When we compared the results from the univariate ALCP-total GWAS to those from the multivariate model (EXT and ALCP-specific), we found robust evidence of distinct risk pathways. We compared the genetic correlations for ALCP-total and ALCP-specific across 99 preregistered phenotypes, focusing here on phenotypes related to personality, substance use, and psychopathology. ALCP-total was correlated with a broad range of personality phenotypes, especially those related to impulsivity. However, after removing the variance due to the shared risk for EXT, most of these associations were no longer significant. Similarly, ALCP-total was genetically correlated with multiple forms of other substance use phenotypes, while ALCP-specific remained correlated only with alcohol consumption and age of smoking initiation, and this latter correlation switched direction. The change in direction could reflect the fact that ALCP-specific captures (1) risk for problematic alcohol use once alcohol becomes available, or (2) risk for other psychiatric problems around their median age of onset, both of which occur during young adulthood [31], forcing the correlation with age of smoking initiation to be positive. It is also possible that this change in direction
