Rumination and impaired cortisol recovery following a social stressor in adolescent depression.

Response styles theory promotes rumination as a central cognitive construct driving negative mood and depression, and past research suggests that at least part of the mechanism driving rumination's depressogenic effect is through inhibiting the individual's ability to shift attentional focus away from negative environmental stimuli. In the current study, we hypothesized that high trait rumination would be associated with impaired recovery of the body's biological response to psychological stress. In a community sample of depressed (n = 31) and non-depressed (n = 33) adolescents we assessed rumination and the more adaptive trait of distraction and problem-solving with the Children's Response Styles Questionnaire (CRSQ; Abela 2000), and diagnostic status was confirmed using the Child and Adolescent Schedule of Affective Disorders and Schizophrenia (K-SADS; Kaufman et al. Journal of the American Academy of Child and Adolescent Psychiatry 36:980-988, 1997). Participants completed the Trier Social Stress Test (TSST; Kirschbaum et al. Neuropsychobiology 28:76-81, 1993), and the focus of our analyses was the change in salivary cortisol concentration between peak cortisol output (25 min post-stressor) and a sample taken during the "Recovery" period 65 minutes post-stressor. Consistent with the predictions of response style theory, among the depressed adolescents only, high trait rumination was associated with delayed post-stressor cortisol recovery, whereas high trait distraction and problem-solving was associated with more rapid recovery. In contrast, response styles were not associated with cortisol recovery in the non-depressed group. These findings implicate impaired post-stress cortisol recovery as a potential mechanism underlying the pathological effect of rumination on the development and maintenance of Major Depressive Disorder (MDD).