Social influences on early developing biological and behavioral systems related to risk for affective disorder

Abstract
Dramatic changes take place in the neural physiology and emotional behavior of the human infant during the first 2 years of life. Evidence suggests that certain variations in the infant's early social environment, such as disturbances in mother-infant interaction that are associated with maternal depression, influence the development of biological systems related to the expression and regulation of emotion, particularly those systems involved in frontal lobe, autonomic, and adrenocortical functioning. In this essay, we provide an overview of the links between maternal depression and disruptions in early social and emotional development, and we highlight parallels between disturbances in biological systems found in depressed adults and those found in infants of mothers experiencing depression. We then discuss the possibility of sensitive periods for the enduring influences of maternal depression on the emotional development of these children and for increased risk for affective disorder. Finally, we point to directions for further research on the nature of the intergenerational transmission of emotional disturbance.