Depressive symptom composites associated with cortisol stress reactivity in adolescents

Background: Altered hypothalamic-pituitary-adrenal (HPA) function is common in youth with major depressive disorder (MDD) but variability in the strength and direction of HPA alterations has prompted a search for symptom-based subtypes with unique neuroendocrine signatures. This study investigated the extent to which depressive symptom composites were differentially associated with cortisol responses to psychosocial stress. Methods: This study examined salivary cortisol responses to the Trier Social Stress Test (TSST) in 145 adolescents who varied in their risk for MDD: 38 had current MDD; 35 were healthy but at high risk for MDD based on having one or both parents with unipolar MDD; and 72 were healthy youth with no personal or family history of a psychiatric disorder. Multilevel models examined within-person change in cortisol levels during a 2h resting phase prior to the TSST and both linear and quadratic changes in cortisol levels following the TSST. Results: Anticipatory cortisol reactivity was lower in MDD youth compared to low-risk youth, and in youth with higher compared to lower depressive symptom severity. Whereas affective symptoms were associated with increased anticipatory cortisol reactivity and more rapid recovery to the TSST, neurovegetative symptoms were associated with decreased anticipatory cortisol reactivity and slower recovery. Limitations: The cross-sectional design does not permit inferences regarding temporal relations between cortisol responses and depressive symptom composites. Conclusions: The present findings suggest that heterogeneity among studies examining HPA reactivity in depressed youth may be driven, in part, by differences in depressive symptom composites across samples.