After all young infants have not yet acquired the capacity for symbolic thought that would allow them to reflect on their experience.
Yet infants can exhibit some of the behavioral and somatic (or bodily) symptoms of depression – for example, loss of interest in activities, loss of weight, or disruption of normal sleep patterns.
Researchers disputed whether true depressive disorder can occur in infancy, but infants can and do experience depression-like states and symptoms.
These symptoms are most likely to be observed in infants who lack a secure attachment relationship or who experience a disruption of their all-important emotional bonds.
Depression in infants