THC Drug Eases Trauma-Related Nightmares: Randomized Trial Opens a New Path for PTSD Sleep Symptoms

For people with post-traumatic stress disorder (PTSD), sleep does not necessarily offer a temporary escape from trauma. Instead, it may be a time when memories repeatedly intrude. A multicenter randomized controlled trial published in *Nature Medicine* found that dronabinol, a prescription drug containing tetrahydrocannabinol (THC), can reduce the frequency and intensity of trauma-related nightmares, providing new clinical evidence for a symptom for which no specifically approved medication is currently available.

This exploratory phase 2 trial used a double-blind, placebo-controlled design, with participants randomly assigned in a one-to-one ratio. Clinical trial registry data show that 170 adults were enrolled; the treatment group took oral dronabinol at bedtime for 10 weeks. The study’s primary endpoint used the clinician-rated CAPS-IV B2 scale to assess the frequency and intensity of nightmares over the previous week. The results showed that the dronabinol group performed better than the placebo group.

According to the trial protocol published in 2023, participants started at 2.5 mg daily, with the dose gradually adjusted during the first 4 weeks according to efficacy and tolerability, up to a maximum of 15 mg daily, followed by 6 weeks at an individualized maintenance dose. This design sought to reflect real-world psychiatric prescribing: rather than giving everyone the same dose, it aimed to identify a tolerable range that balanced symptom improvement with adverse effects.

Dronabinol is a standardized THC pharmaceutical formulation and cannot be directly equated with smoked cannabis or commercially available products with inconsistent compositions. The findings support a prescription drug used at a specific dose, at a specific time, and under medical monitoring—not a broad endorsement of self-treating PTSD with cannabis. A previous short-term trial of smoked cannabis failed to demonstrate an improvement in overall PTSD symptoms over placebo, further underscoring that different formulations and treatment targets cannot be treated as interchangeable.

The clearest signal from the study currently concerns nightmares, rather than proof that dronabinol can treat all symptoms of PTSD. The publicly available abstract has not yet fully presented the magnitude of the effect, complete adverse-event data, whether symptoms recur after discontinuation, or the effects on overall PTSD severity, depression, and daytime functioning. The 10-week treatment period also cannot answer questions about long-term tolerability, the risk of dependence, or sustained efficacy. Longer-term, reproducible trials are still needed, along with comparisons against existing psychotherapies and other medication strategies.

The trial was sponsored by Charité – Universitätsmedizin Berlin; the published protocol lists Bionorica SE and Canopy Growth as funders, with Bionorica also supplying the trial drug and placebo. These arrangements do not in themselves invalidate the results, but complete data, statistical analyses, and disclosures of interests remain essential to assessing clinical value. At this stage, dronabinol is better regarded as a candidate option supported by a randomized trial than as an established new standard of care.