Bidirectional Associations Between Inflammatory Biomarkers and Depressive Symptoms in Adolescents: Potential Causal Relationships

This has been accepted for publication in Clinical Psychological Scienc

Response Styles Theory and Internalizing Symptoms in Adolescence: A Network Approach

Background: Response styles theory is a well-supported etiological theory of internalizing psychopathology. However, evidence indicates that the three response styles (rumination, problem-solving, and distraction) are not orthogonal, highlighting the importance of multivariate tests of this theory. Further, different types of symptoms within a disorder can have different risk factors, suggesting that refinement of theory and response style-focused interventions is possible with the help of analyses that go beyond symptom total scores or diagnoses. Methods: A sample of 567 participants (Mage=12.6 years, 54.1% female) completed measures of response styles, depression symptoms, and anxiety symptoms. A subset of 360 completed these measures a second time (mean/median months apart=18.2/12.4). Internalizing symptoms and response styles were modeled in cross-sectional and cross-lagged panel network models. Results: Rumination was the response style most comorbid with concurrent internalizing symptoms. Social anxiety, negative self-concept, and dysphoria were the symptom domains most comorbid with a classically-defined maladaptive response profile. Distraction was the response style most strongly predictive of future symptoms, whereas negative self-concept, somatic depression, and somatic anxiety were the strongest predictors of future response styles. Conversely, rumination was the response style most strongly predicted by past internalizing symptoms and dysphoria was the symptom subtype most strongly predicted by past response styles. Conclusions: Differential prospective relationships between response styles and symptom subtypes suggest that response style theory, and treatments informed by it, should be conceptualized transdiagnostically and at a more fine-grained level than diagnostic categories

Bidirectional Associations Between Inflammatory Biomarkers and Depressive Symptoms in Adolescents: Potential Causal Relationships

There are inconsistent findings in the literature about the directionality and magnitude of the association between inflammation and depressive symptoms. This study separates predictors into between-person and within-person components in an attempt to gain greater clarity about this relationship. Blood samples were collected and depressive symptoms assessed in 140 adolescents (54% female, 59% Black, Mage = 16.1 years) with at least three blood draws and a total of 394 follow-up evaluations. Multi-level modeling indicated that the within-person effect of TNF-α predicted future total depressive symptoms, suggesting a potential causal relationship. Additionally, there were bidirectional, between-person effects of IL-6 on total depressive symptoms and vice-versa. Exploratory analyses examined the associations between five biomarkers and five subsets of depressive symptoms. These findings inform modeling decisions that may explain inconsistences in the extant literature as well as suggest potential causal relationships between certain biomarkers with significant within-person effects on depressive symptoms, and vice-versa