Cannabidiol in the Treatment of Post-Traumatic Stress Disorder: A Case Series

Objectives: Cannabidiol (CBD) is a non-psychotomimetic cannabinoid compound that is found in plants of the genus Cannabis. Preclinical research has suggested that CBD may have a beneficial effect in rodent models of post-traumatic stress disorder (PTSD). This effect is believed to be due to the action of CBD on the endocannabinoid system. CBD has seen a recent surge in research regarding its potential value in a number of neuro-psychiatric conditions. This is the first study to date examining the clinical benefit of CBD for patients with PTSD.

Methods: This retrospective case series examines the effect of oral CBD administration on symptoms of PTSD in a series of 11 adult patients at an outpatient psychiatry clinic. CBD was given on an open-label, flexible dosing regimen to patients diagnosed with PTSD by a mental health professional. Patients also received routine psychiatric care, including concurrent treatment with psychiatric medications and psychotherapy. The length of the study was 8 weeks. PTSD symptom severity was assessed every 4 weeks by patient-completed PTSD Checklist for the DSM-5 (PCL-5) questionnaires.

Results: From the total sample of 11 patients, 91% (n = 10) experienced a decrease in PTSD symptom severity, as evidenced by a lower PCL-5 score at 8 weeks than at their initial baseline. The mean total PCL-5 score decreased 28%, from a mean baseline score of 51.82 down to 37.14, after eight consecutive weeks of treatment with CBD. CBD was generally well tolerated, and no patients discontinued treatment due to side effects.

Conclusions: Administration of oral CBD in addition to routine psychiatric care was associated with PTSD symptom reduction in adults with PTSD. CBD also appeared to offer relief in a subset of patients who reported frequent nightmares as a symptom of their PTSD. Additional clinical investigation, including double-blind, placebo-controlled trials, would be necessary to further substantiate the response to CBD that was observed in this study.

Pollen dispersal in Yucca filamentosa (Agavaceae): the paradox of self-pollination behavior by Tegeticula yuccasella (Prodoxidae)

We investigated pollen dispersal in an obligate pollination mutualism between Yucca filamentosa and Tegeticula yuccasella. Yucca moths are the only documented pollinator of yuccas, and moth larvae feed solely on developing yucca seeds. The quality of pollination by a female moth affects larval survival because flowers receiving small amounts of pollen or self-pollen have a high abscission probability, and larvae die in abscised flowers. We tested the prediction that yucca moths primarily perform outcross pollinations by using fluorescent dye to track pollen dispersal in five populations of Y. filamentosa. Dye transfers within plants were common in all populations (mean ± 1 SE, 55 ± 3.0%), indicating that moths frequently deposit self-pollen. Distance of dye transfers ranged from 0 to 50 m, and the mean number of flowering plants between the pollen donor and recipient was 5 (median = 0), suggesting that most pollen was transferred among near neighbors. A multilocus genetic estimate of outcrossing based on seedlings matured from open-pollinated fruits at one site was 94 ± 6% (mean ± 1 SD). We discuss why moths frequently deposit self-pollen to the detriment of their offspring and compare the yucca-yucca moth interaction with other obligate pollinator mutualisms in which neither pollinator nor plant benefit from self-pollination.