Loss of exercise- and stress-induced increases in circulating 2-arachidonoylglycerol concentrations in adults with chronic PTSD

Abstract

The endocannabinoid (eCB) system is a modulatory system that is both altered by stress and mediates the effects of acute stress, including contributing to restoration of homeostasis. Earlier studies suggest that circulating eCBs are dysregulated in adults with post-traumatic stress disorder (PTSD); however, it is not known whether circulating eCBs remain responsive to stress. The purpose of this study was to examine eCB and psychological responses to physical (exercise) and psychosocial (Trier Social Stress Test) stressors, using a randomized, counterbalanced procedure in adults with PTSD and healthy controls (N = 20, mean age = 24, SD = 7 yrs). Results from mixed-design, repeated measures ANOVAs revealed significant increases (p < .05) in N-arachidonoylethanolamine (AEA) and oleoylethanolamide (OEA) following exercise and psychosocial stress in both groups. However, only the control group exhibited a significant increase (p < .05) in 2-arachidonoylglycerol (2-AG) following exercise and psychosocial stress exposure. These data extend our current understanding of circulating eCB responsiveness in PTSD, and provide preliminary evidence to suggest that the eCB system is hypoactive in PTSD following exposure to physical and psychosocial stressors.