Misaki N. Natsuaki

An accumulating body of literature has shown a link between early pubertal maturation and internalizing problems, particularly among girls. Our knowledge is, however, limited with regard to what accounts for this association. Based on a hypothesis that early maturing girls have heightened stress sensitivity that increases the risk of internalizing problems, the present investigation examined the roles of pubertal timing and salivary cortisol reactivity to interpersonal stressors in adolescents' internalizing problems. Results from 110 boys and 106 girls (ages 11–16) indicated that early maturing adolescents had increased internalizing symptoms. Early maturing girls' higher levels of internalizing problems were at least partially attributed to their heightened sensitivity to interpersonal stress. Finally, girls' cortisol reactivity to interpersonal challenge was more strongly associated with internalizing problems than boys' reactivity.

The effects of pubertal timing and adolescent dating on trajectories of depressed mood from early adolescence to young adulthood were examined among youths who participated in the National Longitudinal Study of Adolescent Health. Results showed that for both boys and girls, the trajectories of depressed mood between the ages of 12 and 23 took an inverse U‐shape with its peak in mid‐adolescence. Furthermore, pubertal timing was a significant predictor of depressed mood at age 12. The pubertal timing effect was nonlinear, suggesting that at age 12, early and late maturing youths were at risk of experiencing elevated levels of depressed mood. The adverse effect of off‐time maturation gradually dissipated over time. Moreover, in early adolescence, teenagers, particularly girls, were adversely affected by dating, and off‐time physical maturation exacerbated the negative effects of dating. However, the interactive effect of dating and pubertal timing gradually decreased with age. Our findings underscore the importance of examining junctures of biological and social challenges in adolescence to gain better understandings of young people's emotional experiences over time.

This study investigated the prospective links between sibling aggression and the development of externalizing problems using a multilevel modeling approach with a genetically sensitive design. The sample consisted of 780 adolescents (390 sibling pairs) who participated in 2 waves of the Nonshared Environment in Adolescent Development project. Sibling pairs with varying degree of genetic relatedness, including monozygotic twins, dizygotic twins, full siblings, half siblings, and genetically unrelated siblings, were included. The results showed that sibling aggression at Time 1 was significantly associated with the focal child's externalizing problems at Time 2 after accounting for the intraclass correlations between siblings. Sibling aggression remained significant in predicting subsequent externalizing problems even after controlling for the levels of preexisting externalizing problems and mothers' punitive parenting. This pattern of results was fairly robust across models with different informants. The findings provide converging evidence for the unique contribution of sibling aggression in understanding changes in externalizing problems during adolescence.

The prospective effects of observed neighborhood disorder, stressful life events, and parents' engagement in inductive reasoning on adolescents' depressive symptoms were examined using data collected from 777 African American families. Multilevel analyses revealed that stressful life events experienced at age 11 predicted depressive symptoms at age 13. Furthermore, a significant interaction between neighborhood disorder and parents' engagement in inductive reasoning was found, indicating that parental use of inductive reasoning was a protective factor for depressive symptoms particularly for youths living in highly disordered neighborhoods. The importance of examining correlates of depressive symptoms from a contextual framework, focusing on individuals, families, and neighborhood contexts, is emphasized.