Symptoms of problematic alcohol use differ in their genetic associations with comorbid internalizing, externalizing, and neurodevelopmental psychiatric disorders

Background and AimsCertain symptoms of problematic alcohol use (PAU) show associations with comorbid internalizing and externalizing disorders even after controlling for their common PAU factor. Outsized associations between PAU indicators and comorbid psychopathology may reflect distinct etiologic pathways or measurement characteristics that, if unaccounted for, could bias comorbidity estimates with PAU. Although these issues could represent a source of bias in estimates of genetic correlation with PAU, no studies have yet extended this work using genomic data. DesignGenomic structural equation modeling and the Qtrait function identified PAU indicators that showed appreciable residual genetic correlations with eleven comorbid psychiatric disorders and whose associations did not operate strictly through the latent PAU factor. SettingGenome-wide association studies (GWAS) were conducted in a variety of international locations. ParticipantsGWAS used in this study were conducted on 86,979 to 425,166 individuals of European ancestry. MeasurementsThe primary measurements were GWAS summary statistics for various forms of internalizing, externalizing, and neurodevelopmental psychiatric disorders and nine indicators from the Alcohol Use Disorder Identification Test. FindingsPAU indicators assessing alcohol-related consequences (i.e., Injuries, Failed expectations, Guilt/Remorse) each showed appreciable and positive residual genetic associations with multiple comorbid psychiatric conditions spanning various disorder spectra. Alcohol Quantity, 6+ Frequency, Blackouts, and Others concerned did not show direct genetic relationships with comorbid disorders. ConclusionsAlcohol-related consequences share unique genetic underpinnings with multiple psychiatric conditions apart from what is shared with their latent problematic alcohol use factor. Thus, alcohol-related consequences may unduly reflect dysfunction from comorbid psychiatric conditions or related third variables.