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

A systematic review of the beneficial effects of prebiotics, probiotics, and synbiotics on ADHD

BACKGROUND

Children with attention deficit hyperactivity disorder (ADHD) may benefit from probiotics and prebiotics, but the effects are unclear. To determine whether probiotics and prebiotics affect children with ADHD, a systematic review was conducted.

METHODS

The present systematic review analyzed cohort studies and randomized controlled trials that examined whether prebiotics and probiotics are associated with ADHD. Seven randomized controlled trials and two cohort studies met our inclusion criteria.

RESULTS

Research on Lactobacillus rhamnosus GG (LGG) probiotic supplementation showed that children with ADHD had better emotional, physical, social, and school functioning, and a higher health-related quality of life compared to the placebo group. The studies also showed that Synbiotic 2000 reduces markers of intestinal and vascular inflammation in children with ADHD, in part through increasing SCFA levels.

CONCLUSION

The use of probiotics and prebiotics as adjuvants therapy in patients with ADHD is beneficial. Further studies with longer duration, including more participants and a variety of age groups, and using various evaluation techniques such as in vivo observation are required to examine the effects of prebiotics and probiotics on ADHD.

Iron Deficiency in Attention-Deficit Hyperactivity Disorder, Autism Spectrum Disorder, Internalizing and Externalizing Disorders, and Movement Disorders

This article reviews the role of iron in brain development and function, with a focus on the association between iron deficiency (ID) and neuropsychiatric conditions. First, we describe how ID is defined and diagnosed. Second, the role of iron in brain development and function is summarized. Third, we review current findings implicating ID in a number of neuropsychiatric conditions in children and adolescents, including attention deficit hyperactivity disorder and other disruptive behavior disorders, depressive and anxiety disorders, autism spectrum disorder, movement disorders, and other situations relevant to mental health providers. Last, we discuss the impact of psychotropic medication on iron homeostasis.

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.

Large-scale genetic investigation reveals genetic liability to multiple complex traits influencing a higher risk of ADHD

Attention Deficit-Hyperactivity Disorder (ADHD) is a complex psychiatric and neurodevelopmental disorder that develops during childhood and spans into adulthood. ADHD’s aetiology is complex, and evidence about its cause and risk factors is limited. We leveraged genetic data from genome-wide association studies (GWAS) and performed latent causal variable analyses using a hypothesis-free approach to infer causal associations between 1387 complex traits and ADHD. We identified 37 inferred potential causal associations with ADHD risk. Our results reveal that genetic variants associated with iron deficiency anemia (ICD10), obesity, type 2 diabetes, synovitis and tenosynovitis (ICD10), polyarthritis (ICD10), neck or shoulder pain, and substance use in adults display partial genetic causality on ADHD risk in children. Genetic variants associated with ADHD have a partial genetic causality increasing the risk for chronic obstructive pulmonary disease and carpal tunnel syndrome. Protective factors for ADHD risk included genetic variants associated with the likelihood of participating in socially supportive and interactive activities. Our results show that genetic liability to multiple complex traits influences a higher risk for ADHD, highlighting the potential role of cardiometabolic phenotypes and physical pain in ADHD’s aetiology. These findings have the potential to inform future clinical studies and development of interventions.

Brain iron concentrations in the pathophysiology of children with attention deficit/hyperactivity disorder: a systematic review

CONTEXT

Attention deficit/hyperactivity disorder (ADHD) is a neurological disorder associated with iron dysregulation in children. Although previous focus was on examining systemic iron status, brain iron content may be a more reliable biomarker of the disorder.

OBJECTIVE

This systematic review examines whether children with ADHD have lower serum as well as brain iron concentrations, compared with healthy control subjects (HCS).

DATA SOURCES

A systematic literature search was conducted in Medline via PubMed, the Cochrane Library, Web of Science, Embase. and Ovid for papers published between 2000 and June 7, 2019.

DATA EXTRACTION

Studies were included if the mean difference of iron concentration, measured as serum iron, serum ferritin, or brain iron, between children with ADHD and HCS was an outcome measure.

DATA ANALYSIS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Risks of bias within and between studies were assessed using the quality assessment tools of the National Institutes of Health. Of 599 records screened, 20 case-control studies met the inclusion criteria. In 10 of 18 studies in which serum ferritin concentration was assessed, and 2 of 10 studies that assessed serum iron, a significant difference between children with ADHD and HCS was observed. Results of systemic iron levels were inconsistent. In 3 studies in which brain iron concentration was assessed, a statistically significant, lower thalamic iron concentration was found in children with ADHD than in HCS.

