Inhaled cannabis reduces the perceived severity of headaches and migraines by nearly 50 percent, regardless of THC and CBD potency, according to a new study led by Carrie Cuttler, professor of psychology at Washington State University. Despite medical marijuana being legal in 33 of 50 states in the U.S., not much research exists examining its treatment success, and even less when it comes to specific strains and doses. Cuttler’s study, recently published in the Journal of Pain, is the first to use real-time data to evaluate the effectiveness of cannabis for treating headaches and migraines.

Data for the study was pulled from Strainprint, an app for medical cannabis users that allows patients to rate the severity of their pain at the time of cannabis ingestion compared with 20 minutes later. The three options are: reduction of pain, exacerbation of pain and no change. More than 1,300 patients used the self-reporting app to track changes in the severity of headache pain, while 653 used it to track changes in migraine severity.

"Using real-time data in which symptom severity was assessed immediately before and after cannabis use is an improvement upon previous retrospective reports because retrospective reports would be more prone to memory biases and other potential biases which could influence the reported efficacy of cannabis," Cuttler told Laboratory Equipment. "These are also very big data, so we can more appropriately and accurately generalize to the greater population of patients using cannabis to manage these conditions."

According to study results, inhaled cannabis reduced headache severity by 47.3 percent and migraine severity by 49.6 percent. Differences by gender were detected in the results, but on a very small scale—only 1.1 percent and 1.8 percent—limiting the practical application of the knowledge. Nevertheless, the study authors concluded that more women than men reported headache exacerbation, while more men than women reported headache reduction following cannabis use.

The researchers also considered the effect of different cannabis strains and doses in the study results. Within the Strainprint app, users are prompted to enter the strain of cannabis they are about to use by selecting from a list of more than 1,000 strains sold by licensed medical cannabis distributors and cannabis concentrate producers in Canada. The THC and CBD content for each of these strains is prepopulated in the app and was obtained by analyses conducted by one of Health Canada's licensed dealers.

Surprisingly, the researchers noted there was no significant difference in reported pain reduction among cannabis strains that were higher or lower in levels of THC and CBD, the two most popular cannabinoids. This suggests that the hundreds of other cannabinoids present in cannabis actually play a much more prevalent therapeutic role than previously thought. Additionally, for patients in the study, the use of cannabis concentrates, such as CBD oil, was associated with significantly larger reductions in pain ratings. However, Cuttler does not believe this is due to dose as there was an obvious absence of dose effects. More research is needed in both of these areas as subsequent findings could provide medical cannabis patients with more information to guide their cannabis selection.

While Cuttler and team investigated the effects of the cannabis flower and associated concentrates, they did not delve into edibles or other cannabis-infused products.

"We focused only on inhalation because it’s easier to capture the period of intoxication that way," Cuttler said. "Edibles can take variable amounts of time to take effect so it would be harder to know if people were making their second (post-cannabis use) symptom rating when they were intoxicated or not."

Lastly, Cuttler and her co-authors reported not evidence that cannabis caused “overuse headache,” a pitfall of more conventional treatments that can make patients’ headaches worse over time. However, they did see patients using larger doses of cannabis over time, indicating they may be developing tolerance to the drug—an effect commonly seen with traditional pharmaceuticals, including OTC and antibiotics.

"We previously published a study in which we examined changes in anxiety, stress, and depression from before to after cannabis use using Strainprint data. We found 50 to 60 percent reductions in these symptoms," Cuttler said. "We are currently analyzing effects of cannabis on PTSD and OCD symptoms."