Institutional care and iron deficiency increase ADHD symptomology and lower IQ 2.5-5 years post-adoption

Gestational iron deficiency affects the ratio between interneuron subtypes in the postnatal cerebral cortex in mice

Gestational iron deficiency (gID) is highly prevalent and associated with an increased risk of intellectual and developmental disabilities in affected individuals that are often defined by a disrupted balance of excitation and inhibition (E/I) in the brain. Using a nutritional mouse model of gID, we previously demonstrated a shift in the E/I balance towards increased inhibition in the brains of gID offspring that was refractory to postnatal iron supplementation. We thus tested whether gID affects embryonic progenitor cells that are fated towards inhibitory interneurons. We quantified relevant cell populations during embryonic inhibitory neuron specification and found an increase in the proliferation of Nkx2.1+ interneuron progenitors in the embryonic medial ganglionic eminence at E14 that was associated with increased Shh signaling in gID animals at E12. When we quantified the number of mature inhibitory interneurons that are known to originate from the MGE, we found a persistent disruption of differentiated interneuron subtypes in early adulthood. Our data identify a cellular target that links gID with a disruption of cortical interneurons which play a major role in the establishment of the E/I balance.

Iron Deficiency in Infancy and Sluggish Cognitive Tempo and ADHD Symptoms in Childhood and Adolescence

OBJECTIVE

To determine whether iron deficiency in infancy is associated with sluggish cognitive tempo (SCT) or attention-deficit/hyperactive-impulsive (AD-HI) symptoms in childhood and adolescence, and whether such behaviors contribute concurrently and predictively to lower verbal and mathematical abilities.

METHOD

Chilean children (N = 959; 50% male, of Spanish or indigenous descent from working-class backgrounds) were rated by mothers for SCT or AD-HI symptoms at ages 5, 10, and 16 years. Children completed standardized tests assessing verbal and mathematical abilities at ages 5, 10, and 16. At ages 12 and 18 months, children were assessed for iron deficiency.

RESULTS

Adjusting for a comprehensive panel of covariates, greater severity of iron deficiency in infancy was associated with more frequent SCT and AD-HI symptoms at all ages studied. Most effects of iron deficiency on children's verbal and math skills were indirect, mediated through AD-HI behaviors. Children's AD-HI symptoms related to lower verbal and math test scores within age and across age.

CONCLUSIONS

The long-term associations found between infant iron deficiency and SCT and AD-HI behaviors suggest that the neurodevelopmental alterations that stem from postnatal iron deficiency might play an etiological role in the development of ADHD. Screening for early-life nutritional deficiencies among children with SCT or ADHD symptoms might prove useful, and behavioral screening of children with a history of iron deficiency seems warranted. Interventions that support brain development after early nutritional deprivation also would be beneficial.

Iron deficiency and common neurodevelopmental disorders—A scoping review

Background

A wealth of human and experimental studies document a causal and aggravating role of iron deficiency in neurodevelopmental disorders. While pre-, peri-, and early postnatal iron deficiency sets the stage for the risk of developing neurodevelopmental disorders, iron deficiency acquired at later ages aggravates pre-existing neurodevelopmental disorders. Yet, the association of iron deficiency and neurodevelopmental disorders in childhood and adolescence has not yet been explored comprehensively.

In this scoping review, we investigate 1) the association of iron deficiency in children and adolescents with the most frequent neurodevelopmental disorders, ADHD, ASD, and FASD, and 2) whether iron supplementation improves outcomes in these disorders.

Method

Scoping review of studies published between 1994 and 2021 using “iron deficiency / iron deficiency anemia” AND “ADHD” OR “autism” OR “FASD” in four biomedical databases. The main inclusion criterion was that articles needed to have quantitative determination of iron status at any postnatal age with primary iron markers such as serum ferritin being reported in association with ADHD, ASD, or FASD.

Results

For ADHD, 22/30 studies and 4/4 systematic reviews showed an association of ADHD occurrence or severity with iron deficiency; 6/6 treatment studies including 2 randomized controlled trials demonstrated positive effects of iron supplementation. For ASD, 3/6 studies showed an association with iron deficiency, while 3/6 and 1/1 systematic literature review did not; 4 studies showed a variety of prevalence rates of iron deficiency in ASD populations; 1 randomized controlled trial found no positive effect of iron supplementation on behavioural symptoms of ASD. For FASD, 2/2 studies showed an association of iron deficiency with growth retardation in infants and children with prenatal alcohol exposure.

