A prescription cannabis medication containing tetrahydrocannabinol significantly reduced severe nightmares in patients with post-traumatic stress disorder, according to a clinical trial conducted by Charité Universitätsmedizin Berlin in Germany.
The ten-week study found that more than one-third of participants who took liquid dronabinol drops before sleeping experienced a complete elimination of their nightmares, while another 21 percent saw their nightmare frequency cut by at least half.
Post-traumatic stress disorder, known as PTSD, is a mental health condition that can develop after individuals are exposed to severe traumatic events, including natural disasters, serious accidents, acts of violence, or experiences of war.
Recurring nightmares are among the primary symptoms associated with PTSD, forcing patients to relive traumatic memories repeatedly during the night and causing extreme sleep deprivation and fear of sleeping.
The German research institution noted that physicians typically prescribe antidepressants or blood pressure medications to provide relief to patients. However, these conventional treatments are only partially effective for PTSD overall and generally fail to alleviate nightmares.
Evaluating dronabinol treatment
To investigate whether targeted pharmaceutical intervention could offer relief, researchers at Charité conducted a trial to evaluate dronabinol, a prescription medication derived directly from the cannabis plant that contains tetrahydrocannabinol, or THC.
Tetrahydrocannabinol is the primary psychoactive compound found in cannabis. Inside the human body, THC interacts with the endocannabinoid system, a complex cell-signalling network responsible for regulating sleep cycles, stress responses, and emotional memory processing.
Cannabis-based medications are already routinely prescribed when standard treatments prove insufficient for chronic pain management, but their effectiveness against sleep-related psychological symptoms has been less established.
Professor Stefan Röpke, who researches trauma-related disorders at the Department of Psychiatry and Neurosciences at Charité's Campus Benjamin Franklin and served as corresponding author for the study, explained how the active compound acts on dreaming.
Röpke said evidence indicates that THC reduces dream activity during rapid eye movement sleep, the stage of intense dreaming where the brain processes experiences and regulates emotions. By suppressing dream intensity during this phase, the medication relieves nocturnal stress responses.
Clinical trial results
The double-blind, placebo-controlled study enrolled more than 170 patients diagnosed with PTSD who suffered from frequent and intense nightmares. Neither the healthcare professionals managing the trial nor the participants knew who received the active treatment.
Participants received either daily doses of dronabinol drops or an identical-looking placebo formulated with a matching cannabis flavor every night before sleeping over a ten-week period.
At the conclusion of the trial, patients receiving dronabinol demonstrated a significantly greater reduction in nightmare frequency compared to those in the placebo group.
On a standardized measuring scale ranging from zero to eight points, nightmare burden decreased by an average of 3.7 points in the dronabinol group, compared to a 2.2-point reduction among placebo recipients.
About five out of every six patients who received dronabinol felt that their overall health had improved noticeably by the end of the trial period.
The researchers emphasized that while the cannabinoid produced positive effects on sleep quality and nightmare frequency, it did not resolve all PTSD symptoms. Overall PTSD severity and accompanying depression did not display conclusive changes, though most participants reported substantial relief from night-time distress.
Safety profile and future research
The trial demonstrated a favorable safety profile, with no participants experiencing severe side effects or withdrawal symptoms following the discontinuation of nightly doses at the end of the study.
Observed side effects were classified as mild and were limited to symptoms such as dizziness, headache, or increased appetite.
Following these initial findings, the Charité research team plans to conduct further studies to determine whether long-term cannabinoid use remains effective and safe, or whether patients eventually develop a tolerance to the medication over time.
