The longitudinal relation between personality disorder symptoms and depression in adolescence: the mediating role of interpersonal stress.

The relation between personality disorder (PD) symptoms, depression, and interpersonal stress were examined over 6 months in a sample of 143 adolescents from a low-income urban high school. Both self report questionnaires in the full sample and structured interviews in a subset of 54 girls indicated the following: PD symptoms predicted greater depressive symptoms and interpersonal stress over time; PD symptoms were highly stable; depressive symptoms did not predict change in PD symptoms over time. Moreover, an integrative model was supported, wherein the route by which PD symptoms led to greater depression was via the generation of interpersonal stress. These results suggest that adolescents' PD symptoms play a destructive role in the construction of interpersonal circumstances during a key period for depression onset.