Cortisol and Children

Abstract

This paper provides an introduction to cortisol production in children. A brief discussion is presented, noting moderators in the production of cortisol in children, such as age, biological sex, and caregiver attachment. Specifically identifying differences in cortisol production amongst securely attached, insecurely attached, and neglected/abused children. Finally, considerations for future investigators are overviewed. Future papers would benefit from narrowing their search to a sub-population of children (i.e., abused/maltreated).

Keywords: children, cortisol, stress

The hypothalamic-pituitary-adrenal (HPA) axis plays a significant role in disseminating cortisol and seems to be more sensitive to perceived social threats (i.e., being judged, criticized) (Cicchetti, Rogosch, Gunnar, & Toth, 2010; Frigerio, Ceppi, Rusconi, Giorda, Raggi, & Fearon, 2009; Smeeken, Riksen-Walraven, & Bakel, 2007). Cortisol is produced on a diurnal curve; an individual’s cortisol levels are at their highest thirty minutes after waking, declining throughout the day, reaching its lowest point in the evening before bed. Since cortisol levels typically wan throughout the day, cortisol can act as a biomarker to gauge an individual’s response to a particular stressor or to gauge baseline stress levels (Cicchetti, Rogosch, Gunnar, & Toth, 2010; Sims, Guilfoyle, & Parry, 2006).An investigator can assess a child's urine, saliva, or blood samples to measure their cortisol levels. In order to ascertain a child's basal cortisol levels, samples would ideally be collected over a period of time (i.e., at multiple points during the day, over a period of time). The least invasive sample method would be dependent on the child's age.

Sims, Guilfoyle, and Parry (2006) found that the quality of care children receive impacts their cortisol levels throughout the day. However, a child's cortisol production has many moderators, such as age, biological sex, and disposition. Our understanding of children's cortisol production is heavily influenced by the time of day at which the sample is taken (Alink, van IJzendoorn, Bakermans-Kranenburg, Mesman, Juffer, & Koot, 2008). The variance in methodology has led to a fragmented understanding of cortisol activity in children. Frigerio et al. (2009) stated that children's basal cortisol levels are lower than adults and there is more variance in levels amongst individual children. Cicchetti, Rogosch, Gunnar, & Toth (2010) noted that age plays a role in this variance: older children are thought to have higher cortisol levels in the morning and a sharper decrease in the afternoon. Somewhat in-line with this Bernard, Peloso, Laurenceau, Zhang, and Dozier (2015) discuss that cortisol is higher in preschool-aged children and lower in infants and school-aged children.

Lewis and Ramsay (1997) found that heightened cortisol reactivity during the first year of life precipitates an earlier development of self-recognition: the ability to notice and react to internal stimuli. Lewis and Ramsay suggest that the premature development of self-recognition could be indicative of an insecure attachment between the child and caregiver. However, the earlier development of self-recognition does not seem to impact other infant behaviors.

Children who have more social anxiety, less social skills, and less impulse control tend to produce more cortisol throughout the day. It has been suggested that biologically male children seem to be at greater risk for heightened/prolonged cortisol levels (Sims, Guilfoyle, & Parry, 2006). However, Cicchetti, Rogosch, Gunnar, and Toth (2010) did not find biological-sex to play a role in cortisol response or development. It has been postulated that hypercorticism could be indicative of a more engaged coping response, and hypo-corticism might be indicative of a passive coping response (Sims, Guilfoyle, & Parry, 2006).

Contrary to this, Alink, et al., (2008) completed a meta-analysis that found "a small but significant relation between basal levels of cortisol and externalizing behaviors, whereas cortisol reactivity was not consistently associated with externalizing behavior" (p. 441). This finding is less than equivocal to previous findings. Demonstrating a variance and mild-inflation of results in past studies. Alink et al. further discuss that

“the overall association between cortisol and externalizing behaviors appears to be small, but [the authors] found an important age effect. Higher levels of externalizing behavior are associated with higher basal levels of cortisol (hyperactivity) in preschoolers, and with lower basal levels of cortisol (hypoactivity) in school-aged children” (p. 445).

Frigerio et al. (2009) agreed: finding that preschool children with higher basal cortisol levels tend to engage in more aggressive behavior, whereas older children tend to have lower cortisol levels associated with aggression.

Bernard et al. (2015) discussed further that preschool-aged children exhibit heightened and prolonged cortisol production when beginning or changing care settings. Bernard et al. discuss that the transition to child care often leads to peer engagement for the first time. The social stressors associated with this epoch understandably provoke a more intense response as a child learns, perhaps for the first time, how to engage with other children. Those who have spent the first few years of life with their primary caregiver might demonstrate a more pronounced response as they adjust to a new setting with new adult supports.

How a child responds to stress is subject to directional change based on a complex interaction amongst the child, their environment, their genetics, and their social supports (Cicchetti, Rogosch, Gunnar, & Toth, 2010). Child-caregiver attachment is seen as a biologically beneficial mechanism that allows for the modulation of fear and distress through physiological co-regulation processes. When a child is distressed, a secure attachment to their caregiver precipitates movement to the caregiver, allowing for the modulation of distress through co-regulation and supportive engagement. Children with a more secure caregiver attachment demonstrate less cortisol activation, more flexibility, adaptability, and social engagement (Frigerio et al., 2009; Sims, Guilfoyle, & Parry, 2006). Children with stressed attachment figures demonstrate more antisocial tendencies (Sims, Guilfoyle, & Parry, 2006).

