In addition to the serotonin transporter, there is evidence from candidate gene studies that polymorphisms that encode serotonin receptors also are related to neuroticism. This comes from studies of both humans (including genomic imaging studies) and genetically modified mice and includes the 5-HT1A and 5-HTR2A receptors (Golimbet et al., 2002; Lesch & Canli, 2006). Similarly, the G72 gene, which influences glutamate receptor function, has been found in multiple samples to be associated with neuroticism (Rietschel et al., in press). Molecular studies of other promising candidate genes that may be associated with neuroticism have yielded less consistent findings to date (Hettema, An et al., 2006; Lang et al., 2005; Sen et al., 2003; Willis-Owen et al., 2005).