Conclusion

Evidence in favor of screening for iron deficiency and using iron supplementation for pediatric neurodevelopmental disorders comes primarily from ADHD studies and needs to be further investigated for ASD and FASD. Further analysis of study methodologies employed and populations investigated is needed to compare studies against each other and further substantiate the evidence created.

Can Iron Play a Crucial Role in Maintaining Cardiovascular Health in the 21st Century?

In the 21st century the heart is facing more and more challenges so it should be brave and iron to meet these challenges. We are living in the era of the COVID-19 pandemic, population aging, prevalent obesity, diabetes and autoimmune diseases, environmental pollution, mass migrations and new potential pandemic threats. In our article we showed sophisticated and complex regulations of iron metabolism. We discussed the impact of iron metabolism on heart diseases, treatment of heart failure, diabetes and obesity. We faced the problems of constant stress, climate change, environmental pollution, migrations and epidemics and showed that iron is really essential for heart metabolism in the 21st century.

Iron deficiency in infancy and neurocognitive and educational outcomes in young adulthood

This study examines the extent to which iron deficiency in infancy contributes to adverse neurocognitive and educational outcomes in young adulthood directly and indirectly, through its influence on verbal cognition and attention problems in childhood. Young adults (N = 1,000, M age = 21.3 years, 52% female; of Spanish or indigenous descent) from working-class families in Santiago, Chile, completed instruments assessing memory, processing speed, mental flexibility, and educational attainment. Iron status was assessed at ages 6, 12, and 18 months, and verbal intelligence, inattention, and sluggish cognitive tempo (SCT) symptoms were assessed at age 10. Results indicated that young adults who had iron-deficiency in infancy had poor executive control at age 21. Severity of iron deficiency during infancy was associated with lower verbal IQ and more frequent inattention and SCT symptoms in childhood, and with lower educational attainment in young adulthood through its effect on inattention. No additional indirect effects were found. Interventions directed toward improving cognitive and attention deficits linked to early-life iron deficiency appear warranted and could alter the course to adult functioning. Further research on the impact of such interventions would be helpful. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Intestinal parasites may be associated with later behavioral problems in internationally adopted children

Aim

At arrival in new home country, internationally adopted children often have intestinal parasites. International adoptees also exhibit more behavioral problems than their biological peers. We examined whether intestinal parasite infections in international adoptees on arrival in Finland are associated with their later behavioral and emotional problems.

Methods

Data for this study were sourced from the Finnish Adoption Study (FinAdo) based on parental questionnaires for all internationally adopted children under 18 years (n = 1450) who arrived in Finland from 1985 to 2007. A total of 1293 families provided sufficient information on the adoptee’s background, parasitic status on arrival, and behavioral symptoms at the median time of 5 years after arrival (mean age = 7.8 years). Behavioral and emotional disorders were evaluated with the Child Behavior Checklist (CBCL). Statistical analyses were conducted using linear regression.

Results

Of the 1293 families, parents of 206 adoptive children reported intestinal parasites in their adopted children on arrival. Parasite-infected children had subsequently higher CBCL problem scores than the children without parasites (p < 0.001). The association between intestinal parasites and later behavioral problems was stronger than that between intestinal parasites and any other factors measured in this study, except disability.

Limitations

The control group was naturally provided by the adopted children without parasite infections, but we could not compare the adopted children to non-adopted children without a defined parasite infection. We were unable to specify the effects associated with a specific parasite type. It was not possible either to include multiple environmental factors that could have been associated with behavioral problems in the models, which indicated only modest explanatory values.

Conclusions

In this study, intestinal parasite infections in early childhood may be associated with children’s later psychological wellbeing, even in children who move to a country with a low prevalence of parasites. Our findings may support further developments pertaining to the gut-brain theory.

