[Article Review] Exploring the Impact of Early-Life Penicillin Exposure on Gut Microbiome and Brain Gene Expression

Reference

Volkova, A., Ruggles, K., Schulfer, A., Gao, Z., Ginsberg, S. D., & Blaser, M. J. (2021). Effects of early-life penicillin exposure on the gut microbiome and frontal cortex and amygdala gene expression. iScience, 24(7), 102797. https://doi.org/10.1016/j.isci.2021.102797

Review

The study by Volkova et al. (2021) explores the effects of early-life exposure to low-dose penicillin on the gut microbiome and gene expression in the frontal cortex and amygdala of mice. The researchers used a model system that is highly relevant to human exposure and could potentially be developed into a preclinical model for neurodevelopmental disorders. The study found that early-life exposure to low-dose penicillin led to substantial changes in the intestinal microbiota population structure and composition.

Transcriptomic alterations in the study implicated pathways that are perturbed in neurodevelopmental and neuropsychiatric disorders. The researchers also discovered significant effects on the frontal cortex and amygdala gene expression through bioinformatic interrogation, affecting multiple pathways underlying neurodevelopment. Informatic analyses established linkages between specific intestinal microbial populations and the early-life expression of particularly affected genes.

The study by Volkova et al. (2021) provides valuable insights into the potential effects of early-life antibiotic exposure on the gut microbiome and brain gene expression. These findings contribute to the growing body of evidence that supports the importance of the gut-brain axis in neurodevelopmental and neuropsychiatric disorders. This research serves as a foundation for future studies exploring the role of the intestinal microbiome in the normal and abnormal maturation of the central nervous system.

[Article Review] The Gut-Brain Connection: Bacteroidetes-Dominant Microbiome Linked to Enhanced Neurodevelopment in Infancy

Reference

Tamana, S. K., Tun, H. M., Konya, T., Chari, R. S., Field, C. J., Guttman, D. S., Becker, A. B., Moraes, T. J., Turvey, S. E., Subbarao, P., Sears, M. R., Pei, J., Scott, J. A., Mandhane, P. J., & Kozyrskyj, A. L. (2021). Bacteroides-dominant gut microbiome of late infancy is associated with enhanced neurodevelopment. Gut Microbes, 13(1), 1930875. https://doi.org/10.1080/19490976.2021.1930875

Review

The article by Tamana et al. (2021) investigates the association between gut microbiota and early neurodevelopment in infants. The authors analyzed data from 405 infants from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study, using the Bayley Scale of Infant Development (BSID-III) to assess neurodevelopmental outcomes at 1 and 2 years of age. Fecal samples were collected at a mean age of 4 and 12 months for microbiota profiling using 16S rRNA gene sequencing.

The study identified three infant groups based on the relative abundance of gut microbiota at 12 months: Proteobacteria-dominant, Firmicutes-dominant, and Bacteroidetes-dominant clusters. The Bacteroidetes-dominant cluster demonstrated a significant positive association with cognitive, language, and motor development scores at age 2, particularly among male infants. The genus Bacteroides abundance in gut microbiota was positively correlated with cognitive and language scores at age 2. The study found no associations between 4-month microbiota clusters and BSID-II scores.

Tamana et al. (2021) suggest that Bacteroidetes-dominant gut microbiota in late infancy is associated with better neurodevelopment, particularly in males. Enhanced sphingolipid synthesis and metabolism, as well as antagonism or competition between Bacteroides and Streptococcus, were characteristic of Bacteroidetes-dominant gut microbiota. This study contributes valuable insights into the gut-brain connection and the potential impact of gut microbiota on early neurodevelopment.

[Article Review] The Impact of High Screen Time on Cognitive and Behavioral Outcomes in Extremely Preterm Children

Reference

Vohr, B. R., McGowan, E. C., 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 Pediatrics, 175(10), 1025-1034. https://doi.org/10.1001/jamapediatrics.2021.2041

Review

In a cohort study conducted by Vohr et al. (2021), the authors assessed the association of high screen time with cognitive, language, executive function, and behavior outcomes in extremely preterm children (EPT) aged 6 to 7 years. The secondary objective of the study was to examine the association between high screen time and rates of structured physical activity and weight.

The study included 414 EPT children born between February 1, 2005, and February 28, 2009, and evaluated between 2012 and 2016. The cohorts were divided into children exposed to low (≤2 hours per day) vs. high (>2 hours per day) amounts of screen time and by the presence (no vs. yes) of a television/computer in the bedroom.

The findings of the study revealed that high screen time was independently associated with lower full-scale IQ, and increased deficits in executive functions, including metacognition, global executive function, inhibition, and Conners 3rd Edition–Parent Short-Form inattention. Additionally, a television/computer in the bedroom was associated with an increase in inhibition and hyperactivity/impulsivity problems.

