THC-Based Medication Shows Promise for PTSD-Related Nightmares

Nightmares are one of the most distressing symptoms of post-traumatic stress disorder (PTSD), often leaving people reliving traumatic events night after night and dreading sleep itself. Existing medications, including antidepressants and blood pressure drugs, which are sometimes used off-label, frequently fall short of addressing this specific symptom. A new clinical trial from researchers at Charité – Universitätsmedizin Berlin suggests a different approach, using a prescription medication derived from THC (tetrahydrocannabinol), may offer meaningful relief.

The trial, led by Stefan Röpke, M.D., a professor who studies trauma-related disorders at Charité's Department of Psychiatry and Neurosciences, tested dronabinol, a form of THC taken as drops before bedtime. THC interacts with the body's endocannabinoid system, which plays a role in regulating sleep, stress and how the brain processes emotional memories.

“There is evidence suggesting that during REM [rapid eye movement] sleep, the intense dream phases in which the brain processes experiences and regulates emotions, THC reduces dream activity and thereby alleviates nocturnal stress responses,” explained Röpke.

How the trial was designed

The study enrolled 171 adults with PTSD and frequent, intense nightmares, with an average age of 37.9 years; 79.3% of participants were female. Over 10 weeks, participants received either dronabinol, at doses ranging from 2.5 to 15 milligrams, or an identical-looking, cannabis-flavored placebo each night before bed. Neither participants nor their health care providers knew who was receiving the actual medication, a design known as a double-blind, placebo-controlled trial, considered the gold standard in clinical research.

The primary measure researchers tracked was a validated clinical scale assessing nightmare frequency and intensity, evaluated from the start of the trial through week 10.

What the results showed

By the end of the 10-week period, nightmare severity had decreased significantly more in the dronabinol group than in the placebo group. On the study's symptom scale, participants taking dronabinol saw their nightmare burden drop by an average of 3.7 points, compared with a 2.2-point drop among those taking the placebo, a difference researchers described as clearly noticeable to patients.

More than a third of patients taking dronabinol reported that their nightmares disappeared entirely by the end of the study, while another 21% said their nightmare burden had been cut at least in half. According to Röpke, roughly 5 out of 6 patients in the dronabinol group felt their overall health had meaningfully improved.

Safety and side effects

Dronabinol appeared to target nightmares and sleep specifically, rather than improving other PTSD symptoms or accompanying depression, which did not show a clear or consistent change during the trial. Side effects were more common in the dronabinol group, including dizziness, headache and increased appetite, though investigators described these as mild to moderate. Serious adverse events occurred in seven patients taking dronabinol and none taking placebo, while treatment discontinuation due to side effects was low and similar between both groups. Notably, researchers did not observe withdrawal symptoms after participants stopped taking the medication at the end of the study.

What comes next

Because a medication specifically approved for treating trauma-related nightmares does not currently exist in Germany, the team says these findings could represent a meaningful step forward for a symptom that has historically been difficult to treat. Going forward, investigators plan to study whether dronabinol remains effective and safe over longer periods of use, and whether patients might develop tolerance to the medication over time.