We hypothesized that a shared internalizing disorder factor should be strongly related to neuroticism. To test this hypothesis, our study assessed neuroticism with self- and peer-report measures, and assessed mood and anxiety disorders using a semi-structured interview. We used an adolescent sample because adolescence is a developmental period characterized by important changes (Steinberg & Morris, 2001), and because adolescence is a period of increased risk for mood and anxiety disorders. Indeed many mental disorders begin during this time (e.g., Kessler, Berglund et al., 2005).
