In light of this heterogeneity, it is especially notable that the Problems PGSs consistently predicted a steeper slope of consumption frequency across cohorts – the only significant effect in the LGC meta-analysis. This is indicative of a robust biological process driving acceleration of alcohol consumption, and one that may be specific to the peak in emerging adulthood since the same effect was not observed in the older FTC sample. This difference may, however, be a reflection of the lower heritability of AUBs found in older cohorts (18), likely due to secular changes in social constraints on the expression of genetic predispositions. While the genes captured by this latent factor include some in common with other AUBs, such as the well-known alcohol metabolism genes (6), it is only moderately correlated with Consumption, BeerPref, or EXT (26). Further investigation of the genetic influences specific to Problems may therefore be helpful to illuminate the causal processes underlying young adult acceleration of alcohol consumption and their links to later alcohol problems.
