3 - (OP12) Stress Reactivity and Risk Appraisal Mediate the Association Between Major Depressive Disorder and Generalized Anxiety Disorder Symptoms over 18 Years

Introduction: Stress reactivity (SR) is the psychological reaction to perceived demands during stressful situations. Stress risk appraisal (RA) is the evaluation of how disruptive an event is to essential life domains, such as work and interpersonal relationships. SR is the emotional response elicited by stressful events; RA is the cognitive appraisal of the event’s potential disruption to daily life. Although characterized as trait-like, SR and RA may exhibit day-to-day fluctuations in response to daily events. Thus, the variability and mean of SR and RA in response to minor daily stressors may help clarify the stress-appraisal processes that contribute to the long-term heterotypic continuity of symptom severity from Major Depressive Disorder (MDD) to Generalized Anxiety Disorder (GAD). The context-dependent propensities in appraising and responding to daily hassles may inform long-term Cognitive-Behavioral Therapy (CBT) monitoring approaches. As such, we explored how the average level (mean) and variability (standard deviation (SD)) of SR and RA mediated the longitudinal association between MDD and GAD symptom severity.

Methods: The final sample included 735 participants (39.86% female, 94.97% White) from the Midlife Development in the United States (MIDUS) database. Participants had at least 3 out of 7 days of Wave 2 (W2) Daily Diary Project data and completed Wave 1 (W1) and Wave 3 (W3) Composite International Diagnostic Interview-Short Form (CIDI-SF) data. We ran two sets of structural equation mediation models with latent predictor and outcome variables indicated by their respective CIDI-SF items: (1) W1 MDD symptom severity predicting W3 GAD symptom severity; and (2) W1 GAD symptom severity predicting W3 MDD symptom severity. Following MIDUS daily stress measurement conventions, SR was computed as the daily sum of stressor severity and stressor-related negative affect. RA was operationalized as the daily composite of 49 domain-specific stress-risk appraisal items. For each participant, the mean and SD of SR and RA were calculated across all post-random-forest-imputation daily diary entries. Each model contained only one mediator from W2 (SR mean, SR SD, RA mean, RA SD). Autoregressive paths were included to control for baseline levels of the outcome latent variable.

Results: We found a directional asymmetry: significant indirect effects were observed only for the W1 MDD-to-W3 GAD severity pathway, not the reverse. Only higher W2 SR mean and SD showed significant indirect effects in the W1 MDD to W3 GAD pathway (Cohen’s d = 0.243–0.244, p ≤ .031). The dynamics of SR mediated approximately 31–44% of the W1 MDD to W3 GAD association, whereas those of RA mediated approximately 14%. Higher mean levels and fluctuations of SR were associated with more severe GAD symptoms approximately 18 years after W1.

Conclusion: Taken together, SR, but not RA, dynamics may index risk-relevant stress-reactivity processes in daily life, contributing to the heterotypic continuity in symptoms from MDD to GAD. These findings may inform sustainable, long-term CBT SR monitoring strategies that account for individual and contextual differences.