Assessing the diathesis-stress model of adolescent depression in 9- to 14-year-old girls : the combined effect of stressful life events and negative self-schema

While child and adolescent depressive disorders have been historically studied as a downward extension of adult depression, recent research has supported the existence of child and adolescent depression as a distinct disorder and has indicated important developmental differences in symptomatology (Birmaher, Ryan, Williamson, Brent, & Kaufman, 1996; Lewinsohn, Hops, Roberts, Seeley, & Andrews, 1993), as well as greater intensity and endurance of depressive disorders in childhood and adolescence than in adults (Jensen, Ryan, & Prien, 1992). Continued research with adolescence is particularly necessary because such symptomatology can manifest in self destructive or even life threatening behaviors. Symptoms such as depressed mood, irritability, and diminished interest in activities can lead to cognitive, familial, and social problems (Hammen & Rudolph, 1996). There is a particular need to investigate ways to identify individuals at risk for depression, and highlighting interactions between risk factors could make this possible. Childhood and adolescent investigations have under-examined the self-schema and its possible ability to moderate the effect of negative life events on depression. The current study investigated the role of life events as an element that, when combined with distorted and negative cognitions relating to the self, would increase the existence of depressive symptomatology in adolescents. Self-schemas, life events, and interactions of both variables were examined as predictors of the severity of depressive symptomatology in 9- to 14-year old girls in two public school districts in Central Texas. Participants completed a self-report measure of depression, a projective measure of the self-schema, a self-report measure of life events, and a diagnostic interview. As expected, a negative self-schema significantly predicted level of depressive symptomatology. However, the experience of adverse life events did not predict level of depressive symptomatology. Additionally, while analyses demonstrated that adverse life events and negative self-schema together predicted the severity of depressive symptoms to a statistically significant degree, the interaction of the two independent variables did not predict severity of depressive symptoms. Implications of the results, limitations, and recommendations for future research are provided.