A full-spectrum cannabis oil containing high levels of cannabidiol (CBD) was associated with significant reductions in chronic pain and anxiety after three months of use, according to a new human study.
The study, published September 16 in the peer-reviewed journal Drug Science, Policy and Law, examined patients enrolled in Project Twenty21 Australia who were prescribed a specific high-CBD cannabis oil as their only medical cannabis product.
Researchers followed 31 patients for three months, including 22 being treated primarily for chronic pain and nine being treated for anxiety.
The product contained 100 milligrams of CBD per milliliter, along with less than 2 milligrams per milliliter of tetrahydrocannabinol (THC), less than 1 milligram per milliliter of cannabinol (CBN) and multiple naturally occurring terpenes. It was derived from the Charlotte’s Web and Charlotte’s Angel cannabis cultivars.
Among chronic pain patients, median pain severity on the Brief Pain Inventory fell from 5.3 at baseline to 4.0 after three months. Pain interference, which measures the extent to which pain disrupts activities and daily life, declined from 6.0 to 4.4. Both reductions were statistically significant.
Mood and depression scores also improved substantially among the chronic pain group. Median Patient Health Questionnaire-9 scores fell from 12 to 6 during the three-month period.
Researchers said the reductions in pain severity and interference were likely to be clinically meaningful, in addition to being statistically significant.
Results were similarly positive among participants being treated for anxiety.
Median scores on the seven-item Generalized Anxiety Disorder scale fell from 12 at baseline to 7 after three months, a statistically significant five-point reduction. Researchers noted that a change of four points is generally considered the minimum clinically important difference on the scale.
Mood and depression scores among the anxiety group also declined, from a median of 14 to 10.
When researchers combined participants from both groups, they found statistically significant improvements in perceived overall health, mood and sleep compared with baseline.
No adverse events were reported in association with the high-CBD oil during the study.
The researchers cautioned that the findings cannot establish that the cannabis oil caused the improvements. The study included only 31 patients, had no placebo or comparison group, was not blinded and did not use standardized doses. Other factors, including changes in medications, diet or physical activity, could have influenced the results.
Longer-term analysis was also limited by substantial participant attrition after the three-month mark.
Because the product was full-spectrum rather than purified CBD, researchers said it is also possible that its small amounts of THC and CBN, as well as its terpenes and other plant compounds, contributed to the observed effects.
One study author disclosed having previously served as chief scientific officer of Releaf Group and as chief scientific officer of Cann Compounding Pharmacy, which compounds the CBD products examined in the research. Drug Science also receives an unrestricted educational grant from a consortium of medical cannabis companies.
Despite the limitations, researchers said the findings add to evidence suggesting full-spectrum, CBD-dominant cannabis products warrant further investigation for chronic pain and anxiety.
“The 3-month results of our study suggest that this high CBD product may have analgesic properties worthy of further scientific investigation,” the researchers said.
They concluded that larger studies, including randomized controlled trials comparing full-spectrum CBD products with purified CBD and placebo, are needed to determine their efficacy for chronic pain, anxiety and other conditions.
