Dietary patterns and blood fatty acid composition in children with attention-deficit hyperactivity disorder in Taiwan

Metabolomic Markers in Attention-Deficit/Hyperactivity Disorder (ADHD) among Children and Adolescents-A Systematic Review

Attention-Deficit/Hyperactivity Disorder (ADHD), characterized by clinical diversity, poses diagnostic challenges often reliant on subjective assessments. Metabolomics presents an objective approach, seeking biomarkers for precise diagnosis and targeted interventions. This review synthesizes existing metabolomic insights into ADHD, aiming to reveal biological mechanisms and diagnostic potentials. A thorough PubMed and Web of Knowledge search identified studies exploring blood/urine metabolites in ADHD-diagnosed or psychometrically assessed children and adolescents. Synthesis revealed intricate links between ADHD and altered amino acid metabolism, neurotransmitter dysregulation (especially dopamine and serotonin), oxidative stress, and the kynurenine pathway impacting neurotransmitter homeostasis. Sleep disturbance markers, notably in melatonin metabolism, and stress-induced kynurenine pathway activation emerged. Distinct metabolic signatures, notably in the kynurenine pathway, show promise as potential diagnostic markers. Despite limitations like participant heterogeneity, this review underscores the significance of integrated therapeutic approaches targeting amino acid metabolism, neurotransmitters, and stress pathways. While guiding future research, this overview of the metabolomic findings in ADHD suggests directions for precision diagnostics and personalized ADHD interventions.

Nervonic Acid Synthesis Substrates as Essential Components in Profiled Lipid Supplementation for More Effective Central Nervous System Regeneration

Central nervous system (CNS) damage leads to severe neurological dysfunction as a result of neuronal cell death and axonal degeneration. As, in the mature CNS, neurons have little ability to regenerate their axons and reconstruct neural loss, demyelination is one of the hallmarks of neurological disorders such as multiple sclerosis (MS). Unfortunately, remyelination, as a regenerative process, is often insufficient to prevent axonal loss and improve neurological deficits after demyelination. Currently, there are still no effective therapeutic tools to restore neurological function, but interestingly, emerging studies prove the beneficial effects of lipid supplementation in a wide variety of pathological processes in the human body. In the future, available lipids with a proven beneficial effect on CNS regeneration could be included in supportive therapy, but this topic still requires further studies. Based on our and others' research, we review the role of exogenous lipids, pointing to substrates that are crucial in the remyelination process but are omitted in available studies, justifying the properly profiled supply of lipids in the human diet as a supportive therapy during CNS regeneration.

Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a major problem in children and adolescents, characterised by age-inappropriate levels of inattention, hyperactivity, and impulsivity, and is associated with long-term social, academic, and mental health problems. The stimulant medications methylphenidate and amphetamine are the most frequently used treatments for ADHD, but these are not always effective and can be associated with side effects. Clinical and biochemical evidence suggests that deficiencies of polyunsaturated fatty acids (PUFA) could be related to ADHD. Research has shown that children and adolescents with ADHD have significantly lower plasma and blood concentrations of PUFA and, in particular, lower levels of omega-3 PUFA. These findings suggest that PUFA supplementation may reduce the attention and behaviour problems associated with ADHD. This review is an update of a previously published Cochrane Review. Overall, there was little evidence that PUFA supplementation improved symptoms of ADHD in children and adolescents.

OBJECTIVES

To compare the efficacy of PUFA to other forms of treatment or placebo in treating the symptoms of ADHD in children and adolescents.

SEARCH METHODS

We searched 13 databases and two trials registers up to October 2021. We also checked the reference lists of relevant studies and reviews for additional references.

SELECTION CRITERIA

We included randomised and quasi-randomised controlled trials that compared PUFA with placebo or PUFA plus alternative therapy (medication, behavioural therapy, or psychotherapy) with the same alternative therapy alone in children and adolescents (aged 18 years and under) diagnosed with ADHD.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcome was severity or improvement of ADHD symptoms. Our secondary outcomes were severity or incidence of behavioural problems; quality of life; severity or incidence of depressive symptoms; severity or incidence of anxiety symptoms; side effects; loss to follow-up; and cost. We used GRADE to assess the certainty of evidence for each outcome.

MAIN RESULTS

We included 37 trials with more than 2374 participants, of which 24 trials were new to this update. Five trials (seven reports) used a cross-over design, while the remaining 32 trials (52 reports) used a parallel design. Seven trials were conducted in Iran, four each in the USA and Israel, and two each in Australia, Canada, New Zealand, Sweden, and the UK. Single studies were conducted in Brazil, France, Germany, India, Italy, Japan, Mexico, the Netherlands, Singapore, Spain, Sri Lanka, and Taiwan. Of the 36 trials that compared a PUFA to placebo, 19 used an omega-3 PUFA, six used a combined omega-3/omega-6 supplement, and two used an omega-6 PUFA. The nine remaining trials were included in the comparison of PUFA to placebo, but also had the same co-intervention in the PUFA and placebo groups. Of these, four trials compared a combination of omega-3 PUFA plus methylphenidate to methylphenidate. One trial each compared omega-3 PUFA plus atomoxetine to atomoxetine; omega-3 PUFA plus physical training to physical training; and an omega-3 or omega-6 supplement plus methylphenidate to methylphenidate; and two trials compared omega-3 PUFA plus dietary supplement to dietary supplement. Supplements were given for a period of between two weeks and six months. Although we found low-certainty evidence that PUFA compared to placebo may improve ADHD symptoms in the medium term (risk ratio (RR) 1.95, 95% confidence interval (CI) 1.47 to 2.60; 3 studies, 191 participants), there was high-certainty evidence that PUFA had no effect on parent-rated total ADHD symptoms compared to placebo in the medium term (standardised mean difference (SMD) -0.08, 95% CI -0.24 to 0.07; 16 studies, 1166 participants). There was also high-certainty evidence that parent-rated inattention (medium-term: SMD -0.01, 95% CI -0.20 to 0.17; 12 studies, 960 participants) and hyperactivity/impulsivity (medium-term: SMD 0.09, 95% CI -0.04 to 0.23; 10 studies, 869 participants) scores were no different compared to placebo. There was moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups (RR 1.02, 95% CI 0.69 to 1.52; 8 studies, 591 participants). There was also moderate-certainty evidence that medium-term loss to follow-up was likely similar between groups (RR 1.03, 95% CI 0.77 to 1.37; 13 studies, 1121 participants).

AUTHORS' CONCLUSIONS

Although we found low-certainty evidence that children and adolescents receiving PUFA may be more likely to improve compared to those receiving placebo, there was high-certainty evidence that PUFA had no effect on total parent-rated ADHD symptoms. There was also high-certainty evidence that inattention and hyperactivity/impulsivity did not differ between PUFA and placebo groups. We found moderate-certainty evidence that overall side effects likely did not differ between PUFA and placebo groups. There was also moderate-certainty evidence that follow-up was similar between groups. It is important that future research addresses the current weaknesses in this area, which include small sample sizes, variability of selection criteria, variability of the type and dosage of supplementation, and short follow-up times.

