For children reared in institutions for orphaned or abandoned children, multiple aspects of the early environment deviate from species-typical experiences, which may lead to alterations in neurobehavioral development. Although the effects of early deprivation and early life stress have been studied extensively in animal models, less is known about implications for human brain development. This structural neuroimaging study examined the long-term neural correlates of early adverse rearing environments in a large sample of 12-14. year old children (N = 110) who were internationally adopted from institutional care as young children (median age at adoption = 12. months) relative to a same age, comparison group reared with their biological families in the United States. History of institutional rearing was associated with broad changes in cortical volume even after controlling for variability in head size. Results suggested that prefrontal cortex was especially susceptible to early adversity, with significant reductions in volume (driven primarily by differences in surface area rather than cortical thickness) in post-institutionalized youth. Hippocampal volumes showed an association with duration of institutional care, with later-adopted children showing the smallest volumes relative to non-adopted controls. Larger amygdala volumes were not detected in this sample of post-institutionalized children. These data suggest that this temporally discrete period of early deprivation is associated with persisting alterations in brain morphology even years after exposure. Furthermore, these alterations are not completely ameliorated by subsequent environmental enrichment by early adolescence.
Bibliographical noteFunding Information:
The authors thank the families of the Minnesota International Adoption Project, the staff of the Cognitive Development & Neuroimaging Lab (especially Jennifer Wenner) and Human Developmental Psychobiology Lab (especially Bonny Donzella) for their help with this project, as well as Byron Mueller for imaging technical support. The research was supported by a NIMH Center grant P50-MH079513 for the Center for Brain, Gene and Behavioral Research Across Development, B.J. Casey (Director), Megan Gunnar and Kathleen Thomas (Co-PIs of project 2). Trainee support was provided by the University of Minnesota's Center for Cognitive Sciences via a Ruth L. Kirschstein National Research Service Award T32-HD007151 and the University of Minnesota Graduate School Fellowships . Additional funding was provided by the University of Minnesota's Center for Neurobehavioral Development ( T32-MH73129 ) and College of Liberal Arts and the Minnesota Medical Foundation . This work was carried out in part using resources at the University of Minnesota's Center for Magnetic Resonance Research ( P41-RR008079 , P41-EB015894 , P30-NS076408 ), and the Supercomputing Institute .
© 2014 Elsevier Inc.
- Early adversity
- Early deprivation
- Early life stress
- Post-institutionalized youth
- Structural brain development