(PS9-A8) The Mediating Role of Positive Relationships in the Bidirectional Connections Between Depression and Anxiety Symptoms

Introduction: Major depressive disorder (MDD) and generalized anxiety disorder (GAD) co-occur at high rates, often preceding and predicting one another over long durations (Jacobson & Newman, 2017). Interpersonal theories of psychopathology propose that the quality of relationships with significant others can contribute to the etiology and maintenance of these disorders (Hames, Hagan, & Joiner, 2013; Horowitz, 2004). Based on these theories, relationships with others may be a mediator in the longitudinal pathways between MDD and GAD. Considering the increase of perceived and objective social isolation as well as symptoms of anxiety and depression during the COVID-19 pandemic, it is important to understand the interpersonal processes involved in the sequential connections between GAD and MDD to guide treatment and preventative efforts (Salari et al., 2020). Therefore, the current study examined the mediational effect of positive relations with others in the bidirectional relationships between GAD and MDD symptoms over 18 years. 

Methods: Participants were 3,294 community-dwelling adults who took part in the Midlife Development in the U.S. (MIDUS) study. The mean age of the sample at Time 1 (T1) was 45.6 years (SD = 11.4), 54.6% of the sample was female, and 89% were white. Data were collected at three time points spaced about nine years apart. GAD and MDD symptom severity were assessed using the Composite International Diagnostic Interview–Short Form at T1 and Time 3 (T3). Level of positive relations was measured at Time 2 (T2) using the Psychological Well-Being Scale–Positive Relations with Others subscale. Structural equation mediation modeling was used for data analysis.  

Results: Results indicated that T2 positive relations with others significantly mediated the pathway of more severe T1 GAD symptoms predicting elevated T3 MDD symptoms (β = 0.01, 95% CI [0.01, 0.02], p = .007, d = 0.36), accounting for 12.2% of the variance of the T1 MDD–T3 GAD severity relations. This mediational effect remained significant after controlling for age, gender, education, and baseline MDD severity (d = 0.28–0.37). T2 positive relations with others also mediated the connection between T1 MDD symptoms positively predicting T3 GAD severity (β = 0.12, 95% CI [0.04, 0.20], p = .005, d = 0.38) and explained 10.7% of the variance. Moreover, the indirect effect of T2 Positive Relations with Others in the T1 MDD–T3 GAD pathway stayed significant after adjusting for age, gender, education, and baseline GAD symptoms (d = 0.20­–0.31). 

Conclusions: The present findings suggest that a lack of positive relationships with others may mediate the 18-year bidirectional connections between GAD and MDD symptoms. Our results support interpersonal theories of psychopathology and the transdiagnostic impact of social relationships. These findings also highlight the importance of augmenting cognitive-behavioral therapies for GAD and MDD by incorporating strategies that enhance interpersonal functioning (e.g., fostering more positive relationships with significant others) and perceived social support.