Familial risk for bipolar I disorder is associated with erythrocyte omega-3 polyunsaturated fatty acid deficits in youth with attention-deficit hyperactivity disorder

Although attention-deficit/hyperactivity disorder (ADHD) and a family history of bipolar I disorder (BD) increase the risk for developing BD, associated pathoetiological mechanisms remain poorly understood. One candidate risk factor is a neurodevelopmental deficiency in omega-3 polyunsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study investigated erythrocyte EPA+DHA biostatus in psychostimulant-free ADHD youth with ('high-risk', HR) and without ('low-risk', LR) a first-degree relative with BD, and healthy controls (HC). Erythrocyte EPA+DHA composition was determined by gas chromatography, and symptom ratings were performed. A total of n = 123 (HR, n = 41; LR, n = 42; HC, n = 40) youth (mean age: 14.4 ± 2.5 years) were included in the analysis. Compared with HC, erythrocyte EPA+DHA composition was significantly lower in HR (-13%) but not LR (-3%), and there was a trend for HR to be lower than LR (-11%). Both HR and LR differed significantly from HC on all symptom ratings. HR had greater ADHD hyperactivity/impulsive symptom severity, manic symptom severity, and higher parent-reported ratings of internalization, externalization, and dysregulation, compared with LR. ADHD youth with a BD family history exhibit erythrocyte EPA+DHA deficits and a more severe clinical profile, including greater manic and dysregulation symptoms, compared with ADHD youth without a BD family history.

The association between heightened ADHD symptoms and cytokine and fatty acid concentrations during pregnancy

OBJECTIVE

Previous research conducted with samples of children suggest that individuals with attention-deficit/hyperactivity disorder (ADHD) have altered fatty acid concentrations and may have increased systemic inflammation. Whether these differences are also apparent in other populations of individuals with heightened ADHD symptoms (e.g., pregnant adults) is unknown. The goal of the current study was to examine whether there are ADHD-associated differences in polyunsaturated fatty acid concentrations or pro-inflammatory cytokine concentrations during pregnancy, a developmental period when fatty acid concentrations and systemic inflammation have implications for the health of both the pregnant person and the developing child. We hypothesized that plasma levels of the ratio of omega-6s to omega-3s (n-6:n-3) and plasma inflammatory cytokine levels would be higher in individuals with heightened ADHD symptoms, consistent with previous findings in children with ADHD.

METHODS

Data (N = 68) came from a prospective study of pregnant community volunteers who were oversampled for ADHD symptoms. During the 3rd trimester, plasma concentrations of fatty acids and the pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) were assessed. Dietary intake was examined in the 3rd trimester using three 24-h recalls conducted by trained dietitians and by examining plasma levels of conjugated linoleic acid (n-6) and α-linolenic acid (n-3), essential fatty acids that must come from dietary intake.

RESULTS

The group with heightened ADHD symptoms had higher n-6:n-3s (β = 0.30, p < 0.01) and higher TNF-α concentrations (β = 0.35, p < 0.001) relative to controls. There were no group differences in dietary variables, as assessed by self-report and via plasma concentrations of essential fatty acids. IL-6 was not reliably associated with ADHD status in this sample.

CONCLUSION

Pregnant individuals with ADHD, on average, had higher plasma n-6:n-3s and higher TNF-α concentrations relative to controls. A difference was not detected in their dietary intake of fatty acids or other relevant nutrients. Though these null findings are inconclusive, they are consistent with the hypothesis that ADHD-associated differences in plasma fatty acid concentrations are the result of ADHD-associated differences in fatty acid metabolism, rather than simply differences in dietary intake.

Plant monounsaturated fatty acids: Diversity, biosynthesis, functions and uses

Monounsaturated fatty acids are straight-chain aliphatic monocarboxylic acids comprising a unique carbon‑carbon double bond, also termed unsaturation. More than 50 distinct molecular structures have been described in the plant kingdom, and more remain to be discovered. The evolution of land plants has apparently resulted in the convergent evolution of non-homologous enzymes catalyzing the dehydrogenation of saturated acyl chain substrates in a chemo-, regio- and stereoselective manner. Contrasted enzymatic characteristics and different subcellular localizations of these desaturases account for the diversity of existing fatty acid structures. Interestingly, the location and geometrical configuration of the unsaturation confer specific characteristics to these molecules found in a variety of membrane, storage, and surface lipids. An ongoing research effort aimed at exploring the links existing between fatty acid structures and their biological functions has already unraveled the importance of several monounsaturated fatty acids in various physiological and developmental contexts. What is more, the monounsaturated acyl chains found in the oils of seeds and fruits are widely and increasingly used in the food and chemical industries due to the physicochemical properties inherent in their structures. Breeders and plant biotechnologists therefore develop new crops with high monounsaturated contents for various agro-industrial purposes.

Paternal adverse childhood experiences: Associations with infant DNA methylation

Adverse childhood experiences (ACEs), or cumulative childhood stress exposures, such as abuse, neglect, and household dysfunction, predict later health problems in both the exposed individuals and their offspring. One potential explanation suggests exposure to early adversity predicts epigenetic modification, especially DNA methylation (DNAm), linked to later health. Stress experienced preconception by mothers may associate with DNAm in the next generation. We hypothesized that fathers' exposure to ACEs also associates with their offspring DNAm, which, to our knowledge, has not been previously explored. An epigenome-wide association study (EWAS) of blood DNAm (n = 45) from 3-month-old infants was regressed onto fathers' retrospective ACEs at multiple Cytosine-phosphate-Guanosine (CpG) sites to discover associations. This accounted for infants' sex, age, ethnicity, cell type proportion, and genetic variability. Higher ACE scores associated with methylation values at eight CpGs. Post-hoc analysis found no contribution of paternal education, income, marital status, and parental postpartum depression, but did with paternal smoking and BMI along with infant sleep latency. These same CpGs also contributed to the association between paternal ACEs and offspring attention problems at 3 years. Collectively, these findings suggested there were biological associations with paternal early life adversity and offspring DNAm in infancy, potentially affecting offspring later childhood outcomes.

PLS-DA Model for the Evaluation of Attention Deficit and Hyperactivity Disorder in Children and Adolescents through Blood Serum FTIR Spectra

Attention deficit and hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders of childhood. It affects ~10% of the world's population of children, and about 30-50% of those diagnosed in childhood continue to show ADHD symptoms later, with 2-5% of adults having the condition. Current diagnosis of ADHD is based on the clinical evaluation of the patient, and on interviews performed by clinicians with parents and teachers of the children, which, together with the fact that it shares common symptoms and frequent comorbidities with other neurodevelopmental disorders, makes the accurate and timely diagnosis of the disorder a difficult task. Despite the large effort to identify reliable biomarkers that can be used in a clinical environment to support clinical diagnosis, this goal has never been achieved hitherto. In the present study, infrared spectroscopy was used together with multivariate statistical methods (hierarchical clustering and partial least-squares discriminant analysis) to develop a model based on the spectra of blood serum samples that is able to distinguish ADHD patients from healthy individuals. The developed model used an approach where the whole infrared spectrum (in the 3700-900 cm^-1 range) was taken as a holistic imprint of the biochemical blood serum environment (spectroscopic biomarker), overcoming the need for the search of any particular chemical substance associated with the disorder (molecular biomarker). The developed model is based on a sensitive and reliable technique, which is cheap and fast, thus appearing promising to use as a complementary diagnostic tool in the clinical environment.

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.

Perinatal Dietary Polyunsaturated Fatty Acids in Brain Development, Role in Neurodevelopmental Disorders

n-3 and n-6 polyunsaturated fatty acids (PUFAs) are essential fatty acids that are provided by dietary intake. Growing evidence suggests that n-3 and n-6 PUFAs are paramount for brain functions. They constitute crucial elements of cellular membranes, especially in the brain. They are the precursors of several metabolites with different effects on inflammation and neuron outgrowth. Overall, long-chain PUFAs accumulate in the offspring brain during the embryonic and post-natal periods. In this review, we discuss how they accumulate in the developing brain, considering the maternal dietary supply, the polymorphisms of genes involved in their metabolism, and the differences linked to gender. We also report the mechanisms linking their bioavailability in the developing brain, their transfer from the mother to the embryo through the placenta, and their role in brain development. In addition, data on the potential role of altered bioavailability of long-chain n-3 PUFAs in the etiologies of neurodevelopmental diseases, such as autism, attention deficit and hyperactivity disorder, and schizophrenia, are reviewed.

