Genes, Environments, and Time: The Biology of Adversity and Resilience

Abstract

Exposures to adverse environments, both psychosocial and physicochemical, are prevalent and consequential across a broad range of childhood populations. Such adversity, especially early in life, conveys measurable risk to learning and behavior and to the foundations of both mental and physical health. Using an interactive gene-environment-time (GET) framework, we survey the independent and interactive roles of genetic variation, environmental context, and developmental timing in light of advances in the biology of adversity and resilience, as well as new discoveries in biomedical research. Drawing on this rich evidence base, we identify 4 core concepts that provide a powerful catalyst for fresh thinking about primary health care for young children: (1) all biological systems are inextricably integrated, continuously “reading” and adapting to the environment and “talking back” to the brain and each other through highly regulated channels of cross-system communication; (2) adverse environmental exposures induce alterations in developmental trajectories that can lead to persistent disruptions of organ function and structure; (3) children vary in their sensitivity to context, and this variation is influenced by interactions among genetic factors, family and community environments, and developmental timing; and (4) critical or sensitive periods provide unmatched windows of opportunity for both positive and negative influences on multiple biological systems. These rapidly moving frontiers of investigation provide a powerful framework for new, science-informed thinking about health promotion and disease prevention in the early childhood period.

Preventing Childhood Toxic Stress: Partnering With Families and Communities to Promote Relational Health

“…Toxic stress responses are known to alter multiple systems that interact in a reciprocal and dynamic manner: genomic function, brain structure and connectivity, metabolism, neuroendocrineimmune function, the inflammatory cascade, and the microbiome. 13,14 Toxic stress-induced alterations also influence the adoption of maladaptive coping behaviors decades later. [37][38][39][40] Several researchers have noted that many other experiences in childhood are also associated with poor outcomes later in life, and these include being raised in poverty, 41 left homeless, [42][43][44] exposed to neighborhood violence, [45][46][47] subjected to racism, [48][49][50] bullied, 51,52 or punished harshly.…”

“…10,11 This toxic stress framework is powerful, because it taps into a rich and increasingly sophisticated literature describing how early childhood experiences are biologically embedded and influence developmental outcomes across the life course. [12][13][14] This was the focus of the original technical report on toxic stress from the American Academy of Pediatrics (AAP) in 2012. 2 Current threats to child wellbeing and long-term health, such as widening economic inequities, deeply embedded structural racism, the separation of immigrant children from their parents, and a socially isolating global pandemic, make the toxic stress framework as relevant as ever.…”

Trauma-Informed Care

“…Although currently only available in the research setting, biomarkers of this physiologic response have the potential to be more accurate measures of the effects of adversity at the individual level. [131][132][133] Eventually, clinicfriendly, noninvasive biomarkers could also be used to identify patient-specific response to both stressors and therapeutic interventions. 134,135 Screening health care workers for the effects of hearing about and addressing the trauma experiences of others is most commonly achieved with informal selfassessment strategies to identify symptoms or experiences that may be associated with burnout or STS.…”

Asylum-seeking children in shutdown: Neurobiological models

“…Second, the specific pattern of trauma response—in the face of the same event or type of event—can vary from person to person and from child to child (Lanius et al, 2003). Presumably, these variations reflect, in large part, differences in genetic and epigenetic vulnerabilities carried over from previous generations or from events in the child’s own lifetime (Boyce et al, 2021; Miller, 2021) or the process of priming (Bargh, 2014), where one pattern of response is more likely because it has been activated recurrently in an earlier development phase.…”

“…From this point forward, and building on the lessons from history, we specifically adopt a developmental, biopsychosocial (systems) perspective—one in which the shutdown states in asylum-seeking children are understood to emerge via a dynamic relation between children and their context, very broadly conceived (Bowlby, 1988; Engel, 1977; Sameroff, 2014). This systems perspective provides clinicians working in child psychiatry and pediatrics a framework for organizing emerging findings pertaining to the mechanisms by which adverse childhood experiences (ACEs)—for example, maltreatment, family disruption, high parental stress, witnessing violence (including that against a caregiver), caregiver mental illness, criminal behavior in the household, and low socioeconomic status—are biologically embedded to shape adverse physical and mental health outcomes (Agorastos et al, 2019; Appleyard et al, 2005; Boyce et al, 2021; Flaherty et al, 2009; Hyman, 2009; McEwen et al, 2015; Nelson, 2013; Sameroff, 2014). The systems framework allows us to put forward neurobiological models that can help us to understand how the human brain and body respond to extreme fear, terror, or situations from which escape is not possible.…”