Sensitive periods for psychosocial risk in childhood and adolescence and cardiometabolic outcomes in young adulthood

Greater psychosocial risk in childhood and adolescence predicts poorer cardiometabolic outcomes in adulthood. We assessed whether the timing of psychosocial risk from infancy through adolescence predicts cardiometabolic outcomes in young adulthood. Young adults and their mothers participated in a longitudinal study beginning in infancy in Santiago, Chile (N = 1040). At infancy, 5 years, 10 years, and adolescence, mothers reported on depressive symptoms, stressful experiences, support for child development in the home, father absence, parental education, and socioeconomic status (SES) to create a psychosocial risk composite at each time point. Young adults (52.1% female; 21-27 years) provided fasting serum samples and participated in anthropometric and blood pressure (BP) assessments, including a dual-energy X-ray absorptiometry (DXA) scan for measuring body fat. Greater infant psychosocial risk was associated with a greater young adult metabolic syndrome score (β = 0.07, 95% confidence intervals (CI): 0.01 to 0.13, p = 0.02), a higher body mass index and waist circumference composite (β = 0.08, 95% CI: 0.03 to 0.13, p = 0.002), and a higher body fat (DXA) composite (β = 0.07, 95% CI: 0.01 to 0.12, p = 0.02). No psychosocial risk measure from any time point was associated with BP. Infant psychosocial risk predicted cardiometabolic outcomes in young adulthood better than psychosocial risk at 5 years, 10 years, or adolescence, mean of psychosocial risk from infancy through adolescence, and maximum of psychosocial risk at any one time. Consistent with the Developmental Origins of Health and Disease model, findings suggest that infancy is a sensitive period for psychosocial risk leading to poorer cardiometabolic outcomes in young adulthood.

Nutritional Factors in Fetal and Infant Brain Development

Fetal and infant brain development determine the trajectory of the organism across the lifespan. Optimal maternal and infant nutrition during the period of rapid brain development is vital to the integrity of the neural substrate for subsequent lifelong functions. The goal of this review is to educate the reader on the effects of fetal and infant nutrition on the developing human brain. A review of the literature reveals 6 nutrients that have been studied with respect to maternal nutrition and subsequent offspring brain development: folate, iodine, iron, vitamin D, choline, and docosahexaenoic acid (DHA; 22:6n-3). The research is discussed with a focus on the timing of nutrient needs (preconception, prenatally, and postnatally) as well as potential confounding and unobserved variables.

Impairment of the Developing Human Brain in Iron Deficiency: Correlations to Findings in Experimental Animals and Prospects for Early Intervention Therapy

Due to the necessity of iron for a variety of cellular functions, the developing mammalian organism is vulnerable to iron deficiency, hence causing structural abnormalities and physiological malfunctioning in organs, which are particularly dependent on adequate iron stores, such as the brain. In early embryonic life, iron is already needed for proper development of the brain with the proliferation, migration, and differentiation of neuro-progenitor cells. This is underpinned by the widespread expression of transferrin receptors in the developing brain, which, in later life, is restricted to cells of the blood–brain and blood–cerebrospinal fluid barriers and neuronal cells, hence ensuring a sustained iron supply to the brain, even in the fully developed brain. In embryonic human life, iron deficiency is thought to result in a lower brain weight, with the impaired formation of myelin. Studies of fully developed infants that have experienced iron deficiency during development reveal the chronic and irreversible impairment of cognitive, memory, and motor skills, indicating widespread effects on the human brain. This review highlights the major findings of recent decades on the effects of gestational and lactational iron deficiency on the developing human brain. The findings are correlated to findings of experimental animals ranging from rodents to domestic pigs and non-human primates. The results point towards significant effects of iron deficiency on the developing brain. Evidence would be stronger with more studies addressing the human brain in real-time and the development of blood biomarkers of cerebral disturbance in iron deficiency. Cerebral iron deficiency is expected to be curable with iron substitution therapy, as the brain, privileged by the cerebral vascular transferrin receptor expression, is expected to facilitate iron extraction from the circulation and enable transport further into the brain.

