CNR1 and post-traumatic stress disorder: The authors indicated that research to date suggests a good correlation of lower serum AEA levels to increased CB1 receptor binding sites in CNS, as was demonstrated in a PET study of untreated PTSD patients.84 The CB1-selective radioligand [11C]OMAR on PET revealed higher volume of distribution (VT) with lower AEA tone in PTSD (p=0.001) by 19.5% over healthy controls and 14.5% over traumatized patients without PTSD.