Understanding trajectories of externalizing problems: Stability and emergence of risk factors from infancy to middle adolescence.

Despite considerable efforts to understand the processes that underlie the development of externalizing behavior problems, it is still unclear why externalizing problems remain chronically high for some children, emerge early and cease by late childhood for others, and arise in adolescence in some cases. The purpose of this study was to examine how a wide range of child and family risk factors are linked to trajectories of externalizing behavior and how these relationships vary from infancy to middle adolescence. We used data from the community-based Norwegian Tracking Opportunities and Problems (TOPP) study sample (n = 921). A Cholesky factorization model was specified to separate stable and emerging risk doses across four developmental periods (infancy, early and middle childhood, and middle adolescence). Children in the High Stable class were characterized by substantially elevated risk levels in multiple domains throughout the study period. Children in the High Childhood Limited class had very high levels of temperamental emotionality, internalizing symptoms, and maternal mental distress, suggesting a substantial intrinsic emotional basis for their externalizing problems. Intrinsic factors seemed less salient for the Adolescent Onset class. These findings emphasize the need for a dynamic perspective on risk factors and support the importance of prevention and intervention efforts across multiple domains from early childhood and throughout adolescence.