Socioeconomic status, hair cortisol and internalizing symptoms in parents and children

Abstract

Socioeconomic disadvantage is consistently linked with higher risk for internalizing problems, and stress is likely one important mechanism explaining this increased risk. Few studies have examined socioeconomic differences in hair cortisol, a novel biomarker of long-term adrenocortical activity and chronic stress. Moreover, no studies have examined whether differences in hair cortisol might explain socioeconomic disparities in internalizing problems. To address these gaps, we first examined relations of socioeconomic status (SES; family income and parental education) to variation in both parents’ and children’s hair cortisol concentrations (HCC) and then tested whether HCC and perceptions of stress mediated relations of SES to parents’ and children’s internalizing symptoms. Participants were a socioeconomically diverse sample of 35 parents and 26 children (ages 5 to 7). Parents completed questionnaires, and hair samples were collected from parents and children. Parents reported on children’s internalizing symptoms on average 2 years after the initial visit. Results demonstrated that lower parental education was associated with higher HCC for both parents and children. Effects for child HCC held even after controlling for parent HCC. Lower family income was associated with higher parent HCC, but not child HCC. This relation was nonlinear, such that the relation between HCC and income was strongest among the most disadvantaged parents. Furthermore, associations of SES with parental anxiety were significantly mediated by parental perceptions of stress and marginally mediated by parent HCC. These findings suggest that socioeconomic disadvantage is associated with greater accumulation of cortisol in hair in parents and children, and that both perceived and biological markers of stress capture important facets of the experiences that underlie socioeconomic disparities in adult anxiety.

Correlates of hair cortisol concentrations in disadvantaged young children

“…Social exclusion is primarily a multidimensional index of socio‐economic disadvantage designed to capture individuals' capacity to fully participate in society by quantifying their levels of deprivation in a range of dimensions, in addition to economic, such as health, employment, and education, in contrast to the widely used measure of income and rarely examined income poverty, which primarily index economic resources (Hayes et al, ). Although Ursache et al () and Vaghri et al () found no relationship between income and HCC, they did find that HCC was related to parental education, which could arguably be considered a proxy of social exclusion. However, we did not find a relationship between maternal education and HCC in our sample, consistent with Liu, Snidman, Leonard, Meyer, and Tronick (), Rippe et al (), and Vliegenthart et al ().…”

Hair cortisol as a measure of the stress response to social adversity in young children

“…Cross-sectional associations between adversity and higher child hair cortisol have been demonstrated for a small number of sociodemographic characteristics in studies of 1-, 4-, and 6-year-old children, including low parent education (Ursache, Merz, Melvin, Meyer, & Noble, 2017;Vaghri et al, 2013), low family income (Rippe et al, 2016;Windhorst et al, 2017), maternal unemployment (Karlén et al, 2015), and parents being of an ethnic minority (Palmer et al, 2013;Rippe et al, 2016;Windhorst et al, 2017). Of the few studies to examine psychosocial indicators of adversity, including maternal mental health at age 1, 7, and 10-17 years (Flom, St John, Meyer, & Tarullo, 2017;Olstad et al, 2016;Ouellette et al, 2015;Palmer et al, 2013), and family violence at 8 years (Boeckel, Viola, Daruy-Filho, Martinez, & Grassi-Oliveira, 2017), one study has shown evidence for an association between poor maternal mental health and higher child hair cortisol at 1 year (Palmer et al, 2013).…”

“…Of the few studies to examine psychosocial indicators of adversity, including maternal mental health at age 1, 7, and 10-17 years (Flom, St John, Meyer, & Tarullo, 2017;Olstad et al, 2016;Ouellette et al, 2015;Palmer et al, 2013), and family violence at 8 years (Boeckel, Viola, Daruy-Filho, Martinez, & Grassi-Oliveira, 2017), one study has shown evidence for an association between poor maternal mental health and higher child hair cortisol at 1 year (Palmer et al, 2013). However, studies of children aged 1, 6, 7, 8, and 3-18 years have also reported no association between individual indicators of adversity and child hair cortisol, including education (Gerber et al, 2017;Karlén et al, 2015;Rippe et al, 2016;Vliegenthart et al, 2016;Windhorst et al, 2017), income (Ursache et al, 2017;Vaghri et al, 2013), family violence (Boeckel et al, 2017), and mental health (Flom, et al, 2017;Olstad et al, 2016;Ouellette et al, 2015). Only two studies have examined cross-sectional associations between cumulative total counts of adverse exposures and child hair cortisol, both of which found evidence of an association between a higher total adversity count and higher child hair cortisol at 1 year (Karlén et al, 2015) and 9 years of age (Simmons et al, 2016).…”

Socioeconomic risk moderates the association between caregiver cortisol levels and infant cortisol reactivity to emotion induction at 24 months

“…However, several previous studies with mothers have shown that higher socioeconomic risk is associated with higher levels of cortisol (Bosquet Enlow et al, 2018;Clearfield, Carter-Rodriguez, Merali, & Shober, 2014;Tarullo, St. John, & Meyer, 2017;Thayer & Kuzawa, 2014;Ursache, Merz, Melvin, Meyer, & Noble, 2017). …”

“…For instance, human and nonhuman studies have shown that sensitive caregiving behaviors can downregulate a child's cortisol response via social buffering (Caldji, Diorio, & Meaney, 2000;Gunnar & Donzella, 2002). Indeed, studies have shown that higher levels of caregiver's self-reported stress are related to increased infant cortisol activity (Essex, Klein, Cho, & Kalin, 2002;Leung et al, 2010;Ursache et al, 2017). Certainly, one potential factor disrupting caregiver regulation in adverse environments may be increased levels of psychological stress.…”