CONCLUSION

The evidence, though limited, reveals that brain iron rather than systemic iron levels may be more associated with the pathophysiology of ADHD in children. Larger, longitudinal, magnetic resonance imaging studies are needed to examine any correlations of iron deficiency in specific brain regions and symptoms of ADHD.

Magnesium, Iron, Zinc, Copper and Selenium Status in Attention-Deficit/Hyperactivity Disorder (ADHD)

In this study, we critically review the literature concerning the relation of Mg, Fe, Zn, Cu and Se and attention-deficit/hyperactivity disorder (ADHD). Elemental status is estimated using peripheral blood parameters, hair, urine, daily intake and response to supplementation. The observed associations between concentration levels of the elements Mg, Fe, Zn, Cu and Se and ADHD symptoms are contradictory. This is partly due to the heterogeneity and complexity of the disorder. As a trend, lower ferritin and zinc levels can be observed. However, this correlation is not causative, as illustrated by placebo-controlled trials reporting conflicting evidence on the efficacy of supplementation. Well-defined studies on changes in concentration levels of the elements in relation to ADHD symptoms before and after treatment with therapeutics it will be possible to shed more light on the significance of these elements in this behavioral disorder. The discussion on whether a change in concentration of an element is cause or consequence of ADHD is not within the scope of this article.

Attention-Deficit/Hyperactivity Disorder Patients May Have Undiagnosed Narcolepsy

Background

Attention-deficit/hyperactivity disorder (ADHD) patients have many comorbidities. Narcoleptic patients have a big prevalence of ADHD (15%-30%). Both groups suffer from similar symptoms and benefit from the same class of medications. As such, narcolepsy could be masked in ADHD patients. Low serum ferritin has been found both in ADHD patients as well as in patients with narcolepsy.

Materials & methods

We enrolled 26 participants (14 ADHD patients and 12 controls). They answered several questionnaires, and blood samples were obtained from 20 participants. We had clear exclusion criteria.

Results

Using the Ullanlinna Narcolepsy Scale (UNS), we identified three possible narcolepsy patients within the ADHD group and no suspects in the control group. There was a statistically significant negative correlation between serum iron levels and ADHD symptom severity. No correlation was found measuring serum ferritin levels.

Conclusions

Narcolepsy may be more common within ADHD patients than in the general population. Some of these patients could benefit from a change in medication. Low serum iron and ferritin levels could be relevant in ADHD pathophysiology. This requires further exploratory research.

Iron homeostasis alterations and risk for akathisia in patients treated with antipsychotics: A systematic review and meta-analysis of cross-sectional studies

Iron homeostasis may be implicated in the pathophysiology of antipsychotic-related akathisia. We performed a systematic review in six databases from database inception until 03/2020, conducting a meta-analysis of studies investigating iron metabolism in antipsychotic-treated patients with versus without akathisia. Using a fixed- and a random-effects model, standardized mean difference (SMD) was estimated for levels of iron, ferritin, transferrin and total iron-binding capacity. Meta-regression analyses included sex, age, illness duration and antipsychotic treatment and dose. Subgroup analyses included chronic vs. acute akathisia and different diagnoses. Study quality was assessed using the Newcastle-Ottawa scale. In 10 studies (n = 395), compared to non-akathisia patients (n = 213), iron levels were lower in patients with akathisia (n = 182; fixed-effect model: SMD=-0.49, 95%CI=-0.28,-0.70, p<0.001; random-effects model: SMD=-0.55, 95%CI=-0.14,-0.96, p = 0.008). For secondary outcomes, differences were significant regarding lower ferritin levels in patients with akathisia in the fixed-effect model (SMD=-0.32, 95%CI=-0.08,-0.55, p = 0.007), but not in the random-effects model (SMD=-0.29, 95%CI=0.20,-0.79, p = 0.24). None of the moderators/mediators had a significant effect on the group difference of iron levels. Subgroup analyses reported lower iron levels in both patients with chronic and acute akathisia vs. patients without. Iron levels for schizophrenia patients were lower in the fixed-effect model (SMD=-0.55, 95%CI=-0.23, -0.86, p<0.001), while a trend was observed in the random-effects model (SMD=-0.52, 95%CI=-0.07, -1.12, p = 0.08). The studies' quality was overall poor, with one exception. This meta-analysis suggests lower iron levels in akathisia patients, while ferritin differences were significant only in the fixed-effect model. Further data are required to promote the understanding of related pathways.