Infant iron deficiency, iron supplementation, and psychosocial stress as predictors of neurocognitive development in Chilean adolescents

Objective: The aim of the current study was to examine the unique and joint contributions of iron deficiency, iron supplementation, and psychosocial stress in infancy and stress in adolescence to neurocognitive functioning in adolescence.Methods: The current study (N = 796; M_age = 14.4y) involved a prospective cohort of low- and middle-socioeconomic status adolescents in Santiago, Chile. As infants, they had participated in an iron supplementation trial. Infant iron status was assessed at 12-18 months, and mothers answered questions about family psychosocial stress at 6-12 months and in adolescence (maternal depressive symptoms, home support for child development, stressful life events, father absence, socioeconomic status, and parental education). Neurocognitive functioning was assessed in adolescence using the Balloon Analogue Risk Task, Stockings of Cambridge, Trail Making Test, Purdue Pegboard Test, and Wisconsin Card Sorting Test.Results: Greater psychosocial stress in infancy predicted less risk-taking, poorer planning abilities and fluid cognition, and slower processing speed in adolescence. Iron deficiency anemia in infancy predicted less risk-taking. Greater adolescent psychosocial stress predicted difficulties in set-shifting. There were no interactions between infant psychosocial stress and iron deficiency predicting adolescent neurocognitive functioning.Conclusion: These results suggest that interventions to reduce infant psychosocial stress may be more likely to prevent multiple neurocognitive deficits in adolescence than interventions to reduce infant iron deficiency.

Iron Deficiency, Cognitive Functions, and Neurobehavioral Disorders in Children

More than 25% of the world's population is affected by anemia, of which more than 50% suffers from iron deficiency anemia (IDA). Children below 7 years of age are the population group that is most vulnerable to iron deficiency. Iron is an essential element in brain metabolism. Iron deficiency can cause changes in neurotransmitter homeostasis, decrease myelin production, impair synaptogenesis, and decline the function of the basal ganglia. Therefore, IDA adversely affects cognitive functions and psychomotor development. Research has shown that iron deficiency is a frequent comorbidity in attention-deficit/hyperactivity disorder (ADHD) and autism spectrum disorder. Iron deficiency may also induce or exacerbate deficiency of other essential nutrients, which may have a negative impact on the developing brain and other organs in infants. Many nations of the world have programs to control IDA based on the use of iron supplementation, intake of fortified food and drinks, improved food safety, and monitoring of dietary diversity. Based on the current recommendations of the World Health Organization on cost-effectiveness (WHO-CHOICE), iron fortification and iron supplementation programs can be considered cost-effective or even highly cost-effective in most countries of the world to averting cognitive impairment.

Blood Levels of Trace Elements in Children with Attention-Deficit Hyperactivity Disorder: Results from a Case-Control Study

Some trace elements may participate in the pathogenesis of attention-deficit hyperactivity disorder (ADHD). This study aimed to investigate the trace element status of zinc (Zn), copper (Cu), iron (Fe), magnesium (Mg), and lead (Pb) in children with ADHD, and to compare them with normal controls. Associations between examined elements and SNAP-IV rating scores of ADHD symptoms were also assessed. Four hundred nineteen children with ADHD (8.8 ± 2.1 years) and 395 matched normal controls (8.9 ± 1.7 years) were recruited in the study. The concentrations of Zn, Fe, Cu, Mg, and Pb in the whole blood were measured by atomic absorption spectrometry. Lower zinc levels (P < 0.001) and the number out of normal ranges (P = 0.015) were found in children with ADHD when compared with the normal control group. The difference remained when adjusting the factor of BMI z-score. No significant between-group differences were found in levels of other elements. Zinc levels were negatively correlated with parent-rated scores of inattentive subscale of SNAP-IV (r = - 0.40) as well as with total score of SNAP-IV (r = - 0.24). Other significant associations were not observed. The present results indicated that there were alterations in blood levels of zinc, which was associated with the symptom scores of ADHD.

Chronic Energy Depletion due to Iron Deficiency Impairs Dendritic Mitochondrial Motility during Hippocampal Neuron Development

