Table 2.

Univariate SNP heritability (h²_SNP) and standard errors (s.e.)

Phenotype	Population prevalence*	Current Study		Kendler Study**
		h2SNP	s.e.	Twin heritability
Alcohol Dependence Diagnosis	0.08	0.300a	0.136	N/A
DSM-IV Alcohol Dependence Symptoms
Tolerance	0.08	0.242a	0.129	0.440
Withdrawal	0.08	0.281	0.174	0.490
Using longer than intended	0.13	0.324a	0.158	0.380
Unsuccessful attempts to cut down	0.12	0.197	0.146	0.360
Great time spent using/recovering	0.02	0.072	0.104	0.590
Social/Occupation activities foregone	0.01	0.199a	0.091	0.530
Continued use despite problems	0.05	0.237a	0.109	0.450

Table describes proportion of phenotypic variance explained by all autosomal SNPs (h²_SNP) while controlling for all covariates.

Notations - ^a = p-value < 0.05.

^*- Disease prevalence obtained from NESARC (Saha et al., 2006) was used to transform the estimate of the variance explained on the observed scale to that of the underlying scale.

^**- Heritability estimates derived from Kendler et al. 2012. N/A – Not applicable.