New treatment approach for severe sleep disturbances
Berlin, August 5, 2026
Nightmares are among the most distressing symptoms of post-traumatic stress disorder (PTSD)—a condition that can develop following severe traumatic events such as disasters, accidents, acts of violence, or experiences of war. Those affected intensely relive the events at night—as if they were real—over and over again. This results in extreme sleep deprivation and a fear of going to bed. Existing pharmacological treatments often fail to adequately address these nightmares. Researchers at Charité – Universitätsmedizin Berlin therefore investigated whether a prescription medication containing the cannabinoid THC—an active compound found in the cannabis plant—could help. The results were successful: more than half of the treated patients responded to the therapy, and over a third experienced no further nightmares during the study, according to a report in the journal *Nature Medicine*.
Drastic or even life-threatening events can linger like an echo; this is known as PTSD. The brain is unable to process these overwhelming experiences. It stores the memories in such a way that they cannot be voluntarily controlled, causing them to resurface repeatedly. At night, too, people with PTSD relive the trauma again until they wake up—usually in a state of panic. Treatments used to alleviate symptoms include antidepressants and blood-pressure-lowering drugs, but these have limited efficacy and generally do not target the nightmares themselves. To date, no medication specifically approved for treating trauma-related nightmares is available in Germany.
Prof. Stefan Röpke conducts research into trauma-related disorders at the Department of Psychiatry and Psychotherapy at Charité’s Benjamin Franklin Campus. In their search for new treatment options, he and his team—along with other partners—focused on a key constituent of the cannabis plant: tetrahydrocannabinol, or THC for short. This active compound, also known for its psychoactive effects, interacts with the body’s own endocannabinoid system—which plays a role in regulating sleep and stress as well as processing emotional memories. As Stefan Röpke explains: “There is evidence that THC dampens dream activity during REM sleep—the phase of intense dreaming when the brain processes experiences and regulates emotions—thereby mitigating nocturnal stress reactions.”
A Cannabinoid Targeted at Nightmares
Cannabis-based medications are already used in pain management, typically when standard treatments prove insufficient or are not tolerated by patients. This became possible following the enactment of the “Cannabis as Medicine” Act in 2017. Since then, it has been easier to use plant-derived or synthetic cannabinoids for medical and medical-scientific purposes. For their current study, the researchers selected THC derived directly from the cannabis plant in the form of drops—specifically, the prescription drug Dronabinol. Their goal was to determine whether nightmares associated with PTSD could be alleviated in this way and whether such use was safe in this context.
More than 170 patients suffering from post-traumatic stress disorder (PTSD) and frequent, intense nightmares participated in the study. For ten weeks, they received either the active medication or an identical-looking placebo—which also tasted like cannabis—every evening before going to bed. Neither the healthcare providers nor the participants knew who received which preparation—the gold standard of medical research, in other words: a so-called double-blind, placebo-controlled study.
The results are clear: by the end of the study period, nightmares had decreased significantly more in the dronabinol group than in the placebo group. On a scale of zero to eight points, the nightmare burden dropped by an average of 3.7 points, compared to just 2.2 points in the placebo group—a difference clearly perceptible to those affected. “More than a third of those treated with dronabinol reported experiencing no nightmares at all after ten weeks. Another 21 percent reported that their nightmare burden had been at least halved,” said Stefan Röpke. “Overall, about five out of six patients in the dronabinol group perceived their health status as having significantly improved.”
No dependency or severe side effects
According to the study findings, the cannabinoid had a specific effect on nightmares and sleep, but not on all PTSD symptoms. There were no clear changes in the severity of the trauma-related disorder or any accompanying depression. Nevertheless, the majority of participants experienced significant relief, as the distressing nightly relief of the traumatic events was interrupted and restful sleep became possible again.
The medication did not cause severe side effects. However, researchers did frequently observe moderate to mild adverse effects such as dizziness, headaches, and increased appetite. The study team did not detect any withdrawal symptoms after the study period ended and the evening doses were discontinued. In the next phase of research, the team aims to determine whether long-term use of the cannabinoid remains effective and safe, or if a tolerance effect develops over time.
*Roepke S et al. Dronabinol for nightmares in post-traumatic stress disorder: a randomized controlled trial. Nat Med 2026 Aug 05. doi: 10.1038/s41591-026-04546-9
About the study
The study was initiated and led by Charité. Additional participating researchers were affiliated with the Charité Department of Psychiatry at St. Hedwig Hospital, the University Medical Center Hamburg-Eppendorf, and the Central Institute of Mental Health in Mannheim. The project was supported by Bionorica SE.
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