(PS3-6) Bipolarity of Positive Affect and Negative Affect in Adults with Major Depressive Disorder with a Current Major Depressive Episode and Healthy Controls

Background

People vary in how they experience positive affect (PA) and negative affect (NA). For some, PA and NA can co-exist as a rich and nuanced emotional state. For others, PA and NA exhibit bipolarity, such that one is much less common when the other is present. Depression symptom severity has been found to be associated with stronger bipolarity of PA and NA (Dejonckheere et al. 2018). The present study aims to evaluate whether these patterns are also observed when the sample includes those with a clinical diagnosis of major depressive disorder (MDD).

Methods

We recruited adults with MDD during a current major depressive episode and a healthy comparison group who did not meet criteria for any history of psychiatric illness (72% were White, 96% were not Hispanic or Latino, 73% identified as female). Participants completed clinician-rated assessments including the Mini-International Neuropsychiatric Interview (MINI) and Structured Interview Guide for the Hamilton Depression Rating Scale (SIGH-D). Participants additionally completed the self-report Beck Depression Inventory-II (BDI-II). Participants completed a daily diary questionnaire every evening for 3 months, including daily ratings of positive affect (feeling cheerful, excited, at peace) and negative affect (feeling depressed/down, angry, irritated, anxious) on a scale of 0 to100. Participants with at least 30 daily diary responses were included in the current study to increase reliability of within-person analyses. Data were nested within individuals. After accounting for potential effects of time, we calculated the Pearson’s correlation between positive and negative affect composites for each individual. At the between-person level, these estimates were then examined as correlates of depressive symptoms using clinician diagnosis, clinician-rated SIGH-D, and self-reported BDI-II scores.

Results

The final sample included 74 participants, 32 of whom were in the MDD group. The within-person correlation between PA and NA tended to be negative (M=-.28), but there was substantial variability in these correlations (range = -.87 to .25). The correlation between PA and NA did not differ across diagnostic groups, t(59.64) = 0.42, p = .67. There was not a significant association between the PA-NA correlation and depression severity scores from the BDI-II r(72)=-.18, p=.13 or the clinician-rated SIGH-D, r(72)=-.21, p=.08.

Discussion

Our findings fail to support the hypothesis that depression symptom severity is associated with a more negative within-person correlation between positive and negative affect. Although non-significant, the magnitude of association observed in this study was reasonably in line with that reported in prior research (Dejonckheere et al. 2018). In future studies, researchers should utilize larger samples which would be better positioned to detect small effects. Researchers should also evaluate indices of affect bipolarity beyond within person correlations alone to further evaluate whether depression is associated with affect bipolarity.