Interestingly, in addition to generating PGs, COX-2 also metabolizes endogenous cannabinoids (eCBs; anandamide and 2-arachidonoylglycerol) (Kozak et al., 2000; 2001), and several eCB augmentation strategies, including inhibition of fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL), have been found to attenuate anxiety- and depression-related behaviors (Fu et al., 2003; Griebel and Holmes, 2013; Gunduz-Cinar et al., 2013; Hill et al., 2009; Ruehle et al., 2012). This evidence concerns the gene PTGS2 and major depressive disorder.