The authors concluded that high screen time contributes to adverse cognitive, executive function, and behavior outcomes at ages 6 to 7 years in children born at less than 28 weeks. This study emphasizes the need for clinicians to be aware of the risks for EPT children and discuss both the benefits and risks of screen time with families.

[Article Review] The Long-term Impact of Being Born Small for Gestational Age on Cognitive Performance

Reference

Eves, R., Mendonça, M., Bartmann, P., & Wolke, D. (2020). Small for gestational age—cognitive performance from infancy to adulthood: an observational study. BJOG: An International Journal of Obstetrics & Gynaecology, 127(13), 1600-1606. https://doi.org/10.1111/1471-0528.16341

Review

Eves et al. (2020) aimed to investigate the cognitive performance of individuals born small for gestational age (SGA) from infancy to adulthood and determine if the effect depends on the SGA reference used. The study involved 414 participants, including 197 term-born and 217 very preterm/very low birth weight (VP/VLBW) individuals, and used neonatal or fetal growth references to classify SGA. The results indicated that SGA is associated with an eight-point lower IQ compared to appropriate for gestational age, regardless of the reference used. The difference was evident throughout development but narrowed minimally in adulthood. Moreover, the authors found that low socioeconomic status and a poor parent-infant relationship were associated with lower IQ, which was comparable to the effects of SGA.

The study’s strengths lie in its comprehensive evaluation of cognitive performance across different developmental stages and its consideration of potential confounding factors such as VP/VLBW, socioeconomic status, and parent-infant relationship. The use of two SGA references also increases the study’s validity. However, the study's limitations include the lack of ethnic diversity in the sample and the use of only one measure for parent-infant relationship assessment. Nonetheless, the findings suggest that social factors should be considered for interventions aimed at improving cognitive development in SGA individuals.

The study’s findings have significant implications for healthcare providers and policymakers. Identifying SGA individuals and providing appropriate interventions could potentially mitigate the risk of lower IQ throughout development. Additionally, the study’s results suggest the importance of addressing social determinants of health to improve cognitive outcomes in individuals born to SGA. Healthcare providers could potentially screen for SGA individuals and offer developmental interventions while considering potential social factors affecting cognitive performance.

[Article Review] How Very Preterm Birth or Very Low Birth Weight Impacts Intelligence in Adulthood

Reference

Eves, R., Mendonça, M., Baumann, N., Ni, Y., Darlow, B. A., Horwood, J., Woodward, L. J., Doyle, L. W., Cheong, J., Anderson, P. J., Bartmann, P., Marlow, N., Johnson, S., Kajantie, E., Hovi, P., Nosarti, C., Indredavik, M. S., Evensen, K.-A. I., Räikkönen, K., Heinonen, K., Zeitlin, J., & Wolke, D. (2021). Association of very preterm birth or very low birth weight with intelligence in adulthood: An individual participant data meta-analysis. JAMA Pediatrics, 175(8), e211058. https://doi.org/10.1001/jamapediatrics.2021.1058

Review

In this article, Eves et al. (2021) assessed the differences in adult IQ between individuals born very preterm (VPT) or with very low birth weight (VLBW) and term-born individuals. The authors conducted a systematic review of published data and a meta-analysis of individual participant data (IPD) from cohorts in two consortia (RECAP and APIC). The study included 2135 adults (1068 VPT/VLBW and 1067 term-born participants) born between 1978 and 1995.

The researchers found that VPT/VLBW participants had mean adult IQ scores that were 0.78 SD lower than term-born participants, equivalent to a difference of 12 IQ points. Among VPT/VLBW participants, lower gestational age, lower birth weight z scores, the presence of neonatal bronchopulmonary dysplasia or any grade of intraventricular hemorrhage, and lower maternal educational levels were all significantly associated with lower IQ scores in adulthood.

The findings from this IPD meta-analysis provide valuable insights into the factors associated with lower adult IQ in individuals born with VPT or VLBW. The study emphasizes the importance of addressing neonatal morbidities and maternal educational levels as potential interventions to improve long-term cognitive outcomes for this population.

[Article Review] Early SSRI Treatment in 22q11.2 Deletion Syndrome: A Promising Path for Cognition and Brain Development?

Reference

Mancini, V., Maeder, J., Bortolin, K., Schneider, M., Schaer, M., & Eliez, S. (2021). Long-term effects of early treatment with SSRIs on cognition and brain development in individuals with 22q11.2 deletion syndrome. Translational Psychiatry, 11, 336. https://doi.org/10.1038/s41398-021-01480-3

Review

The present study by Mancini et al. (2021) investigates the long-term effects of early treatment with selective serotonin reuptake inhibitors (SSRIs) on cognition and brain development in individuals with 22q11.2 deletion syndrome (22q11DS). This genetic disorder has the highest risk for schizophrenia, making it an ideal population for studying the development of individuals at risk for psychosis. The authors conducted a retrospective cohort study with 98 participants, aged 10 to 32, diagnosed with 22q11DS, and followed up 2–4 times.

