Cannabis for PTSD in 2019: The Systematic Evidence Was Still Thin Despite Growing Interest
A systematic review of all published evidence found promising signals — especially nabilone for nightmares — but not enough rigorous research to confirm cannabis effectively treats PTSD.
Quick Facts
What This Study Found
This systematic review gathered everything published through May 2019 on cannabis and synthetic cannabinoids for PTSD. The interest was clearly growing: patients were increasingly turning to cannabis, and several U.S. states listed PTSD as a qualifying condition for medical marijuana.
The most consistent finding across studies was nabilone's effectiveness for PTSD-related nightmares and sleep disturbance. Several studies reported significant reductions in nightmare frequency and severity. For broader PTSD symptoms — hyperarousal, avoidance, re-experiencing — the results were more mixed. Some observational studies showed symptom improvement, but the methodological quality was generally low.
The reviewers found that most available evidence came from case reports, case series, and open-label studies rather than randomized controlled trials. The gap between patient demand and scientific evidence remained wide.
Key Numbers
- Nabilone: most consistent evidence, particularly for nightmare reduction
- Most evidence from case reports, case series, and open-label studies
- Searched through May 2019 across three databases
- PTSD is a qualifying condition for medical cannabis in multiple U.S. states
How They Did This
Systematic review following PRISMA guidelines. Searched PubMed, Cochrane Library, and Web of Science through May 2019. Included all study types reporting on cannabis or synthetic cannabinoids for PTSD treatment. Organized results by substance type (plant-based cannabis vs synthetic cannabinoids).
Why This Research Matters
By 2019, cannabis for PTSD had become one of the most politically charged topics in medical marijuana debates. Veterans' groups advocated strongly for access. States were adding PTSD to qualifying conditions. But this review showed the evidence base hadn't kept pace with the policy. The strongest signal — nabilone for nightmares — was specific and replicable, but the broader claim that cannabis treats PTSD remained unsupported by rigorous evidence.
That doesn't mean cannabis doesn't help. It means the research hadn't been done properly enough to say either way with confidence.
The Bigger Picture
This review, combined with the earlier Steenkamp 2017 review (RTHC-00044), paints a consistent picture: two years of additional research hadn't substantially closed the evidence gap. The endocannabinoid system's role in stress and fear processing remained biologically compelling, nabilone for nightmares remained the standout finding, and the need for large randomized controlled trials remained urgent.
What This Study Doesn't Tell Us
Most included studies were low quality (case reports, case series, open-label designs). Publication bias likely favored positive results. Cannabis products varied widely across studies in type, dose, and route. Cannot distinguish between symptom improvement and general anxiolytic effects. Search was limited to three databases.
Questions This Raises
- ?Why hasn't the research quality caught up with patient demand for cannabis as PTSD treatment?
- ?Is nabilone specifically effective for nightmares, or would whole-plant cannabis work too?
- ?Could cannabis be effective for specific PTSD symptom clusters (like sleep) but not others?
Trust & Context
- Evidence Grade:
- Systematic review with proper methodology, but the underlying studies were mostly low-quality observational designs. The review is rigorous; the evidence it found was not.
- Study Age:
- Published in 2019. Some additional RCTs have been published since, though the evidence base remains limited.
- Original Title:
- Use of medicinal cannabis and synthetic cannabinoids in post-traumatic stress disorder (PTSD): A systematic review
- Published In:
- Medicina (Kaunas), 55(9), 525 (2019) — Medicina (Kaunas) is a peer-reviewed journal focusing on medical research.
- Authors:
- Orsolini, Laura(2), Chiappini, Stefania(6), Volpe, Umberto, De Berardis, Domenico, Latini, Roberto, Papanti, Gabriele Duccio, Corkery, John Martin
- Database ID:
- RTHC-02212
Evidence Hierarchy
Analyzes all available research on a topic using a structured method.
What do these levels mean? →Frequently Asked Questions
Does cannabis help PTSD?
The most consistent finding is that nabilone (a synthetic cannabinoid) helps with PTSD nightmares. For other PTSD symptoms, the evidence was too limited and low-quality to draw conclusions as of 2019.
Should I use cannabis for my PTSD?
The science couldn't answer that definitively as of this review. Nabilone for nightmares had the best evidence. For broader PTSD treatment, the research wasn't rigorous enough to confirm or deny benefit.
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Cite This Study
https://rethinkthc.com/research/RTHC-02212APA
Orsolini, Laura; Chiappini, Stefania; Volpe, Umberto; De Berardis, Domenico; Latini, Roberto; Papanti, Gabriele Duccio; Corkery, John Martin. (2019). Use of medicinal cannabis and synthetic cannabinoids in post-traumatic stress disorder (PTSD): A systematic review. Medicina (Kaunas), 55(9), 525. https://doi.org/10.3390/medicina55090525
MLA
Orsolini, Laura, et al. "Use of medicinal cannabis and synthetic cannabinoids in post-traumatic stress disorder (PTSD): A systematic review." Medicina (Kaunas), 2019. https://doi.org/10.3390/medicina55090525
RethinkTHC
RethinkTHC Research Database. "Use of medicinal cannabis and synthetic cannabinoids in post..." RTHC-02212. Retrieved from https://rethinkthc.com/research/orsolini-2019-medicinal-cannabis-ptsd
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.