In summary, we find that approximately one quarter of children experience elevated levels of internalizing symptoms at some point between ages 4 and 11.5. The course of these problems varies, with few (3.2%) experiencing high and sustained symptoms, others experiencing gradually increasing (5.7%) or decreasing (7.0%) symptoms over time, and yet others (9.4%) experiencing a transient increase in symptoms during mid-childhood. Children in any of these trajectories are slightly less likely to use alcohol at age 13.8. Given relatively modest levels of statistical significance and effect sizes that would not necessary meet significance criteria in smaller samplers, we cannot assert that individuals in a particular trajectory are differentially “protected”, nor can we determine whether the observed associations are due to a causal relationship. Symptoms of phobia and separation anxiety appear to drive the observed negative associations, though additional research is warranted as we were unable to assess whether the temporal course of construct-specific problems is relevant. Likewise, future studies on longitudinally assessed, population-based samples should examine how the relationship between internalizing symptoms and alcohol use changes from childhood into adolescence and young adulthood.
