Hippocampal volume indexes neurobiological sensitivity to the effect of pollution burden on telomere length in adolescents

The growing interdisciplinarity of developmental psychopathology: Implications for science and training

The field of developmental psychopathology has grown exponentially over the past decades, and has become increasingly multifaceted. The initial focus on understanding abnormal child psychology has broadened to the study of the origins of psychopathology, with the goals of preventing and alleviating disorder and promoting healthy development. In this paper, we discuss how technological advances and global events have expanded the questions that researchers in developmental psychopathology can address. We do so by describing a longitudinal study that we have been conducting for the past dozen years. We originally planned to examine the effects of early adversity on trajectories of brain development, endocrine function, and depressive symptoms across puberty; it has since become an interdisciplinary study encompassing diverse domains like inflammation, sleep, biological aging, the environment, and child functioning post-pandemic, that we believe will advance our understanding of neurobehavioral development. This increase in the breadth in our study emerged from an expansion of the field; we encourage researchers to embrace these dynamic changes. In this context, we discuss challenges, opportunities, and institutional changes related to the growing interdisciplinarity of the field with respect to training the next generation of investigators to mitigate the burden of mental illness in youth.

Clearing the air: A systematic review of studies on air pollution and childhood brain outcomes to mobilize policy change

Climate change, wildfires, and environmental justice concerns have drawn increased attention to the impact of air pollution on children's health and development. Children are especially vulnerable to air pollution exposure, as their brains and bodies are still developing. The objective of this systematic review was to synthesize available empirical evidence on the associations between air pollution exposure and brain outcomes in developmental samples (ages 0-18 years old). Studies were identified by searching the PubMed and Web of Science Core Collection databases and underwent a two-phase screening process before inclusion. 40 studies were included in the review, which included measures of air pollution and brain outcomes at various points in development. Results linked air pollution to varied brain outcomes, including structural volumetric and cortical thickness differences, alterations in white matter microstructure, functional network changes, metabolic and molecular effects, as well as tumor incidence. Few studies included longitudinal changes in brain outcomes. This review also suggests methodologies for incorporating air pollution measures in developmental cognitive neuroscience studies and provides specific policy recommendations to reduce air pollution exposure and promote healthy brain development by improving access to clean air.

Early life stress predicts trajectories of emotional problems and hippocampal volume in adolescence

Exposure to early life stress (ELS) has been consistently associated with adverse emotional and neural consequences in youth. The development of brain structures such as the hippocampus, which plays a significant role in stress and emotion regulation, may be particularly salient in the development of psychopathology. Prior work has documented smaller hippocampal volume (HCV) in relation to both ELS exposure and risk for psychopathology. We used longitudinal k-means clustering to identify simultaneous trajectories of HCV and emotional problems in 155 youth across three assessments conducted approximately two years apart (mean baseline age = 11.33 years, 57% female). We also examined depressive symptoms and resilience approximately two years after the third timepoint. We identified three clusters of participants: a cluster with high HCV and low emotional problems; a cluster with low HCV and high emotional problems; and a cluster with low HCV and low emotional problems. Importantly, severity of ELS was associated with greater likelihood of belonging to the low HCV/high symptom cluster than to the low HCV/low symptom cluster. Further, low HCV/high symptom participants had more depressive symptoms and lower resilience scores than did participants in the low HCV/low symptom, but not than in the high HCV/low symptom cluster. Our findings suggest that smaller HCV indexes biological sensitivity to stress. This adds to our understanding of the ways in which ELS can affect hippocampal and emotional development in young people and points to hippocampal volume as a marker of susceptibility to context.

Neighborhood disadvantage and parenting predict longitudinal clustering of uncinate fasciculus microstructural integrity and clinical symptomatology in adolescents

Parenting behaviors and neighborhood environment influence the development of adolescents' brains and behaviors. Simultaneous trajectories of brain and behavior, however, are understudied, especially in these environmental contexts. In this four-wave study spanning 9-18 years of age (N=224 at baseline, N=138 at final assessment) we used longitudinal k-means clustering to identify clusters of participants with distinct trajectories of uncinate fasciculus (UF) fractional anisotropy (FA) and anxiety symptoms; we examined behavioral outcomes and identified environmental factors that predicted cluster membership. We identified three clusters of participants: 1) high UF FA and low symptoms ("low-risk"); 2) low UF FA and high symptoms ("high-risk"); and 3) low UF FA and low symptoms ("resilient"). Adolescents in disadvantaged neighborhoods were more likely to be in the resilient than high-risk cluster if they also experienced maternal warmth. Thus, neighborhood disadvantage may confer neural risk for psychopathology that can be buffered by maternal warmth, highlighting the importance of considering multiple environmental influences in understanding emotional and neural development in youth.

Biological sensitivity to adolescent-parent discrepancies in perceived parental warmth

Introduction

Parenting behaviors are formative to the psychological development of young people; however, parent and adolescent perceptions of parenting are only moderately correlated with each other. Whereas discrepant perceptions may represent a normative process of deindividuation from caregivers in some adolescents, in others a discrepancy might predict psychological maladjustment. The biological sensitivity to context model provides a framework from which individual differences in development can be estimated in adolescents whose perceptions of parenting diverge from those of their parents.

Methods

At baseline we obtained diurnal cortisol samples from US adolescents (M = 13.37 years of age, SD = 1.06) as well as parents' and adolescents' ratings of parental warmth; we obtained adolescent-reported symptoms of psychopathology at baseline and again at follow-up two years later (N = 108, 57.5% female). We estimated waking cortisol, cortisol awakening response, and daytime cortisol slopes using piecewise regression models.

Results

Lower adolescent than parent ratings of parental warmth predicted increased externalizing symptoms at follow-up. Higher waking cortisol and steeper cortisol awakening response and daytime slopes predicted increased internalizing symptoms at follow-up. Further, discrepant ratings of parental warmth interacted with cortisol awakening response and daytime slopes such that greater discrepancies predicted greater increases in externalizing symptoms in adolescents with steeper cortisol slopes.

Conclusions

These findings indicate that steeper changes in cortisol production throughout the day index a greater sensitivity to perceived parental warmth. Lower adolescent than parent ratings of parental warmth may represent dysfunction in the parental relationship rather than a normative process of deindividuation in adolescents with steeper diurnal cortisol slopes.