Dietary Profiles, Nutritional Biochemistry Status, and Attention-Deficit/Hyperactivity Disorder: Path Analysis for a Case-Control Study

This study aims to investigate dietary and nutritional biochemistry profiles of attention-deficit/hyperactivity disorder (ADHD) and to explore their potential relationship by path analysis. We enrolled 216 children with ADHD and 216 age-, height- and gender-matched controls from 31 elementary schools in Taiwan. Dietary intake of the participants was assessed using a food frequency questionnaire (FFQ). Fasting blood samples were collected to determine the serum levels of multiple nutritional markers. Moreover, we employed a structural equation model (SEM) to link diet, nutritional markers and ADHD. Compared to healthy control, ADHD children had significantly lower serum levels of vitamin B12, folate, vitamin B6, ferritin concentration, and monounsaturated fatty acids (MUFA), but higher levels of serum saturated fatty acids (SFA), n-6/n-3 fatty acid ratio, and inorganic phosphorous concentration. Children with ADHD had more intake of nutrient-poor foods such as high sugar and high fat foods, and had less intake of vegetable, fruit, protein-rich foods than their counterpart. SEM analysis showed that the poor nutritional biochemistry profiles linked the association between unhealthy dietary patterns and ADHD. In conclusion, an unhealthy dietary pattern may be a predecessor of the poor nutritional biochemistry status, and managing diet and nutrition conditions should be considered to improve ADHD symptoms in children.

Increased Serum Hepcidin Levels in Children and Adolescents with Attention Deficit Hyperactivity Disorder

Objective

In this study, we aimed to evaluate the serum hepcidin levels in attention deficit hyperactivity disorder (ADHD) patients that were newly diagnosed with no history of psychotropic drugs.

Methods

A total of 70 ADHD patients and 69 healthy controls were enrolled in our study. During the diagnosis, the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime version were applied. The sociodemographic data form, Turgay DSM-IV-Based Child and Adolescent Behavior Disorders Screening and Rating Scale, and Conners’ Rating Scales-Revised: Long Form were used for the clinical evaluation. Serum hepcidin levels were measured and compared between the groups.

Results

No significant difference between the groups in terms of age (p=0.533) and gender (p=0.397) was determined. In addition, the groups did not differ significantly for the other sociodemographic variables recorded. Serum hepcidin levels were found to be significantly higher in the patients with ADHD than healthy controls (p=0.019).

Conclusion

To the best of our knowledge, this study is the first to evaluate the total serum hepcidin levels in ADHD patients. Our study findings may suggest that high levels of hepcidin may cause iron dysregulation in ADHD patients. However, further studies are required to establish a definite conclusion.

Transcranial sonography in psychiatry as a potential tool in diagnosis and research

OBJECTIVES

During the last two decades transcranial sonography (TCS) of the brain parenchyma evolved from a pure research tool to a clinical relevant neuroimaging method especially in Parkinson's disease and related movement disorders. The aim of this systematic review is to update and summarise the published TCS findings in psychiatric disorders and critically address the question whether TCS may be a valuable tool for the diagnosis or differential diagnosis of psychiatric disorders similarly to the field of movement disorders.

METHODS

This paper provides detailed information about the perspectives and limitations of TCS, including guidelines for the scanning procedures, assessment of midbrain structures and discusses the potential causes of the ultrasound abnormalities in psychiatric disorders.

RESULTS

Changes in the echogenicity of subcortical brain structures were detected in different disorders, such as obsessive-compulsive disorder, autism spectrum disorder, schizophrenia, panic disorder, attention-deficit/hyperactivity (ADHD), bipolar disorder and depressive disorder. Although the physical properties of brain tissue underlying the echogenic features in TCS are largely unknown, no alternative technique provides the same insight into the specific central nervous structural characteristics.

CONCLUSIONS

Urgent research questions to further clarify the underlying pathophysiological and structural alterations are further outlined to bring this promising technique to the clinic.

