Repeatedly getting angry, hitting, shaking or yelling at children is linked with smaller brain structures in adolescence, according to a new study published in Development and Psychology.
It was conducted by Sabrina Suffren, PhD, at Université de Montréal and the CHU Sainte Justine Research Centre in partnership with researchers from Stanford University.
The harsh parenting practices covered by the study are common and even considered socially acceptable by most people in Canada and around the world.
“The implications go beyond changes in the brain. I think what’s important is for parents and society to understand that the frequent use of harsh parenting practices can harm a child’s development,” said Suffren, the study’s lead author.
“We’re talking about their social and emotional development, as well as their brain development.”
Serious child abuse (such as sexual, physical and emotional abuse), neglect and even institutionalization have been linked to anxiety and depression later in life.
Previous studies have already shown that children who have experienced severe abuse have smaller prefrontal cortexes and amygdala, two structures that play a key role in emotional regulation and the emergence of anxiety and depression.
In this study, researchers observed that the same brain regions were smaller in adolescents who had repeatedly been subjected to harsh parenting practices in childhood, even though the children did not experience more serious acts of abuse.
“These findings are both significant and new. It’s the first time that harsh parenting practices that fall short of serious abuse have been linked to decreased brain structure size, similar to what we see in victims of serious acts of abuse,” said Suffren, who completed the work as part of her doctoral thesis at UdeM’s Department of Psychology, under the supervision of Professors Françoise Maheu and Franco Lepore.
She added that a study published in 2019 “showed that harsh parenting practices could cause changes in brain function among children, but now we know that they also affect the very structure of children’s brains.”
Children monitored since birth at CHU Sainte-Justine
One of this study’s strengths is that it used data from children who had been monitored since birth at CHU Saint-Justine in the early 2000s by Université de Montréal’s Research Unit on Children’s Psychosocial Maladjustment (GRIP) and the Quebec Statistical Institute. The monitoring was organized and carried out by GRIP members Dr. Jean Séguin, Dr. Michel Boivin and Dr. Richard Tremblay.
As part of this monitoring, parenting practices and child anxiety levels were evaluated annually while the children were between the ages of 2 and 9. This data was then used to divide the children into groups based on their exposure (low or high) to persistently harsh parenting practices.
“Keep in mind that these children were constantly subjected to harsh parenting practices between the ages of 2 and 9. This means that differences in their brains are linked to repetitive exposure to harsh parenting practices during childhood,” said Suffren who worked with her colleagues to assess the children’s anxiety levels and perform anatomical MRIs on them between the ages of 12 and 16.
This study is the first to try to identify the links between harsh parenting practices, children’s anxiety and the anatomy of their brains.
About the study
“Prefrontal cortex and amygdala anatomy in youth with persistent levels of harsh parenting practices and subclinical anxiety symptoms over time during childhood,” by Sabrina Suffren et al, was published by Development and Psychology on March 22,
Adolescence is characterized by an increase in risk taking behaviors. Current neuroscience work views risk taking in adolescence to be derived in part from distinct developmental trajectories of two neural systems (Casey et al., 2008): one underlying the assessment of value and risk associated with appetitive/aversive stimuli (i.e., the valuation system), and a second system exerting control over the pursuit or avoidance of risky options (i.e., the control system). Prior neuroimaging research has linked maltreatment and brain functioning underlying risky decision making by showing that maltreated individuals exhibit blunted reward-related brain activation (Hanson et al., 2015) and impaired regulation-related brain activation (Lim et al., 2015). However, the ways in which different maltreatment experiences (abuse and neglect) may be related to the development of two underlying neural processes of risky decision making (the valuation and the control systems) during adolescence is not clearly understood.
There are two predominant perspectives in the neuroscience literature that address how childhood adversity affects the developing brain. One perspective rooted in stress physiology emphasizes the similarities of childhood adversity effects, arguing that because disruptions in physiological stress responses are the main consequence of various adverse experiences (e.g., poverty, parental deprivation, or exposure to violence), they converge in their effects and thus can be grouped together as “childhood adversity” (Sapolsky, 2017; Smith and Pollak, 2020).
This cumulative approach emphasizes the high prevalence of co-occurring adversity types and focuses more on the number of adverse life events influencing development than the nature of these events (Hughes et al., 2017; Smith and Pollak, 2020). In contrast, another perspective rooted in developmental psychopathology proposes a dimensional approach to measuring childhood adversity, arguing that threat and deprivation are two central dimensions of childhood adversity whose influences on neurobiological development are substantially distinct (McLaughlin and Sheridan, 2016; Sheridan and McLaughlin, 2014).
Considering childhood maltreatment through the lens of violations in the expectable environment (Nelson and Gabard-Durnam, 2020), child maltreatment reflects experiences that are expected but do not occur (i.e., neglect), or that do occur but are atypical in some way (i.e., abuse). Consistent with the conceptualization of threat and deprivation according to the dimensional approach (McLaughlin and Sheridan, 2016; Sheridan and McLaughlin, 2014), abuse refers to acts of commission involving harm, or threat of harm, whereas neglect refers to acts of omission involving deprivation (Rogosch & Cicchetti, 1994).
