Abstract

     Despite widespread acceptance that prenatal symptoms of depression in mothers are detrimental to infants’ long-term emotional and cognitive development, little is known about the mechanisms that may integrate outcomes across these domains. Rooted in the integrative perspective that emotional development is grounded in developing cognitive processes, we hypothesized that prenatal symptoms of depression in mothers would be associated with delays in neural maturation that support sociocognitive function in infants, leading to more problematic behaviors. We used a prospective longitudinal study of mothers (N = 92) and their infants to test whether self-reported symptoms of depression in mothers during the second and third trimesters were associated with neural development and infant outcomes at 4 months of age. While controlling for postpartum symptoms of depression, more prenatal symptoms of depression in mothers predicted less neural maturation in the parietal region of 4-month-old infants. Less neural maturation, in turn, was associated with greater infant negativity, suggesting neural maturation as a putative mechanism linking maternal symptoms of depression with infant outcomes. Differences in neural regions and developmental timing are also discussed.

۱- Introduction

     Early environmental characteristics play a significant role in infant cognition-emotion interactions, ultimately leading to both short- and long-term infant outcomes. The prenatal environment is particularly salient, as prenatal stress in the form of maternal depressive symptoms positively predicts negative emotional reactivity (Davis et al., 2007, Diego et al., 2005) and negatively predicts cognitive function in infants (Barker et al., 2013), effects which can persist well into adolescence (de Bruijn et al., 2009, Luoma et al., 2001, Luoma et al., 2004). Research aimed at understanding the effects of maternal depression on infant outcomes have traditionally tested emotion and cognition as separate effects in streams of development. Yet, contemporary theory and mounting empirical work underscore both the overlap and the interplay between putatively cognitive and emotional trajectories of development, particularly early infancy (Bell and Wolfe, 2004, Calkins and Bell, 2010). Nonetheless, the mechanisms for such overlap remain largely unknown. During infancy, the maturation of neural architecture that supports cognitive and emotional processing may provide insight into their integration during a sensitive period of development (Deave et al., 2008, Luoma et al., 2001). Thus, the current study was designed to test an integrative pathway, infant neural maturation, by which maternal symptoms of prenatal depression may impact infant development.

۳- Results

۳-۱ Preliminary analyses

     Descriptive statistics and correlations among study variables are reported in Table 1. Symptoms of maternal depression showed moderate stability over time, with the greatest stability observed across the two prenatal assessments. At the bivariate level, greater numbers of maternal depressive symptoms in the second trimester of pregnancy were associated with smaller frontal alpha-delta ratio scores at age 4 months but were unrelated to parietal alpha-delta ratio scores. Maternal depressive symptoms in the third trimester did not show bivariate associations with infant alpha-delta ratios at frontal or parietal sites. Greater negative affect in infants at 4 months of age was associated with greater numbers of maternal depressive symptoms in the second trimester and at the postpartum assessment. Maternal symptoms of depression were not associated with mother-reported infant behaviors or observed positivity in infants at the bivariate level.