Complementary effects of pine bark extract supplementation on inattention, impulsivity, and antioxidative status in children with attention-deficit hyperactivity disorder: A double-blinded randomized placebo-controlled cross-over study

The purpose of this study was to investigate the complementary effects of polyphenolic compounds from pine bark extract (PE) as a strong antioxidative substrate on the symptoms of inattention and impulsivity in children with attention-deficit hyperactivity disorder (ADHD). This was a randomized, double-blind, crossover, placebo-controlled study that included two experimental units (4 weeks with PE supplementation and 4 weeks with placebo supplementation) separated by a 2-week washout period. ADHD participants were supplemented with 25 mg or 50 mg PE. We recruited 20 participants (17 boys and 3 girls) with a mean age of 10.0 ± 2.1 years. PE supplementation caused a significant reduction in the inattention and hyperactivity-impulsivity items of SNAP-IV. During the period of PE supplementation, the item of commissions in the Continuous Performance Test III (CPT III) significantly decreased, which was used to evaluate the symptoms of inattention and impulsivity. In addition, the erythrocytic reduced glutathione/oxidized glutathione ratio significantly increased, and the plasma TBARs level significantly decreased after 4 weeks of PE supplementation. However, there was no significant correlation between CPT III (commission) and antioxidative status indictors. PE supplementation may have potential effects of ameliorating inattention and impulsivity, and elevating the antioxidative status in children with ADHD.

Unique Trans-fatty Acid Profile in Children With Attention Deficit Hyperactivity Disorder

Background: Attention deficit hyperactivity disorder (ADHD) is the most common developmental disorder in children. Studies suggest an association between fatty acids composition and ADHD pathogenesis. We aimed to investigate whether children diagnosed with ADHD present unique fatty acid profiles in red blood cells (RBC), as compared to children without ADHD. Method: We examined 60 children aged 6-14 years, out of which 32 were diagnosed with ADHD, and 28 were not. Blood was collected from all children to quantify an array of 26 fatty acids from RBC membranes. Fatty acid methyl esters were generated by acid transesterification and analyzed by gas chromatography. Results: We found that children with ADHD presented unique fatty acid profiles on RBC membranes with significantly higher levels of most of the trans-fatty acids (Total trans-fatty acids 0.64 ± 0.21 vs. 0.49 ± 0.18 p = 0.003) and lower levels of docosahexaenoic acid (DHA), as compared to controls (4.06 ± 0.79 vs. 4.68 ± 1.37 p = 0.040). Additionally, total trans-fatty acids were higher in children with extremely severe clinical ADHD condition score, as compared to milder ADHD scores and to control children (0.72 ± 0.18, 0.64 ± 0.20, 0.61 ± 0.22, 0.49 ± 0.18, p = 0.010, accordingly). Conclusion: Children with ADHD have higher levels of trans-fatty acids in RBCs, compared to children without ADHD. This study points to a possible link between trans-fatty acids and ADHD. Understanding these findings and the clinical meaning will potentially contribute to a more targeted dietary intervention.

The Acer truncatum genome provides insights into nervonic acid biosynthesis

Acer truncatum (purpleblow maple) is a woody tree species that produces seeds with high levels of valuable fatty acids (especially nervonic acid). However, the lack of a complete genome sequence has limited both basic and applied research on A. truncatum. We describe a high-quality draft genome assembly comprising 633.28 Mb (contig N50 = 773.17 kb; scaffold N50 = 46.36 Mb) with at least 28 438 predicted genes. The genome underwent an ancient triplication, similar to the core eudicots, but there have been no recent whole-genome duplication events. Acer yangbiense and A. truncatum are estimated to have diverged about 9.4 million years ago. A combined genomic, transcriptomic, metabonomic, and cell ultrastructural analysis provided new insights into the biosynthesis of very long-chain monounsaturated fatty acids. In addition, three KCS genes were found that may contribute to regulating nervonic acid biosynthesis. The KCS paralogous gene family expanded to 28 members, with 10 genes clustered together and distributed in the 0.27-Mb region of pseudochromosome 4. Our chromosome-scale genomic characterization may facilitate the discovery of agronomically important genes and stimulate functional genetic research on A. truncatum. Furthermore, the data presented also offer important foundations from which to study the molecular mechanisms influencing the production of nervonic acids.

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.

Effects of Malania oleifera Chun Oil on the Improvement of Learning and Memory Function in Mice

BACKGROUND

The fruits of Malania oleifera Chun & S. K. Lee have been highly sought after medically because its seeds have high oil content (>60%), especially the highest known proportion of nervonic acid (>55%). Objective of the Study. The objective was to explore the effects of different doses of Malania oleifera Chun oil (MOC oil) on the learning and memory of mice and to evaluate whether additional DHA algae oil and vitamin E could help MOC oil improve learning and memory and its possible mechanisms.

METHODS

After 30 days of oral administration of the relevant agents to mice, behavioral tests were conducted as well as detection of oxidative stress parameters (superoxide dismutase, malondialdehyde, and glutathione peroxidase) and biochemical indicators (acetylcholine, acetyl cholinesterase, and choline acetyltransferase) in the hippocampus.

RESULTS

Experimental results demonstrated that MOC oil treatment could markedly improve learning and memory of mouse models in behavioral experiments and increase the activity of GSH-PX in hippocampus and reduce the content of MDA, especially the dose of 46.27 mg/kg. The addition of DHA and VE could better assist MOC oil to improve the learning and memory, and its mechanism may be related to the inhibition of oxidative stress and restrain the activity of AChE and also increase the content of ACh.

CONCLUSION

Our results demonstrated that MOC oil treatment could improve learning and memory impairments. Therefore, we suggest that MOC oil is a potentially important resource for the development of nervonic acid products.

Trim the fat: the role of omega-3 fatty acids in psychopharmacology

The American Psychiatric Association (APA) currently recommends the use of omega-3 fatty acid supplementation for depressive disorders, impulse-control disorders, and psychotic disorders in treatment guidelines. This review examines the evidence for efficacy of omega-3 fatty acids in depressive disorders, bipolar disorder, anxiety disorders, post-traumatic stress disorder (PTSD), and psychosis. Meta-analysis of randomized-controlled trials of omega-3 fatty acids for depression are inconclusive, with strong evidence of publication bias, sizable heterogeneity between included studies, and substantial methodological shortcomings in included trials. The large amount of heterogeneity in findings of RCTs of omega-3 fatty acids for unipolar depression is likely attributable to highly heterogeneous sample populations that are given different omega-3 supplements [which differ widely in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content, ratio, and dosage] as either adjunctive or monotherapy of other existing treatments, and then measure several different outcomes of depression symptomatology with likely incomplete blinding. Evidence of efficacy of omega-3 supplementation in treating psychosis, PTSD, anxiety, and bipolar mania is minimal. The current guidelines recommending the use of omega-3 fatty acids in adulthood psychiatric conditions should be revisited, especially given several recent negative studies examining the effects of omega-3 fatty acids for cardiovascular disease. Recommending likely ineffective treatment to patients, no matter how benign the side-effect profile, has opportunity cost (e.g. other more effective medications or therapies not being utilized) and likely affects patient compliance with other evidence-based treatments.

