Medical cannabis may ease anxiety, depression and chronic pain, a study of the first 400 New Zealand patients to be prescribed cannabidiol (CBD) has found.
The study, published in the British Journal of General Practice Open on Wednesday, was carried out by University of Auckland researchers and GP Dr Graham Gulbransen, who opened New Zealand's first medical cannabis clinic.
By looking at patients who sought CBD prescriptions from Gulbransen's Auckland clinic between December 2017 and 2018, researchers found “marked” improvements of quality of life, and decreased pain and anxiety after using CBD oil.
However, three in 10 people who reported feedback for the study did not receive any benefits from CBD use.
Products containing CBD – approved by the United States Food and Drug Administration for the treatment of two childhood seizure disorders – were legalised for prescription by New Zealand doctors in 2017.
But evidence suggests they could also be used to help treat anxiety and chronic pain and may reduce psychotic symptoms of schizophrenia.
Most patients living with non-cancer chronic pain and anxiety-related mental health conditions who took CBD oil for four weeks self-reported significant improvements in their quality of life, the research found.
Those with cancer or neurological conditions also reported improved quality of life, but to a lesser degree.
A little more than half of patients prescribed CBD in this study (54 per cent) were women – 214 – and 183 were men.
Patients were asked to rate their own pain, anxiety, debility and depression before taking CBD, and then again four weeks later.
They were also asked to rate their satisfaction with CBD after four weeks.
About a quarter – 110 patients – completed all assessments, while a little under two-thirds (250 people) gave satisfaction feedback.
After taking CBD oil, those with non-cancer pain symptoms reported improved mobility and ability, and less pain, anxiety and depression.
Patients with mental health related symptoms reported improved ability to complete activities, as well as reduced pain, anxiety and depression.
Seventy per cent of those who rated their satisfaction with CBD use said it was “good, very good or excellent”, while the other 30 per cent reported no benefit.
Ten per cent of participants experienced adverse side effects, including sedation and vivid dreams.
Two people (less than 1 per cent) reported their pre-existing condition getting worse.
University of Auckland Professor Bruce Arroll said the findings showed CBD was well-tolerated in most patients and could “markedly” ease symptoms in a range of hard-to-treat conditions.
While the study had its limitations – largely participant drop-out – the findings underlined the need for more research to help “fully realise the potential” of medical cannabis, Arroll said.