Two SNPs (rs6424532 [LOC105378800], and rs2402273 [LSM8/CTTNBP2]) had a marginally significant indirect effect on broad depression through log of pack-years among males (p = 4.0 × 10−3 and p = 4.1 × 10−3, respectively). Here, CTTNBP2 is linked to major depressive disorder.