A new placebo-controlled medical trial looking at the use of vaporized marijuana to treat migraines found that people who took either THC or a combination of THC and CBD were more likely to report pain relief after a two-hour period than people who received a placebo.

Results of the study, presented at the American Headache Society’s annual meeting in Minneapolis last month, found that more than two in three migraine-sufferers reported pain relief after using a THC product (68.9 percent of participants) or combination THC–CBD product (67.2 percent)—a significant difference from the placebo group, of whom 46.6 percent reported pain relief after two hours.

Of participants who used a CBD product, meanwhile, just over half (52.6 percent) reported headache relief, a difference the study did not describe as statistically significant.

People were also significantly more likely to report freedom from pain after two hours if they’d received the THC–CBD intervention, with 34.5 percent of that group reporting pain freedom, compared to 15.5 percent in the placebo group.

Meanwhile 27.9 percent of participants who took THC alone and 22.8 percent of those who took CBD alone said they were pain-free after two hours.

“Acute migraine treatment with 6% THC+11% CBD was superior to placebo at 2 hours post-vaporization with sustained benefits at 24 and 48 hours.”

The combined THC–CBD group also showed more sustained pain relief after 24 and 48 hours.

“This is the first placebo-controlled study in this space,” study investigator Nathaniel M. Schuster, a pain and headache neurologist and University of California San Diego (UCSD) anesthesiology professor, told Medscape Medical News, which first reported on the recent American Headache Society presentation.

“It’s the first real—to me—compelling evidence for the anti-migraine effects of cannabis in humans,” the researcher added.

In addition to pain, participants were also asked about how the marijuana—all of which was provided through the National Institute on Drug Abuse (NIDA) Drug Supply Program—affected the most bothersome symptoms of their migraines, for example discomfort caused by lights or sounds.

“What we found is that it does have effects on the photophobia and phonophobia,” Schuster said, “and that’s an important finding,”

For example, among the combined THC–CBD group, which overall appeared to show the broadest significant benefits, 56.9 percent reported improvement in photophobia (light sensitivity) and 74.1 percent had improvement in phonophobia (sound sensitivity)—compared to 37.9 percent and 51.7 percent, respectively, in the placebo group.

By contrast, those who took cannabinoids did not show any significant difference from the placebo group when it came to nausea or vomiting.

“Vaporized 6% THC+11% CBD cannabis flower was superior to placebo for pain relief, pain freedom, and [most bothersome symptom] freedom at 2 hours as well as 24-hour sustained pain freedom and sustained MBS freedom and 48- hour sustained MBS freedom.”

There were no serious adverse events reported in the study, which has been published as a preprint by The Lancet, through there was some cognitive impairment noted among subsets who received THC, either alone (26.2 percent) or in combination with CBD (12.1 percent). Some patients who didn’t receive a psychoactive treatment also reported cognitive impairment, including 7.0 percent of those in the CBD group and 5.2 percent in the placebo group.

Overall, Schuster told Medscape, the findings suggest a combination of THC and CBD could offer patients a viable alternative treatment for pain and other migraine symptoms.

While research into marijuana’s effects on pain and chronic pain in general have stepped up in recent years, trials around marijuana and migraines are less common. Other Schedule I substances, meanwhile, have also shown promise when it comes to reducing headache-related pain.

A study published earlier this year, for instance, found that people who’ve used so-called “classic psychedelics,” such as psilocybin or LSD, are less likely to report having frequent bad headaches.

To come to that conclusion, researchers gathered data from 11,419 records collected from 1999 to 2000 as part of the British Child Development Study 1958, which follows a cohort of people born over the course of a single week in March 1958.

Specifically, they looked at responses to three questions: “Do you often have bad headaches?” “Have you ever tried LSD, also known as acid or trips?” and “Have you ever tried magic mushrooms?”

The team’s analysis showed that “lifetime use of classic psychedelics was associated with 25% lower odds of having frequent bad headaches.”

A separate report on the medical use of psychedelics published by the U.S. Government Accountability Office (GAO) this year listed headache disorders as a promising application.

Psychedelics “appear to show promise for patients with certain headache disorders and cancer pain,” GAO said, apparently by reducing inflammation and altering pain perception through interactions with the brain’s serotonin receptors.

A Republican New Hampshire House member, Rep. Kathleen Paquette, separately this year shared how cluster headaches affect her life and asked colleagues to approve a bill that would remove criminal penalties around psilocybin.

Psilocybin is “believed to help people like me by potentially interrupting and preventing headache cycles,” Paquette said. “It is thought to reduce inflammation in the brain, alter pain perception and reset the neural pathways that interrupts these painful cycles.”

“Very occasional use of small, non-hallucinogenic, microdoses—and at times, even a single dose—has been known to increase remission periods or even stop a cycle completely in its tracks,” she added. “As little as a single dose has the power to allow someone relief when there hasn’t been any for years or even decades. It has the power to give someone back their ability to be present for their family, to give someone back their dignity and, most of all, making psilocybin available to someone like me has the power to save lives.”

Last year the National Center for Complementary and Integrative Health (NCCIH), which is part of the National Institutes of Health, also published an informational web page about psilocybin, acknowledging the substance as a possible treatment for alcohol use disorder, anxiety and depression and also highlighted psilocybin research being funded by the federal government into the drug’s effects on pain, migraines, psychiatric disorders and various other conditions.

Photo courtesy of Chris Wallis // Side Pocket Images.