Attention-deficit/hyperactivity disorder is associated with reduced levels of serum low-density lipoprotein cholesterol in adolescents. Data from the population-based German KiGGS study

Objectives: Attention-deficit/hyperactivity disorder (ADHD) is a multifactorial, complex and the most common neurodevelopmental disorder in childhood. In this analysis, we tested the hypothesis that altered serum lipid patterns are associated with ADHD. Methods: Using data from the nationwide, population-based German Health Interview and Examination Survey for Children and Adolescents (KiGGS), we compared serum levels of total cholesterol, high-density (HDL) and low-density lipoprotein (LDL) cholesterol, and also triglycerides, in participants with physician-diagnosed and/or suspected ADHD, as defined by a value of ≥7 on the hyperactivity-inattention subscale of the Strengths and Difficulties Questionnaire (SDQ), with non-ADHD controls. Results: Among 6,898 participants aged between 11 and 17 years, 666 (9.7%) had a physician-based diagnosis of ADHD and/or suspected ADHD. We found correlations between the parent-rated SDQ scores on the hyperactivity-inattention subscale and concentrations of triglycerides (r = 0.064, p < .001), total cholesterol (r = -0.026, p = .033), HDL cholesterol (r = -0.059, p < .001) and LDL cholesterol (r = -0.027, p = .031). In multivariate models, low serum levels of LDL cholesterol remained a significant predictor of ADHD (Exp(β) = 0.382, 95% confidence interval = 0.165-0.888, p = .025). Conclusions: Our findings in a large, nationwide and representative sample of German adolescents demonstrated a small, but significant and inverse link between LDL cholesterol levels and symptoms of ADHD. Further studies are required to decipher the biochemical mechanisms behind this relationship.

Effect of omega-3 plus methylphenidate as an alternative therapy to reduce attention deficit-hyperactivity disorder in children

BACKGROUND

Attention deficit-hyperactivity disorder (ADHD) is one of the most common chronic behavioral disorders in school-aged children.

PURPOSE

This study aimed to evaluate the effect of omega-3 supplementation as an alternative therapy for ADHD, which can be caused by vitamin and mineral deficiencies.

METHODS

This was a double-blinded clinical trial study. Sixty-six children with ADHD (aged 6-12 years) referred to our child and adolescent psychiatric educational and therapeutic clinic were selected based on Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. Instruments including the Parent ADHD Rating Scale were used to assess ADHD at 0, 2, 4, and 8 weeks during the study.

RESULTS

The results showed no statistically significant difference between the methylphenidate with omega-3 group and methylphenidate with placebo group based on the Parents ADHD Rating Scale between week 0 (P≥0.96) and week 8 (P≥0.75). There were no significant intergroup differences between the Inattention (P≥0.48) and hyperactivity/impulsivity (P≥0.80) subscale scores on the Parents ADHD Rating Scale. The most common drug complications in the methylphenidate with placebo and methylphenidate with omega-3 groups were anorexia (27 [54%] vs. 41 [60.29%], respectively) and diarrhea (10 [20%] vs. 8 [11.76%], respectively), but the differences were not statistically significant (P> 0.05).

CONCLUSION

Our results demonstrate that a specific dose of omega-3 for 8 weeks had no effect on ADHD.

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.

Children's Attention-Deficit/Hyperactivity Disorder Symptoms Predict Lower Diet Quality but Not Vice Versa: Results from Bidirectional Analyses in a Population-Based Cohort

BACKGROUND

As an adjuvant for medication, dietary changes focused on specific nutrients have been proposed to prevent or reduce attention-deficit/hyperactivity disorder (ADHD) symptoms. However, whether an overall healthy dietary pattern is associated with ADHD symptom severity during childhood remains unclear. Furthermore, it is not clear what the direction of this association is.

OBJECTIVES

We aimed to examine the association between dietary patterns and ADHD symptoms in school-aged children. In addition, we aimed to identify the temporal direction of this association-that is, whether dietary patterns predict ADHD symptoms or vice versa.

METHODS

We analyzed data from 3680 children participating in the Generation R Study, a prospective cohort in Rotterdam, Netherlands. ADHD symptoms were assessed with parent-report questionnaires at ages 6 and 10 y using the Child Behavior Checklist. Dietary intake was assessed at the age of 8 y with a validated food-frequency questionnaire. We computed a diet quality score reflecting adherence to dietary guidelines. We examined bidirectional associations of diet quality with ADHD symptom scores using multivariable linear regression analysis and cross-lagged modeling.

RESULTS

Linear regressions showed that more ADHD symptoms at age 6 y were associated with a lower diet quality score at age 8 y (SD score = -0.08; 95% CI: -0.11, -0.05) but that diet quality at age 8 y was not associated with ADHD symptoms at age 10 y. Cross-lagged models confirmed a unidirectional relation from ADHD symptoms to diet quality but not vice versa. Associations did not differ by overweight status or between boys and girls.

CONCLUSION

Our study suggests that children with more ADHD symptoms may be at higher risk of an unhealthy diet but that overall diet quality does not affect ADHD risk.

The effectiveness of omega-3 supplementation in reducing ADHD associated symptoms in children as measured by the Conners' rating scales: A systematic review of randomized controlled trials

Omega-3 supplements are considered to have anti-inflammatory effects which may be beneficial as inflammation has been linked to ADHD. The aim of this review is to examine the effectiveness of omega-3 supplementation at reducing ADHD symptoms in children and adolescents. Medline, Cinahl+, PsycINFO, Cochrane and Embase were searched for trials investigating the effects of omega-3 supplementation in children and adolescents with ADHD. The primary outcome measure was a mean difference in Conners' rating scale (CRS) between the intervention and placebo group. Search terms used include ADHD, omega-3, fish oils, eicosapentaenoic acid, docosahexaenoic acids, alpha-linolenic acid and Conners' rating scale. Randomized controlled trials examining the efficacy of omega-3 supplementation in children and adolescents as measured by CRS were included. Studies using a combination of polyunsaturated fatty acids or any other rating scale were excluded. Seven trials were included in this review, totalling 926 participants. We found no evidence of publication bias or heterogeneity between trials. Overall, there was a slightly greater reduction in CRS score in favour of the experiment group. One study found a greater reduction in score in favour of the placebo group. Neither findings were statistically significant. There is little supportive evidence to validate the claim of omega-3 supplementation to reduce the degree of ADHD symptoms experienced by children and adolescents. Both experiment and control groups saw similar reductions in Conners rating scale score.

Dietary Long-Chain Omega-3 Fatty Acids Are Related to Impulse Control and Anterior Cingulate Function in Adolescents

Impulse control, an emergent function modulated by the prefrontal cortex (PFC), helps to dampen risky behaviors during adolescence. Influences on PFC maturation during this period may contribute to variations in impulse control. Availability of omega-3 fatty acids, an essential dietary nutrient integral to neuronal structure and function, may be one such influence. This study examined whether intake of energy-adjusted long-chain omega-3 fatty acids [eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)] was related to variation in impulse control and PFC activity during performance of an inhibitory task in adolescents (n = 87; 51.7% female, mean age 13.3 ± 1.1 years) enrolled in a longitudinal neuroimaging study. Intake of DHA + EPA was assessed using a food frequency questionnaire and adjusted for total energy intake. Inhibitory control was assessed using caregiver rating scale (BRIEF Inhibit subscale) and task performance (false alarm rate) on a Go/No-Go task performed during functional MRI. Reported intake of long-chain omega-3 was positively associated with caregiver ratings of adolescent ability to control impulses (p = 0.017) and there was a trend for an association between intake and task-based impulse control (p = 0.072). Furthermore, a regression of BOLD response within PFC during successful impulse control (Correct No-Go versus Incorrect No-Go) with energy-adjusted DHA + EPA intake revealed that adolescents reporting lower intakes display greater activation in the dorsal anterior cingulate, potentially suggestive of a possible lag in cortical development. The present results suggest that dietary omega-3 fatty acids are related to development of both impulse control and function of the dorsal anterior cingulate gyrus in normative adolescent development. Insufficiency of dietary omega-3 fatty acids during this developmental period may be a factor which hinders development of behavioral control.

