CBD Shows Promise in Non-cancer Pain Treatment, Study Finds

A new study of the first 400 patients to be prescribed cannabidiol (CBD) oil in New Zealand suggests that the cannabinoid may be beneficial for treating patients suffering with symptoms of non-cancer pain and mental health conditions. 

Although one CBD-based therapy has already been recognized as an approved treatment by the US Food and Drug Administration for two drug-resistant forms of epilepsy, this study adds to a wealth of international evidence supporting the clinical use of the cannabinoid in treating an expanded list of conditions.

CBD beneficial for non-cancer chronic pain and mental health conditions

The study, published in the British Journal of General Practice Open, was the result of collaboration between researchers at the University of Auckland and GP Dr Graham Gulbransen, who opened the first medical cannabis clinic in New Zealand.

The quantitative observational study examined the first 400 patients to be assessed for CBD at Dr Gulbransen’s clinic. The prescription of CBD by a medical doctor has been legal in New Zealand since September 2017, and the patients in this study presented to the clinic between December 2017 and December 2018.

At the outset, patients were classified by their clinician into one of four categories based on their presenting medical symptoms: non-cancer chronic pain symptoms, neurological symptoms, mental health-related symptoms, or cancer symptoms. Patients were then contacted for a follow-up screening after a period of at least three weeks of using CBD as a part of their routine clinical assessment.

Through studying this patient data, the researchers found statistically significant improvements in the cohorts presenting with non-cancer pain symptoms and mental health-related symptoms. Non-cancer pain patients reported significant improvements to their self-reported mobility, ability to complete usual activities, pain, and feelings of anxiety or depression. Those with mental health problems also reported improvements to their ability to complete activities and their feelings of anxiety or depression.

Patients in the group presenting with neurological symptoms, including multiple sclerosis, Parkinson’s disease, and tremors, experienced no statistically significant differences during the CBD treatment. Those with cancer symptoms only experienced narrowly significant improvement in their self-reported pain.

High patient satisfaction, but researchers still urge caution

Patient-reported satisfaction in the CBD treatment was high overall. For the 250 patients for whom these data were available, 70 percent reported some level of positive satisfaction with CBD use, with the remaining 30 percent reporting no benefit.

Cases of adverse side effects were low and tolerable; the most common negative symptoms were sedation and vivid dreaming. In total, approximately 10 percent of patients who completed the follow-up reported experiencing an adverse effect. Positive side effects, notably an improved appetite and improved sleep, were reported by 15 percent of the follow-up cohort.

“Our findings show that CBD is well-tolerated in most patients and can markedly ease symptoms in a range of hard-to-treat conditions, and that there are people keen to access this and self-fund the medication (about $300 per month),” said Bruce Arroll, senior author in the study and a professor at the University of Auckland, to the New Zealand Doctor.

While the study generally demonstrates the positive potential benefit that CBD could have in treating anxiety and pain, the researchers do note that the results should be interpreted with some caution, as the study was affected by several limitations.

Principally, there was a large loss of study participants due to patients not attending the follow-up consultation, and due to cost barriers. Of the 400 total patients at the beginning of the study, only 253 completed such a follow-up. More than 60 patients didn’t complete the follow-up assessment after choosing not to take the CBD prescribed. The high cost of CBD oil, severe illnesses, and consumption of illicit cannabis products were all reported as reasons for these absences.

The researchers also note that due to the high cost of CBD treatment in New Zealand (approximately USD$300 for 2500 milligrams of the oil and USD$150 for an initial consultation), patients may be more likely to overestimate the effects of the treatment.

“The study has limitations due to drop-out and other factors, but the findings are consistent with other evidence and underline the need for more research to allow us to fully realize the therapeutic potential of medical cannabis,” said Professor Arroll.

Cannabis extracts and clinical treatment

The New Zealand study adds to a mixed picture for research into the clinical use and effectiveness of CBD and other cannabinoids.

A recent review published in the British Medical Journal called into question the ability of cannabinoid extracts to treat pain, after an examination of six randomized controlled trials found that cannabinoids were no better at affecting patients’ self-reported pain scores than placebos.

All six studies focused on the use of cannabinoid extracts, such as tetrahydrocannabinol (THC) extract and combination THC:CBD extracts, in treating specifically cancer-related pain. Unlike the New Zealand study, which did see a statistically significant improvement in self-reported pain, the BMJ review did not.

“I think there is great interest in cannabinoid medicines from the general public at the moment,” Mike Bennett, a professor of palliative medicine at the University of Leeds and co-author of the review, told Analytical Cannabis following the study’s publication. “But in cancer pain, using this particular product, we can't see a positive benefit.”

“So, I think for now, the evidence doesn't support these cannabinoid medicines for the management of cancer pain. But I can imagine that more research using different sorts of cannabinoid products and different outcome measures might need to be done to [make] me more certain.”

The findings of the recent New Zealand study also contradict a review published in the Lancet Psychiatry, which found little evidence to support the use of pharmaceutical grade THC or CBD in relieving symptoms of depression or anxiety, as well as for attention-deficit hyperactivity disorder (ADHD), Tourette syndrome, post-traumatic stress disorder (PTSD), or psychosis.

“There is a notable absence of high-quality evidence to properly assess the effectiveness and safety of medicinal cannabinoids compared with placebo,” said Louisa Degenhardt, a professor at the University of New South Wales and lead author of the study, in a statement. “And until evidence from randomized controlled trials is available, clinical guidelines cannot be drawn up around their use in mental health disorders.”