A clinical diagnosis of AUD is often required to define cases for genetic studies. An alternative strategy would be to use AUDIT to infer AUD case status; however, it has not been clear whether and how to perform meta-analyses between AUDIT scores and alcohol dependence. A GWAS meta-analysis for AUDIT and alcohol dependence could be simplified if a threshold could be used to define cases and controls based on AUDIT scores, an approach that was used by Mbarek et al. (50). We have provided empirical evidence about genetic correlations between AUDIT and alcohol dependence using dichotomized AUDIT scores, and found thresholds for AUDIT that produced high genetic correlations with AUD (Figure 3). Genetic correlations increased as the upper threshold for cases was made more stringent, although the standard errors for all of these estimates were overlapping. The genetic correlation with alcohol dependence appeared to asymptote when case status was defined as ≥12; therefore, this threshold could be used to define case status. We also considered various thresholds for defining controls and found that ≤4 produced a high genetic correlation with alcohol dependence while also retaining the largest number of subjects.
