Children living in low-income households who endure family instability and emotionally distant caregivers are at risk of having impaired cognitive abilities according to new research from the University of Rochester.
The study of 201 low-income mother-child pairs, conducted at , tracked the levels of the stress hormone, cortisol, in the children at ages 2, 3, and 4. It found that specific forms of family adversity are linked to both elevated and low levels of cortisol in children. Children with either the elevated or low cortisol levels also had lower than average cognitive ability at age 4.
鈥淲hat we were interested in seeing is whether specific risk factors of children living in poverty might be related to children鈥檚 cortisol levels,鈥� said lead author Jennifer Suor, a PhD candidate in clinical psychology. 鈥淭hen we looked to see if the hormone levels are predictive of significant differences in the children鈥檚 ability to think.鈥�
The study, published in the journal , shows that children in low-income, stressful home environments鈥攕pecifically homes with family instability and harsh and disengaged mothers鈥攃an have adverse levels of cortisol in their bodies, which previously studies have associated with having damaging effects on the structure and function of children鈥檚 brains.
Understanding how cortisol affects the brain鈥檚 cognitive abilities, though, is still unclear. “The exact mechanisms through which too much or too little cortisol affects cognitive functioning aren’t fully understood,” said coauthor Melissa L. Sturge-Apple, assistant professor of psychology.
“Researchers hypothesize that too much cortisol can have toxic effects on parts of the brain that are important for cognitive functioning, and too little might hinder the body’s ability to recruit the biological resources necessary for optimal cognitive functioning,” Sturge-Apple said.
鈥淢oderate amounts of cortisol is a good thing, though, it helps facilitate cognitive functioning,鈥� added Suor. 鈥淚n the right amount it makes you rise to the occasion and it helps recruit important cognitive resources like memory and the ability to reason. But it鈥檚 a problem when we have too much or too little cortisol.鈥�
The children with family instability or harsh and emotionally distant caregivers at age 2, had elevated cortisol levels, while children with only family instability at age 2, had lower than average cortisol levels. 鈥淲e were surprised to find that the children鈥檚 cortisol levels, which we test from a cheek swab, didn鈥檛 change鈥攖hey remained relatively stable over the three years,鈥� Suor said.
Family instability includes frequent changes in care providers, household members, or residence. Such instability, the researchers said, reflects a general breakdown of the family鈥檚 ability to provide a predictable and stable environment for the child.
Suor added that 鈥渢here are other environmental and biological factors that might contribute to children’s lower cognitive functioning. However, our research, as well as previous studies, has indicated that cortisol plays a role in cognitive functioning.鈥�
鈥淭here is a public awareness relevance to this study. We saw really significant disparities in the children鈥檚 cognitive abilities at age four鈥攔ight before they enter kindergarten,鈥� Suor said. 鈥淪ome of these kids are already behind before they start kindergarten, and there is research that shows that they鈥檙e unlikely to catch up.鈥�
The researchers said that prevention and intervention could help these at-risk children. 鈥淥ur findings support the need for an investment in community-based interventions that can strengthen parent-child relationships and reduce family stress very early in a child鈥檚 life,鈥� Suor said.
鈥淎 lot of research that we鈥檝e done at Mt. Hope shows that using preventative interventions can help moms parent their children in ways that may lead to improvements in their children鈥檚 cortisol.鈥�
Patrick Davies and Liviah Manning, from the University of Rochester, and Dante Cicchetti, from the University of Minnesota and Mt. Hope Family Center, coauthored the study. The National Institute of Mental Health supported the research.
