Differences in Genetic Correlations between Posttraumatic Stress Disorder and Alcohol Use Disorder-Related Phenotypes Compared to Alcohol Consumption-Related Phenotypes

Abstract

BackgroundPosttraumatic Stress Disorder (PTSD) tends to co-occur with greater alcohol consumption as well as alcohol use disorder (AUD). However, it is unknown whether the same etiologic factors that underlie PTSD-AUD comorbidity also contribute to PTSD-alcohol consumption.MethodsWe used summary statistics from large-scale genome-wide association studies (GWAS) of European-ancestry (EA) and African-ancestry (AA) participants to estimate genetic correlations between PTSD (both the diagnosis and re-experiencing symptoms) and a range of alcohol consumption-related and AUD-related phenotypes (e.g., drinks per week, max drinks, consumption, AUD).ResultsIn EAs, there were positive genetic correlations between PTSD phenotypes and AUD-related phenotypes (i.e., Alcohol Use Disorders Identification Test (AUDIT) problem score, maximum alcohol intake, AUD, and alcohol dependence) (rGs: .132-.533, all FDR adjusted p<.05). However, the genetic correlations between PTSD phenotypes and alcohol consumption -related phenotypes (i.e., drinks per week, AUDIT consumption score, AUDIT total score, and a combination of consumption and problems) were negatively associated or non-significant (rGs: -.417- -.042, FDR adjusted p: <.05-NS). For AAs, the direction of correlations was sometimes consistent and sometimes inconsistent with that in EAs, and the ranges were larger (rGs for AUD--related: -.275 -.266, FDR adjusted p: NS, alcohol consumption-related: .145-.699, FDR adjusted p: NS).ConclusionsThese findings illustrate that the genetic associations between consumption and problem alcohol phenotypes and PTSD differ in both strength and direction. Thus, the genetic factors that may lead someone to develop PTSD and consume large quantities of alcohol are not the same as those that lead someone to develop PTSD-AUD.