Iron and ADHD: time to move beyond serum ferritin levels

Brain iron concentration in childhood ADHD: A systematic review of neuroimaging studies

Iron deficiency may play a role in the pathophysiology of Attention Deficit/Hyperactivity Disorder (ADHD). Due to its preponderant function in monoamine catecholamine and myelin synthesis, brain iron concentration may be of primary interest in the investigation of iron dysregulation in ADHD. This study reviewed current evidence of brain iron abnormalities in children and adolescents with ADHD using magnetic resonance imaging methods, such as relaxometry and quantitative susceptibility mapping, to assess brain iron estimates. The study was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A literature search was performed for studies published between January 1, 2008 and July 7, 2023 in Medline, Scopus and Proquest. Regions of interest, brain iron index values and phenotypical information were extracted from the relevant studies. Risk of bias was assessed using a modified version of the National Heart, Lung, and Blood Institute quality assessment tool. Seven cross-sectional studies comparing brain iron estimates in children with ADHD with neurotypical children were included. Significantly reduced brain iron content in medication-naïve children with ADHD was a consistent finding. Two studies found psychostimulant use may increase and normalize brain iron concentration in children with ADHD. The findings were consistent across the studies despite differing methodologies and may lay the early foundation for the recognition of a potential biomarker in ADHD, although longitudinal prospective neuroimaging studies using larger sample sizes are required. Lastly, the effects of iron supplementation on brain iron concentration in children with ADHD need to be elucidated.

Serum Biomarker Analysis in Pediatric ADHD: Implications of Homocysteine, Vitamin B12, Vitamin D, Ferritin, and Iron Levels

The current diagnosis of attention deficit hyperactivity disorder (ADHD) is based on history, clinical observation, and behavioral tests. There is a high demand to find biomarkers for the diagnosis of ADHD. The aim of this study is to analyze the serum profiles of several biomarkers, including homocysteine (Hcy), vitamin B12, vitamin D, ferritin, and iron, in a cohort of 133 male subjects (6.5-12.5 years), including 67 individuals with an ADHD diagnosis based on DSM-V criteria and 66 age-matched healthy boys (healthy controls, HC). Assessments for ADHD included the Iowa Conners' Teacher Rating Scale (CPRS) and the ADHDT test, as well as cognitive assessments using the Wechsler Intelligence Scale for Children-Revised (WISC-R) and the TROG-2 language comprehension test. Hcy and iron were quantified using spectrophotometry, while vitamin B12 and total 25-hydroxy vitamin D levels were determined using an electrochemiluminescence immunoassay (ECLIA) and ferritin was measured using a particle-enhanced immunoturbidimetric assay. The results showed significantly increased Hcy levels and decreased vitamin B12 levels in ADHD patients compared to HCs. Multiple logistic regression analysis indicated that Hcy is a potential prognostic indicator for ADHD. These results suggest that elevated homocysteine and decreased vitamin B12 may serve as markers for the diagnosis and prognosis of ADHD.

Brain tissue iron neurophysiology and its relationship with the cognitive effects of dopaminergic modulation in children with and without ADHD

Children with attention-deficit/hyperactivity disorder (ADHD) exhibit impairments in response inhibition. These impairments are ameliorated by modulating dopamine (DA) via the administration of rewards or stimulant medication like methylphenidate (MPH). It is currently unclear whether intrinsic DA availability impacts these effects of dopaminergic modulation on response inhibition. Thus, we estimated intrinsic DA availability using magnetic resonance-based assessments of basal ganglia and thalamic tissue iron in 36 medication-naïve children with ADHD and 29 typically developing (TD) children (8-12 y) who underwent fMRI scans and completed standard and rewarded go/no-go tasks. Children with ADHD additionally participated in a double-blind, randomized, placebo-controlled, crossover MPH challenge. Using linear regressions covarying for age and sex, we determined there were no group differences in brain tissue iron. We additionally found that higher putamen tissue iron was associated with worse response inhibition performance in all participants. Crucially, we observed that higher putamen and caudate tissue iron was associated with greater responsivity to MPH, as measured by improved task performance, in participants with ADHD. These results begin to clarify the role of subcortical brain tissue iron, a measure associated with intrinsic DA availability, in the cognitive effects of reward- and MPH-related dopaminergic modulation in children with ADHD and TD children.

