Timing of Early-Life Stress and the Development of Brain-Related Capacities.

Erin P Hambrick,Thomas W Brawner,Bruce D Perry

doi:10.3389/fnbeh.2019.00183

Abstract

Early-life stress (ELS) poses risks for developmental and mental health problems throughout the lifespan. More research is needed regarding how specific ELS experiences influence specific aspects of neurodevelopment. We examined the association between ELS, defined as severe adversity (e.g., domestic violence, caregiver drug use) and severe relational poverty (e.g., caregiver neglect, lack of caregiver attunement), occurring during the first 2 months of life and a variety of brain-related, clinician-rated functions, including self-regulation and relational capacities. Interdisciplinary clinicians using the Neurosequential Model of Therapeutics (NMT), an approach to clinical problem solving, reported on the timing and type of treatment-seeking children’s (N = 2,155; 8–10 years) stressful experiences during four developmental periods: Perinatal (0–2 months), Infancy (2–12 months), Early Childhood (13 months to 4 years), and Childhood (4–11 years). They also reported on children’s current functioning in 32 brain-related domains (e.g., sleep, arousal, impulsivity, empathy, concrete cognition). Non-negative matrix factorization (NMF) was conducted on the 32 brain-related domains to identify latent factors, yielding four factors comprising Sensory Integration, Self-Regulation, Relational, and Cognitive functioning. Regularized hierarchical models were then used to identify associations between ELS and each latent factor while controlling for stress occurring during subsequent developmental periods, and children’s current degree of relational health. ELS (stress occurring during the first 2 months of life), specifically a severe lack of positive relational experiences (e.g., caregiver neglect, lack of caregiver attunement), was associated with the Sensory Integration and Self-Regulation factors. The Relational factor was better explained by stress occurring during childhood, and the Cognitive factor by stress occurring during infancy and childhood. Implications for how the timing and type of stress experiences may influence brain-related outcomes that are observed in clinical settings are discussed. Future directions include longitudinal follow-ups and greater specification of environmental variables, such as types of interventions received and when they were received, that may interact with ELS experiences to influence brain-related outcomes.

Highlights

Research in animal models over the last 40 years has demonstrated that stressors experienced early in life can alter key neural networks in, and functioning of, the developing brain (Bath et al, 2013; Bedrosian et al, 2018)
Because the measured brain-related functions meet the non-negativity constraint, we found that the non-negative factors obtained by negative matrix factorization (NMF) facilitated interpretation of the latent categories of interest
The degree of severe adversity/stress and relational poverty experiences was similar across all developmental periods and across Parts A and B (Figure 1)

Summary

Introduction

Research in animal models over the last 40 years has demonstrated that stressors experienced early in life can alter key neural networks in, and functioning of, the developing brain (Bath et al, 2013; Bedrosian et al, 2018). In the more recent past, child trauma has been deemed a ‘‘public health crisis’’ by researchers (Magruder et al, 2016) and major news outlets (Blakemore, 2018), while public systems in early childhood, education, mental health, child welfare, juvenile justice and health are pushing to define and create ‘‘trauma-informed’’ practice, programs and policy (Pachter et al, 2017) Despite these intensive and expensive efforts in policy and practice, relatively little is known about the specific mechanisms by which early-life stress (ELS) or more broadly ‘‘ACEs’’ influence development to create the cascade of correlated functional consequences (Maniam et al, 2014). One-size-fits-all interventions do not reliably work for this subset of children who present with a diverse set of problems that can include severe sensory sensitivities, impulsivity and regulatory problems, relational impairments, and cognitive deficits (Perry, 2017)

Methods

Results

Discussion

Conclusion