This multi-wave longitudinal study investigated potential transactional and accumulating influences among co-rumination, interpersonal stressors, and internalizing symptoms among a sample of early and middle adolescents (N=350; 6th–10th graders). Youth completed self-report measures of co-rumination at Times 1, 2, and 4, and negative life events, internalizing symptoms (general depressive, specific anhedonic depressive, anxious arousal, general internalizing) and externalizing problems at all four time points (5 weeks between each assessment across 4 months). Results supported hypotheses. First, baseline co-rumination predicted prospective trajectories of all forms of internalizing symptoms but not externalizing problems. Second, baseline co-rumination predicted generation of interpersonal dependent, but not interpersonal independent or non-interpersonal stressors. Third, interpersonal dependent events partially mediated the longitudinal association between baseline co-rumination and prospective internalizing symptoms. Fourth, a transactional, bi-directional set of associations was supported in that initial internalizing symptoms and stressors predicted later elevations in co-rumination, and in turn, co-rumination predicted later symptoms through the mediating role of interpersonal stressors to complete both streams in the transactional chain of influence. Finally, girls and older adolescents exhibited higher co-rumination, but neither age nor sex moderated any associations. These findings are discussed within a transactional, developmental cascade model.

The tendency to co-ruminate, or frequently discuss and rehash problems with peers may serve as one mechanism in the dramatic rise in depression observed during adolescence, particularly among adolescent girls. The goal of the current study was to test the hypothesis that adolescents’ levels of co-rumination would predict the onset of clinically significant depressive episodes over a 2-year follow-up. A second goal was to determine whether levels of co-rumination would mediate gender differences in risk for depression onset. Both hypotheses were supported. Results of survival analysis revealed that adolescents with higher, compared to lower levels of co-rumination at the initial assessments exhibited a significantly shorter time to depression onset. Levels of co-rumination also mediated the gender difference in time to depression onset. Importantly, these results were maintained even when statistically covarying adolescents’ baseline levels of depressive symptoms and rumination. Finally, co-rumination also predicted the course of illness in terms of episode severity and duration. Results suggest that co-rumination contributes unique risk for the development of depression in adolescents.

The goal of the current study was to examine the role of brooding rumination in children at risk for depression. We found that children of mothers with a history of major depression exhibited higher levels of brooding rumination than did children of mothers with no depression history. Examining potential mechanisms of this risk, we found no evidence for shared genetic influences (BDNF or 5-HTTLPR) or modeling of mothers’ rumination. However, we did find that children with a history of prior depressive disorders exhibited higher current levels of brooding rumination than children with no depression history. Importantly, children’s brooding predicted prospective onsets of new depressive episodes over a 20-month follow-up even when we statistically controlled for depressive symptom levels at the initial assessment, suggesting that the predictive effect of brooding rumination in children was not due simply to co-occurring depressive symptoms.

The autonomic nervous system (ANS) has demonstrated utility for identifying alterations in emotion processing associated with common psychopathology, including depression and anxiety. To date though the majority of this ANS research has several limitations. Most studies have examined parasympathetic and sympathetic branches separately, requiring activity in the other branch be inferred. This is problematic as each branch may function independently. Composite indices such as cardiac autonomic balance (CAB) and cardiac autonomic regulation (CAR) which examine the relative input between respiratory sinus arrhythmia (RSA) and pre‐ejection period (PEP) should provide more comprehensive measures of autonomic functioning and thus stronger predictors of psychopathology. However, the sympathetic branch is driven by multiple neurotransmitter systems, thus PEP does not necessarily reflect overall SNS arousal. We propose two new metrics for assessing ANS functioning associated with psychopathology: parasympathetic effects on cardiac control (RSA) relative to sympathetic effects on the eccrine system (electrodermal activity, EDA), which we term cross‐system autonomic balance (CSAB) and regulation (CSAR). Eighty‐five women (18–37) completed a baseline physiological assessment with parasympathetic (RSA) and sympathetic indices (PEP, EDA), along with self‐reported depressive and anxiety symptoms. Lower CSAB, indicating sympathetic dominance driven by cholinergic neurotransmission, was associated with higher depressive and anxiety symptoms. Lower CAB indicating sympathetic dominance driven by beta‐adrenergic neurotransmission was associated specifically with depressive symptoms. CSAB was a more robust index than RSA. Results support the utility of assessing multiple composite ANS indices for identifying physiological substrates of alterations in emotion regulation associated with internalizing disorders.

Co-rumination, the social process of frequently discussing and rehashing problems with peers, is hypothesized to increase risk for depression, particularly for girls. Although there is growing evidence for a relation between co-rumination and depressive symptoms in youth, it remains unclear whether these results generalize to diagnosable episodes of depression. Using a retrospective behavioral high-risk design with 81 children aged 9-14 years, we tested the hypothesis that children currently exhibiting high levels of co-rumination would be more likely to have a history of depressive diagnoses than children with low levels of co-rumination. The results supported this hypothesis. In addition, the link between co-rumination and history of depressive diagnoses was maintained even when we excluded children with current diagnoses and statistically controlled for children's current depressive symptoms, suggesting that the relation is not due simply to current levels of depression.