Cannabis-based medicines show promising results in treating generalized anxiety disorder

Cannabis-based medicinal products might help to improve symptom severity, sleep quality, and health-related quality of life in those with anxiety, according to new research published in the journal Psychopharmacology. The findings highlight the need for further research, including randomized controlled trials, to investigate the effectiveness of these products.

Anxiety disorders are widespread mental health conditions affecting a significant number of individuals worldwide. Generalized anxiety disorder (GAD) is a common form of anxiety, characterized by persistent worry and accompanied by physical and mental symptoms. GAD can have a negative impact on the quality of life and is associated with increased suicidality and completed suicide.

The current first-line pharmacological treatments for GAD in the UK include selective serotonin reuptake inhibitors (SSRIs) and other medications. However, a substantial percentage of individuals do not respond to these treatments, and SSRIs can take several weeks to be effective and may have significant side effects. Thus, there is a need for new treatment options, especially for individuals who do not benefit from current pharmaceutical options.

The researchers explored the potential of the endocannabinoid system as a target for pharmacological intervention. Cannabidiol (CBD), a compound found in cannabis, has shown anxiolytic effects in pre-clinical and clinical studies, while another cannabis compound, delta-9-tetrahydrocannabinol (THC), has been associated with acute increases in anxiety. The interaction between CBD and THC is complex, and their exact ratio and pharmacological effects are not fully understood.

To study the effects of cannabis-based medicinal products in treating GAD, the researchers utilized data from the UK Medical Cannabis Registry. The registry, managed by Sapphire Medical Clinics, records patient data from individuals prescribed cannabis-based medicinal products. The study involved analyzing data from a larger cohort of patients treated with cannabis-based medicinal products for GAD, allowing for better analysis of longer-term outcomes.

“Since medical cannabis first became available in the UK for specialist doctors to prescribe to eligible patients in 2018, it has been clear to us that it is important to grow the evidence base on the efficacy and safety of these products,” explained study author Simon Erridge, the head of research at Sapphire Medical Clinics.

“Due to the limitations on researching the medicinal properties of cannabis, there has been a paucity of high-quality clinical data to inform the decisions of guideline bodies and clinicians. As such most medical cannabis products are unlicensed in the UK and can only be considered as an option for patients who have failed to benefit from licensed medical options.”

“By setting up the UK Medical Cannabis Registry, which this paper uses data from, we hope to achieve three things,” Erridge said. “Firstly, to have a robust pharmacovigilance system to capture the adverse events associated with medical cannabis therapy, to evaluate its safety.”

“Secondly, we hope to provide evidence of real-world evidence of its effects on people with chronic health conditions, including anxiety, to inform current clinical practice. Finally, through using this data in the right way we can help inform future randomised controlled trials to accelerate clinical translation.”

The researchers analyzed data from 302 patients, including demographic information, product details (type of product, dosage), patient-reported outcome measures, adverse events, and other medications used by the patients. The primary focus was on changes in anxiety symptoms, sleep quality, and health-related quality of life outcomes, which were assessed using standardized questionnaires.

Results from the study showed that patients treated with cannabis-based medicinal products experienced significant improvements in anxiety, sleep quality, and health-related quality of life at 1, 3, and 6 months after prescription. Around 50% of patients experienced a clinically significant reduction in anxiety symptoms. Adverse events were reported in about 13% of patients, with no severe or life-threatening side effects.

“The key findings from this paper were that in patients with generalized anxiety disorder prescribed medical cannabis we saw significant changes in anxiety, health-related quality of life, and sleep quality,” Erridge told PsyPost. “These changes were seen as early as one month and up to 6 months follow up.”

“These findings support the data we have shown through previous studies, but the finding that stands out to us is that 43.6% of participants at 6 months reported a clinically significant improvement in their generalized anxiety symptoms. As mentioned, in the UK, to be prescribed medical cannabis you must have previously found no benefit from licensed therapies, such as selective serotonin receptor inhibitors or tricyclic antidepressants. Whilst medical cannabis is not a panacea and will not work for all individuals, to observe that number of individuals reporting changes in their anxiety was fascinating.”

However, the sample in this study may not be entirely representative of the general population with GAD due to certain characteristics of the participants. For example, a majority of the participants were males, and a significant proportion had prior or current experience with non-medical cannabis use before enrolling in the registry. These characteristics may introduce some bias and limit the generalizability of the findings to the broader GAD population.

“Whilst real-world evidence such as this has many benefits, it is important to always understand that whilst we can see signals of change in the patients who take part, randomized controlled trials will still be required to determine the exact effects of medical cannabis on generalized anxiety disorder,” Erridge said. “However, through conducting this type of research, we hope it can help inform those randomized controlled trials going forward.”

Although the study has limitations, including potential bias and lack of a placebo-controlled group, it provides valuable real-world data on the potential benefits and safety of cannabis-based medicinal products in treating GAD. The findings suggest the need for further research, including randomized controlled trials, to establish the efficacy and safety of cannabis-based medicinal products in managing anxiety disorders.

The study, “Clinical outcome data of anxiety patients treated with cannabis-based medicinal products in the United Kingdom: a cohort study from the UK Medical Cannabis Registry“, was authored by Raphael Rifkin-Zybutz, Simon Erridge, Carl Holvey, Ross Coomber, Jessica Gaffney, Will Lawn, Daniela Barros, Urmila Bhoskar, Gracia Mwimba, Kavita Praveen, Chris Symeon, Simmi Sachdeva-Mohan, James J. Rucker, and Mikael H. Sodergren.