Methods
Administered PTSD
RECRUITMENT
This trial was registered on ClinicalTrials.gov (NCT02517424) and approved by the Clinical Research Ethics Board at the University of British Columbia (H16-01026). Participants provided written informed consent prior to participating. The study was designed as a randomized blinded placebo-controlled cross-over study with three conditions: placebo cannabis (< 1% THC and < 1% CBD), cannabis with 10 + / − 2% THC and 10 + / − 2% CBD, and cannabis with 10 + / − 2% THC and < 1% CBD. These chemovars were selected to allow for a proposed comparison between a psychoactively inert product and cannabis products that varied in CBD but were equivalent in THC. The cross-over design was selected in an attempt to efficiently allow comparisons of all three groups while providing access to one of the two active study drug conditions for all participants. Participants were provided a portable cannabis vaporizer and two grams of cannabis per day for three weeks of ad lib use. Target recruitment was for 42 participants. Thirty-two individuals were assessed for eligibility; 24 did not meet inclusion criteria and two declined to participate. Failure to meet our recruitment target resulted in the study terminating with only six participants (age range 35–65; 1 female) enrolled of whom five completed the entire protocol. Due to low power, we revised our analysis to aggregate active conditions and test within-subject change from baseline to the end of active treatment. The primary outcome was a change in scores on the Clinician Administered PTSD Scale (CAPS-5) [Consort flow design. Note: Stages 1 and 2 include 2 weeks of washout/cessation followed by 3 weeks of ad lib cannabis use