The Effects of Full Spectrum Hemp Oil on Extinction of Stress-Enhanced Fear Learning: A Rat Model of PTSD

Despite overwhelming evidence for more effective treatments, there are only 2 FDA-approved drugs for Post-Traumatic Stress Disorder (PTSD). Indeed, roughly 50% of PTSD patients experience relief from conventional pharmaceuticals and only one third experience full remission. The Cannabis plant is a promising novel treatment for PTSD as the endocannabinoid system plays a role in stress, emotion, cognition and fear memory consolidation, retrieval, reconsolidation and extinction. Cannabidiol (CBD), one of the most studied phytocannabinoids in the Cannabis plant, has anxiolytic effects, however, the effects of full spectrum hemp oil that contains all of the active compounds from the cannabis plant with less than 0.3% THC has not been studied. Therefore, the present study examined the effects of full spectrum hemp oil on fear extinction following stress-enhanced fear learning (SEFL), a rodent model of PTSD. Adult male rats were assigned to either a no-trauma control (no-shock) or a trauma (15 shocks) group, and to either a control (peanut butter) or hemp oil (dissolved in peanut butter) group and tested for fear expression across five extinction trials. Compared to the no-trauma group, SEFL produced robust freezing in the trauma group in the original context, in a novel context following a single shock and during the first four extinction trials. However, within the trauma group there were no significant differences in freezing between the hemp oil and vehicle treated rats across the 5 extinction trials. These results suggest that full spectrum hemp oil did not significantly affect extinction of SEFL.