Gene-environment interaction in teacher-rated internalizing and externalizing problem behavior in 7- to 12-year-old twins.

Background: Internalizing and externalizing problem behavior at school can have major consequences for a child and is predictive for disorders later in life. Teacher ratings are important to assess internalizing and externalizing problems at school. Genetic epidemiological studies on teacher-rated problem behavior are relatively scarce and the reported heritability estimates differ widely.

Heritability of anxious-depressive and withdrawn behavior: age-related changes during adolescence.

Objective: To explain the differential course of anxiety and depression in individuals from childhood to adulthood by examining age-related changes in the genetic and environmental etiology of anxious and depressive symptoms.

Method: A sample of 1470, 1839, and 2023 Dutch twins aged 12, 14, and 16 years reported on symptoms of anxious depression (AD) and withdrawn behavior (WB), using the Youth Self Report (YSR). AD and WB were analyzed with bivariate cross-sectional genetic models for each age group to obtain estimates of the relative influence of genes (A), shared (C), and nonshared (E) environment.

Genetic and environmental contributions to self-report obsessive-compulsive symptoms in Dutch adolescents at ages 12, 14, and 16.

Objective: To determine the contributions of genetic and environmental influences to variation in self-report of obsessive-compulsive (OC) symptoms in a population-based twin sample of adolescent boys and girls.

Method: Self-report ratings on the eight-item Youth Self-Report Obsessive-Compulsive Scale were collected in Dutch mono- and dizygotic twin pairs who participated at age 12 (N = 746 twin pairs), 14 (N = 963 pairs), or 16 years (N = 1,070 pairs). Structural equation modeling was used to break down the variation in liability to OC symptoms into genetic and environmental components.