Fruit and Vegetable Consumption and Their Association With the Indicators of Iron and Inflammation Status Among Adolescent Girls

BACKGROUND

The objective of this study was to identify an association among dietary components, iron, and inflammatory status among adolescent girls.

METHOD

Dietary information for 85 adolescent girls was collected through food frequency questionnaires. Biomarkers of iron and inflammatory status were analyzed.

RESULTS

We found that 28.2% of adolescent girls had anemia and 65.9% girls were iron-deficient. Girls who did not consume guava had 3.8-fold (95% confidence interval =1.1-9.4; p = 0.020) increased the risk of having low serum iron levels. Girls who consumed amaranth had significantly (p = 0.024) higher serum hepcidin levels (n = 44; 129.7 ± 81.40 pg/mL vs n = 41; 94.6 ± 55.8 pg/mL) as well as ferritin levels (n = 44; 19.7 ± 16.4 µg/L vs n = 41; 14.0 ± 10.2 µg/L). Overall consumption of fruits and green leafy vegetables among girls significantly affects their iron status.

CONCLUSIONS

Regular consumption of vitamin C-rich fruits and green leafy vegetable intake are imperative for improvement of iron status among adolescent girls.

Reduced microbiome alpha diversity in young patients with ADHD

ADHD is a psychiatric disorder which is characterized by hyperactivity, impulsivity and attention problems. Due to recent findings of microbial involvement in other psychiatric disorders like autism and depression, a role of the gut microbiota in ADHD pathogenesis is assumed but has not yet been investigated. In this study, the gut microbiota of 14 male ADHD patients (mean age: 11.9 yrs.) and 17 male controls (mean age: 13.1 yrs.) was examined via next generation sequencing of 16S rDNA and analyzed for diversity and biomarkers. We found that the microbial diversity (alpha diversity) was significantly decreased in ADHD patients compared to controls (pShannon = 0.036) and that the composition (beta diversity) differed significantly between patients and controls (pANOSIM = 0.033, pADONIS = 0.006, pbetadisper = 0.002). In detail, the bacterial family Prevotellacae was associated with controls, while patients with ADHD showed elevated levels of Bacteroidaceae, and both Neisseriaceae and Neisseria spec. were found as possible biomarkers for juvenile ADHD. Our results point to a possible link of certain microbiota with ADHD, with Neisseria spec. being a very promising ADHD-associated candidate. This finding provides the basis for a systematic, longitudinal assessment of the role of the gut microbiome in ADHD, yielding promising potential for both prevention and therapeutic intervention.

Attention deficit-hyperactivity disorder is associated with allergic symptoms and low levels of hemoglobin and serotonin

This study investigated whether common comorbidities or biochemical factors, such as allergic disease, anemia, inflammation, and neurotransmitters, are singly or additively associated with an increased risk of attention deficit–hyperactivity disorder (ADHD). We recruited 216 children diagnosed with ADHD and 216 age-, sex-, height-, weight-, and class-matched controls from 31 elementary schools in Taipei, Taiwan. The International Study of Asthma and Allergies in Childhood questionnaire was used to measure allergic symptoms. Fasting venous blood was collected and analyzed for complete blood count, white blood cell differential count, immunoglobulin (Ig) E level, and serotonin (5-HT) level. The results showed that symptoms of both rhinitis (OR = 2.08, 95% CI = 1.42–3.05) and eczema (OR = 1.72, 95% CI = 1.02–2.88) were significantly associated with increased risk of ADHD. Children with ADHD showed considerably lower levels of hemoglobin (p = 0.001) and 5-HT (p < 0.001) and higher IgE level (p < 0.001) and eosinophil count (p = 0.001) than did control children. ADHD risk increased with the number of aforementioned biochemical risk factors present (one factor: OR = 1.87, 95% CI = 0.87–4.18; two factors: OR = 2.90, 95% CI = 1.29–6.48; three factors: OR = 4.47, 95% CI = 1.97–10.13; four factors: OR = 6.53, 95% CI = 2.43–17.57). Findings suggest that either ADHD’s etiology is multidimensional or the aforementioned conditions have shared etiology with ADHD.

