ACE STUDY.

CHILDHOOD TRAUMA ISN’T SOMETHING YOU JUST GET OVER AS YOU GROW UP. PEDIATRICIAN NADINE BURKE HARRIS EXPLAINS THAT THE REPEATED STRESS OF ABUSE, NEGLECT AND PARENTS STRUGGLING WITH MENTAL HEALTH OR SUBSTANCE ABUSE ISSUES HAS REAL, TANGIBLE EFFECTS ON THE DEVELOPMENT OF THE BRAIN. THIS UNFOLDS ACROSS A LIFETIME, TO THE POINT WHERE THOSE WHO’VE EXPERIENCED HIGH LEVELS OF TRAUMA ARE AT TRIPLE THE RISK FOR HEART DISEASE AND LUNG CANCER. AN IMPASSIONED PLEA FOR PEDIATRIC MEDICINE TO CONFRONT THE PREVENTION AND TREATMENT OF TRAUMA, HEAD-ON.

Mechanisms of neuroplasticity linking early adversity to depression: developmental considerations

Tiffany C. Ho and Lucy S. King2

Early exposure to psychosocial adversity is among the most potent predictors of depression. Because depression commonly emerges prior to adulthood, we must consider the fundamental principles of developmental neuroscience when examining how experiences of childhood adversity, including abuse and neglect, can lead to depression. Considering that both the environment and the brain are highly dynamic across the period spanning gestation through adolescence, the purpose of this review is to discuss and integrate stress-based models of depression that center developmental processes. We offer a general framework for understanding how psychosocial adversity in early life disrupts or calibrates the biobehavioral systems implicated in depression. Specifically, we propose that the sources and nature of the environmental input shaping the brain, and the mechanisms of neuroplasticity involved, change across development. We contend that the effects of adversity largely depend on the developmental stage of the organism. First, we summarize leading neurobiological models that focus on the effects of adversity on risk for mental disorders, including depression. In particular, we highlight models of allostatic load, acceleration maturation, dimensions of adversity, and sensitive or critical periods. Second, we expound on and review evidence for the formulation that distinct mechanisms of neuroplasticity are implicated depending on the timing of adverse experiences, and that inherent within certain windows of development are constraints on the sources and nature of these experiences. Finally, we consider other important facets of adverse experiences (e.g., environmental unpredictability, perceptions of one’s experiences) before discussing promising research directions for the future of the field.