Lack of educational impact of video game addiction in children and adolescents diagnosed with ADHD: A cross-sectional study

Introduction

The use of video games has become widespread worldwide. Excessive use of video games is increasingly becoming a matter of concern, particularly in patients diagnosed with Attention Deficit Hyperactivity Disorder (ADHD). Currently, internet gaming disorder (IGD) is not included within the DSM-5-chapter Disorders related to substances and addictive disorders.

Methods

This is a post-hoc descriptive naturalistic study comparing children and adolescents diagnosed with ADHD with and without IGD. We used the 85% cut-off point of the test ADITEC-V for video game addiction to split our sample of ADHD patients into those with IGD (>=85%) and those without IGD (<85%).

Results

13 (25%) out of the 51 children and adolescents with ADHD included in our study had an IGD. Patients with IGD had a first contact with internet, smartphones, and videogames at a very early age (5.67 ± 3.31, 6.33 ± 4.60, and 7.50 ± 2.61, respectively). However, only age at first contact with the internet was statistically significantly different when comparing ADHD patients with and without IGD (8.68 ± 2.71 vs. 5.67 ± 3.31, t = 3.166, df = 47, p = 0.01). Different neurodevelopmental, clinical, and neuropsychological measures converging in impulsivity is a risk factor for IGD. Unexpectedly, we found no association between IGD and poor academic achievement.

Discussion

Future studies may include randomized controlled trials for treating IGD, the study of social adjustment as a protective factor against developing an IGD, and the role of serious and non-serious video games in the development of an IGD, among others. Additional research is clearly needed on IGD.

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.

Serum ferritin levels in children with attention deficit hyperactivity disorder and tic disorder

BACKGROUND

Iron plays an important role in neurodevelopmental functions in the brain. Serum ferritin levels are different in children with attention deficit hyperactivity disorder and tic disorder than in healthy children.

AIM

To explore the current status of iron deficiency in children with neurodevelopmental disorders and its sex and age effects.

METHODS

A total of 1565 children with attention deficit hyperactivity disorder (ADHD), 1694 children with tic disorder (TD), 93 children with ASD and 1997 healthy control children were included between January 1, 2020, and December 31, 2021 at Beijing Children's Hospital. We describe the differences in age levels and ferritin levels between different disease groups and their sex differences. The differences between the sexes in each disease were analyzed using the t test. The incidence rate of low serum ferritin was used to describe the differences between different diseases and different age groups. A chi-square test was used to analyze the difference in the incidence of low serum ferritin between the disease group and the control group. Analysis of variance was used for comparisons between subgroups, and regression analysis was used for confounding factor control.

RESULTS

A total of 1565 ADHD patients aged 5-12 years were included in this study, and the average serum ferritin levels of male and female children were 36.82 ± 20.64 μg/L and 35.64 ± 18.56 μg/L, respectively. A total of 1694 TD patients aged 5-12 years were included in this study, and the average serum ferritin levels of male and female children were 35.72 ± 20.15 μg/L and 34.54 ± 22.12 μg/L, respectively. As age increased, the incidence of low serum ferritin in ADHD and TD first decreased and then increased, and 10 years old was the turning point of rising levels. The incidence of ADHD with low serum ferritin was 8.37%, the incidence of TD with low serum ferritin was 11.04%, and the incidence of the healthy control group with low serum ferritin was 8.61%, among which male children with TD accounted for 9.25% and female children with TD accounted for 11.62%. There was a significant difference among the three groups (P < 0.05). In addition, there were 93 children with ASD with an average serum ferritin level of 30.99 ± 18.11 μg/L and a serum ferritin incidence of 15.05%.

CONCLUSION

In conclusion, low serum ferritin is not a risk factor for ADHD or TD. The incidence of low serum ferritin levels in children with ADHD and TD between 5 and 12 years old decreases first and then increases with age.

