The objective of the proposed translational study is to test a model, based upon basic science studies, exploring multisystem impairments in PTSD including endocannabinoid (eCB) and glucocorticoids in the modulation of fear memories by examining the cannabinoid type 1 (CB1) receptor in a PTSD fear circuit as well as glucocorticoid function. The investigators propose that impaired eCB signaling in PTSD resulting in the maladaptive neurobehavioral response to the stressor is associated with an upregulation of the CB1 receptors and insufficient glucocorticoid signaling.