ABSTRACT
BACKGROUND: Atypical neurocognitive responses to emotional stimuli are core features of unipolar depression (UD) and bipolar disorder (BD). For mothers with these mood disorders, this may influence interactions with their infants and consequently infant development. The study aimed to investigate psychophysiological and cognitive responses to infant emotional stimuli, and their relation to mother-infant interaction and infant development, in mothers with BD or UD in full or partial remission. METHODS: Four months after birth, mothers' cognitive responses to emotional infant stimuli were assessed with computerized tasks, while their facial expressions, galvanic skin responses (GSR), gazes, and fixations were recorded. Infant development and mother-infant interactions were also assessed. RESULTS: We included 76 mothers: 27 with BD, 13 with UD, and 36 without known psychiatric disorders, and their infants. Mothers with BD and UD were in full or partial remission and showed blunted GSR and spent less time looking at infant stimuli (unadjusted p values < 0.03). Mothers with BD showed subtle positive neurocognitive biases (unadjusted p values<0.04) and mothers with UD showed negative biases (unadjusted p values < 0.02). Across all mothers, some measures of atypical infant emotion processing correlated with some measures of delays in infant development and suboptimal mother-infant interaction (unadjusted p values<0.04). CONCLUSIONS: Mothers with mood disorders in full or partial remission showed atypical cognitive and psychophysiological response to emotional infant stimuli, which could be associated with mother-infant interactions and infant development. The study is explorative, hypothesis generating, and should be replicated in a larger sample. Investigation of the long-term implications of reduced maternal sensitivity is warranted.
ABSTRACT
Mothers' sensitive responses to their infants have evolutionary importance and are likely hardwired into the maternal brain. Mood disorders are associated with aberrant neural processing of emotion in regions overlapping with 'maternal sensitivity networks' which could compromise maternal processing of infant signals. This systematic review aimed to integrate findings from studies of neural responses to infant stimuli in healthy mothers and in mothers with mood disorders. We included original studies using functional brain imaging and electrophysiological techniques. The databases psycINFO and PubMed were searched for eligible articles until January 2019. Twenty-seven studies met the inclusion criteria, none of which investigated mothers with bipolar disorder or remitted unipolar disorder. Studies were characterized by large methodological heterogeneity. The most consistent findings were that healthy mothers exhibit stronger and faster neural responses to infant stimuli than non-mothers in key emotional processing regions including the amygdala, insula and orbitofrontal cortex, which is accentuated for own infants. Motherswith acute depression display blunted neural responses within these regions which correlates with greater depression severity.