Increase serum cortisol in young guinea pig offspring in response to maternal iron deficiency

Iron deficiency (ID) has been reported as a risk factor in the pathology of attention-deficit/hyperactivity disorder, although the mechanisms seem unclear. Previous results from our research group showed that guinea pig offspring born from ID dams were significantly more active in the Open Field Test than the controls. This behavior could potentially be associated to stress. We therefore hypothesized that maternal iron deficiency (MID) elevates the offspring serum cortisol, a biomarker of stress, during childhood and possibly at mature age. Twenty-four female guinea pigs were fed an iron-sufficient (IS) diet (114 mg/kg) or ID diet (11.7 mg/kg) during the gestation and lactation. Pups in both groups were weaned at postnatal day (PNd) 9 and given an IS diet. Hematocrit and serum cortisol levels were measured in dams at every trimester of gestation and in pups at PNd24 and 84. We found no impact of MID on dam's cortisol values. However, our findings indicate that MID increased cortisol secretion in the offspring during childhood, cortisol values being significantly elevated in ID than IS pups at PNd24 (P < .05). During adulthood (PNd84), both groups showed comparable cortisol levels. The elevated cortisol secretion observed in the offspring born from ID mothers during childhood may indicate increased stress reactivity which may have contributed to the higher level of activity when tested in a novel open environment. These findings suggest that MID can potentially act as internal stressor affecting the early development conceivably leading to increased stress levels in the children.

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.

The effect of adding ferrous sulfate to methylphenidate on attention-deficit/hyperactivity disorder in children

Attention deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in children with several complications. This study was conducted to investigate the effect of adding ferrous sulfate to methylphenidate in decreasing ADHD symptoms. This study was a double-blind, randomized clinical trial. In this study, 42 nonanemic children with ADHD and serum ferritin below 30 mg/ml were enrolled according to convenience sampling and randomly assigned to two groups of 21 each, cases and controls. The two groups were matched for age and sex. The case group was administered with ferrous sulfate 5 mg/kg in addition to methylphenidate up to 1 mg/kg and the control group with methylphenidate alone. The scores on child symptoms inventory-4 (CSI-4) were recorded at baseline and after 2 months of treatment. Data were analyzed by t-test, Pearson's correlation coefficient, and repeated measures ANOVA in SPSS 16. The scores on CSI-4 decreased significantly at month 2 in both groups (P < 0.001). The scores on attention deficit and hyperactivity subscales of the CSI-4 were significantly lower in the case group than the control group (P < 0.05). The total score on CSI-4 decreased more markedly in the case group (P < 0.04). Use of ferrous sulfate plus methylphenidate can be effective in reducing ADHD symptoms in nonanemic children with low serum ferritin.

Relationship of serum ferritin level and tic severity in children with Tourette syndrome

PURPOSE

Tics can be considered hyperkinetic movements akin to restless leg syndrome (RLS). Drawing the analogy of iron deficiency as an etiology of RLS, it is conceivable that iron deficiency may underlie or worsen tics in Tourette syndrome (TS). The purpose of this study was to evaluate the relationship between serum ferritin levels and tic severity, as well as consequent impact on life, in children with TS.

METHODS

Children <18 years, diagnosed with TS during 2009-2015, were reviewed. Only those with serum ferritin testing were included. The following data were collected: tic severity, impact on life, medication, comorbidities, blood count, and serum ferritin at diagnosis and follow-up.

RESULTS

In fifty-seven patients, M:F = 2:1, serum ferritin was 48.0 ± 33.28 ng/mL, tic severity score 2.3 ± 0.80, impact on life score 2.2 ± 0.93, and composite score 4.57 ± 1.6. Serum ferritin was not influenced by comorbid obsessive compulsive disorder (OCD), attention deficit hyperactive disorder (ADHD), or anxiety (P > 0.16). Thirty-eight percent with low serum ferritin (≤50 ng/mL) (n = 37) had severe tics (>5 composite score), compared with 25% in normal ferritin group (n = 20). Over 6-12 months, tic severity score improved in both iron treated groups, deficient (2.70 to 1.90) and sufficient (2.40 to 1.95), whereas tics worsened or remained the same when not treated with iron.

CONCLUSIONS

Our data suggest iron deficiency may be associated with more severe tics with higher impact on TS children, independent of the presence of OCD, ADHD, or anxiety. Iron supplementation showed a trend towards improvement of tic severity upon follow-up. We suggest a double-blind, placebo-controlled prospective study to reach a definite conclusion.

