Chunk #9 — Basic methodology of genetic epidemiology: an overview of twin studies — Principle 1: Genetic influences change in importance across adolescence
This shift in the importance of genetic influences on alcohol use outcomes has also been demonstrated with specific genes across multiple independent studies conducted by different research group. The GABRA2 receptor gene, ALDH2, and multiple monoamine genes were found to be associated with alcohol use outcomes in young adulthood, but not earlier in development (Dick et al., 2006b; Guo et al., 2007; Irons et al., 2012). Interestingly, genes associated with alcohol use outcomes in adulthood appear to be associated with behavior problems earlier in adolescence (Dick et al., 2006b), which brings us to Principle 2.
