an alternative to prescription opioids for pain management. However, outdated societal attitudes toward cannabis have resulted in barriers to progress as its use is still considered, at a federal level, and in other countries around the world with prohibitive policies, to be controversial. Perceptions of cannabis have been blighted by the hysterical political and social campaigns of the past that branded cannabis as a dangerous drug.
This means that patients who are using cannabis for their symptoms are often hesitant to divulge this information to doctors, especially in jurisdictions where their cannabis use is prohibited. There are a lot of us like that. In the UK, a recent survey by YouGov for the Centre for Medicinal Cannabis, revealed that there were 1.4 million people in the UK using illicit cannabis for medical problems as of 2019 (7).
A Little Personal Note From Me
Having lived with chronic pain for nearly a decade now, cannabis provides pain relief and eases other associated symptoms such as depression, irritability and insomnia. It allows me to live a life I wouldn’t have thought possible a few years ago. With cannabis laws as they are in the UK, it’s much more socially acceptable to admit to using strong painkillers like opioids than cannabis for a chronic pain condition. It’s my hope that cannabis will soon be seen as the legitimate and effective medicine that it is.
- Goldberg DS, McGee SJ. Pain as a global public health priority. BMC Public Health. 2011 Oct 6;11:770. doi: 10.1186/1471-2458-11-770. PMID: 21978149; PMCID: PMC3201926.
- Maccarrone, M. Cannabinoids therapeutic use: what is our current understanding following the introduction of THC, THC:CBD oromucosal spray and others? Expert Rev. Clin. Pharmacol.10, 443–455 (2017).
- Whiting PF, Wolff RF, Deshpande S, et al. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis. JAMA. 2015;313(24):2456–2473. doi:10.1001/jama.2015.6358
- Habib G, Artul S. Medical Cannabis for the Treatment of Fibromyalgia. J Clin Rheumatol. 2018 Aug;24(5):255-258. doi: 10.1097/RHU.0000000000000702. PMID: 29461346.
- Campbell G, Hall WD, Peacock A et al. Effect of cannabis use in people with chronic non-cancer pain prescribed opioids: findings from a 4-year prospective cohort study.Lancet Public Health. 2018; 3: e341-e350
- Centers for Disease Control and Prevention. Prescription opioid data. 2019b. https://www.cdc.gov/drugoverdose/data/prescribing.html.