During development, neurons require highly integrated metabolic machinery to meet the large energy demands of growth, differentiation, and synaptic activity within their complex cellular architecture. Dendrites/axons require anterograde trafficking of mitochondria for local ATP synthesis to support these processes. Acute energy depletion impairs mitochondrial dynamics, but how chronic energy insufficiency affects mitochondrial trafficking and quality control during neuronal development is unknown. Because iron deficiency impairs mitochondrial respiration/ATP production, we treated mixed-sex embryonic mouse hippocampal neuron cultures with the iron chelator deferoxamine (DFO) to model chronic energetic insufficiency and its effects on mitochondrial dynamics during neuronal development. At 11 days in vitro (DIV), DFO reduced average mitochondrial speed by increasing the pause frequency of individual dendritic mitochondria. Time spent in anterograde motion was reduced; retrograde motion was spared. The average size of moving mitochondria was reduced, and the expression of fusion and fission genes was altered, indicating impaired mitochondrial quality control. Mitochondrial density was not altered, suggesting that respiratory capacity and not location is the key factor for mitochondrial regulation of early dendritic growth/branching. At 18 DIV, the overall density of mitochondria within terminal dendritic branches was reduced in DFO-treated neurons, which may contribute to the long-term deficits in connectivity and synaptic function following early-life iron deficiency. The study provides new insights into the cross-regulation between energy production and dendritic mitochondrial dynamics during neuronal development and may be particularly relevant to neuropsychiatric and neurodegenerative diseases, many of which are characterized by impaired brain iron homeostasis, energy metabolism and mitochondrial trafficking.SIGNIFICANCE STATEMENT This study uses a primary neuronal culture model of iron deficiency to address a gap in understanding of how dendritic mitochondrial dynamics are regulated when energy depletion occurs during a critical period of neuronal maturation. At the beginning of peak dendritic growth/branching, iron deficiency reduces mitochondrial speed through increased pause frequency, decreases mitochondrial size, and alters fusion/fission gene expression. At this stage, mitochondrial density in terminal dendrites is not altered, suggesting that total mitochondrial oxidative capacity and not trafficking is the main mechanism underlying dendritic complexity deficits in iron-deficient neurons. Our findings provide foundational support for future studies exploring the mechanistic role of developmental mitochondrial dysfunction in neurodevelopmental, psychiatric, and neurodegenerative disorders characterized by mitochondrial energy production and trafficking deficits.

Peripheral iron levels in children with attention-deficit hyperactivity disorder: a systematic review and meta-analysis

There is growing recognition that the risk of attention-deficit hyperactivity disorder (ADHD) in children may be influenced by micronutrient deficiencies, including iron. We conducted this meta-analysis to examine the association between ADHD and iron levels/iron deficiency (ID). We searched for the databases of the PubMed, ScienceDirect, Cochrane CENTRAL, and ClinicalTrials.gov up to August 9^th, 2017. Primary outcomes were differences in peripheral iron levels in children with ADHD versus healthy controls (HCs) and the severity of ADHD symptoms in children with/without ID (Hedges' g) and the pooled adjusted odds ratio (OR) of the association between ADHD and ID. Overall, seventeen articles met the inclusion criteria. Peripheral serum ferritin levels were significantly lower in ADHD children (children with ADHD = 1560, HCs = 4691, Hedges' g = -0.246, p = 0.013), but no significant difference in serum iron or transferrin levels. In addition, the severity of ADHD was significantly higher in the children with ID than those without ID (with ID = 79, without ID = 76, Hedges' g = 0.888, p = 0.002), and there was a significant association between ADHD and ID (OR = 1.636, p = 0.031). Our results suggest that ADHD is associated with lower serum ferritin levels and ID. Future longitudinal studies are required to confirm these associations and to elucidate potential mechanisms.

Iron Deficiency Affects Seizure Susceptibility in a Time- and Sex-Specific Manner

Iron deficiency (ID) affects more than three billion people worldwide making it the most common micronutrient deficiency. ID is most prevalent during gestation and early life, which is of particular concern since its impact on the developing central nervous system is associated with an increased risk of a wide range of different psychiatric disorders later in life. The cause for this association is not known, but many of these same disorders are also associated with an imbalance between excitation and inhibition (E/I) within the brain. Based on this shared impairment, we asked whether ID could contribute to such an imbalance. Disruptions in the E/I balance can be uncovered by the brain’s response to seizure inducing insults. We therefore tested the seizure threshold under different nutritional models of ID. We found that mice which were postnatally exposed to ID (and were acutely ID) had a decreased seizure threshold and increased susceptibility to certain seizure types. In contrast, mice that were exposed to ID only during gestation had an increased seizure threshold and low seizure incidence. We suggest that exposure to ID during gestation might alter the cellular components that contribute to the establishment of a proper E/I balance later in life. In addition, our data highlight the importance of considering the window of vulnerability since gestational ID and postnatal ID have significantly different consequences on seizure probability.

