Neurophysiological Reward Responsiveness, Exposure to Stressors, and Depressive Symptoms Across the Perinatal Period

Abstract

Perinatal depression (i.e., depression during pregnancy and following childbirth) is associated with negative outcomes for both mothers and their offspring. There is an urgent need to identify underlying processes associated with perinatal depression to reduce burden. Outside of the perinatal period, alterations in positive valence systems function, particularly reward responsiveness, have been associated with depression. Electroencephalography can be used to derive time domain and time-frequency domain measures of reward responsiveness across the perinatal period, including the reward positivity (RewP) and delta and theta power, respectively. Exposure to life stressors is also an established predictor of depression and has been found to impact and interact with reward responsiveness, such that the combination of greater exposure to stressors and reduced reward responsiveness has been associated with depression. Additionally, biological changes unique to the perinatal period appear to directly influence reward responsiveness, making the perinatal period a unique life stage to examine dynamic relations between reward responsiveness and depression. Although research supports the conceptualization that blunted reward responsiveness precedes depression onset, a recent study in youth found bidirectional associations between reward responsiveness and depression across time. Associations between changes in reward responsiveness and depression, as well as interactive effects with stress, have not been examined in the perinatal period and may inform understanding of underlying mechanism of perinatal depression. The present study examined bidirectional associations between reward responsiveness (i.e., RewP, delta, and theta) and depression across the perinatal period using random-intercept cross-lagged panel models as well as interactive effects with lifetime stressor exposure through linear regressions in a sample of 117 pregnant adults. Results provide partial support that reduced reward responsiveness as measured by RewP predicts depressive symptoms during pregnancy, and that this association does not appear to be reciprocal across the perinatal period. Lifetime stressor exposure did not significantly interact with depressive symptoms in predicting reward responsiveness, nor with reward responsiveness in predicting depressive symptoms. This work highlights important future directions for the further exploration of these associations during the perinatal period and contributes to the larger literature examining underlying mechanisms of depression.