Glutamic acid decarboxylase (GAD) is the major enzyme responsible for the synthesis of the neurotransmitter γ-aminobutyric acid (Fenalti et al. 2007) and dysregulation of GAD function has been implicated in neuropsychiatric disorders, such as schizophrenia (Akbarian and Huang 2006). This evidence concerns the gene GAD1 and schizophrenia.