2024 breakthroughs: The latest research shaping the future of cannabis-based medicines

The importance of medical cannabis research

Medical cannabis has now been legalised in a number of countries around the world, including the UK. Moreover, acceptance of the medicinal value of this ancient plant - among the public, lawmakers, and healthcare professionals - is becoming increasingly widespread. Observational studies, clinical trials, and scientific reviews are crucial in improving our understanding of the medicinal mechanisms of cannabis and further improving access to these potentially life-changing medicines.

So, let’s look at some of the most noteworthy breakthroughs in medical cannabis published so far this year.

Clinical studies

Medical cannabis and the entourage effect in the treatment of anxiety

In April, a new double-blind, placebo-controlled trial was published in the Journal, Drug and Alcohol Dependence. The study aimed to assess whether cannabis terpenoid, D-Limonene, can mitigate the acute anxiogenic effects of THC in healthy adults. 

Twenty participants completed nine sessions in which they inhaled vaporised THC alone (15mg or 30mg), D-Limonene (1mg or 5 mg), the same doses of both THC and D-Limonene together, or placebo.

The study found that while administration of THC alone was associated with higher ratings of anxiousness, nervousness, and paranoia, combined administration of 30mg THC and 15 mg D-limonene significantly reduced ratings of these anxiety-like effects. The authors of the study concluded that D-Limonene is potentially able to mitigate the anxiety-inducing effects of THC - a promising finding for future trials and prescribing of medical cannabis for anxiety.

Vaporised cannabis vs placebo in the treatment of migraines

In another randomised, double-blind, placebo-controlled crossover trial, published in February, researchers aimed to examine the efficacy of medical cannabis for the treatment of acute migraine. A total of 92 participants were treated for four migraine attacks, each time using a different variant. This included vaporising a THC-dominant variant,(6% THC), a CBD-dominant (11% CBD) cultivar, a 6% THC+11% CBD variant, and a placebo. 

The THC+CBD was superior to placebo at achieving pain relief, pain freedom, and ‘most bothersome symptom’ freedom at 2 hours, as well as sustained pain freedom at 24 hours and sustained MBS freedom at 24 and 28 hours. Moreover, the THC-dominant formulation was superior to placebo for pain relief at two hours post-treatment. 

This adds to a relatively limited evidence base indicating the potential benefit of medical cannabis for migraine.

Oral CBD in the treatment of mild to moderate anxiety

A second double-blind, placebo-controlled, randomised trial also assessed an oral solution of CBD in patients with mild to moderate anxiety. The multicenter trial enrolled 178 participants from across India who were randomised to receive CBD or placebo for the treatment of mild to moderate anxiety.

The oral CBD solution was found to be safe with no serious adverse events reported. Moreover, participants in the CBD group reported greater improvements in anxiety and sleep compared with the placebo group. The findings further support the potential of cannabis-based medicines in the treatment of anxiety - which represents an increasing burden on society.

Observational studies

The effects of medical cannabis on health-related quality of life

In September, an observational study assessing changes in health-related quality of life following the initiation of medical cannabis treatment was published in the Journal of Cannabis Research. The study followed 438 participants prescribed medical cannabis for any of more than 20 qualifying conditions at baseline (before medical cannabis treatment) and three months.

Quality of life was measured across eight domains: physical functioning, role limitations due to physical health problems, emotional well-being, role limitations due to emotional problems, social functioning, energy/fatigue, bodily pain, and general health. Improvements were observed in all eight domains after three months of medical cannabis treatment.

The study will continue to collect outcome data from participants 6, 9, and 12 months. Nonetheless, the current findings demonstrate the potentially significant effect of medical cannabis treatment on short-term quality of life in patients with a wide range of medical conditions.

Patient-reported efficacy of cannabis for chronic musculoskeletal pain

In the summer, self-reported data on cannabis use and perceived efficacy were collected from chronic musculoskeletal (MSK) pain patients at the Orthopaedic Clinic at the University Health Network, Toronto, Canada. The authors of the study aimed to examine the rate, patterns of use, and perceived efficacy of cannabis among MSK pain patients. 

Of the 629 participants, almost a quarter (23%) reported past or present cannabis use to manage their MSK pain. Of those, 63.7% perceived cannabis to be very or somewhat effective and 26.6% considered it to be slightly effective at managing their pain. Furthermore, among non-users, almost two-thirds expressed an interest in cannabis to manage their pain; however, they reported barriers to access, including lack of knowledge and stigma.

Medical cannabis for treating post-traumatic stress disorder and comorbid depression

In March, a real-world observational study was published in the BJPsych Open journal. The study aimed to “document the prevalence of depression among individuals seeking [medical cannabis] to treat PTSD and to examine whether the effectiveness of [medical cannabis] varies by depression status. 

The researchers assessed data from 238 people with PTSD seeking medical cannabis treatment, in addition to follow-up data from 116 people. Self-reported PTSD symptoms were assessed at baseline and three months; a total of 77% of participants met screening criteria for depression, which is associated with higher levels of PTSD symptomatology, and poorer quality of life, sleep, and general health. 

The study found that PTSD symptoms improved significantly following three months of medical cannabis treatment, with a greater improvement observed in patients with comorbid depression. These findings once again highlight the potential of medical cannabis for common mental health conditions.

French pilot medical cannabis programme yields “overwhelmingly positive” results

In 2021, the French government launched their medical cannabis pilot programme - a trial to provide up to 3,000 patients with access to cannabis-based medicines for five approved indications (refractory neuropathic pain, drug-resistant epilepsy, spasticity in multiple sclerosis (MS), cancer-related symptoms, and palliative care). After being extended earlier this year, the pilot programme will now run until the end of 2024; however, some key findings have been announced. 

According to a recent news report, the trial has had “overwhelmingly positive” early results with around 60% of patients finding medical cannabis beneficial for relieving their symptoms. As a result of these and other findings, the - national agency for the safety of medicines and health products - has announced that medical cannabis will be made available in France in 2025.

Final thoughts

2024 has been a great year for medical cannabis research, with new studies reinforcing existing evidence of the diverse potential of these medications. However, they often also highlight the persistent barriers to access and, in some cases, further meaningful research. 

It is our hope that future research will not only continue to improve our understanding of medical cannabis but also serve to remove stigma and improve access to patients who are still in need of effective treatment options.