Withdrawing methylphenidate in relation to serum levels of ferritin and zinc in children and adolescents with attention-deficit/hyperactivity disorder

Iron and zinc have been associated with attention-deficit/hyperactivity disorder (ADHD), executive functioning, and response to methylphenidate, given their link with the dopaminergic system. This study aimed to investigate the effect of withdrawing methylphenidate after long-term treatment on serum levels of ferritin and zinc; and if baseline (pre-discontinuation) serum levels of these nutritional markers moderated the effects of withdrawing methylphenidate on ADHD and oppositional defiant disorder (ODD) symptoms, and working memory. Blood samples were collected from 63 children and adolescents who participated in a randomized, placebo-controlled methylphenidate discontinuation study. They were assigned to either seven weeks of continued treatment with methylphenidate or to gradual withdrawal to placebo. With mixed models for repeated measures we (i) compared changes in ferritin and zinc serum levels between both groups, and (ii) investigated moderating effects of ferritin and zinc on the effects of discontinuation on ADHD and ODD symptoms, and working memory. We additionally explored correlations of baseline and change serum levels with respective symptom scores. Withdrawing methylphenidate led to a decrease in ferritin levels. Higher baseline ferritin was associated with a larger increase (i.e., worsening) of teacher-rated hyperactivity-impulsivity and ODD symptoms after withdrawal; and higher baseline zinc with a larger increase in number of errors on the working memory task after withdrawal. Serum levels did not correlate with ADHD and ODD symptoms. Our preliminary results suggest that ferritin and zinc may be potential biomarkers for the effectiveness of long-term treatment with methylphenidate.

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.

ICP-MS Assessment of Hair Essential Trace Elements and Minerals in Russian Preschool and Primary School Children with Attention-Deficit/Hyperactivity Disorder (ADHD)

The objective of the present study was to investigate the relationship between hair essential trace element and mineral content and ADHD in preschool (4-6 years old) and primary school children (6-10 years old) in relation to age and gender. Hair essential trace element and mineral content in 90 Russian children with ADHD and 90 age- and gender-matched neurotypical controls were assessed using inductively coupled plasma mass-spectrometry after microwave digestion. The obtained data demonstrate that hair Co, Cu, Mn, Si, and Zn contents in ADHD children was significantly reduced by 18%, 10%, 27%, 16%, and 19% as compared to the control values, respectively. The most significant decrease in children with ADHD was observed for hair Mg levels, being 29% lower than those in neurotypical children. After adjustment for age and gender, the observed difference in hair element content was more characteristic for preschool children and girls, respectively. Multiple linear regression analysis demonstrated that in a crude model (hair element levels as predictors), only hair Zn content was significantly inversely associated with ADHD (β = - 0.169; p = 0.025). Adjustment for anthropometric parameters (model 2) did not increase the predictive ability of the model, although it improved the association between hair Zn and ADHD in children (β = - 0.194; p = 0.014). Hypothetically, the observed alterations may at least partially contribute to neurobehavioral disturbances in children with ADHD. Moreover, the results of the present study raise the question about the potential benefits of Zn and Mg supplementation in children with ADHD. However, further detailed studies are required to investigate micronutrient deficiencies in ADHD.

Restless legs syndrome and iron deficiency in adults with attention-deficit/hyperactivity disorder

STUDY OBJECTIVE

The association between restless legs syndrome (RLS), periodic leg movements during sleep (PLMS) and iron deficiency has been reported in children with attention-deficit/hyperactivity disorder (ADHD); however little is known in adults. The aim of this study was to assess frequencies of RLS, PLMS and other leg movements (LM) and iron deficiency and their relationships with ADHD phenotype in adults with ADHD.

METHODS

Two hundred adults with ADHD (112 males, median age 31 years) were evaluated on lifetime ADHD symptoms and sleep characteristics. RLS was diagnosed according to standard criteria. Serum ferritin levels were measured, with iron deficiency defined as <50 ng/mL. A subgroup of 48 ADHD patients with RLS, 48 ADHD without RLS and 48 controls underwent a polysomnography to record sleep, LM, and PLMS.

RESULTS

RLS was diagnosed in 33.0%, associated with earlier onset of ADHD, hyperactive presentation and more severe lifetime ADHD symptoms. Iron deficiency was found in 35.5% with higher frequency in patients with RLS. LM were more frequent in ADHD patients, with higher LM periodicity levels in those with comorbid RLS in comparison to controls. However, PLMS index did not differ between groups. Patients with ADHD and RLS had higher frequency of iron deficiency than other groups.

CONCLUSIONS

In a large sample of adults with ADHD, we individualized a subgroup characterized by earlier and severe ADHD symptoms, RLS, higher LM during sleep and iron deficiency. This endophenotype may reflect a different neurobiological mechanism that remains to be further studied.