The Role of Nutritional Supplements in the Treatment of ADHD: What the Evidence Says

Attention-deficit hyperactivity disorder (ADHD) is a common behavioral disorder in children and adolescents and may persist into adulthood. Insufficient nutritional supply of long-chain polyunsaturated fatty acids (LC-PUFAs) and other components including various minerals has been suggested to play a role in the development of ADHD symptoms. This review presents the evidence regarding the role of nutritional PUFA, zinc, iron, and magnesium supplements in the treatment of ADHD with a focus on the critical evaluation of the relevant literature published from 2014 to April 2016. The evaluation of therapeutic nutritional LC-PUFA supplementation in ADHD has shown mixed and inconclusive results and at best marginal beneficial effects. The benefits of PUFAs are much smaller than the effect sizes observed for traditional pharmacological treatments of ADHD. The effectiveness of PUFA supplements in reducing medication dosage has been suggested but needs to be confirmed. Zinc, iron, and magnesium supplementation may reduce ADHD symptoms in children with or at high risk of deficiencies in these minerals. However, convincing evidence in this regard is lacking.

Iron Status in Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis

Background

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common psychiatric disorders in children. However, the pathogenesis of ADHD remains unclear. Iron, an important trace element, is implicated in brain function and dopaminergic activity. Recent studies have investigated the association between iron deficiency and ADHD, but the results are inconsistent.

Methods

A systemic search of MEDLINE, EMBASE, Web of Science and Cochrane Library databases was supplemented by manual searches of references of key retrieved articles. Study quality was evaluated using the Newcastle-Ottawa Scale. The standardised mean difference (SMD) and 95% confidence intervals (CIs) were calculated using a random-effects model. H² and I² were used to evaluate the heterogeneity, and sensitivity, subgroup and meta-regression analyses were conducted to explore the reason of heterogeneity.

Results

The search yielded 11 studies published before July 25, 2016. Of these, 10 studies, comprising 2191 participants and 1196 ADHD cases, reported serum ferritin levels, and six studies, comprising 617 participants and 369 ADHD cases, reported serum iron levels. Serum ferritin levels were lower in ADHD cases (SMD = -0.40, 95% CI = -0.66 to -0.14). However, we found no correlation between serum iron levels and ADHD (SMD = -0.026, 95% CI = -0.29 to 0.24). Meta-regression analysis indicated that publication year, age, gender, sample size, and Hb levels did not significantly influence the pooled estimates of serum ferritin.

Conclusion

Lower serum ferritin rather than serum iron is associated with ADHD in children.

Loss of NCB5OR in the cerebellum disturbs iron pathways, potentiates behavioral abnormalities, and exacerbates harmaline-induced tremor in mice

Iron dyshomeostasis has been implicated in many diseases, including a number of neurological conditions. Cytosolic NADH cytochrome b5 oxidoreductase (NCB5OR) is ubiquitously expressed in animal tissues and is capable of reducing ferric iron in vitro. We previously reported that global gene ablation of NCB5OR resulted in early-onset diabetes and altered iron homeostasis in mice. To further investigate the specific effects of NCB5OR deficiency on neural tissue without contributions from known phenotypes, we generated a conditional knockout (CKO) mouse that lacks NCB5OR only in the cerebellum and midbrain. Assessment of molecular markers in the cerebellum of CKO mice revealed changes in pathways associated with cellular and mitochondrial iron homeostasis. (59)Fe pulse-feeding experiments revealed cerebellum-specific increased or decreased uptake of iron by 7 and 16 weeks of age, respectively. Additionally, we characterized behavioral changes associated with loss of NCB5OR in the cerebellum and midbrain in the context of dietary iron deprivation-evoked generalized iron deficiency. Locomotor activity was reduced and complex motor task execution was altered in CKO mice treated with an iron deficient diet. A sucrose preference test revealed that the reward response was intact in CKO mice, but that iron deficient diet consumption altered sucrose preference in all mice. Detailed gait analysis revealed locomotor changes in CKO mice associated with dysfunctional proprioception and locomotor activation independent of dietary iron deficiency. Finally, we demonstrate that loss of NCB5OR in the cerebellum and midbrain exacerbated harmaline-induced tremor activity. Our findings suggest an essential role for NCB5OR in maintaining both iron homeostasis and the proper functioning of various locomotor pathways in the mouse cerebellum and midbrain.