Finally, we observed evidence for association with TSNAX-DISC1, a finding that at p = 1.46 × 10−7 is less compelling statistically than the others described here but which gains interest in the context of our previous observations of association of common (2) and rare (31) variants at this locus with opioid dependence. We also previously observed an association of an SNP near CCDC88A, a protein that interacts with DISC1, with alcohol dependence (3). The DISC1 protein product plays a role in cognitive function (32) and several psychiatric traits and is emerging as an important contributor to SD risk.
