Parenting Moderates Childhood Brain Stress Response

Child brain development benefits from a positive parenting style and environment.

The mechanism for this positive effect is unclear but moderation of the stress response in the growing child is an area of research interest.

Haroon Sheikh and colleagues from the University of Ontario in Canada recently published results on a study of parenting and brain development in children.

In their study, a cohort of 46 six year old girls underwent brain imaging using a technique known as diffusion tensor imaging or DTI. DTI provides a measure of brain white matter integrity.

This study is informative because all the girls participated in an earlier study of stress reactivity at three years of age. High stress reactivity as measured by serum cortisol response is known to be linked to vulnerability to mood and anxiety disorders.

The key elements in the design of this study including the following:

• Subjects: 45 six year old girls from a larger ongoing longitudinal study of children
• Stress response status: At three years of age participants underwent a two phase study of stress response. A baseline salivary cortisol assay was collected. A second cortisol level was obtained during a stressful task. Subjects were grouped in four categories based on levels of cortisol.
• Parenting assessment: Parents and child participated in a play task. Parents were rated on a measure of parental negative and positive affect.
• MRI scanning: A 3 Telsa brain imaging scan was completed on average two and one-half years following the baseline cortisol and parenting assessment

The main findings from the study included the following:

• High stress reactivity at baseline was linked to lower white matter integrity in prefrontal and basal brain regions (left thalamus, right anterior cingulate cortex and right superior frontal gyrus)
• Positive parental affectivity reduced the brain white matter effects of stress (cortisol) response in the right anterior cingulate cortex and right superior frontal gyrus
• Children with high stress responses at baseline but a positive parental affect environment showed brain integrity findings similar to low stress reactivity children

This is an important study because it suggests an interaction between parental environment and adverse effects of a high stress response in three year old girls. Genetic factors likely contribute to level of stress response in three year old girls. A positive parental style appears to reduce or eliminate adverse effects of high stress reactivity on critical white matter brain development.

The implications of the study are important. High-risk children for mood and anxiety disorders may benefit from early identification and parental training to reduce risk for later psychological morbidity.

Readers with more interest in this study can access the free full-text manuscript by clicking on the PMID link below.

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Sheikh HI, Joanisse MF, Mackrell SM, Kryski KR, Smith HJ, Singh SM, & Hayden EP (2014). Links between white matter microstructure and cortisol reactivity to stress in early childhood: evidence for moderation by parenting. NeuroImage. Clinical, 6, 77-85 PMID: 25379418