Using cannabis could help people who are struggling with post-traumatic stress disorder, a B.C. study has found.
The study, a partnership between the B.C. Centre on Substance Use and the University of B.C., found that having PTSD was strongly associated with suffering a major depressive period and suicidal ideation among people who did not use cannabis. The link was not present in those who did use cannabis.
The data, published in late 2019 in the Journal of Psychopharmacology, is the first of its kind, said lead author and centre research associate Stephanie Lake.
The key, she said, was being able to use Statistics Canada data rather than waiting for clinical trials to finish up.
“There’s really been a rise in the number of Canadians who were using cannabis for PTSD,” Lake said. “We’ve seen a lot of patient reports of success with PTSD and cannabis, but we’ve yet to see a clinical study.”
The researchers used data related to the cannabis use and mental health of 24,000 people, and drew conclusions about how the drug interacts with the disorder. The information is particularly relevant in Canada, which has one of the highest rates of PTSD worldwide at 9.2 per cent of the population.
Of the 24,089 people in the study, 420 had a current PTSD diagnosis. Of those, 106 people, or 28.2 per cent, reported using cannabis in the past year, compared to 11.2 per cent of those who did not have PTSD.
Non-users with PTSD were seven times more likely to have a major depressive episode and nearly five times more likely to have suicidal thoughts, compared with users of cannabis.
Lake, who is also a PhD student at UBC’s School of Population and Public Health, said the research was too broad to discern why cannabis had the effect it did, but it did point to what use was most helpful for PTSD.
“We saw that compared to non-users, lower risk [cannabis] users were at a reduced likelihood of major depressive episodes and suicidal ideation, but higher risk users were at a higher chance,” she said. Higher-risk users show signs of cannabis use disorder, which is a compulsive use of pot and an inability to stop.
M-J Milloy, a professor of cannabis science at UBC, said the findings open up further avenues to study cannabis.
“One of the important results of the study is it really supports our plans to move forward with clinical trials,” he said.
“There’s clearly lots of patients self-medicating with cannabis, but there’s a real gap with our clinical knowledge.”
Milloy said legalization and regulation would help narrow what kinds of cannabis work best for PTSD, because patients and researchers would be assured of the strain and the THC or CBD content.
“We know that many people believe certain strains of cannabis work better, [while] some people want to use cannabis edibles, or prefer high CBD,” he said.
“As scientists, we want figure out if these preferences are real so we can optimize them for PTSD treatment.”