Concepts of what constitutes health, and theories about how health is produced and optimized, are constantly evolving in response to myriad social and cultural expectations shaped by our contemporary worldview, scientific advances, improvements in health interventions, and the changing capacity of the health system. Stimulated originally by a series of studies demonstrating how growth during early life is related to chronic health conditions that emerge many decades later, new research is demonstrating how complex developmental processes integrate a range of biological, behavioral, social, and environmental influences that modify gene expression, modulate physiologic and behavioral function, and dynamically shape different pathways of health production. These empirical findings are highlighting the limitations of the more mechanistic biomedical and biopsychosocial models of health, which fail to offer comprehensive explanations about such phenomena as the developmental origins of health, how stress affects current and future health, and the consequences of dynamic interactions between individuals and their environments over time. The comfort and certainty of simple, linear, and deterministic causal pathways are giving way to the uncomfortable uncertainty of nonlinear causal clusters that are networked together into complex, multilevel, interactive, and relational systems. Informed by new theoretical perspectives emerging from such fields of study as developmental psychology, systems biology, epigenetics, the developmental origins of chronic disease, and evolutionary developmental biology, a coherent transdisciplinary framework is emerging which we call Life Course Health Development (LCHD) and which is presented in this chapter as a set of seven principles: (1) health development, (2) unfolding, (3) complexity, (4) timing, (5) plasticity, (6) thriving, and (7) harmony. LCHD offers a new perspective that will guide future scientific inquiry on health development and facilitate synthesis of medicine and public health that links treatment, prevention, and health promotion and catalyzes more integrated and networked strategies for designing, organizing, and implementing multilevel health interventions that transcend individual and population dichotomies. We hope that the LCHD framework presented here, coupled with our explanatory narrative, will encourage theory building and testing, inspire innovative transdisciplinary research, and mature the framework into a scientific model with descriptive, explanatory, and predictive utility. Furthermore, we hope that LCHD will shine a light on the conundrum of how little attributable risk is explained in many studies of chronic disease, how early experience conditions future biological response patterns, and how these early experiences play through complex, environmentally influenced, and developmentally plastic health development pathways.
Copyright 2018, The Author(s).