Researchers from Stanford University School of Medicine have found that people who use cannabis for pain relief from chronic migraines are six times more likely to suffer from rebound headaches or headaches brought on by overusing medication than those who do not use the substance.
"Many people with chronic migraine are already self-medicating with cannabis, and there is some evidence that cannabis can help treat other types of chronic pain," said Niushen Zhang, M.D., one of the study's authors.
"However, we found that people who were using cannabis had significantly increased odds of also having medication overuse headache, or rebound headache, compared to people who were not using cannabis."
For the study, the researchers examined medical records from 368 people who reported chronic migraines (defined as 15 or more days of headaches per month) for at least a year. Among these people, 150 used cannabis.
In particular, the researchers focused on evidence of headaches associated with medication overuse and their contributing factors. These included frequency of migraines, overuse of other medications for acute migraines, and how long they had experienced chronic migraines.
All in all, the researchers found that 212 of the people examined had medication overuse headaches, whereas 156 did not. Notably, they found that people who used cannabis were six times more likely than those who did not use the substance to have a meditation overuse headache. The researchers also found that people who used opioids were also more likely to use cannabis.
Somewhat explaining their results, the researchers said that previous studies have demonstrated that both opioids and cannabis affect an area of the brain known as the periaqueductal gray. This brain region plays a role in autonomic function, motivated behavior, and behavioral responses to threats and has been linked to migraines.
While interesting results, the researchers say that their findings are limited as the study was conducted retrospectively. As such, before firm conclusions can be drawn, longitudinal studies are required that further explore the cause and effect of cannabis use and medication overdose headaches among patients suffering from chronic migraines.