The participants were divided into three groups: those without psychiatric disorders and no psychotropic medications (n = 30), those with psychotic symptoms but not treated with SSRIs (n = 30), and those receiving SSRI treatment (n = 38). The authors observed increased IQ scores and developmental trajectories in participants treated with SSRIs, including those with psychotic symptoms. Additionally, the thickness of frontal regions and hippocampal volume were relatively increased in the treated group. The magnitude of the outcomes was inversely correlated to the age at the onset of the treatment.

This study provides preliminary evidence that early long-term treatment with SSRIs may attenuate the cognitive decline associated with psychosis in 22q11DS and developmental brain abnormalities. The findings hold promise for identifying novel strategies to improve cognitive and brain development in individuals with 22q11DS, as well as other populations at risk for psychosis. However, more research is needed to confirm and expand these findings and to explore the potential benefits and risks of early SSRI treatment in this population.

[Article Review] Unraveling the Mysteries of Decision Acuity and Its Impact on Mental Health

Reference

Moutoussis, M., Garzón, B., Neufeld, S., NSPN Consortium, Guitart-Masip, M., Dolan, R. J. (2021). Decision-making ability, psychopathology, and brain connectivity. Neuron, 109(10), 1595-1610. https://doi.org/10.1016/j.neuron.2021.04.019

Review

The article by Moutoussis et al. (2021) examines the concept of "decision acuity," which they define as a general decision-making ability. The authors argue that decision acuity is distinct from intelligence quotient (IQ) and has implications for mental health, specifically in terms of social functioning and aberrant thinking. They also explore the relationship between decision acuity and brain connectivity.

In their study, Moutoussis et al. (2021) analyzed data from 830 young participants, who completed 32 decision-making tasks. The authors found a common factor across these tasks, which they termed decision acuity. This factor was distinct from IQ and appeared to represent a general decision-making ability. Furthermore, lower decision acuity was associated with increased psychopathology, such as aberrant thinking and decreased social functioning.

The researchers also investigated the neural basis of decision acuity by analyzing resting-state functional connectivity in the participants' brains. They discovered that decision acuity and IQ had distinct neural signatures, suggesting that the two constructs are separate cognitive processes. Importantly, the relationship between decision acuity and functional connectivity remained stable even when measured in the same individuals 18 months later, indicating that decision acuity is a consistent and measurable construct.

This study contributes to the field of computational psychiatry by introducing a new cognitive construct, decision acuity, which has potential implications for understanding mental health. The findings suggest that decision acuity may be a crucial factor in understanding psychopathology, particularly in relation to poor social function and aberrant thought patterns. Furthermore, the distinction between decision acuity and IQ sheds light on the complex nature of human cognition and the neural networks that underlie it.

Future research could explore the potential applications of decision acuity in clinical settings, as well as the development of interventions aimed at improving decision-making abilities and addressing associated psychopathology. Additionally, more in-depth investigations into the specific brain networks involved in decision acuity could provide valuable insights into the neural mechanisms that govern this cognitive process.

[Article Review] Revolutionizing Psychometric Test Norms: How Continuous Norming Outperforms Conventional Methods

Reference

Lenhard, W., & Lenhard, A. (2021). Improvement of Norm Score Quality via Regression-Based Continuous Norming. Educational and Psychological Measurement, 81(2), 229-261. https://doi.org/10.1177/0013164420928457

Review

In their article, Lenhard and Lenhard (2021) compared semiparametric continuous norming (SPCN) with conventional norming methods to improve the quality of norm scores in psychometric tests. The authors simulated test scales with varying item numbers and difficulties and used random samples to model norm scores through either conventional ranking procedures or SPCN. Cross-validation and error measures were computed using a representative sample of 840,000 individuals.

The results indicated that both approaches benefitted from an increase in sample size, but SPCN achieved optimal results with smaller samples compared to conventional norming. Furthermore, conventional norming performed worse in terms of data fit, age-related errors, and missing values in norm tables. The authors questioned the general recommendations for sample sizes in test norming due to the varying data fit in conventional norming with fixed subsample sizes.

Lenhard and Lenhard (2021) concluded that test norms should be based on statistical models of raw score distributions rather than simply compiling norm tables via conventional ranking procedures. This study highlights the potential for SPCN to improve norm score quality in psychometric testing, which may lead to better interpretation and utility of test results in educational and psychological settings.

