The results for association of MANEA with CD were substantially weaker in the discovery (family-based) data sets. However, these samples were ascertained through sibling pairs with CD or opioid dependence. They are, thus, much less informative for association analyses of these traits compared with those with CIP, because, in the absence of data from parents, the family-based approach requires at least 1 discordant sibling pair. To determine whether the association with MANEA is specific to the paranoia that often complicates CD, we compared MANEA SNPs and haplotypes in controls with distinct samples of subjects with CD (but no paranoia) and subjects with CIP. In the AA group, CD and CIP were significantly and comparably associated with several SNPs. Both traits showed identical patterns of association with a particular haplotype in the EA group. Thus, our study suggests that MANEA is associated with both CD and paranoia. It is also possible that MANEA is more strongly associated with CIP than CD because CIP is characteristic of a genetic subgroup of CD that is influenced by MANEA. Additional studies in independent samples
