Effects of interpersonal violence-related post-traumatic stress disorder (PTSD) on mother and child diurnal cortisol rhythm and cortisol reactivity to a laboratory stressor involving separation

Abstract

Women who have experienced interpersonal violence (IPV) are at a higher risk to develop posttraumatic stress disorder (PTSD), with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis and impaired social behavior. Previously, we had reported impaired maternal sensitivity and increased difficulty in identifying emotions (i.e. alexithymia) among IPV-PTSD mothers. One of the aims of the present study was to examine maternal IPV-PTSD salivary cortisol levels diurnally and reactive to their child's distress in relation to maternal alexithymia. Given that mother-child interaction during infancy and early childhood has important long-term consequences on the stress response system, toddlers' cortisol levels were assessed during the day and in response to a laboratory stressor. Mothers collected their own and their 12-48month-old toddlers' salivary samples at home three times: 30min after waking up, between 2-3pm and at bedtime. Moreover, mother-child dyads participated in a 120-min laboratory session, consisting of 3 phases: baseline, stress situation (involving mother-child separation and exposure to novelty) and a 60-min regulation phase. Compared to non-PTSD controls, IPV-PTSD mothers - but not their toddlers, had lower morning cortisol and higher bedtime cortisol levels. As expected, IPV-PTSD mothers and their children showed blunted cortisol reactivity to the laboratory stressor. Maternal cortisol levels were negatively correlated to difficulty in identifying emotions. Our data highlights PTSD-IPV-related alterations in the HPA system and its relevance to maternal behavior. Toddlers of IPV-PTSD mothers also showed an altered pattern of cortisol reactivity to stress that potentially may predispose them to later psychological disorders.

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

“…This result is consistent with cross-species research in both rodents and nonhuman primates showing that the caregiver buffers offspring stress response by regulating HPA axis activity (Moriceau & Sullivan, 2006;Sanchez et al, 2015). That is, around 24 months, the infant may have sufficiently developed social cognitive skills and be better able to interpret subtle and indirect cues from the caregiver, thus facilitating social buffering (Feldman, 2007;Frith, 2008;Hostinar et al, 2014;Tomasello et al, 2005 & Gunnar, 2016;Cordero et al, 2017), and in particular among low-income children (Raffington et al, 2018). The fact that we found a potential maternal buffering effect at 24 months, but not at 7 or 15, possibly indicates a developmental effect.…”

“…In turn, because socioeconomic risk was associated with higher maternal cortisol levels, it may be the case that socioeconomic risk was indirectly affecting infant cortisol activity through the caregiver's stress physiology. Several studies have found flat or blunted cortisol responses in infants and toddlers who experienced early life stress (e.g., Sturge-Apple et al, 2012;Koss, Mliner, Donzella, & Gunnar, 2016;Cordero et al, 2017), and in particular among low-income children (Raffington et al, 2018). Importantly, flat or blunted cortisol responses to stressors may be an adaptive response in the short term; however, they may negatively impact later cognitive, behavioral, and physical health outcomes (Blair, Granger, & Razza, 2005;Ginty, Phillips, Roseboom, Carroll, & Derooij, 2012;Taylor, 2010).…”

Intergenerational transmission of trauma effects: putative role of epigenetic mechanisms

“…Lower cortisol and blunted cortisol reactivity were present in preadolescent boys and girls with maternal PTSD, even after controlling for youth traumatic event history and mental health symptoms. A blunted cortisol reactivity to stress was observed in even younger offspring, toddlers aged 12‐48 months, in association with maternal PTSD occurring as a result of interpersonal violence. Infants of women exposed to maternal child abuse also displayed lower baseline cortisol when examined at 6 months of age.…”

Intimate partner violence indirectly dysregulates child diurnal adrenocortical functioning through positive parenting

“…For example a recent study of hair cortisol, which provides a window into overall adrenocortical arousal across the past weeks or months, revealed a positive association between mothers' report of injury events and child cortisol (Boeckel, Viola, Daruy-Filho, Martinez, & Grassi-Oliveira, 2017). To date, only one study has examined child diurnal cortisol rhythms in relation to IPV (Cordero et al, 2017). Cordero and colleagues found no association between IPV exposure and diurnal cortisol across the day, however, cortisol was only collected on one day and the sample contained only 12 IPV exposed and 8 control toddlers (Cordero et al, 2017).…”

“…In particular, research has consistently documented a link between mothers' experience of IPV and lower levels of warm, supportive, and positive parenting (Chiesa et al, 2018;Gustafsson et al, 2012;Levendosky & Graham-Bermann, 2000); whereas research on the extent to which IPV relates to autonomy supportive versus harsh and controlling parenting is less clear (Chiesa et al, 2018;Levendosky & Graham-Bermann, 2000). Physiologically, IPV has been found to flatten mothers' cortisol diurnal rhythms (Kim et al, 2015;Saxbe et al, 2015) due to heightened evening/ bedtime levels of cortisol (Kim et al, 2015;Pico-Alfonso, Garcia-Linares, Celda-Navarro, Herbert, & Martinez, 2004), or reduced waking cortisol when paired with posttraumatic stress disorder (Cordero et al, 2017). However, few studies have examined the potential for IPV to indirectly impact child diurnal cortisol regulation through dysregulations in maternal behavior and physiology.…”