Brain iron levels in attention-deficit/hyperactivity disorder normalize as a function of psychostimulant treatment duration

Brain iron homeostasis is a dopamine-related mechanism that may be modified with long-term psychostimulant treatment in attention-deficit/hyperactivity disorder (ADHD). We previously reported that while medication-naïve youth with ADHD have reduced brain iron compared to controls and psychostimulant-medicated patients, no differences were detected between the latter groups. In this follow-up study, we examined whether the duration of psychostimulant treatment correlates with the degree of iron normalization. Brain iron was indexed with MRI using an advanced method called magnetic field correlation (MFC) imaging and the conventional R2* proton transverse relaxation rate method. MFC was acquired in 30 psychostimulant-medicated youth with comorbid-free ADHD and 29 age-matched controls (all males). R2* was acquired in a subset of these individuals. Region-of-interest analyses for MFC and R2* group differences and within-group correlations with age and years of psychostimulant treatment were conducted in the globus pallidus (GP), putamen (PUT), caudate nucleus (CN), thalamus (THL) and red nucleus. No significant MFC and R2* group differences were detected. However, while all regional MFC and R2* significantly increased with age in the control group, MFC and R2* increased in the GP, PUT, CN and THL with psychostimulant treatment duration in the ADHD group to a greater degree than with age. Our findings suggest that while youth with ADHD may have less prominent age-related brain iron increases than that seen in typical development, long-term use of psychostimulant medications may compensate through a normalizing effect on basal ganglia iron. Longitudinal studies following ADHD patients before and after long-term psychostimulant treatment are needed to confirm these findings.

Can we predict treatment response in children with ADHD to a vitamin-mineral supplement? An investigation into pre-treatment nutrient serum levels, MTHFR status, clinical correlates and demographic variables

BACKGROUND

Intent-to-treat analyses from a randomized controlled trial showed significant between-group differences favouring micronutrient treatment on the Clinical Global Impression-Improvement, but no group differences on clinician, parent and teacher ratings of overall ADHD symptoms. There was an advantage of micronutrients over placebo in improving overall function, emotional regulation, aggression, and reducing impairment as well as improving inattention based on clinician but not parent observation. No group differences were observed on hyperactive-impulsive symptoms. We investigated predictors of response defined by pre-treatment variables.

METHOD

We conducted analyses of data from a clinical trial of children (7-12 years) with ADHD, whereby participants were randomized to receive micronutrients or placebo for 10 weeks followed by a 10 week open-label (OL) phase. We included only children who had been exposed to micronutrients for a full 10 week period and demonstrated satisfactory adherence, either in RCT phase (n = 40) or OL phase (those who received placebo during RCT phase; n = 31). Seven outcomes were examined: change in ADHD symptoms (clinician/parent), ADHD responder, overall responder, change in mood, change in functioning, and change in aggression. Demographic, developmental variables, current clinical and physical characteristics, MTHFR genotype at two common variants, and pre-treatment serum/plasma levels (vitamin D, B₁₂, folate, zinc, copper, iron, ferritin, potassium, calcium, magnesium, and homocysteine) were all considered as putative predictors.

RESULTS

Substantial nutrient deficiencies pre-treatment were observed only for vitamin D (13%) and copper (15%), otherwise most children entered the trial with nutrient levels falling within expected ranges. Regression analyses showed varying predictors across outcomes with no one predictor being consistently identified across different variables. Lower pre-treatment folate and B₁₂ levels, being female, greater severity of symptoms and co-occurring disorders pre-treatment, more pregnancy complications and fewer birth problems were identified as possible predictors of greater improvement for some but not all outcome measures although predictive values were weak. Lower IQ and higher BMI predicted greater improvement in aggression.

CONCLUSIONS

This study replicates Rucklidge et al. (2014b) showing the limited value of using serum nutrient levels to predict treatment response although we cannot rule out that other non-assayed nutrient levels may be more valuable. Additionally, no specific demographic or clinical characteristics, including MTHFR genetic status, were identified that would preclude children with ADHD from trying this treatment approach.

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.

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.