[Article Review] Building Resistance Against Online Misinformation: Unraveling the Bad News Game

Reference

Roozenbeek, J., Maertens, R., McClanahan, W., & van der Linden, S. (2021). Disentangling Item and Testing Effects in Inoculation Research on Online Misinformation: Solomon Revisited. Educational and Psychological Measurement, 81(2), 340-362. https://doi.org/10.1177/0013164420940378

Review

In the article, "Disentangling Item and Testing Effects in Inoculation Research on Online Misinformation: Solomon Revisited" (2021), Roozenbeek, Maertens, McClanahan, and van der Linden address methodological questions about the effectiveness of the "Bad News" game, an online fake news inoculation tool. The authors investigate the potential item and testing effects, which may influence the observed intervention effects. Their study, based on two online experiments with a total of 2,159 participants, showed that while item effects somewhat influenced inoculation interventions, testing effects did not.

The researchers found that inoculation interventions were effective at improving people's ability to identify misinformation techniques, without making them more skeptical of real news. These findings suggest that the "Bad News" game is a promising tool for building cognitive resistance against misinformation online. By examining the item and testing effects, this study provides valuable insights into the methodological issues in evaluating real-world psychological interventions.

[Article Review] Mediterranean Diet and Cognitive Function: A Review on the Relationship with Brain Aging

Reference

Corley, J., Cox, S. R., Taylor, A. M., Hernandez, M. V., Maniega, S. M., Ballerini, L., Wiseman, S., Meijboom, R., Backhouse, E. V., Bastin, M. E., Wardlaw, J. M., & Deary, I. J. (2020). Dietary patterns, cognitive function, and structural neuroimaging measures of brain aging. Experimental Gerontology, 142, 111117. https://doi.org/10.1016/j.exger.2020.111117

Review

This article by Corley et al. (2020) investigates the cross-sectional associations between dietary patterns, cognitive function, and neuroimaging measures of brain health in healthy older adults. The study used data from 511 participants in the Lothian Birth Cohort 1936, with a mean age of 79.3 years. The researchers used principal component analysis of food frequency questionnaire items to identify two dietary patterns: a Mediterranean-style dietary pattern and a processed dietary pattern.

The Mediterranean-style dietary pattern was found to be associated with better verbal ability, while associations with global cognitive function, visuospatial ability, and memory did not survive correction for multiple comparisons. The processed dietary pattern was associated with lower cognitive scores, but these associations were attenuated after adjusting for prior childhood cognitive ability. The only remaining association was with verbal ability. Neither dietary pattern was found to be associated with brain volumes or white matter microstructure.

The authors concluded that adherence to a Mediterranean-style diet is associated with better cognitive functioning but not better brain structural integrity in older adults. Specific features of the Mediterranean diet, such as green leafy vegetables and a low intake of red meat, were found to be associated with better cognitive functioning.

This study provides valuable insights into the potential benefits of adhering to a Mediterranean-style diet for maintaining cognitive health in older adults. However, further research is needed to explore the potential mechanisms underlying these associations and to determine if these findings can be generalized to different populations.

[Article Review] Uncovering the Impact of Cannabis on Youth IQ: A Comprehensive Review

Reference

Power, E., Sabherwal, S., Healy, C., O'Neill, A., Cotter, D., & Cannon, M. (2021). Intelligence quotient decline following frequent or dependent cannabis use in youth: a systematic review and meta-analysis of longitudinal studies. Psychological Medicine, 51(2), 194-200. https://doi.org/10.1017/S0033291720005036

Review

In their recent study, Power et al. (2021) aimed to investigate the relationship between frequent and dependent cannabis use among youth and subsequent decline in Intelligence Quotient (IQ). The authors conducted a systematic review and meta-analysis of cohort studies that included pre- and post-exposure measures of IQ in non-treatment-seeking samples.

The authors searched Embase, PubMed, and PsychInfo databases from their inception until 24 January 2020, and pre-registered their review on PROSPERO (ID no. CRD42019125624). A total of seven cohort studies were identified, including 808 cases and 5308 controls. The studies were of moderate to high quality, and there was a low level of statistical heterogeneity (I2 = 0.2%) among them.

The results indicated a significant effect of frequent or dependent cannabis use in youth on IQ change, with a Cohen's d of -0.132 (95% CI -0.198 to -0.066) and p < 0.001. This translates to an average decline of approximately 2 IQ points following exposure to cannabis in youth. The authors suggest that future studies should include longer follow-up periods to assess the magnitude of developmental impact.

This study is an important addition to the literature on the effects of cannabis use on cognitive functioning and intelligence, particularly in young people. By providing a rigorous, systematic review and meta-analysis, Power et al. (2021) offer valuable insights into the potential negative consequences of frequent or dependent cannabis use on IQ and overall cognitive development.