Transcriptome analysis reveals crucial genes involved in the biosynthesis of nervonic acid in woody Malania oleifera oilseeds

BACKGROUND

Malania oleifera Chun et Lee (Olacaceae), an evergreen broad-leaved woody tree native to southwest China, is an important oilseed tree. Its seed oil has a high level of nervonic acid (cis-tetracos-15-enoic acid, over 60%), which is essential for human health. M. oleifera seed oil is a promising source of nervonic acid, but little is known about the physiological and molecular mechanisms underlying its biosynthesis.

RESULTS

In this study, we recorded oil accumulation at four stages of seed development. Using a high-throughput RNA-sequencing technique, we obtained 55,843 unigenes, of which 29,176 unigenes were functionally annotated. By comparison, 22,833 unigenes had a two-fold or greater expression at the fast oil accumulation stage than at the initial stage. Of these, 198 unigenes were identified as being functionally involved in diverse lipid metabolism processes (including de novo fatty acid synthesis, carbon chain elongation and modification, and triacylglycerol assembly). Key genes (encoding KCS, KCR, HCD and ECR), putatively responsible for nervonic acid biosynthesis, were isolated and their expression profiles during seed development were confirmed by quantitative real-time PCR analysis. Also, we isolated regulatory factors (such as WRI1, ABI3 and FUS3) that are putatively involved in the regulation of oil biosynthesis and seed development.

CONCLUSION

Our results provide novel data on the physiological and molecular mechanisms of nervonic acid biosynthesis and oil accumulation in M. oleifera seeds, and will also serve as a starting point for biotechnological genetic engineering for the production of nervonic acid resources.

Striatal transcriptome of a mouse model of ADHD reveals a pattern of synaptic remodeling

Despite the prevalence and high heritability of Attention-Deficit/Hyperactivity Disorder (ADHD), genetic etiology remains elusive. Clinical evidence points in part to reduced function of the striatum, but which specific genes are differentially expressed and how they sculpt striatal physiology to predispose ADHD are not well understood. As an exploratory tool, a polygenic mouse model of ADHD was recently developed through selective breeding for high home cage activity. Relative to the Control line, the High-Active line displays hyperactivity and motor impulsivity which are ameliorated with amphetamine. This study compared gene expression in the striatum between Control and High-Active mice to develop a coherent hypothesis for how genes might affect striatal physiology and predispose ADHD-like symptoms. To this end, striatal transcriptomes of High-Active and Control mice were analyzed after mice were treated with saline or amphetamines. The pseudogene Gm6180 for n-cofilin (Cfl1) displayed 20-fold higher expression in High-Active mice corresponding with reduced Cfl1 expression suggesting synaptic actin dysregulation. Latrophilin 3 (Lphn3), which is associated with ADHD in human populations and is involved in synapse structure, and its ligand fibronectin leucine rich transmembrane protein 3 (Flrt3), were downregulated in High-Active mice. Multiple genes were altered in High-Active mice in a manner predicted to downregulate the canonical Wnt pathway. A smaller and different set of genes including glyoxalase (Glo1) were differentially regulated in High-Active as compared to Control in response to amphetamine. Together, results suggest genes involved in excitatory synapse regulation and maintenance are downregulated in ADHD-like mice. Consistent with the molecular prediction, stereological analysis of the striatum from a separate set of mice processed for imunohistochemical detection of synaptophysin revealed approximately a 46% reduction in synaptophysin immunoreactivity in High-Active relative to Control. Results provide a new set of molecular targets related to synapse maintenance for the next generation of ADHD medicines.

Association between altered lipid profiles and attention deficit hyperactivity disorder in boys

BACKGROUND

Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder, which is multifactorial, complex, and seen most commonly in childhood.

AIMS

The aim of this study was to examine the hypothesis that altered serum lipid profiles are associated with ADHD.

METHODS

The study inluded 32 boys diagnosed with ADHD according to DSM-IV-R criteria and a control group of 29 healthy subjects. All patients were assessed with The Kiddie Schedule for Affective Disorders and Schizophrenia Present and Lifetime Version, the Turgay DSM-IV-based Disruptive Behavior Disorders Child and Adolescent Rating and Screening Scale, the Conners Parent Rating Scale-Revised Long Form, and the Conners Teacher Rating Scale. Measurements were taken of fasting plasma total cholesterol (T-Chol), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and 1-day food intake levels, and the groups were compared.

RESULTS

The mean TC, LDL, and HDL levels were significantly lower in the ADHD group than the control group (p = .005, p < .001, p = .002, respectively). There was no significant difference between the groups' TG levels (p = .295). No significant differences were determined between the combined-type ADHD patients and the predominantly inattentive subtype of ADHD in respect to the lipid profile.

CONCLUSION

The results of this study add to the growing body of evidence indicating an association between serum cholesterol and ADHD in boys. Further genetic and molecular studies are required to elucidate the biochemical mechanisms underlying this relationship.

Supplementation with polyunsaturated fatty acids (PUFAs) in the management of attention deficit hyperactivity disorder (ADHD)

While pharmacotherapy and psychosocial interventions are recommended as the primary frontline treatment for attention deficit hyperactivity disorder (ADHD), alternative approaches to managing ADHD are becoming increasingly popular among patients and their families. Supplementation with polyunsaturated fatty acids (PUFAs) is an example of this. PUFA supplementation is not recommended by guidelines for managing ADHD; however, patients may still decide to use it. To provide direction to healthcare professionals (HCPs) managing ADHD, eight international experts in the field of adult and child ADHD came together for the Continuum Education Board: Omega Supplements in ADHD meeting. This commentary summarises the panel's consensus that current evidence suggests PUFA supplementation has a small beneficial effect on behaviour in children with ADHD, and that further high-quality research is needed to clearly evaluate and define its role in the management of ADHD of children, adolescents and adults. The panel concluded that in cases where patients use PUFA supplementation, HCPs should be comfortable explaining the potential gains that they may have and their possible side effects. The panel also concluded HCPs should not reinforce the idea that PUFA supplementation should replace treatment approaches with a more robust evidence base for managing ADHD.

Omega-3 Polyunsaturated Fatty Acids in Youths with Attention Deficit Hyperactivity Disorder: a Systematic Review and Meta-Analysis of Clinical Trials and Biological Studies

The role of omega-3 polyunsaturated fatty acids (omega-3 or n-3 PUFAs) in the pathogenesis and treatment of children and adolescents with attention deficit hyperactivity disorder (ADHD) is unclear. A systematic review followed by meta-analysis was conducted on: (1) randomized controlled trials (RCTs) assessing the effects of n-3 PUFAs on clinical symptoms and cognition in children and adolescent with ADHD; and (2) case-control studies assessing the levels of n-3 PUFAs in blood and buccal tissues of children and adolescents with ADHD. In seven RCTs, totalling n=534 randomized youth with ADHD, n-3 PUFAs supplementation improves ADHD clinical symptom scores (g=0.38, p<0.0001); and in three RCTs, totalling n=214 randomized youth with ADHD, n-3 PUFAs supplementation improves cognitive measures associated with attention (g=1.09, p=0.001). Moreover, children and adolescents with ADHD have lower levels of DHA (seven studies, n=412, g=-0.76, p=0.0002), EPA (seven studies, n=468, g=-0.38, p=0.0008), and total n-3 PUFAs (six studies, n=396, g=-0.58, p=0.0001). In summary, there is evidence that n-3 PUFAs supplementation monotherapy improves clinical symptoms and cognitive performances in children and adolescents with ADHD, and that these youth have a deficiency in n-3 PUFAs levels. Our findings provide further support to the rationale for using n-3 PUFAs as a treatment option for 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.

