ST. PAUL — Minnesotans who use medical pot to treat post-traumatic stress disorder are reporting less anxiety and improvements in mood and sleep, according to a new state health survey.

About three-quarters of survey respondents said medical cannabis has helped them cope with their PTSD, a report released Thursday, July 18, by the Minnesota Department of Health shows. And about seven in 10 respondents reported “clinically meaningful improvement” on a tool that measures the severity of PTSD symptoms.

“This study shows many patients with PTSD enrolled in the program are experiencing substantial benefits,” said Dr. Tom Arneson, a research manager in the health department’s Office of Medical Cannabis.

About 18% of the more than 17,000 patients enrolled in the program use medical cannabis for PTSD. The health department added the disorder to the medical cannabis program’s list of qualifying conditions effective August 2017.

Researchers surveyed 751 PTSD patients who enrolled in the program in the five months after their condition was added. Though PTSD is often linked to military service, just 19% of respondents came from that background.

When asked about the most important benefit, 23% of patients reported they had less anxiety, 16% said they slept better, 13% said their mood improved and 12% said they were in less pain.

Just 4% of respondents reported little to no benefit from medical cannabis treatment. About 20% of those surveyed experienced side effects. Some reported increases in anxiety, which can sometimes occur with cannabis use.

“That just is a little bit of a caution to approach this carefully,” Arneson said, noting that new patients should start at a low dose and increase it in increments.

Because the results come from a survey instead of a clinical trial, Arneson said researchers cannot say if the cannabis is what improved patients’ symptoms. That would require researchers to conduct a clinical trial where they monitor a comparison group of patients who do not use medical cannabis.

“We can’t make strong statements about that, just as we can’t about anything in the program because we’re not carrying out clinical trials,” Arneson said.

The report featured select comments from patients who use medical cannabis for PTSD.

“Feeling less anxious and having to deal with less chronic pain has overall improved my quality of life a great deal,” one patient said. “I have more moments of happiness, and it’s opened up many doors to me that I have had shut for a long time.”