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 Investigation of Symptoms and Diagnoses of Adult-Attention Deficit/ Hyperactivity Disorder in Women with Iron Deficiency Anemia

INTRODUCTION

The aim of this study was to investigate symptoms and diagnoses of Adult-Attention Deficit/Hyperactivity Disorder (ADHD) in women with iron deficiency anemia, to evaluate relationship between ADHD with clinical features and to compare with the women without iron deficiency anemia.

METHODS

Eighty-three newly diagnosed iron deficiency anemia patients and 70 healthy controls were included in this study. All participants were assessed using a sociodemographic form, Structured Clinical Interview I (SCID-I), Wender Utah Rating Scale (WURS); Moreover, participants having WURS scores 36 and above were also assessed using the Adult ADD/ADHD Evaluation Scale and interviewed according to DSM-5 criteria.

RESULTS

In the study, 22.9% of patients with iron deficiency anemia and 12.9% of healthy controls were found to have WURS scores 36 and above. Fifteen patients (18.1%) in iron deficiency anemia group and two patients (2.9%) in control group had adult ADHD, when they were evaluated with Adult ADD/ADHD Evaluation Scale and interviewed according to DSM-5 criteria (p=0.007). The patients with iron deficiency anemia had significantly higher WURS scores compared to controls (p=0.002). The levels of iron and ferritin had negative correlation (r=-0.166, p<0.05; r=-0.255, p<0.01, respectively) and the levels of serum iron binding capacity had positive correlation (r=0.255, p<0.01) with the scores of WURS.

CONCLUSION

The prevalence of adult ADHD is higher than those reported for general population in patients with iron deficiency anemia. Early diagnose and treatment of adult ADHD may positively contribute to the patients with iron deficiency anemia.

The Mediterranean Diet and ADHD in Children and Adolescents

OBJECTIVES

Although attention-deficit/hyperactivity disorder (ADHD) has been related to nutrient deficiencies and "unhealthy" diets, to date there are no studies that examined the relationship between the Mediterranean diet and ADHD. We hypothesized that a low adherence to a Mediterranean diet would be positively associated with an increase in ADHD diagnosis.

METHODS

A total of 120 children and adolescents (60 with newly diagnosed ADHD and 60 controls) were studied in a sex- and age-matched case-control study. ADHD diagnosis was made according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision. Energy, dietary intake, adherence to a Mediterranean diet, and familial background were measured. Logistic regression was used to determine associations between the adherence to a Mediterranean diet and ADHD.

RESULTS

Lower adherence to a Mediterranean diet was associated with ADHD diagnosis (odds ratio: 7.07; 95% confidence interval: 2.65-18.84; relative risk: 2.80; 95% confidence interval: 1.54-5.25). Both remained significant after adjusting for potential confounders. Lower frequency of consuming fruit, vegetables, pasta, and rice and higher frequency of skipping breakfast and eating at fast-food restaurants were associated with ADHD diagnosis (P < .05). High consumption of sugar, candy, cola beverages, and noncola soft drinks (P < .01) and low consumption of fatty fish (P < .05) were also associated with a higher prevalence of ADHD diagnosis.

CONCLUSIONS

Although these cross-sectional associations do not establish causality, they raise the question of whether low adherence to a Mediterranean diet might play a role in ADHD development. Our data support the notion that not only "specific nutrients" but also the "whole diet" should be considered in ADHD.

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.

Hormone disorder and vitamin deficiency in attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASDs)

BACKGROUND

The aim of this study was to analyze thyroid hormones and antibodies, ferritin, vitamins B12 and D, adrenal and gonadal steroid levels, and celiac antibodies in children diagnosed with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD).

METHODS

Between February 2014 and July 2014, a total of 77 children and adolescents (31 girls, 46 boys) who were admitted to the Van Training and Research Hospital were included in the study. The study population was divided into three groups including ADHD (n=34), ASD (n=16), and age- and sex-matched healthy controls (n=27). The diagnosis of ADHD was made on the basis of Diagnostic and Statistical Manual of Mental Disorders - Fifth Edition (DSM-5) and DSM-4 Turkish version with the diagnostic interview and Disruptive Behavior Disorder Rating Scale (DBDRS). The diagnosis of ASD was based on the DSM-4 and DSM-5 Turkish version with the diagnostic interview and the Childhood Autism Rating Scale (CARS). The blood samples were obtained between 8:00 and 9:00 A.M.

