Placebo-Controlled, Triple-Blind, Randomized Crossover Pilot Study of the Safety and Efficacy of Four Different Potencies of Smoked Marijuana in 76 Veterans with Chronic, Treatment-Resistant Posttraumatic Stress Disorder (PTSD)
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This study was the first randomized placebo-controlled trial of smoked cannabis for posttraumatic stress disorder (PTSD) which explored whether three different concentrations of smoked marijuana could help reduce PTSD symptoms in 76 U.S. veterans with chronic, treatment-resistant PTSD. Participants were U.S. veterans, aged 18 or older with a diagnosis of PTSD that did not improve after trying either medication or psychotherapy.
The study used a double-blind, cross-over design, where participants were randomly assigned to receive three weeks of either active treatment or placebo and then were re-randomized after a 2-week washout period to receive one of the other three active treatments in Stage 2. The treatments consisted of High THC (approximately 12% THC and < 0.05% CBD), High CBD (11% CBD and 0.50% THC), THC+CBD (approximately 7.9% THC and 8.1% CBD), and placebo (< 0.03% THC and < 0.01% CBD).
All treatment groups, including placebo, showed good tolerability and significant improvements in PTSD symptoms during three weeks of treatment. However, no active treatment with cannabis outperformed placebo.
Study Data
Pilot Study of the Safety and Efficacy of Four Different Potencies of Smoked Marijuana in 76 Veterans With PTSD
- High THC cannabis, Three weeks of smoking cannabis containing more THC than CBD with amount smoked limited to no more than 1.8 g per day.
- High CBD cannabis, Three weeks of smoking cannabis containing more CBD than THC with amount smoked limited to no more than 1.8 g per day.
- THC/CBD cannabis, Three weeks of smoking cannabis containing equal amounts of THC and CBD with smoking limited to no more than 1.8 g per day.
- Placebo cannabis, Three weeks of smoking cannabis with low levels of THC and CBD with smoking limited to no more than 1.8 per day.
Study Timeline
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$2 Million Grant Proposal Submitted to State of Colorado for Multi-Site Study
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Petition Receives 100,000 Signatures (and Counting) for Medical Marijuana Research in Arizona
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Second Letter from Rick Doblin to University of Arizona in Support of Dr. Sue Sisley
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University of Arizona Fires Medical Marijuana Researcher Dr. Sue Sisley
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NIDA Admits to Not Having Marijuana Required for Research, Causing More Delays for PTSD Study
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Public Health Service Approves Medical Marijuana Study, Marking Historic Shift in Federal Policy
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Arizona State Senator Blocks Funding for Medical Marijuana Research
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Public Health Service Blocking FDA-Approved Medical Marijuana Research for PTSD
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Rick Doblin to HHS: When Will You Stop Obstructing FDA-Approved Marijuana Research?
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Three Months Later, Researchers Still Waiting for Response from Public Health Service
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Marijuana for PTSD: Institutional Review Board Approves Study Protocol
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Marijuana for PTSD: Protocol Submitted for Third Time to IRB
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Marijuana for PTSD: IRB Requests Changes to Study Protocol, Researchers Respond
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Medical Marijuana Research Shackled by Politics?
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Marijuana for PTSD: Protocol Submitted to Institutional Review Board
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Arizona Medical Association Challenges NIDA Blockade of Medical Marijuana Research
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Medical Marijuana: New Arizona Law and Study for U.S. Veterans with PTSD
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NIDA/PHS Rejects Marijuana/PTSD Protocol, Blocking MAPS FDA-Reviewed Study
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NIDA/PHS Completes Review of Marijuana for PTSD Protocol; MAPS Awaits Response
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FDA Accepts Marijuana for PTSD Protocol

