Reduced prefrontal cortex response to own vs. unknown emotional infant faces in mothers with bipolar disorder

Motherhood involves functional brain adaptations within a broad neural network purported to underlie sensitive caregiving behavior. Bipolar disorder (BD) is associated with aberrant brain response to emotional faces within a similar network, which may influence BD mothers' sensitivity to infant faces. This functional magnetic resonance imaging (fMRI) study aimed to investigate whether mothers with BD display aberrant neural responses to own infant faces compared to healthy mothers. Twenty-six mothers with BD in remission and 35 healthy mothers underwent fMRI during which they viewed happy and distressed still facial photographs of their own and of unknown infants. After the scan, mothers viewed the pictures again on a computer screen and rated the intensity of infants' facial emotions and their own emotional response to infant face images. Mothers with BD displayed lower left dorsolateral prefrontal cortex (dlPFC) response compared to healthy mothers to own vs. unknown infant faces specifically and abnormal positive functional connectivity between the left and right amygdala and prefrontal regions. BD mothers further displayed stronger deactivation of precuneus and occipital regions to all happy vs. distressed infant faces. After the scan, they rated their infants' distress and own response to their infants' distressed faces less negatively than healthy mothers. Blunted dlPFC response and aberrant fronto-limbic connectivity while viewing own infant faces and less negative ratings of own infants' distress in BD mothers may affect their responses to their own infants in real-life mother-infant interactions.