The main goal of the current study was to address these two competing perspectives by examining cumulative maltreatment experiences versus differentiated measurement of abuse and neglect experiences related to brain development.
Extant neuroscience work presents structural and functional brain sequelae of caregiving adversity, such as abuse and neglect. The neural processes affected in individuals with a history of childhood maltreatment are predominantly in fronto-limbic networks (including the medial prefrontal cortex, orbitofrontal cortex, anterior cingulate cortex, hippocampus, and amygdala).
For the effects of child maltreatment on the control system, a few functional neuroimaging studies using inhibitory control tasks indicate that youths who experienced neglectful and/or abusive care demonstrate heightened activation in the dorsomedial frontal regions which have been linked to inhibitory control and conflict/error processing (Bruce et al., 2013; Lim et al., 2015; Mueller et al., 2010).
First, maltreated foster pre-adolescents (90 % experienced physical neglect and 55 % physical abuse) showed higher activation in the anterior cingulate cortex and middle frontal gyrus compared to their nonmaltreated counterparts (Bruce et al., 2013).
Second, physically abused adolescents showed higher activation in the anterior cingulate cortex as well as bilateral pre-supplementary and supplementary motor area, compared to nonmaltreated adolescents (Lim et al., 2015).
Third, neglected adolescents exhibited higher activation in the inferior frontal cortex and striatum compared to nonmaltreated adolescents (Mueller et al., 2010). Finally, Blair et al. (2019) examined how abuse and neglect were associated with brain activation during an emotion-based inhibitory control task and found that abuse (but not neglect) was differentially related to brain regions that were involved response control versus emotional processing.
Specifically, greater abuse was related to lower activation in the brain regions involved in response control and motor responding (such as the inferior parietal lobule and postcentral gyrus) but higher activation in the brain regions involved in responding to or representing affective information (such as the rostromedial frontal cortex, middle temporal gyrus, and superior temporal gyrus) among adolescents.
Turning to functional neuroimaging studies examining maltreatment and the valuation system, findings indicate that maltreatment is associated with a blunted neural response to reward cues in the orbito-striatal network. Specifically, adolescents with emotional neglect showed blunted development of ventral striatum activity related to reward expectancy over two years (Hanson et al., 2015), and this finding is consistent with another study demonstrating that young adults with childhood maltreatment exhibited blunted anticipatory reward activity in the left basal ganglia relative to young adults without maltreatment experience (Dillon et al., 2009).
Similarly, adolescents primarily with neglect and emotional abuse showed blunted striatum activation related to expected value representation for both approach and avoidance trials, compared to nonmaltreated adolescents (Gerin et al., 2017). Unexpectedly, Gerin and colleagues (2017) found that maltreated adolescents showed greater activation in the putamen during expected value representation while avoiding possible punishment (avoidance trials).
This result suggests altered brain activation during reinforcement learning among maltreated youths; that is, for those whose environments are laden with threat-related cues, avoiding probable punishment may be particularly rewarding.
Although prior research has focused on maltreatment effects on reward processing, choosing high-risk yet high-reward options may be explained not only by the neural processes reacting to the value of the reward but also by the neural processes evaluating the risk associated with the rewarding options. Indeed, value-based decision-making research has shown that risky choices are driven by neural computations associated with the likelihood of receiving rewards as well as the value of rewards (d’Acremont and Bossaerts, 2008; Mohr et al., 2010).
However, it is not known how maltreatment experiences may be related to neural processing of risk valuation. The current investigation integrates the two lines of developmental neuroscience research—adversity effects of the valuation system and adversity effects of the control system—while focusing on risk processing in the valuation system in order to better understand how developmental trajectories of the two primary neural systems related to risk taking may be differentially affected by experiences of maltreatment.
Although different subtypes of child maltreatment tend to co-occur, experiences of different subtypes appear to be distinct enough to differentially influence neurodevelopment. To date, no prospective longitudinal study has examined how abuse and neglect may be differentially related to developmental trajectories of brain functioning throughout adolescence.
Following the dimensional model of childhood adversity (McLaughlin and Sheridan, 2016; Sheridan and McLaughlin, 2014), the current longitudinal study elucidates the effect of child maltreatment on neurodevelopment by evaluating differential contributions of two core dimensions underlying maltreatment: threat (i.e., abuse) and deprivation (i.e., neglect). We further tested whether there are cumulative effects of maltreatment, regardless of dimensions, based on the view that varied types of early adversity converge in producing similar problems later on (e.g., Sapolsky, 2017; Smith and Pollak, 2020). We used conditional latent growth curve modeling to examine dimensional versus cumulative effects of child maltreatment on developmental trajectories of the valuation and the control systems in adolescence.
reference link: https://www.sciencedirect.com/science/article/pii/S187892932100030X?via%3Dihub
Original Research: Closed access.
“Prefrontal cortex and amygdala anatomy in youth with persistent levels of harsh parenting practices and subclinical anxiety symptoms over time during childhood” by Sabrina Suffren et al. Development and Psychopathology