Neuroscience of child and adolescent health development

Recent advances in technology and neuroscience have increased our understanding of human neuro- development. In particular, research on neuroplasticity and psychosocial genomics lends compelling support to a biopsychosocial perspective by elucidating mechanisms through which psychosocial forces and environments shape neurobiology. This article summarizes selected results from recent investigations of neuroplasticity and psychosocial genomics, which demonstrate complex interaction between genes, epigenetic processes, and environmental experience that confers neural growth into adulthood. Coun- seling psychologists working with children and adolescents need to be familiar with recent literature to be more effective in their work so that they can provide developmentally appropriate counseling services. Social cognitive theory and resilience theory are introduced to illustrate how counseling psychologists can incorporate neuroscience research findings in a counseling context and hypotheses are proposed for future counseling psychology research. Advances in pediatric neuroscience over the past decade are beginning to reveal the complex systems involved in neural plas- ticity. This article introduces selected recent findings regarding multiple influences in child and adolescent neural development. Current thinking on how the brain "remodels" itself from birth to young adulthood is presented, with a special emphasis on adoles- cent development. The influence of trauma and toxic stress on neurobiology is also reviewed. Throughout, counseling psycholo- gists are encouraged to think about how this new knowledge can inform their treatment of young clients and caretakers, as well as how scholars of the field might contribute to the important work being done to better understand the connections between observ- able human behavior and neural development. It was historically thought that the human brain was structurally mature by the end of early childhood (Mann, 1984) and the nature versus nurture debate that dominated the mid-20th century posited unidirectional models of child development that assigned varying degrees of influence independently to genes and environment (Meaney, 2010). It is now thought that a complex interplay of genetic inheritance and environmental experience, mediated by epigenetic processes, shapes the brain from the womb to adult- hood. The epigenome is a set of chemical compounds, which, in response to environmental stimuli such as nutrition, toxins, or traumatic experiences, directly alter the expression of one's genes, muting some and activating others. Although the exact specifica- tions of a model for the epigenome is currently under debate (Riddihough & Zahn, 2010), the importance of its role in adjusting the genome in response to environmental conditions is well ac- cepted. Moreover, the implications of the epigenetic process be- come more important as counseling psychologists seek to design interventions capable of yielding lasting changes in complex psy- chosocial behaviors (Meaney, 2010). Exactly how the epigenome influences brain development is not yet well understood. Much of what we know about the moderation of genetic expression due to environmental variables comes to us from animal models and some adult human studies that combine genotyping, examination of deoxyribonucleaic acid (DNA) meth- ylation differences, and either neuroimaging or postmortem exam- ination. Longitudinal neuroimaging of typical brain development throughout childhood to adulthood has laid the foundation for better understanding possible points of intervention that may con- fer maximal inoculation against environmental stressors. Much research is yet needed, and how counseling psychologists might contribute to this work is discussed in this selective review along with ideas for incorporating neuroscience findings into day-to-day counseling intervention work. The focus of the review is neuro- typical development, with special attention to the adolescent brain and how trauma influences neurological development.