. 2021 Feb 18;26(6):e13015. doi: 10.1111/adb.13015

TABLE 3.

Results for gene‐based analyses between CADM2 and factors from the Principal Components Analyses

Factor	25Up		S4S		NTR		UKB		Meta‐analysis
Factor	p	N	p	N	p	N	p	N	p	N	% R ² top	#SNPs	% R ²
Lifetime substance use ^a	0.581	2076	0.733	2,389					0.723	4,465	0.09%	12	0.58%
Tobacco (ab)use ^b	0.057	2076	0.085	2,389	0.084	9,471	4.34e‐05	348,950	8.45e‐06	362,886	0.13%	44	2.47%
Lifetime smoking ^c							1.01e‐22	348,950			0.02%	80	0.24%
Risky alcohol use^d							5.84e‐13	348,950			0.01%	63	0.10%
Self‐control^e					2.28e‐08	9,471					0.24%	44	2.76%

Note: Factors were extracted if they had an eigenvalue above 1 and explained ≥10% of the variance in the data, resulting in five factors in total, of which two could be detected in multiple cohorts. Below the table, the factor indicators (variables with factor loading >0.4 on the factor) per sample are given. p = MAGMA p‐value (when bold: p < 0.05, when bold and underscored: p < 0.01.); N = sample size per factor and cohort; %R ² top = percentage of variance explained by the top SNP; #SNPs = number of independent SNPs in CADM2 (LD R ² = 0.1%) included in the meta‐analysis; % R ² based on those independent SNPs (SNP IDs are shown in Table S4).

Abbreviations: 25Up, 25 and Up; NTR, Netherlands Twin Register; MAGMA, Multi‐marker Analysis of GenoMic Annotation; S4S, Spit for Science; SNP, single nucleotide polymorphism; UKB, UK Biobank.

^{^a}

Lifetime substance use was defined by ever used cannabis, ever used tobacco and ever used other substances in 25UP and by ever used cannabis and ever used other substances in S4S.

^{^b}

Tobacco (ab)use was defined by nicotine dependence and average cigarettes per day in 25UP, by regular tobacco use, average tobacco using days and ever used tobacco in S4S, by the same variables in NTR, and by nicotine dependence, average cigarettes per day, and age at smoking initiation in UKB.

^{^c}

Lifetime smoking was defined by regular tobacco use and ever used tobacco in UKB.

^{^d}

Risky alcohol use was defined by problematic alcohol use (AUDIT), regular alcohol use, and average alcohol units per month in UKB.

^{^e}

Self‐control was defined by disinhibition, sensation seeking, and ADHD in NTR.