Differential Developmental Associations of Material Hardship Exposure and Adolescent Amygdala–Prefrontal Cortex White Matter Connectivity

Abstract

Accumulating literature has linked poverty to brain structure and function, particularly in affective neural regions; however, few studies have examined associations with structural connections or the importance of developmental timing of exposure. Moreover, prior neuroimaging studies have not used a proximal measure of poverty (i.e., material hardship, which assesses food, housing, and medical insecurity) to capture the lived experience of growing up in harsh economic conditions. The present investigation addressed these gaps collectively by examining the associations between material hardship (ages 1, 3, 5, 9, and 15 years) and white matter connectivity of frontolimbic structures (age of 15 years) in a low-income sample. We applied probabilistic tractography to diffusion imaging data collected from 194 adolescents. Results showed that material hardship related to amygdala–prefrontal, but not hippocampus–prefrontal or hippocampus–amygdala, white matter connectivity. Specifically, hardship during middle childhood (ages 5 and 9 years) was associated with greater connectivity between the amygdala and dorsomedial pFC, whereas hardship during adolescence (age of 15 years) was related to reduced amygdala–orbitofrontal (OFC) and greater amygdala–subgenual ACC connectivity. Growth curve analyses showed that greater increases of hardship across time were associated with both greater (amygdala–subgenual ACC) and reduced (amygdala–OFC) white matter connectivity. Furthermore, these effects remained above and beyond other types of adversity, and greater hardship and decreased amygdala–OFC connectivity were related to increased anxiety and depressive symptoms. Results demonstrate that the associations between material hardship and white matter connections differ across key prefrontal regions and developmental periods, providing support for potential windows of plasticity for structural circuits that support emotion processing.

Early childhood household instability, adolescent structural neural network architecture, and young adulthood depression: A 21-year longitudinal study

“…Participants were excluded if more than 5 % of slides were replaced and images for 10 participants who had most replaced slices were further visually inspected. These data were also utilized and described in previous publications ( Calabrese et al, 2022 , Goetschius et al, 2019 , Goetschius et al, 2020 , Hardi et al, 2022a ; Hein et al, 2018 ).…”

“…While unpredictable maternal signals have been linked to density of preadolescence white matter corticolimbic structures ( Granger et al, 2021 ), little is known about how unstable environment across early childhood relate to network organization of structural connections. Furthermore, most work examining white matter tractography relating to early adverse experiences and psychopathology have focused on specific major white matter tracts ( Granger et al, 2021 , Hanson et al, 2013 , Hein et al, 2018 ) or microstructures ( Goetschius et al, 2020 , Hardi et al, 2022a ), which do not capture the spatial characteristics of structural networks that represent information exchange in the brain ( Bullmore and Sporns, 2009 , Menon, 2011 , Rubinov and Sporns, 2010 ). Measures of network organization can be accomplished by applying graph analysis to reconstructed white matter fibers streamlines using diffusion magnetic resonance imaging (dMRI) data ( Nucifora et al, 2007 ).…”

The future of neuroscience in developmental psychopathology

“…For example, in examining the brain as a mediator (Figure 3), greater neighborhood disadvantage was linked to worse response inhibition via prefrontal activation during a cognitive control task (Tomlinson et al, 2020). As another example, greater household instability in childhood predicted depressive symptoms in young adulthood via more efficient neural information flow during adolescence (Hardi, Goetschius, Tillem, et al, 2023).…”

Poverty, Brain Development, and Mental Health: Progress, Challenges, and Paths Forward

“…While most studies have primarily focused on cross-sectional associations, increasing efforts have been made to examine longitudinal trajectories of brain development as a function of poverty exposure (Evans 2004, Hanson et al 2013, Tooley et al 2021. Furthermore, identifying specificity across both different experiences of poverty and different neuroimaging modalities (Goetschius et al 2020b, Hardi et al 2022, McLaughlin & Sheridan 2016 has increased understanding of the mechanisms and processes through which poverty relates to brain and socioemotional development. Finally, important work is underway using a randomized controlled trial to examine the effects of poverty reduction on brain development and cognition (Troller-Renfree et al 2022).…”

“…To integrate these multilevel data, a structural equation approach can be employed to capture the shared variance between different poverty measures, or combined scores can be computed to capture cumulative effects of poverty exposure (Mueller & Parcel 1981). Another approach is to test whether specific measures of poverty have unique contributions for brain development, such as material hardship (Hardi et al 2022), household instability (Hardi et al 2023b), and neighborhood-level poverty (Taylor et al 2020) over and above family income or other metrics of poverty. Evidence for both the potential accumulated effect and specificity of poverty experience is important for informing targeted interventions.…”