N-3 (Omega-3) Fatty Acids: Effects on Brain Dopamine Systems and Potential Role in the Etiology and Treatment of Neuropsychiatric Disorders

BACKGROUND & OBJECTIVE

A number of neuropsychiatric disorders, including Parkinson's disease, schizophrenia, attention deficit hyperactivity disorder, and, to some extent, depression, involve dysregulation of the brain dopamine systems. The etiology of these diseases is multifactorial, involving genetic and environmental factors. Evidence suggests that inadequate levels of n-3 (omega- 3) polyunsaturated fatty acids (PUFA) in the brain may represent a risk factor for these disorders. These fatty acids, which are derived from the diet, are a major component of neuronal membranes and are of particular importance in brain development and function. Low levels of n-3 PUFAs in the brain affect the brain dopamine systems and, when combined with appropriate genetic and other factors, increase the risk of developing these disorders and/or the severity of the disease. This article reviews the neurobiology of n-3 PUFAs and their effects on dopaminergic function.

CONCLUSION

Clinical studies supporting their role in the etiologies of diseases involving the brain dopamine systems and the potential of n-3 PUFAs in the treatment of these disorders are discussed.

The potential relevance of docosahexaenoic acid and eicosapentaenoic acid to the etiopathogenesis of childhood neuropsychiatric disorders

Over the last 15 years, considerable interest has been given to the potential role of omega-3 polyunsaturated fatty acids (PUFAs) for understanding pathogenesis and treatment of neurodevelopmental and psychiatric disorders. This review aims to systematically investigate the scientific evidence supporting the hypothesis on the omega-3 PUFAs deficit as a risk factor shared by different pediatric neuropsychiatric disorders. Medline PubMed database was searched for studies examining blood docosahexaenoic acid (DHA) or eicosapentaenoic acid (EPA) status in children with neuropsychiatric disorders. Forty-one published manuscripts were compatible with the search criteria. The majority of studies on attention-deficit/hyperactivity disorder (ADHD) and autism found a significant decrease in DHA levels in patients versus healthy controls. For the other conditions examined-depression, juvenile bipolar disorder, intellectual disabilities, learning difficulties, and eating disorders (EDs)-the literature was too limited to draw any stable conclusions. However, except EDs, findings in these conditions were in line with results from ADHD and autism studies. Results about EPA levels were too inconsistent to conclude that EPA could be associated with any of the conditions examined. Finally, correlational data provided, on one hand, evidence for a negative association between DHA and symptomatology, whereas on the other hand, evidence for a positive association between EPA and emotional well-being. Although the present review underlines the potential involvement of omega-3 PUFAs in the predisposition to childhood neuropsychiatric disorders, more observational and intervention studies across different diagnoses are needed, which should integrate the collection of baseline PUFA levels with their potential genetic and environmental influencing factors.

Nutritional status and feeding problems in pediatric attention deficit-hyperactivity disorder

BACKGROUND

Children with attention deficit-hyperactivity disorder (ADHD) may be at risk of nutrient deficiency due to the inability to sit through meals. This comparative cross-sectional study was therefore carried out to determine the nutritional status and feeding problems of ADHD children aged 4-12 years.

METHODS

Sociodemographic data, anthropometric measurements and 3 day dietary intake record were collected from 54 ADHD children and 54 typical development (TD) children. The Behavioral Pediatrics Feeding Assessment Scale was used to assess feeding problems.

RESULTS

Mean subject age was 8.6 ± 2.1 years. On anthropometric assessment, 11.1% of the ADHD children had wasting, while 1.9% had severe wasting. In contrast, none of the TD children had wasting. Approximately 5.6% of the ADHD children had stunting, as compared with 3.7% of the TD children, while none of the TD children had severe stunting compared with 3.7% of the ADHD children. More than half of the ADHD children had mid-upper arm circumference (MUAC) below the 5th percentile, indicating undernutrition, compared with only 35.2% of TD children. More than one-third of the ADHD children had feeding problems compared with 9.3% of TD children. There was a significant negative relationship between the ADHD children's feeding problems and bodyweight (r = -0338, P = 0.012), body mass index (r = -0322, P = 0.017) and MUAC (r = -0384, P = 0.004).

CONCLUSION

Almost half of the ADHD children had suboptimal nutrition compared with 11.1% of the TD children. It is imperative to screen ADHD children for nutritional status and feeding problems to prevent negative health impacts later on.

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.

Gas chromatography determination of fatty acids in the human erythrocyte membranes - A review

Blood fatty acid measurements can reflect exogenously consumed fatty acids allowing to resolve some metabolic disorders (e.g. diabetes, anorexia) or mental disorders (e.g. depression, anxiety, schizophrenia). For this purpose, fatty acids can be determined in the whole blood or various blood fractions such as the plasma, serum or erythrocytes. Measurement of fatty acids in the whole blood by dried blood spot technique is becoming increasingly popular and is often used mainly for the screening of newborns due to the use of the small sample volume. The most popular is determination of fatty acids in plasma or serum samples. While the profile of plasma fatty acids fluctuates based on daily dietary intake, the red blood cell membrane composition of fatty acids reflects the 2-3 month dietary intake. Such results can be more reflective in contrast to the plasma/serum and therefore the present review will summarize available information on gas chromatography determination of fatty acids in human red blood cell membranes. Selection of extraction and derivatization reagents as well as presentation of chromatographic conditions will be discussed here.

Serum lipid profile and fatty acid composition of erythrocyte phospholipids in children and adolescents with primary hyperlipidemia

This study aimed at characterizing the fatty acid (FA) composition of red blood cell (RBC) phospholipids in children and adolescents with primary hyperlipidemia, and to ascertain potential association with serum lipid profile and dietary factors. At this purpose, 54 probands aged 6-17 years were recruited. Subjects showed a low omega-3 index (eicosapentaenoic acid, EPA + docosahexaenoic acid, DHA <4%). Compared to males, females had a trend toward lower levels of total monounsaturated fatty acids (MUFA) and MUFA/saturated fatty acids (SFAs) ratio in RBCs. An inverse relationship between MUFA concentration in RBCs and serum cholesterol or HDL-C/triglycerides ratio was found. Omega-6 polyunsaturated fatty acids (n-6 PUFA) were positively associated to serum HDL-C levels, and inversely to dietary cholesterol. Fiber intake was positively associated with MUFA/SFA ratio. In conclusion, we provide the first experimental data on phospholipid FA composition of RBCs in hyperlipidemic children, showing sex differences and an overall low omega 3-index.

A non-targeted metabolite profiling pilot study suggests that tryptophan and lipid metabolisms are linked with ADHD-like behaviours in dogs

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a prevalent and multifactorial neuropsychiatric disorder in the human population worldwide. Complex etiology and clinical heterogeneity have challenged the research, diagnostics and treatment of the disease. Hyperactive and impulsive behaviour has also been observed in dogs, and they could offer a physiologically relevant model for human ADHD. As a part of our ongoing study to understand the molecular etiology of canine anxiety traits, this study was aimed to pilot an approach to identify metabolic biomarkers in canine ADHD-like behaviours for research, diagnostics and treatment purposes.

METHODS

We collected fresh plasma samples from 22 German Shepherds with varying ADHD-like behaviours. All dogs were on the same controlled diet for 2 weeks prior to sampling. A liquid chromatography combined with mass spectrometry (LC-MS)-based non-targeted metabolite profiling was performed to identify plasma metabolites correlating with the ADHD-like behaviour of the dogs.

