COMT and schizophrenia: While most of the research on COMT genotypes and schizophrenia has been focused on the impairments associated with the Val variant, emerging lines of evidence have also pointed to the possibility that the Met-variant may predispose schizophrenia patients to aggression and violence (Strous et al., 1997; Lachman et al., 1998; Nolan et al., 2000; Liou et al., 2001; Han et al., 2004, 2006; Kim et al., 2008; Tosato et al., 2011; Bhakta et al., 2012; Singh et al., 2012).