In analyses similar to our analyses of candidate SNPs, we evaluated three sets of candidate genes: 18 that have been implicated in P3 amplitude or related measures (P3-specific candidate genes, see first column of Table S4 for a list); 204 genes that are likely relevant to understanding the endophenotypes examined in this special issue because they are part of the major neurotransmitter and neuromodulator systems (dopamine, noradrenaline, acetylcholine, GABA, glutamate, and serotonin), they are part of the endogenous cannabinoid and opioid systems, or they are involved in metabolizing nicotine and alcohol (endophenotype-general candidate genes, see first column of Table S5); and 92 genes identified by the Consortium on the Genetics of Schizophrenia as related to similar endophenotypes (COGS candidate genes, see first column of Table S6). Bonferroni correction was used to determine the significance of genes in each set, with thresholds of 2.78 × 10−3, 2.45 × 10−5, and 5.43 × 10−4 for the three sets, respectively.
