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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Four New Participants Enroll in Smoked Marijuana Trial for Chronic PTSD in Veterans
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7 New Participants Enroll in Smoked Marijuana Trial for Chronic PTSD in Veterans
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4th, 5th, and 6th Participants Enrolled in Smoked Marijuana Trial for Chronic PTSD in Veterans
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Second and Third Participants Self-Administered Treatment in Trial of Marijuana for Chronic PTSD in Veterans
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Marijuana for PTSD: First Participant Enrolled in First-Ever Trial of Marijuana for Chronic PTSD in Veterans
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Marijuana for PTSD: In-Person Participant Screening Begins in Arizona
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Marijuana for PTSD: Participant Screening Begins in Phoenix, Arizona
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Marijuana for PTSD: Marijuana Received from NIDA at Phoenix Site
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Marijuana for PTSD: NIDA Approves Order of 6.3kg of Marijuana
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Marijuana for PTSD: Investigator Meetings and Initiation Visits Begin
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Marijuana for PTSD: DEA Approves First-Ever Trial of Medical Marijuana for PTSD in Veterans
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Marijuana for PTSD: Phoenix Site Seeks Study Coordinator
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Marijuana for PTSD: Dr. Sue Sisley Speaks to American Legion about Barriers to Research
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Marijuana for PTSD: DEA Inspects Johns Hopkins Trial Site
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Medical Marijuana for PTSD: Protocol Submitted to DEA
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Medical Marijuana for PTSD: Johns Hopkins IRB Approves Protocol Design
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NIDA Provides Marijuana Cost and Availability Information
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Public Health Service Approves Amended Protocol
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Revised Grant Application Approved; Sue Sisley to Receive Researcher of the Year Award
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MAPS Receives $2 Million Grant from Colorado for Study of Medical Marijuana for PTSD