Hair Zinc and Severity of Symptoms Are Increased in Children with Attention Deficit and Hyperactivity Disorder: a Hair Multi-Element Profile Study

Determination of bioelement levels in hair is an emerging non-invasive approach for screening bioelement deposition. However, the role of essential bioelement levels in hair and attention deficit/hyperactivity disorder (ADHD) risk or severity is largely unknown. In this study, we have compared multi-element hair profiles between healthy and ADHD Thai children. In addition, the correlations between bioelements and ADHD symptoms according to Diagnostic and Statistical Manual of Mental Disorders, 5th edition, diagnostic criteria were identified. A case-control study was conducted in 111 Thai children (45 newly diagnosed ADHD and 66 matched healthy), aged 3-7 years, living in Bangkok and suburban areas. Levels of 39 bioelements in hair were measured by ICP-MS. Among the analyzed bioelements, Cu/Zn and P/Zn ratios in ADHD children were significantly lower than those in healthy children. Indeed, increased hair Zn level was correlated with more symptoms of inattention, hyperactivity, and total ADHD symptoms. Higher Zn content was also associated with being female and older age. Furthermore, Zn in hair was positively correlated with levels of Ca, Mg, and P; however, it showed a negative correlation with Al, As, Fe, and Mo. These findings warrant further confirmation in a large-scale study. Thai Clinical Trials Registry (TCTR) study ID: 20151113001.

The Effects of Prenatal Iron Deficiency and Risperidone Treatment on the Rat Frontal Cortex: A Proteomic Analysis

Prenatal iron deficiency (pID) has been described to increase the risk for neurodevelopmental disorders such as autism and schizophrenia; however, the precise molecular mechanisms are still unknown. Here, we utilized high-throughput MS to examine the proteomic effects of pID in adulthood on the rat frontal cortex area (FCA). In addition, the FCA proteome was examined in adulthood following risperidone treatment in adolescence to see if these effects could be prevented. We identified 1501 proteins of which 100 were significantly differentially expressed in the FCA at postnatal day 90. Pathway analysis of proteins affected by pID revealed changes in metabolic processes, including the tricyclic acid cycle, mitochondrial dysfunction, and P13K/Akt signaling. Interestingly, most of these protein changes were not present in the adult pID offspring who received risperidone in adolescence. Considering the link between pID and several neurodevelopmental disorders such as autism and schizophrenia these presented results bring new perspectives to understand the role of iron in metabolic pathways and provide novel biomarkers for future studies of pID.

ADHD, Lifestyles and Comorbidities: A Call for an Holistic Perspective - from Medical to Societal Intervening Factors

The review examines Attention Deficit Hyperactivity Disorder (ADHD in its Child and Adult form) and its various presentations (Hyperactive Impulsive, Inattentive, and Combined) with a particular focus on environmental (incl. social factors), lifestyles and comorbidities. It is argued that ADHD is best understood in a holistic and interactive context and a vast empirical literature is presented to illustrate the point: Environmental factors include stress in general as well as exposure to toxins (phthalates, bisphenol A). Social factors are illustrated by effects of social deprivation and seduction to unhealthy lifestyles. Maternal lifestyle during pregnancy is pointed out (particularly her exposure to nicotine, alcohol, caffeine, and drugs, even seemingly benign medications like acetaminophen), which all tend to be related to ADHD. Family environment is discussed with respect to protective effect of (mainly authoritative and autocratic) parenting styles. Societal factors include mainly economic and political issues: income inequality and poverty (low SES is an ADHD risk factor) and a growing moral dilemma between a humanistic effort to globally spread the knowledge of ADHD and the medicalization and commercialization of the disorder. The second part of the review is devoted to ADHD related lifestyles and resulting comorbidities (e.g., food addiction and obesity, substance abuse, electronic media dependencies and conduct and personality disorders). Although ADHD is a neurodevelopmental disorder, its assessment and treatment are also linked to environmental, behavioral and social factors and their interactions.

