A prescription drug derived from cannabis sharply reduced the nightmares that torment many people with post-traumatic stress disorder (PTSD), a rigorous clinical trial found — though it did not clearly ease PTSD overall.
Led by Charité – Universitätsmedizin Berlin with several German medical centers, the study tested dronabinol, prescription THC drops, in more than 170 PTSD patients who suffered frequent, severe nightmares. Over the 10-week double-blind, placebo-controlled trial, nightmare severity fell by an average of 3.7 points on a 0–8 scale in the dronabinol group, versus 2.2 points on placebo. The results were published August 5, 2026 in Nature Medicine.
What patients experienced
More than a third of patients on dronabinol said their nightmares stopped entirely after ten weeks, and about 21% had at least a 50% reduction in nightmare burden; roughly 83% felt markedly better overall. Side effects were mild to moderate — dizziness, headaches and increased appetite, more common with the drug — with no severe effects and no withdrawal symptoms detected.
The important limits
The trial had clear boundaries: researchers could not conclusively show that dronabinol reduced overall PTSD severity or accompanying depression, only the nightmares specifically. Long-term safety and whether tolerance develops still need study. Dronabinol is a prescription, controlled medicine, not something to self-treat with.
This article describes a clinical-trial result and is not medical advice. Do not start, stop or change any medication without consulting a qualified healthcare professional.