RESULTS

There was a statistically significant difference in vitamin B12 and D levels and ferritin values among the three groups. The ASD group had the highest ferritin and the lowest vitamins B12 and D levels. Vitamin D levels of the ADHD group were significantly lower compared to the healthy controls.

CONCLUSIONS

Our study results highlight the importance of supplementation of vitamins B12 and D in the ASD and ADHD patients.

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.

Incorporating Informatics for Integrating Biology and the Bedside (i2b2) into Predoctoral Trainee Curriculum to Evaluate Student-Generated Hypotheses

As part of the Clinical and Translational Science Institute predoctoral TL1 training program at the Pennsylvania State University, a multidisciplinary team of predoctoral trainees representing the Chemistry, Neurosurgery, Nutritional Sciences, and Public Health Sciences departments were introduced to the NIH-sponsored Informatics for Integrating Biology and the Bedside (i2b2) database to test the following student-generated hypothesis: children with iron deficiency anemia (IDA) are at increased risk of attention deficit-hyperactivity disorder (ADHD). Children aged 4-12 and 4-17 years were categorized into IDA and control groups. De-identified medical records from the Penn State Milton S. Hershey Medical Center (HMC) and the Virginia Commonwealth University Medical Center (VCUMC) were used for the analysis. Overall, ADHD prevalence at each institution was lower than 2011 state estimates. There was a significant association between IDA and ADHD in the 4-17-year-old age group for all children (OR: 1.902 [95% CI: 1.363-2.656]), Caucasian children (OR: 1.802 [95% CI: 1.133-2.864]), and African American children (OR: 1.865 [95% CI: 1.152-3.021]). Clinical and Translational Science Award (CTSA) infrastructure is particularly useful for trainees to answer de novo scientific questions with minimal additional training and technical expertise. Moreover, projects can be expanded by collaborating within the CTSA network.

Attention enhancing effects of methylphenidate are age-dependent

The psychostimulant methylphenidate (MPH, Ritalin®) is used to treat a variety of cognitive disorders. MPH is also popular among healthy individuals, including the elderly, for its ability to focus attention and improve concentration, but these effects have not been shown to be comparable between aged and adult subjects. Thus, we tested whether MPH would improve performance in sustained attention in both adult and aged rats. In addition, we tested the impact of visual distraction on performance in this task and the ability of MPH to mitigate the effects of distraction. Adult (6-12 months) and aged (18-22 months) male Sprague-Dawley rats were given oral MPH, and their cognitive and motor abilities were tested. Results suggest that while MPH improves task performance in adults; there is no improvement in the aged animals. These outcomes suggest that the use of MPH for cognitive enhancement in elderly individuals may be ineffective.

Attention-deficit/hyperactivity disorder, iron deficiency, and obesity: is there a link?

The exact etiopathophysiology of attention-deficit/hyperactivity disorder (ADHD) remains elusive, likely because of its phenotypic heterogeneity. Given the involvement of iron in neurocognitive and behavioral functions, iron deficiency (ID) has been suggested as a possible etiopathophysiological factor in a subsample of individuals with ADHD. Most studies assessing ID in ADHD have focused on serum ferritin, a marker of peripheral iron status. Results from these studies are mixed, and the largest studies failed to find a significant association between ADHD and low serum ferritin levels. However, serum ferritin may be influenced by several conditions, including inflammatory status. Increasing evidence, especially from epidemiological studies, points to a significant association between ADHD and obesity. Interestingly, obesity is associated with a chronic inflammatory status, characterized by ID with normal-to-high serum ferritin levels. This article reviews the literature on iron status in ADHD and on the relationship between ADHD and obesity; discusses a possible link among ADHD, ID, and obesity; and proposes that comorbid obesity contributes to ID, via chronic inflammation, in a subsample of individuals with ADHD. Thus, the comorbidity between ADHD and obesity suggests moving beyond serum ferritin levels and assessing the molecular pathways of chronic inflammation that lead to ID in individuals with ADHD and obesity. In turns, this may pave the way for novel treatment strategies for cognitive and behavioral dysfunctions related to ID in ADHD.

Multimodal MR imaging of brain iron in attention deficit hyperactivity disorder: a noninvasive biomarker that responds to psychostimulant treatment?

PURPOSE

To comprehensively assess brain iron levels in typically developing control subjects and patients with attention deficit hyperactivity disorder (ADHD) when psychostimulant medication history is accounted for.

