Co-Development of Internalizing Problem Behaviors in Adolescence: Genetic and Temperamental Origins.

Adolescence, that is, the period of life between 12 and 22 years of age, is a crucial phase for the development of internalizing problems. However, the development of these problems and the developmental interplay among them are not entirely clear. The present project studies three types of internalizing problems (i.e., loneliness, depressive mood, and social anxiety) and uses a comprehensive model of temperament and its associated neurobiology as overarching theoretical framework. Two research objectives can be distinguished. First, both temperamental and genetic factors are used to predict changes over time for each type of internalizing problem. Second, the developmental interplay among the three problem behaviors and moderation of this interplay by the same temperamental and genetic factors will be analyzed. The project will use data from three large longitudinal studies, both ongoing and just completed, on community samples of adolescents (Ns = 1116, 1388, and 1555), and will extend the first of these studies, for which extensive genetic information is available, with three additional data waves and improved measures of temperament. Advanced statistical techniques uniquely suited to predict intra-individual change (i.e., latent growth curve modeling and latent class growth analysis) and to study moderators of the developmental interplay between different behaviors (i.e., cross-lagged analysis with multiple groups) will be used to analyze the data.