We have previously observed hyperarousal and anxiety, as well as fear generalization and resistance to extinction in mice deficient for the GABA synthesizing enzyme glutamic acid decarboxylase (GAD)65 (Stork et al., 2000a; Bergado-Acosta et al., 2008; Sangha et al., 2009), suggesting that GABA synthesis is a critical factor for several PTSD-related phenomena. This evidence concerns the gene GAD2 and Anxiety.