Moreover, since schizophrenia and other psychiatric disorders may have shared genetic etiology (Berrettini, 2000; Bramon and Sham, 2001; Cardno et al., 2002; Craddock et al., 2009; Huang et al., 2010; Cross-Disorder Group of the Psychiatric Genomics Consortium Lee et al., 2013), several studies have also investigated the association between NRG1 rs6994992 and other psychiatric disorders such as bipolar disorder (e.g., Green et al., 2005; Cassidy et al., 2006; Thomson et al., 2007; Georgieva et al., 2008; Goes et al., 2009). This evidence concerns the gene NRG1 and schizophrenia.