For the DSM-IV dependence diagnosis, findings were not replicated in Yale-Penn EA participants (Supplemental Table S4); effect sizes were consistently in the same direction, but smaller (e.g. rs1409568: β = −0.072, p=0.6). Consistent with our finding, the T allele of rs1409568 was associated with a reduced likelihood of cannabis dependence among the AA participants from Yale-Penn (β = −0.18, p = 0.028). When results from all datasets, discovery and replication (EA and AA), were meta-analyzed together (Ncase=3,757, Ncontrol=9,931), rs1409568 remained associated with DSM-IV cannabis dependence at a trend level (β = −0.28; p = 2.9E-7). In addition, there was no evidence from our meta-analysis for association between cannabis dependence diagnosis or symptom counts with previously identified loci for cannabis use (i.e., top 10 signals from Stringer et al(13)) and top EA locus from Sherva et al (8) – Supplemental Table S5).
