ADHD identified a genomic region containing CDH13 (16q21–16q24) [66]. Based on these results, a candidate gene study of CDH13 and ADHD was performed that found a gene-wide significant association at one SNP (rs11150556) [67]. In addition, CDH13 has also been implicated by GWAS in depression (rs10514585) [68], extraversion (rs4783307, rs8056579) [69], agreeableness (rs9940706) [69] and response to antipsychotic therapy (rs17216786) [70], as well as in a meta-analysis for extraversion (rs8057458) [71]. Variants in CDH13 have also been significantly associated with adiponectin levels in two GWAS [72], [73]. None of the SNPs implicated by the above studies were strongly associated with our factors, nor were any of the above-mentioned SNPs in strong LD with rs3784943. Thus, while this gene has attracted significant attention, particularly in the psychiatric genetics literature, these studies have not converged on a single genetic regulator or putative mechanism of regulation for this gene for possibly corresponding phenotypic effects. Intriguingly, it has recently been reported that CDH13 knockout mice show decreases in conditioned place preference to cocaine (J. Drgonova, SFN abstract #871.11/D64), which is highly consistent with a difference in the subjective response to amphetamine that we observed.