RESULTS

649 molecular features correlated with ADHD-like behavioural scores (p_raw < 0.05), and three of them [sn-1 LysoPC(18:3), PC(18:3/18:2) and sn-1 LysoPE(18:2)] had significant correlations also after FDR correction (pFDR < 0.05). Phospholipids were found to negatively correlate with ADHD-like behavioural scores, whereas tryptophan metabolites 3-indolepropionic acid (IPA) and kynurenic acid (KYNA) had negative and positive correlations with ADHD-like behavioural scores, respectively.

CONCLUSIONS

Our study identified associations between canine ADHD-like behaviours and metabolites that are involved in lipid and tryptophan metabolisms. The identified metabolites share similarity with earlier findings in human and rodent ADHD models. However, a larger replication study is warranted to validate the discoveries prior to further studies to understand the biological role of the identified metabolites in canine ADHD-like behaviours.

Maternal Malnutrition in the Etiopathogenesis of Psychiatric Diseases: Role of Polyunsaturated Fatty Acids

Evidence from human studies indicates that maternal metabolic state and malnutrition dramatically influence the risk for developing psychiatric complications in later adulthood. In this regard, the central role of polyunsaturated fatty acids (PUFAs), and particularly n-3 PUFAs, is emerging considering that epidemiological evidences have established a negative correlation between n-3 PUFA consumption and development of mood disorders. These findings were supported by clinical studies indicating that low content of n-3 PUFAs in diet is linked to an increased susceptibility to psychiatric disorders. PUFAs regulate membrane fluidity and exert their central action by modulating synaptogenesis and neurotrophic factor expression, neurogenesis, and neurotransmission. Moreover, they are precursors of molecules implicated in modulating immune and inflammatory processes in the brain. Importantly, their tissue concentrations are closely related to diet intake, especially to maternal consumption during embryonal life, considering that their synthesis from essential precursors has been shown to be inefficient in mammals. The scope of this review is to highlight the possible mechanisms of PUFA functions in the brain during pre- and post-natal period and to evaluate their role in the pathogenesis of psychiatric diseases.

Omega-3 and Omega-6 Polyunsaturated Fatty Acid Levels and Correlations with Symptoms in Children with Attention Deficit Hyperactivity Disorder, Autistic Spectrum Disorder and Typically Developing Controls

Background

There is evidence that children with Attention Deficit Hyperactivity Disorder (ADHD) and Autistic Spectrum Disorder (ASD) have lower omega-3 polyunsaturated fatty acid (n-3 PUFA) levels compared with controls and conflicting evidence regarding omega-6 (n-6) PUFA levels.

Objectives

This study investigated whether erythrocyte n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were lower and n-6 PUFA arachidonic acid (AA) higher in children with ADHD, ASD and controls, and whether lower n-3 and higher n-6 PUFAs correlated with poorer scores on the Australian Twin Behaviour Rating Scale (ATBRS; ADHD symptoms) and Test of Variable Attention (TOVA) in children with ADHD, and Childhood Autism Rating Scale (CARS) in children with ASD.

Methods

Assessments and blood samples of 565 children aged 3–17 years with ADHD (n = 401), ASD (n = 85) or controls (n = 79) were analysed. One-way ANOVAs with Tukey’s post-hoc analysis investigated differences in PUFA levels between groups and Pearson’s correlations investigated correlations between PUFA levels and ATBRS, TOVA and CARS scores.

Results

Children with ADHD and ASD had lower DHA, EPA and AA, higher AA/EPA ratio and lower n-3/n-6 than controls (P<0.001 except AA between ADHD and controls: P = 0.047). Children with ASD had lower DHA, EPA and AA than children with ADHD (P<0.001 for all comparisons). ATBRS scores correlated negatively with EPA (r = -.294, P<0.001), DHA (r = -.424, P<0.001), n-3/n-6 (r = -.477, P<0.001) and positively with AA/EPA (r = .222, P <.01). TOVA scores correlated positively with DHA (r = .610, P<0.001), EPA (r = .418, P<0.001) AA (r = .199, P<0.001), and n-3/n-6 (r = .509, P<0.001) and negatively with AA/EPA (r = -.243, P<0.001). CARS scores correlated significantly with DHA (r = .328, P = 0.002), EPA (r = -.225, P = 0.038) and AA (r = .251, P = 0.021).

Conclusions

Children with ADHD and ASD had low levels of EPA, DHA and AA and high ratio of n-6/n-3 PUFAs and these correlated significantly with symptoms. Future research should further investigate abnormal fatty acid metabolism in these disorders.

The Essentiality of Arachidonic Acid in Infant Development

Arachidonic acid (ARA, 20:4n-6) is an n-6 polyunsaturated 20-carbon fatty acid formed by the biosynthesis from linoleic acid (LA, 18:2n-6). This review considers the essential role that ARA plays in infant development. ARA is always present in human milk at a relatively fixed level and is accumulated in tissues throughout the body where it serves several important functions. Without the provision of preformed ARA in human milk or infant formula the growing infant cannot maintain ARA levels from synthetic pathways alone that are sufficient to meet metabolic demand. During late infancy and early childhood the amount of dietary ARA provided by solid foods is low. ARA serves as a precursor to leukotrienes, prostaglandins, and thromboxanes, collectively known as eicosanoids which are important for immunity and immune response. There is strong evidence based on animal and human studies that ARA is critical for infant growth, brain development, and health. These studies also demonstrate the importance of balancing the amounts of ARA and DHA as too much DHA may suppress the benefits provided by ARA. Both ARA and DHA have been added to infant formulas and follow-on formulas for more than two decades. The amounts and ratios of ARA and DHA needed in infant formula are discussed based on an in depth review of the available scientific evidence.

Docosahexaenoic acid biostatus is associated with event-related functional connectivity in cortical attention networks of typically developing children

OBJECTIVE

Although extant preclinical evidence suggests that the long-chain omega-3 fatty acid docosahexaenoic acid (DHA) is important for neurodevelopment, little is known about its role in human cortical structural and functional maturation. In the present cross-sectional study, we investigated the relationship between DHA biostatus and functional connectivity in cortical attention networks of typically developing children.

METHODS

Male children (aged 8-10 years, n = 36) were divided into 'low-DHA' (n = 18) and 'high-DHA' (n = 18) biostatus groups by a median split of erythrocyte DHA levels. Event-related functional connectivity during the performance of a sustained attention task (identical pairs continuous performance task (CPT-IP)) was conducted using functional magnetic resonance imaging. A voxelwise approach used the anterior cingulate cortex (ACC) as the seed-region.

RESULTS

Erythrocyte DHA composition in the low-DHA group (2.6 ± 0.9%) was significantly lower than the high-DHA group (4.1 ± 1.1%, P ≤ 0.0001). Fish intake frequency was greater in the high-DHA group (P = 0.003) and was positively correlated with DHA levels among all subjects. The low-DHA group exhibited reduced functional connectivity between the ACC and the ventrolateral prefrontal cortex, insula, precuneus, superior parietal lobule, middle occipital gyrus, inferior temporal gyrus, and lingual gyrus compared with the high-DHA group (P < 0.05; corrected). The low-DHA group did not exhibit greater ACC functional connectivity with any region compared with the high-DHA group. On the CPT-IP task, the low-DHA group had slower reaction time (P = 0.03) which was inversely correlated with erythrocyte DHA among all subjects.

DISCUSSION

These data suggest that low-DHA biostatus is associated with reduced event-related functional connectivity in cortical attention networks of typically developing children.

