The maternal brain: Neural responses to infants in mothers with and without mood disorder

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.