When an insecurely attached child is distressed, they may not seek engagement with their caregiver, or they may actively avoid them. Children who are not securely attached to their caregiver tend to have issues with self-regulation, flexibility, and struggle behaviorally under stress (Frigerio et al., 2009). Children with an insecure caregiver attachment are more susceptible to cortisol activation during difficult caregiver interactions (Smeeken, Riksen-Walraven, & Bakel, 2007). This heightened cortisol response leads to dysregulation-induced behaviors in the child; difficulty with co-regulation amongst the child-caregiver dyad and frustration on behalf of the caregiver, leading to further negative interactions (Sims, Guilfoyle, & Parry, 2006).

Children who are abused and/or maltreated are at higher risk for experiencing depression in childhood and into adulthood (Cicchetti, Rogosch, Gunnar, & Toth, 2010). This is thought to be due to a genetic predisposition in the 5-HTTLPR gene. 5-HTTLPR is a polymorphism involved in the transcription of serotonin in the serotonin transporter gene. The short allele of 5-HTTLPR has been associated with heightened cortisol-stress response in children (Cicchetti, Rogosch, Gunnar, & Toth, 2010; Frigerio et al., 2009). Heightened cortisol activation, as seen in abused/ maltreated children, is thought to play a role in the phenotype of depression within this population.

Cicchetti, Rogosch, Gunnar, & Toth (2010) discusses how early abuse/neglect leads to a dysregulation of the HPA-axis that often follows children into adulthood. These long-standing neuroendocrine impacts are due to the rapid amount of brain development which happens in the first five years of life (Bernard et al., 2015). Children who experience abuse/maltreatment before the age of five demonstrated more internalizing behaviors. Those children also exhibited a flattening of cortisol production during the day.

Diurnal cortisol flattening can lead to cardiovascular impairments and immune dysfunction. Prolonged activation of the HPA can lead to overproduction of glucocorticoids, which can cause cognitive impairments, health problems, and in children: difficulty with memory. Overactivation of the HPA axis can lead to the loss of hippocampal neurons. Hypocorticism has been positively correlated with false recognition memory in children who have been maltreated/abused (Cicchetti, Rogosch, Howe, & Toth, 2010).

In a typical population (i.e., not abused/maltreated), when children produce more cortisol at night, it could lead to hypocortisolism in the morning (Bernard et al., 2015). Children who have insomnia coupled with shorter sleep duration exhibit heightened HPA activation. This activation leads to heightened cortisol levels in the morning and evening. While some children demonstrate insomnia symptoms, they still get an adequate amount of sleep. Only children who have insomnia symptoms and do not get enough sleep show heightened cortisol production (Fernandez et al., 2014).

Future investigators of cortisol and children should include: specificity of behaviors being measured, cognizance of biasing amongst behavioral reporters (i.e., caregivers may under-report behavioral difficulties), acquisition of pre-stressor baseline, cognizance of hypocortical response making it challenging to track a behavioral reaction, sensitivity to testing environment which may evoke a skewed baseline, and cognizance of stressor in relation to child's disposition (e.g., shy children may be more stressed by social situations than extroverted children) (Alkin, et. al). It may be beneficial for future investigators to also elucidate the many moderators of cortisol production in children ( Bernard et al., 2015).

Frigerio et al.(2009) suggest that an enzyme produced in oral mucosa known as alpha-amylase (AA) might be a more sensitive biomarker for sympathetic nervous system (SNS) activation. AA production increases under even mild stressors and correlates with typically thought of physiological activation patterns of the SNS (increase in heart rate, systolic blood pressure). A deeper understanding of AA production in times of stress may prove to be a valuable biomarker in understanding cortisol mediators in children.

In sum, there is much to be explored of how cortisol impacts a child’s behavior. Cortisol's impact on a child's behavior is highly dependent on a myriad of factors, including age, possibly biological sex, caregiver attachment, and the child's subjective experience of environmental stressors. More consistent methodological implementations are needed in order to fully understand children's basal cortisol levels throughout different developmental periods.

References

Alink, L. R. A., van IJzendoorn, M. H., Bakermans-Kranenburg, M. J., Mesman, J., Juffer, F., &

Koot, H. M. (2008). Cortisol and externalizing behavior in children and adolescents: Mixed meta-analytic evidence for the inverse relation of basal cortisol and cortisol reactivity with externalizing behavior.Developmental Psychobiology, 50, 427-450. https://doi.org/10.1002/dev.20300

Bernard, K., Peloso, E., Laurenceau, J., Zhang, Z., & Dozier, M. (2015). Examining Change in Cortisol Patterns During the 10-Week Transition to a New Child-Care Setting.ChildDevelopment,86(2),456–471. https://doi-org.tcsedsystem.idm.oclc.org/10.1111/cdev.12304

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PaperMadeline SteinJune 30, 2020psychophysiology