Endocannabinoid Responses Following an Aerobic Exercise Session in Individuals with and without Post-Traumatic Stress Disorder

Abstract

Recent therapeutic interventions have targeted the endocannabinoid (eCB) system in an effort to improve symptoms of Post-Traumatic Stress Disorder (PTSD). Exercise may be one such treatment approach, as exercise has been shown to increase circulating concentrations of endocannabinoids (anandamide, AEA; 2-arachidonylglycerol, 2AG) and related biogenic lipids (oleoylethanolamine, OEA; palmitoylethanolamine; PEA) in healthy individuals. However, the eCB responses to exercise in individuals with PTSD have not been investigated. PURPOSE: The purpose of this study was to examine eCB responses following aerobic exercise in individuals with and without PTSD. METHODS: Twenty-four (12 PTSD and 12 control) men and women (26± 6 yrs) participated in this study. Participants engaged in an aerobic exercise session in which they walked or ran on a treadmill for 30 minutes at a moderate-intensity (70-75% MHR; 12–15 RPE). Blood draws were performed before and after exercise in order to quantify circulating concentrations of eCBs. Data were analyzed using 2 (group: PTSD, control) x 2 (time: pre-, post-exercise) repeated measures ANOVAs and Cohen’s d effect size calculations. RESULTS: There were no significant (p > 0.05) differences between groups in RPE, HR, treadmill speed or incline throughout the exercise session. AEA, 2-AG, and OEA were found to increase significantly (p < 0.05) in both groups following exercise, while PEA did not change (p > 0.05) following exercise. Effect size calculations indicated the healthy controls vs. adults with PTSD experienced a greater magnitude of change for AEA (controls = 1.21; PTSD = 0.45), 2-AG (controls = 0.43; PTSD = 0.21) and OEA (controls = 0.70; PTSD = 0.46). CONCLUSION: These findings suggest that the eCB system is activated in adults with PTSD following moderate-intensity aerobic exercise. However, further research examining the eCB system is warranted as the magnitude of change for eCBs and related biogenic lipids was greater among healthy controls compared to individuals with PTSD. Supported by the UW Virginia Horne Henry Fund and the Advancing a Healthier Wisconsin Endowment at the Medical College of Wisconsin