MATERIALS AND METHODS

This prospective study was approved by the institutional review board, and informed consent was obtained. Brain iron was indexed noninvasively by using magnetic resonance (MR) imaging relaxation rates (R2, R2*, R2') and magnetic field correlation (MFC) in the globus pallidus, putamen, caudate nucleus, and thalamus for 22 patients with ADHD (12 medication-naïve patients and 10 with a history of psychostimulant treatment) and 27 control subjects (age range, 8-18 years). Serum iron measures were also collected. Subgroup differences were analyzed with data-appropriate omnibus tests followed by post hoc pairwise comparisons; false discovery rate correction was conducted to control for multiple comparisons.

RESULTS

Medication-naïve ADHD patients had significantly lower striatal and thalamic MFC indexes of brain iron than did control subjects (putamen, P = .012; caudate nucleus, P = .008; thalamus, P = .012) and psychostimulant-medicated ADHD patients (putamen, P = .006; caudate nucleus, P = .010; thalamus, P = .021). Conversely, the MFC indexes in medicated patients were comparable to those in control subjects. No significant differences were detected with R2, R2*, R2', or serum measures.

CONCLUSION

Lower MFC indexes of striatal and thalamic brain iron in medication-naïve ADHD patients and lack of differences in psychostimulant-medicated patients suggest that MFC indexes of brain iron may represent a noninvasive diagnostic biomarker that responds to psychostimulant treatment.

Meeting iron needs for infants and children

PURPOSE OF REVIEW

Iron deficiency early in life is associated with impaired neurological development. This study reviews the latest research on how to best meet iron requirements in infants and children.

RECENT FINDINGS

There is concurrent evidence that delayed cord clamping is well tolerated and improves infant iron stores. Iron supplements or enriched complementary foods starting before 6 months of life do not reduce iron deficiency prevalence in low-risk populations. However, for low birth weight infants, iron supplements before 6 months of life have long-term benefits. Iron deficiency anaemia (IDA) during the second half year of life is rare in countries with high compliance to iron-rich complementary foods, but remains a major problem globally. In high-risk populations, iron supplementation reduces IDA and possibly improves growth. However, increased risk of infections is a concern and optimal preventive strategies have not yet been determined. Finally, there is concurrent evidence that iron supplementation of anaemic school-aged children reduces IDA and possibly improves neuropsychological outcomes.

SUMMARY

Interventions for prevention of iron deficiency should be prioritized in risk groups. However, the unclear long-term benefits and possible risk of adverse effects, particularly increased infections in developing countries, prompt further large-scale, double-blinded trials.

Moderators of treatment response in adults with ADHD treated with a vitamin-mineral supplement

BACKGROUND

To date there has been no research investigating moderators of response to micronutrient treatment of mental illness, specifically baseline nutrient levels.

METHOD

We conducted analyses of data from a randomized placebo-controlled trial (RCT) of 80 adults (≥16years) with Attention-Deficit/Hyperactivity Disorder (ADHD), whereby participants were treated acutely (8weeks) with micronutrients or placebo followed by an open-label (OL) phase of 8weeks whereby all participants received micronutrients. To ensure that all participants had been exposed to the micronutrients for 8weeks, only those 64 who had adhered to the treatment protocol and completed 8weeks on nutrients were included in the data analysis: 34 from the group that had been randomized to the micronutrient arm, and 30 from the group that had been randomized to the placebo group and hence had only received nutrients in the OL phase. Six outcomes were examined: change in ADHD symptoms (self/clinician), ADHD responder, Clinical Global Impression-Improvement (CGI-I), change in mood, and change in Global Assessment of Functioning (GAF). Demographic, developmental and psychiatric history, current clinical characteristics, and baseline nutrient levels were all considered as putative predictors.

RESULTS

There were significant changes in all outcome variables after 8weeks exposure to the micronutrients. Among the nutrients recorded at baseline, substantial deficiencies (27%) were only observed for vitamin D. However, other than an association showing that higher iron at baseline was correlated with higher baseline depression scores, baseline nutrient levels were not correlated with baseline psychiatric variables/current clinical characteristics. Regression analyses revealed that higher baseline ferritin and lower baseline copper and vitamin D levels were associated with a better response to treatment for some but not all outcomes. None of the other nutrient levels was found to be associated with outcome, including zinc, vitamin B12, iron, and folate. There were no childhood risk factors, demographic variables or clinical correlates that contraindicated micronutrient treatment; more severe symptoms at baseline and greater number of developmental risk factors predicted greater treatment response.

