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. 2021 Oct 6;2(4):389–399. doi: 10.1016/j.bpsgos.2021.09.007

Table 2.

Results of the Two-Sample Bidirectional Mendelian Randomization Analyses Between DB and Smoking and Alcohol Use Behavior

Exposure Outcome SNPs, n F IVW
 Weighted Median
 Weighted Mode
 MR-Egger (SIMEX)
 GSMR
β 95% CI p β 95% CI p β 95% CI p β 95% CI p SNPs, n β 95% CI p
DB Smoking initiation 40 37.41 0.39 0.24 to 0.54 2.0 × 10−7 0.25 0.13 to 0.37 3.2 × 10−5 0.15 −0.06 to 0.36 .180 0.43 0.09 to 0.77 .017 33 0.342 0.27 to 0.41 1.7 × 10−20
DB Cigarettes/day 38 37.61 0.14 0.01 to 0.27 .029 −0.01 −0.12 to 0.10 .895 −0.06 −0.16 to 0.04 .284 −0.31 −0.60 to −0.02 .041 34 0.178 0.09 to 0.26 3.3 × 10−5
DB Smoking cessation 40 37.33 −0.20 −0.33 to −0.07 .002 −0.11 −0.25 to 0.03 .118 0.02 −0.24 to 0.28 .873 0.17 −0.11 to 0.45 .254 37 −0.190 −0.29 to −0.09 9.9 × 10−5
DB Alcohol/week 40 37.41 −0.01 −0.04 to 0.02 .472 −0.002 −0.03 to 0.03 .897 0.01 −0.02 to 0.04 .545 −0.04 −0.11 to 0.03 .341 35 −0.020 −0.04 to 0.00 .043
DB Alcohol use disorder 46 37.00 0.26 0.08 to 0.44 .004 0.16 −0.10 to 0.42 .245 0.14 −0.12 to 0.40 .288 n.a. n.a. n.a. 43 0.310 0.10 to 0.52 .003
Smoking Initiation DB 317 27.53 0.17 0.14 to 0.20 9.9 × 10−31 0.15 0.12 to 0.18 8.0 × 10−21 0.15 0.05 to 0.25 .004 n.a. n.a. n.a. 296 0.186 0.17 to 0.21 6.4 × 10−72
Alcohol/week DB 80 28.61 0.04 −0.13 to 0.21 .632 0.052 −0.12 to 0.22 .543 −0.17 −2.07 to 1.73 .859 −0.24 −0.54 to 0.06 .133 74 0.0719 −0.05 to 0.20 .261
Alcohol Dis. 5 × 10−8 DB 7 26.35 −0.02 −0.06 to 0.02 .299 −0.02 −0.06 to 0.02 .480 −0.01 −0.08 to 0.06 .833 n.a. n.a. n.a. 7 0.00016 −0.04 to 0.04 .993
Alcohol Dis. 1 × 10−5 DB 25 21.94 −0.01 −0.03 to 0.01 .328 −0.01 −0.03 to 0.01 .654 −0.01 −0.06 to 0.04 .652 n.a. n.a. n.a. 24 −0.0078 −0.02 to 0.01 .365

n.a. indicates that MR-Egger results were not reported because of limited reliability based on the I2 measure being <0.60. F > 10 generally indicates the instrument is sufficiently strong.

DB, disruptive behavior; Dis., disorder; F, F-statistic indicating instrument strength; GSMR, generalized summary data–based Mendelian randomization; IVW, inverse variance weighted regression; SIMEX, simulation extrapolation; SNP, single nucleotide polymorphism.