Accordingly, the low and non-significant h2SNP estimates for Problems and Maxdrinks may reflect the presence of other genetic factors, insufficient statistical power, or both (Supplementary Table 4). There are other potential explanations specific to the study and outcomes. First, recall bias is potentially an issue for Maxdrinks since ~50% of drinkers in our sample report having blacked out when drinking. There is also an overall elevation in misuse and associated problems during this age range which may reflect more environmental factors and mask genetic variation. Additionally, reports of alcohol misuse and associated consequences may reflect a certain degree of bravado at this age, when some youth may have less developmental perspective on alcohol problems. It is likely inappropriate to interpret these results as an indication that genetic factors do not impact alcohol Problems and Maxdrinks in this population, particularly given the positive associations between S4S-derived GPS and alcohol outcomes in an independent sample. Indeed, non-significant h2SNP estimates can mask meaningful genetic variation that simply does not account for a substantial component of phenotypic variance. In the current study, the rs671 variant within ALDH2, which is common in East Asian populations and is known to impact risk for AUD (Edenberg, 2007),
