Overview of Cannabidiol (CBD). A review of the scientific literature.
There are at least 114 different cannabinoids found within cannabis plants and more than 1,100 other compounds called terpenoids and flavonoids[i]. The most well-known cannabinoids are δ-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). However, awareness of other cannabinoids including Cannabigerol (CBG) and Cannabidiolic acid (CBDA) appears to be increasing in consumers.
Globally, the cannabis landscape is changing. US states including California, Oregon, Alaska, Maine, Massachusetts, Washington, Nevada, and Colorado allow the sale of cannabis for recreational purposes[ii]. Canada and Uruguay have legalised recreational use of cannabis and several European countries have lessened or abolished criminal sanctions for cannabis possession and use[iii]. In the U.K, interpretation of the legislative framework prohibits cannabis products where the value of THC is greater than 0.2%, other cannabinoids are considered legal for general sale.
In the illicit and unregulated market, cannabis consumption has been associated with recreational drug use and criminality. It has generally been consumed by smoking (with or without tobacco) or ingested with food. The primary function for cannabis consumption has been to increase feelings of being stoned or high. However, there has been a cohort of cannabis users who speak to its therapeutic properties, particularly for chronic pain and improvement of wellbeing. In the unregulated market, administering cannabinoids for therapeutic purposes has been difficult, when considering the knowledge and expertise needed alongside ensuring quality control.
Decriminalisation of cannabis is generally popular in western countries. Favourable media coverage, particularly focusing on young children in need of cannabis oil to treat tumours[iv] and reduce instances of seizures[v] has created significant awareness and empathy towards cannabis’ therapeutic properties. It is likely that Governments will continue towards less restrictive policies and legalisation for cannabis products if specific cannabinoids continue to demonstrate improvements for health related problems.
Review of the scientific literature
The scientific evidence base for cannabis’ effects on mental and physical health at individual and population level are somewhat sparse. However, based on evidence available in published literature, we know that:
- Cannabinoids exert palliative effects in patients with cancer and inhibit tumour growth in laboratory animals.
- The best-established palliative effect of cannabinoids in cancer patients is the inhibition of chemotherapy-induced nausea and vomiting[vi].
- Cannabinoids may lead to several positive psychological effects, including a reduction in depression and anxiety, which could result in improved sleep[x],[xi], though further research is needed to establish a strong causal effect.
- Cannabinoids are selective antitumor compounds and can kill tumour cells without affecting their non-transformed counterparts[xii].
- There are risks and benefits associated specifically with THC:
- THC is associated with exacerbation in core psychotic and cognitive deficits in schizophrenia[xiii].
- These appear to be mitigated by CBD, which appear to have a protective factor:
- THC increases anxiety, as well as levels of intoxication, sedation, and psychotic symptoms, but there is a trend for a reduction in anxiety following administration of CBD[xvi].
- There is evidence to show that cannabinoids can improve health outcomes
- THC and CBD are the two most researched cannabinoids, the profile of CBD is relatively safe when compared to THC.
- Further decriminalisation of cannabis is likely globally.
- In medicines or consumer markets, greater control over cannabinoid content and safer administration should improve.
- Sustained media coverage, interest from health advocates and researchers will support greater knowledge in expanding the evidence base for cannabinoids on health outcomes.
- Providing the best cannabinoid profiles for those wishing to improve symptoms of physical or mental health will be rooted in strong links scientific intelligence, market awareness and changes in the legislative environment.
We expect the consumer and medicines market to grow and see significant potential in both.
[i] Andre CM, Hausman JF, Guerriero G. Cannabis sativa: The Plant of the Thousand and One Molecules. Front Plant Sci. 2016;7:19. Published 2016 Feb 4. doi:10.3389/fpls.2016.00019
[ii] Room, R. (2014), Legalising a market for cannabis. Addiction, 109: 345-351. doi:10.1111/add.12355
[iii] Rosmarin A, Eastwood N. A quiet revolution: drug decriminalisation policies in practice across the globe. 2012. http://www.release.org.uk/publications/quiet-revolution-drug- decriminalisation-policies-practice-across-globe
[iv] Study looks at cannabis ingredient’s ability to help children’s tumours | Science | The Guardian. Available from: https://www.theguardian.com/society/2017/may/02/study-cannabis-cannabidiol-cbd-ability-to-help-children-brain-tumours
[v] Boy with severe epilepsy who was treated with cannabis oil is now 300 days seizure-free. The Independent. 2017. Available from: http://www.independent.co.uk/news/uk/home-news/billy-caldwell-cannabis-oil-boy-seizures-stopped-cured-prescription-medical-marijuana-a7933066.html
[vi] Tramèr MR, Carroll D, Campbell FA, Reynolds DJ, Moore RA, McQuay HJ. Cannabinoids for control of chemotherapy induced nausea and vomiting: quantitative systematic review. BMJ. 2001;323(7303):16–21. doi:10.1136/bmj.323.7303.16
[vii] Berry EM, Mechoulam R. Tetrahydrocannabinol and endocannabinoids in feeding and appetite. Pharmacol Ther. 2002 Aug;95(2):185–90.
[viii] Pertwee RG. Cannabinoid receptors and pain. Prog Neurobiol. 2001 Apr;63(5):569–611.
[ix] Walker JM, Huang SM. Cannabinoid analgesia. Pharmacol Ther. 2002 Aug;95(2):127–35.
[x] Robson P. Therapeutic aspects of cannabis and cannabinoids. Br J Psychiatry. 2001 Feb;178:107–15.
[xi] Walsh D, Nelson KA, Mahmoud FA. Established and potential therapeutic applications of cannabinoids in oncology. Support Care Cancer. 2003 Mar;11(3):137–43.
[xii] Guzmán M. Cannabinoids: potential anticancer agents. Nature Reviews Cancer. 2003 Dec;3(10):745.
[xiii] D’Souza DC, Abi-Saab WM, Madonick S, Forselius-Bielen K, Doersch A, Braley G, et al. Delta-9-tetrahydrocannabinol effects in schizophrenia: Implications for cognition, psychosis, and addiction. Biological Psychiatry. 2005 Mar 15;57(6):594–608.
[xiv] Forti MD, Morgan C, Dazzan P, Pariante C, Mondelli V, Marques TR, et al. High-potency cannabis and the risk of psychosis. The British Journal of Psychiatry. 2009 Dec;195(6):488–91.
[xv] Di Forti M, Sallis H, Allegri F, Trotta A, Ferraro L, Stilo SA, et al. Daily Use, Especially of High-Potency Cannabis, Drives the Earlier Onset of Psychosis in Cannabis Users. Schizophr Bull. 2014 Nov 1;40(6):1509–17.
[xvi] Fusar-Poli P, Crippa JA, Bhattacharyya S, Borgwardt SJ, Allen P, Martin-Santos R, et al. Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing. Arch Gen Psychiatry. 2009 Jan 1;66(1):95–105.