CONCLUSIONS

Further research looking at nutrients more broadly is required to confirm these initial observations about ferritin, vitamin D and copper; however, the results suggest that serum nutrient levels have limited value for identifying who will respond to treatment.

Parent-reported sleep problems, symptom ratings, and serum ferritin levels in children with attention-deficit/hyperactivity disorder: a case control study

Background

Sleep problems are common among children with attention-deficit/hyperactivity disorder (ADHD). Serum ferritin levels have been associated with the severity of symptoms and sleep disturbances among children with ADHD. This study was conducted to investigate parent-reported sleep problems in a sample of Egyptian children with ADHD and to examine the relationship between their sleep, symptom-ratings, and low serum ferritin levels.

Methods

Parents of 41 ADHD children, aged 6 to 12 years, filled out the Children’s Sleep Habits Questionnaire (CSHQ) and Conners’ Parent Rating Scale-Revised: Long Version (CPRS-R:L) in Arabic. Serum ferritin levels were determined with an enzyme-linked immunosorbent assay. The parents of the 62 controls filled out the CSHQ.

Results

The ADHD group showed significantly higher scores in CSHQ subscales and total score. Children with serum ferritin levels <30 ng/mL had more disturbed sleep. There were significant negative correlations between sleep duration subscale, total score of CSHQ, and serum ferritin levels. There were no significant differences in hyperactivity, cognitive problems/inattention, oppositional, or ADHD index subscale scores between children with serum ferritin levels <30 ng/mL and those with serum ferritin levels ≥30 ng/mL.

Conclusions

Sleep problems are common, and this study suggests an association between low serum ferritin levels and sleep disturbances.

A delicate balance: Iron metabolism and diseases of the brain

Iron is the most abundant transition metal within the brain, and is vital for a number of cellular processes including neurotransmitter synthesis, myelination of neurons, and mitochondrial function. Redox cycling between ferrous and ferric iron is utilized in biology for various electron transfer reactions essential to life, yet this same chemistry mediates deleterious reactions with oxygen that induce oxidative stress. Consequently, there is a precise and tightly controlled mechanism to regulate iron in the brain. When iron is dysregulated, both conditions of iron overload and iron deficiencies are harmful to the brain. This review focuses on how iron metabolism is maintained in the brain, and how an alteration to iron and iron metabolism adversely affects neurological function.

The iron status of children and youth in a community mental health clinic is lower than that of a national sample

OBJECTIVE

Iron plays a key role in brain function, and a deficiency of iron has been implicated in various cognitive, motor, and psychiatric disorders. Because of recent evidence that iron deficiency may be related to attention-deficit/hyperactivity disorder (ADHD) and other psychiatric disorders, the goal of this study was to compare the iron status of children and youth seen in a community mental health clinic with a national sample of same-aged subjects.

METHODS

In this study, a consecutive series of 108 patients (79 males) referred to a community mental health clinic was compared with a National Health and Nutrition Examination Survey (NHANES) sample on measures of iron status. Wilcoxon sign rank and median tests were used to compare distributions of ferritin. Quantile regression was performed to compare the ferritin level in the two samples while adjusting for demographic differences. Chi squared (χ2) was used to compare rates of low hemoglobin in the two samples.

RESULTS

The iron status of the clinic sample, as measured by ferritin levels (median=23 μg/L), was significantly lower than that of the national sample (median=43 μg/L). After adjustment for age, gender, and race, the clinic sample was found to have 19.2 μg/L lower ferritin than the national sample (95% CI from 7.6 to 30.9, p value=0.001). There were also significantly more subjects in the clinic sample with low hemoglobin than in the national sample. There were no differences in ferritin levels between those patients in the clinic sample with and without an ADHD or other specific psychiatric diagnosis.

CONCLUSIONS

The ferritin levels of children and youth in a mental health clinic sample were significantly lower than those of the same-aged subjects in a national sample. Therefore, compromised iron status may be an additional biological risk factor for cognitive, behavioral, and psychiatric problems in pediatric populations served by the community mental health clinic.