Medical cannabis has been an important part of natural medicine for thousands of years, with countless societies around the world thought to have used this ancient crop to treat a wide variety of ailments. Today, cannabis is one of the most commonly used drugs in the world – and a significant proportion of the millions of global consumers primarily use cannabis for these long-acknowledged medicinal properties.
Despite an extremely impactful period of prohibition, medical cannabis is now legally available in several countries around the world, including in the UK. The rescheduling of cannabis in November 2018 opened the doors to allow clinicians to prescribe cannabis-based medicines for the first time in almost half a century. Private clinics can now routinely prescribe medical cannabis for a wide range of health conditions, including epilepsy, chronic pain, and depression. However, due to the associated costs, reports show that the vast majority of patients are still sourcing their medicine from the black market.
Medical Cannabis and Depression
Depression can present itself as a symptom of other condition(s) or as a disorder in itself. It is increasingly common – particularly among teenagers and young adults – with an estimated 1 in 6 people experiencing depression in the UK alone. Common treatments for depression include the use of antidepressants. While these medications can be effective, they are often linked to a number of unwanted side effects. As such, a growing number of people with depression are increasingly turning to alternative therapies.
For a long time, doctors, lawmakers, and police have explicitly linked cannabis use to psychosis and the development of various mental health conditions. A number of studies have also supported these claims, with evidence suggesting that cannabis use is more prevalent among populations with anxiety, depression, and psychotic symptoms; however, it remains unclear which of these is the cause and which is the effect. As the authors of one study note: “Rather than being causative, however, non-medicinal cannabis use may instead represent an attempt at self-medication during a prodromal period.”
Evidence suggests that cannabis is becoming increasingly popular among patients with anxiety disorders, and countless other conditions for which depression is a common comorbidity. Furthermore, a growing number of patients are also interested in medical cannabis as a direct treatment for depression itself.
Is there any evidence?
Clinical evidence assessing the therapeutic potential of cannabis for depression remains limited. Studies that have been published on the subject have demonstrated mixed results that often vary based on the type of cannabis product used. It is commonly reported that THC exposure – the most common psychoactive cannabinoid produced by the cannabis plant – may be linked to increased feelings of anxiety and depression. However, some evidence suggests that other preparations and derivatives of cannabis – such as CBD-rich products – may actually have therapeutic benefits for the management of depression symptoms.
A recent observational study that assessed the patient-reported outcomes of depression and anxiety in cannabis users and none cannabis users found that “medical cannabis use was associated with lower self-reported depression… at baseline.” Furthermore, the initiation of medical cannabis was associated with significantly decreased depression symptoms during the study’s follow-up period.
Another study, published in 2020, observed 1,819 people who completed 5,876 cannabis self-administration sessions using the ReleafApp™ in a three-year period. The aim of the study was to gain real-time insights into the effects of consuming cannabis flower for treating the symptoms of depression. The authors concluded that, at least in the short term, “the vast majority of patients that use cannabis experience antidepressant effects, although the magnitude of the effect and extent of side effect experiences vary with chemotypic properties of the plant.”
How does it work?
Research suggests that the potential anti-depressant and anxiolytic (anxiety-relieving) effects of cannabis are linked to the interaction between cannabinoids and the Endocannabinoid System (ECS). The ECS is a receptor system that is expressed throughout the central nervous system and the immune system. Evidence shows that the ECS plays a significant role in a number of vital processes – including mood regulation.
The interactions between cannabinoids such as THC and CBD, and receptors (CB1 and CB2) in the ECS are believed to trigger a number of actions. While not all of the biological pathways are completely understood, cannabinoids have been seen to trigger the production and release of endocannabinoids (made in our bodies) such as anandamide (AEA) and 2-arachidonoyl glycerol (2-AG). Anadamide – which is named after the Sanskrit word for “bliss” – is thought to play a regulatory role on the brain reward circuit. Moreover, evidence shows that the regulation of the endocannabinoid system “plays an important role in vulnerability to stress, a major risk factor of Major depressive disorder.”
Can medical cannabis be prescribed for depression in the UK?
While evidence remains limited and uncertain, medical cannabis treatment for depression is becoming increasingly common. Patients with depression can now – at least potentially – access medical cannabis via private clinics in the UK; however, NHS prescriptions for the condition remain non-existent. According to current guidelines, medical cannabis can be prescribed by a specialist clinician for any condition for which there is evidence of its potential efficacy – including depression.
A number of clinics in the UK state that medical cannabis can be considered as a treatment for depression where first-line treatments have proven ineffective. For more information on how to obtain a medical cannabis prescription in the UK, take a look at leafie’s extensive guide.