Developmental Timing of Stress Effects on the Brain

The physiological stress response integrates endocrine, autonomic, and neural structures and pathways to respond and adapt to an organism’s environment. This integration is dynamic throughout development, with certain periods of rapid change for each system. With the introduction of chronic stress, physiological responses that may be adaptive in the immediate context can have long-term consequences for physical and emotional health, influencing systems differently depending upon developmental status at the time of stress exposure. From the nonhuman literature, prenatal, infancy, and adolescence are developmental stages that seem especially sensitive to major stress exposures. Human studies are less conclusive. Although much work has been done on prenatal stress and certain stressors (e.g., deprivation) during infancy and early childhood, more work is needed that addresses the challenges of isolating periods of environmental insults as well as carefully considering how prior developmental and subsequent experiences moderate exposure to major stress conditions at different points in development. Information on the transition from childhood to adolescence is especially sparse. A more comprehensive understanding of these developmental processes will enable a more targeted approach to ameliorating negative consequences of stress with both prevention and intervention.