Research Spotlights: August 2021

High daily screen time linked to cognitive and behavioral problems in preterm children

Previous research has demonstrated that preterm birth and increased screen time are independently associated with a risk of adverse child development and behavioral outcomes. However, the combined association between high screen time in early school age and adverse cognitive, executive function, language, and behavior outcomes in extremely preterm children is not highly documented. A study sponsored by the NICHD aims to answer this question.

To examine this question, the researchers used a cohort study that includes 414 Extremely Premature (EPT) children born at less than 28 weeks between 2005 and 2009 and evaluated at two age points: 6 years 4 months to 7 years 2 months. Of the 414 children included in the analysis (227 (55 percent) boys), a total of 238 children (57 percent) had high screen time (>2 hours per day), and 266 (64 percent) had a television/computer in their bedroom. Outcomes included growth parameters and results from the Wechsler Intelligence Scale for Children-IV, the Behavior Rating Inventory of Executive Function, the Developmental Neuropsychological Assessment, the Conners 3rd Edition–Parent Short-Form, and the Social Communication Questionnaire.

High screen time was associated with (1) a lower full-scale IQ, (2) higher association with deficits in executive functions, (3) lower global executive function and impulse control, and (4) and inattention. Furthermore, a television/computer in the bedroom was also associated with an increase in inhibition and hyperactivity/impulsivity. The findings of this study suggest that high screen time is related to adverse cognitive, executive function, and behavior outcomes at ages 6 to 7 years in children born extremely preterm.

Although the directionality cannot be completely ruled out (e.g., increased screen time might be used to calm bad behavior), these findings suggest that a high level of screen time could have a negative impact on children who were born extremely premature. The implication is that health care professionals should discuss both the benefits and risks of screen time with families who have extremely premature children.

Vohr BR, McGowan EC, Bann C, Das A, Higgins R, Hintz S; Eunice Kennedy Shriver National Institute of Child Health and Human Development Neonatal Research Network. 2021. Association of High Screen-Time Use With School-age Cognitive, Executive Function, and Behavior Outcomes in Extremely Preterm Children. JAMA Pediatr. Jul 12:e212041. doi: 10.1001/jamapediatrics.2021.2041. Epub ahead of print. PMID: 34251406; PMCID: PMC8276120.

Variable mental health of college students during the COVID-19 pandemic

What is the best strategy for coping with life during the pandemic for young adults in college? A study partly supported by the NIMH aims to address this question. To examine the correlates to positive mental health outcomes, this mixed-method study examined the experiences of college students during the COVID-19 pandemic through surveys and experience sampling data collected over two academic quarters [n1 = 253 (Spring 2019); n2 = 147 (Spring 2020)]. Researchers also collected data through semi-structured interviews with 27 undergraduate students.

Descriptively, they found that students in both the 2019 and 2020 cohorts who demonstrated more mental health symptoms at the initial assessment at the beginning of each semester showed worse psychosocial functioning throughout the entire semester relative to other students. Furthermore, rates of distress increased faster in 2020 than in 2019 for individuals that showed more mental health symptoms at the start of each semester.

Comparing 2019 and 2020, there was no average change in students’ levels of depressive symptoms, anxiety, stress, or loneliness. However, thematic analysis of the interviews showed differences in the students’ experiences and variation in how the students adapted to the pandemic. More specifically, the researchers found that students who used positive/problem-focused strategies (such as seeking advice, cognitive reappraisal, creating a plan, focusing on the positive aspects, initiating remote study, or organized hangout sessions with peers) tended toward lower mental distress compared to students who disengaged from social activity or ignored their stressors.

Although the researchers could not rule out reverse causality (the more resilient students took positive steps to help them cope), these findings suggest that behavioral interventions that are problem-focused and oriented toward peer role modeling could have a beneficial impact.

Morris ME, Kuehn KS, Brown J, Nurius PS, Zhang H, Sefidgar YS, et al. 2021. College from home during COVID-19: A mixed-methods study of heterogeneous experiences. PLoS ONE 16(6): e0251580.

Gut bacteria are associated with how infants experience fear

In 1-year-old infants, the gut microbiome is associated with fear behavior according to a recent study supported by the NINDS, NIGMS, NIDDK, NIMH, and the National Science Foundation. The first year of life is a crucial period for the establishment of the gut microbiome, as well as for brain development and the development of fear behavior. Previous research has linked the variation in the infant gut microbiome to cognitive development. However, the gut microbiome’s relationship with the development of fear behavior is unknown.

To determine if the gut microbiome is connected to the establishment of fear behavior, the researchers designed a pilot study with 34 infants who were controlled for factors that could impact the gut microbiome. The infants had two study visits: visit 1 at the age of 1 month, visit 2 at approximately 1 year, and a phone interview at 6 months. Data collected at each visit included sociodemographic; medical; feeding history; State Trait Anxiety Inventory; Life Experiences Survey; Infant Behavior Questionnaire-Revised; neuroimaging; and a fecal sample, which characterized the infants’ microbiome. Behavioral tasks assessed infants’ fear response by examining infant attachment as the caregiver and a stranger enter and exit the room and the expression of non-social fear in response to a person wearing masks in front of the infant.

In this pilot study, the researchers saw significant associations between specific features of the gut microbiome and the strength of infant fear responses. For example, children with microbiomes dominated by a small set of bacteria at 1 month of age were more fearful at 1 year of age. Additionally, the content of the microbial community at 1 year of age was related to fear responses in that compared with less fearful children; infants with heightened fear responses again had microbiomes dominated by a small set of bacteria. This connection between the children’s gut microbiome and responses to strangers only applied when strangers were wearing masks. This may be due to how different parts of the brain are involved in processing potentially frightening situations. MRI brain imaging revealed the content of the microbial community at 1 year was associated with the size of the amygdala, a brain region that involved in making decisions about potential threats.

In summary, this small pilot study indicates associations of the human infant gut microbiome with fear behavior and possible relationships with fear-related brain structures, such as the amygdala, but further validation of these finding will be necessary in the future with a larger number of participants. Since behavioral inhibition in infancy has been shown to predicts future internalizing psychopathology as an adult, this study may have implications for psychiatric disorders and behavioral problems characterized by abnormal fear reactivity.

Carlson, A.L., Xia, K., Azcarate-Peril, M.A. et al. 2021. Infant gut microbiome composition is associated with non-social fear behavior in a pilot study. Nat Commun 12, 3294.