Critical appraisal of omega-3 fatty acids in attention-deficit/hyperactivity disorder treatment

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder. The classical treatment of ADHD where stimulant medication is used has revealed severe side effects and intolerance. Consequently, the demand to search for alternative treatment has increased rapidly. When comparing levels of omega-3 polyunsaturated fatty acids (ω-3 PUFAs) in ADHD patients with those in age-matching controls, lower levels are found in ADHD patients' blood. ω-3 PUFAs are essential nutrients and necessary for a proper brain function and development. Additionally, there are strong indications that ω-3 PUFA supplements could have beneficial effects on ADHD. However, the results of ω-3 PUFA supplementation studies show a high variability. Therefore, we reviewed recent studies published between 2000 and 2015 to identify effective treatment combinations, the quality of design, and safety and tolerability of ω-3-containing food supplements. We searched the databases MEDLINE, PubMed, and Web of Science with keywords such as "ADHD" and "ω-3/6 PUFA" and identified 25 studies that met the inclusion and exclusion criteria. The results of these ω-3 PUFA studies are contradictory but, overall, show evidence for a successful treatment of ADHD symptoms. Tolerability of the given supplements was high, and only mild side effects were reported. In conclusion, there is evidence that a ω-3 PUFA treatment has a positive effect on ADHD. It should be added that treatment could be more effective in patients with mild forms of ADHD. Moreover, the dosage of stimulant medication could be reduced when used in combination with ω-3 PUFA supplements. Further studies are necessary to investigate underlying mechanisms that can lead to a reduction of ADHD symptoms due to ω-3 PUFA treatments and also to determine the optimal concentrations of ω-3 PUFAs, whether used as single treatment or in combination with other medication.

Biochemical and Psychological Effects of Omega-3/6 Supplements in Male Adolescents with Attention-Deficit/Hyperactivity Disorder: A Randomized, Placebo-Controlled, Clinical Trial

BACKGROUND

An abnormality in long chain-polyunsaturated fatty acid (LC-PUFA) levels has been implicated in attention-deficit/hyperactivity disorder (ADHD). Studies evaluating LC-PUFA supplementation for therapeutic efficacy in ADHD have shown mixed and, therefore, inconclusive results.

METHODS

Seventy-six male adolescents (age 12-16 years, mean = 13.7) with ADHD were assessed for the effects of 12 weeks omega-3 and omega-6 supplements on biochemical and psychological outcomes in a randomized, placebo-controlled, clinical trial. The primary outcome measure was change in the Conners' Teacher Rating Scales (CTRS) following 12 weeks of supplementation of LC-PUFA or placebo. At baseline, the placebo and treatment groups had comparable levels of LC-PUFA as measured by red blood cell phosphatidylcholine. In the treatment group, supplementation enhanced eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and total omega-3 fatty acid levels.

RESULTS

No superiority of LC-PUFAs to placebo was observed on the primary outcome. Further, there were no reliable treatment effects on aggression, impulsivity, depression, and anxiety.

CONCLUSIONS

Future studies should use larger sample sizes and longer supplementation period to detect small-modest effects for clinical recommendations in ADHD.

ω-3 Long-Chain Polyunsaturated Fatty Acids and Fatty Acid Desaturase Activity Ratios as Eventual Endophenotypes for ADHD

OBJECTIVE

Epidemiological studies suggest that long-chain polyunsaturated fatty acids (LC-PUFAs) may be suitable as endophenotypes for ADHD. To be appropriated vulnerability traits, endophenotypes should be altered in unaffected relatives of index cases. Serum profiles of LC-PUFAs in unaffected relatives of ADHD patients remain understudied. The main objective of this study was to compare serum LC-PUFAs in ADHD patients, unaffected relatives of index cases, and general-population unaffected participants.

METHOD

LC-PUFA profiles of 72 participants (27 ADHD patients, 27 unaffected relatives, and 18 general-population participants) were obtained by gas chromatography-mass spectrometry (GC-MS). Groups were compared by parametrical statistics.

RESULTS

Unaffected females from the general population presented lower Docosapentaenoic acid (DPA; p = .0012) and a-linolenic acid (ALA; p = .0091) levels compared with ADHD females and unaffected relatives. In addition, docosahexaenoic acid (DHA)/ALA and DHA/DPA ratios, addressing desaturase activity, were significantly lower in ADHD patients and unaffected relatives of ADHD patients in the female-subgroup (p = .022 and .04, respectively).

CONCLUSION

DHA/ALA, DHA/DPA, serum DPA, and serum ALA may be suitable as endophenotypes for ADHD women.

Reduced Symptoms of Inattention after Dietary Omega-3 Fatty Acid Supplementation in Boys with and without Attention Deficit/Hyperactivity Disorder

Attention deficit/hyperactivity disorder (ADHD) is one of the most common child psychiatric disorders, and is often treated with stimulant medication. Nonpharmacological treatments include dietary supplementation with omega-3 fatty acids, although their effectiveness remains to be shown conclusively. In this study, we investigated the effects of dietary omega-3 fatty acid supplementation on ADHD symptoms and cognitive control in young boys with and without ADHD. A total of 40 boys with ADHD, aged 8-14 years, and 39 matched, typically developing controls participated in a 16-week double-blind randomized placebo-controlled trial. Participants consumed 10 g of margarine daily, enriched with either 650 mg of eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) each or placebo. Baseline and follow-up assessments addressed ADHD symptoms, fMRI of cognitive control, urine homovanillic acid, and cheek cell phospholipid sampling. EPA/DHA supplementation improved parent-rated attention in both children with ADHD and typically developing children. Phospholipid DHA level at follow-up was higher for children receiving EPA/DHA supplements than placebo. There was no effect of EPA/DHA supplementation on cognitive control or on fMRI measures of brain activity. This study shows that dietary supplementation with omega-3 fatty acids reduces symptoms of ADHD, both for individuals with ADHD and typically developing children. This effect does not appear to be mediated by cognitive control systems in the brain, as no effect of supplementation was found here. Nonetheless, this study offers support that omega-3 supplementation may be an effective augmentation for pharmacological treatments of ADHD (NCT01554462: The Effects of EPA/DHA Supplementation on Cognitive Control in Children with ADHD; http://clinicaltrials.gov/show/NCT01554462).

Low serum sphingolipids in children with attention deficit-hyperactivity disorder

Background: Attention deficit-hyperactivity disorder (ADHD) is the most prevalent neuropsychiatric condition in childhood. ADHD is a multifactorial trait with a strong genetic component. One neurodevelopmental hypothesis is that ADHD is associated with a lag in brain maturation. Sphingolipids are essential for brain development and neuronal functioning, but their role in ADHD pathogenesis is unexplored. We hypothesized that serum sphingolipid levels distinguish ADHD patients from unaffected subjects.

Methods: We characterized serum sphingolipid profiles of ADHD patients and two control groups: non-affected relatives and non-affected subjects without a family history of ADHD. Sphingolipids were measured by LC-MS/MS in 77 participants (28 ADHD patients, 28 related controls, and 21 unrelated controls). ADHD diagnosis was based on the Diagnostic and Statistical Manual of Mental Disorders (DSM IV-TR). Diagnostic criteria were assessed by two independent observers. Groups were compared by parametrical statistics.

Results: Serum sphingomyelins C16:0, C18:0, C18:1, C24:1, ceramide C24:0, and deoxy-ceramide C24:1 were significantly decreased in ADHD patients at 20–30% relative reductions. In our sample, decreased serum sphingomyelin levels distinguished ADHD patients with 79% sensitivity and 78% specificity.

Conclusions: Our results showed lower levels of all major serum sphingomyelins in ADHD. These findings may reflect brain maturation and affect neuro-functional pathways characteristic for ADHD.