Serotonin transporter polymorphism moderates the effects of caregiver intrusiveness on ADHD symptoms among institutionalized preschoolers

Research consistently chronicles a variety of mental health difficulties that plague institutionally reared children, including attention-deficit/hyperactivity disorder (ADHD), even if not all institutionalized children evince such problems. In seeking to extend work in this area, this research on gene × environment (GXE) interplay investigated whether the effect of the quality of institutional care-most notably, caregiver intrusiveness-on ADHD symptoms is moderated by the serotonin transporter (5-HTTLPR) polymorphism. One hundred and twenty-seven institutionalized preschoolers were evaluated using the Child Behavior Checklist. Caregiver-rated attention problems and hyperactivity were unrelated to both 5-HTTLPR polymorphism and caregiver intrusiveness. A significant GXE effect, independent of age at placement or duration of institutionalization, emerged, however, consistent with the differential-susceptibility hypothesis: s/s homozygotes manifest the most and least ADHD symptoms when they experienced, respectively, more and less intrusive caregiving. These results provide new insight into the reasons why some institutionalized children, but not others, exhibit ADHD symptoms.

Nutritional status of foster children in the U.S.: Implications for cognitive and behavioral development

OBJECTIVE

Children in foster care are at greater risk for poor health, physical, cognitive, behavioral, and developmental outcomes than are children in the general population. Considerable research links early nutrition to later cognitive and behavioral outcomes. The aim of this narrative review is to examine the prevalence of poor nutrition and its relation to subsequent health and development in foster children.

METHOD

Relevant studies for inclusion were identified from numerous sources (e.g., PubMed, Google Scholar, and reference sections). Inclusion criteria were studies published between 1990 and 2016 of (i) the nutritional status of children in foster care or (ii) the nutritional status of children exposed to early adversity (e.g., low-income and internationally adopted children) or (iii) the developmental effects of poor nutrition and micronutrient deficiencies.

RESULTS

Two key findings that have adverse implications for cognitive development emerged: (i) the prevalence of anemia and iron-deficiency anemia is higher among foster children than among the general population of children in the U.S., and (ii) the developmental demands of catch-up growth post-placement may lead to micronutrient deficiencies even after children have begun sufficient dietary intake of these nutrients. Moreover, there is a paucity of recent studies on the nutritional status of children in foster care, despite the multiple factors that may place them at risk for malnutrition.

CONCLUSION

Attention to nutritional status among care providers and medical professionals may remove one of the possible negative influences on foster children's development and in turn significantly alter their trajectories and place them on a more positive path early in life. Recommendations for further research, policy, and practice are discussed.

Iron Deficiency Parameters in Children and Adolescents with Attention-Deficit/Hyperactivity Disorder

The aim of this study is to compare iron deficiency parameters in patients with stimulant-naive attention-deficit/hyperactivity disorder (ADHD) and healthy controls, to investigate whether there are differences among the ADHD presentations, and to evaluate the relationship between ADHD symptom severity and serum ferritin levels. In addition, ADHD-Predominantly Inattentive (ADHD-PI) patients with restrictive hyperactivity/impulsivity symptoms were evaluated as a separate group with "restrictive inattention presentation" (ADHD-Rest) and were compared with other groups. Patients with ADHD-Rest are typically defined as having six or more symptoms of inattention and fewer than three symptoms of hyperactivity/impulsivity. A total of 200 ADHD cases consisting of 100 ADHD-Combine (ADHD-C) and 100 ADHD-PI and a total of 100 healthy control cases were included in the study. The Schedule for Affective Disorders and Schizophrenia for School Age Children-Present and Lifetime Version was performed in a semi-structured interview during the diagnosis. The Turgay DSM-IV-Based Child and Adolescent Behavior Disorders Screening and Rating Scale, the Conners' Rating Scale-Revised: Long Form (Parent-Teacher) (CPRSR:L, CTRS-R:L) were used for clinical evaluation. Hemogram, serum iron, iron binding capacity and serum ferritin levels were assessed. There were no significant differences between the ADHD patients and the healthy control cases in terms of iron deficiency parameters. Further, there were no significant differences among the ADHD presentations in terms of the same parameters, nor were there any significant differences when the groups were examined after the identification of the ADHD-Rest. The CPRS-R:L Hyperactivity and the CTRS-R:L Hyperactivity scores were negatively correlated with serum ferritin level in the ADHD group. To our knowledge, our current study is the first to compare serum ferritin levels in ADHD-Rest with other presentations of ADHD, and included the largest number of patients that were classified by ADHD presentations. Elucidation of these findings is important for both the etiology and treatment of ADHD.