Developmental timing of environmental exposures is another important consideration for G–E studies, and evidence suggests that sensitive developmental periods may differ for U.S. racial/ethnic subgroups due to differences in alcohol use over the lifespan. One longitudinal study of a U.S. national sample72 showed an upward trend in heavy drinking by African Americans and, to a lesser extent, Latinos/Hispanics occurring in their 30s. This trend was accompanied by an increase in alcohol problems among African Americans starting in their mid-20s into their late 30s, which eventually exceeded those of Whites and Latinos/Hispanics. Thus, when assessing G–E relationships in groups with later onset of drinking, timing of the environmental exposure assessment should coincide with the periods in which the individuals may be starting to drink or escalating their alcohol use.
