Total red blood cell concentrations of omega-3 fatty acids are associated with emotion-elicited neural activity in adolescent boys with attention-deficit hyperactivity disorder

Interpretability of Spatiotemporal Dynamics of the Brain Processes Followed by Mindfulness Intervention in a Brain-Inspired Spiking Neural Network Architecture

Mindfulness training is associated with improvements in psychological wellbeing and cognition, yet the specific underlying neurophysiological mechanisms underpinning these changes are uncertain. This study uses a novel brain-inspired artificial neural network to investigate the effect of mindfulness training on electroencephalographic function. Participants completed a 4-tone auditory oddball task (that included targets and physically similar distractors) at three assessment time points. In Group A (n = 10), these tasks were given immediately prior to 6-week mindfulness training, immediately after training and at a 3-week follow-up; in Group B (n = 10), these were during an intervention waitlist period (3 weeks prior to training), pre-mindfulness training and post-mindfulness training. Using a spiking neural network (SNN) model, we evaluated concurrent neural patterns generated across space and time from features of electroencephalographic data capturing the neural dynamics associated with the event-related potential (ERP). This technique capitalises on the temporal dynamics of the shifts in polarity throughout the ERP and spatially across electrodes. Findings support anteriorisation of connection weights in response to distractors relative to target stimuli. Right frontal connection weights to distractors were associated with trait mindfulness (positively) and depression (inversely). Moreover, mindfulness training was associated with an increase in connection weights to targets (bilateral frontal, left frontocentral, and temporal regions only) and distractors. SNN models were superior to other machine learning methods in the classification of brain states as a function of mindfulness training. Findings suggest SNN models can provide useful information that differentiates brain states based on distinct task demands and stimuli, as well as changes in brain states as a function of psychological intervention.

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.

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.

Event-related potential differences in children supplemented with long-chain polyunsaturated fatty acids during infancy

Long-chain polyunsaturated fatty acids (LCPUFA) have been shown to be necessary for early retinal and brain development, but long-term cognitive benefits of LCPUFA in infancy have not been definitively established. The present study sought to determine whether LCPUFA supplementation during the first year of life would result in group differences in behavior and event-related potentials (ERPs) while performing a task requiring response inhibition (Go/No-Go) at 5.5 years of age. As newborns, 69 children were randomly assigned to infant formulas containing either no LCPUFA (control) or formula with 0.64% of total fatty acids as arachidonic acid (ARA; 20:4n6) and various concentrations of docosahexaenoic acid (DHA; 22:6n3) (0.32%, 0.64% or 0.96%) for the first 12 months of life. At 5.5 years of age, a task designed to test the ability to inhibit a prepotent response (Go/No-Go) was administered, yielding both event-related potentials (ERPs) and behavioral data. Behavioral measures did not differ between groups, although reaction times of supplemented children were marginally faster. Unsupplemented children had lower P2 amplitude than supplemented children to both Go and No-Go conditions. N2 amplitude was significantly higher on No-Go trials than Go trials, but only for supplemented children, resulting in a significant Group × Condition interaction. Topographical analysis of the ERPs revealed that the LCPUFA-supplemented group developed a novel period of synchronous activation (microstate) involving wider anterior brain activation around 200 ms; this microstate was not present in controls. These findings suggest that LCPUFA supplementation during the first 12 months of life exerts a developmental programming effect that is manifest in brain electrophysiology. A video abstract of this article can be viewed at: https://www.youtube.com/watch?v=oM2leg4sevs.

Adult emotionality and neural plasticity as a function of adolescent nutrient supplementation in male rats

The present study explored the effects of supplementing male rats with either choline, omega-3 fatty acids, or phytoestrogens, from weaning into early adulthood, on emotionality and hippocampal plasticity. Because of the neuroprotective properties of these nutrients, we hypothesized that they would positively affect both behavior and hippocampal function when compared to non-supplemented control rats. To test this hypothesis, male Sprague Dawley rats were assigned to one of four nutrient conditions after weaning: 1) control (normal rat chow); 2) choline (supplemented in drinking water); 3) omega 3 fatty acids (daily oral supplements); or 4) phytoestrogens (supplemented in chow). After 4weeks on their respective diets, a subset of rats began 3weeks of behavioral testing, while the remaining behaviorally naïve rats were sacrificed after 6weeks on the diets to assess numbers of adult-born hippocampal neurons using the immature neuron marker, doublecortin. The results revealed that choline supplementation affected emotional functioning; compared to rats in other diet conditions, rats in this group were less anxious in an open field and after exposure to predator odor and showed less behavioral despair after forced swimming. Similar behavioral findings were evident following supplementation with omega-3 fatty acids and phytoestrogen supplementation, though not on all tests and not to the same magnitude. Histological findings followed a pattern consistent with the behavioral findings: choline supplementation, followed by omega-3 fatty acid supplementation, but not phytoestrogen supplementation, significantly increased the numbers of new-born hippocampal neurons. Choline and omega-3 fatty acids have similar biological functions-affecting cell membranes, growth factor levels, and epigenetically altering gene transcription. Thus, the present findings suggest that targeting nutrients with these effects may be a viable strategy to combat adult psychopathologies.

Omega-3 fatty acid and nutrient deficits in adverse neurodevelopment and childhood behaviors

Nutritional insufficiencies of omega-3 highly unsaturated fatty acids (HUFAs) may have adverse effects on brain development and neurodevelopmental outcomes. A recent meta-analysis reported a small to modest effect size for the efficacy of omega-3 in youth. Several controlled trials of omega-3 HUFAs combined with micronutrients show sizable reductions in aggressive, antisocial, and violent behavior in youth and young adult prisoners. Studies of HUFAs in youth, however, remain lacking. As the evidence base for omega-3 HUFAs as potential psychiatric treatment develops, dietary adjustments to increase omega-3 and reduce omega-6 HUFA consumption are sensible recommendations based on general health considerations.

Omega-3 fatty acid and ADHD: blood level analysis and meta-analytic extension of supplementation trials

Interest in the value of omega-3 (n-3) fatty acid supplementation for treatment of ADHD remains high. No prior meta-analysis has examined whether ADHD is associated with alterations in blood lipid levels and meta-analyses of supplementation have reached conflicting conclusions.

METHODS

We report two new meta-analyses. Study 1 examined blood levels of omega-3 fatty acids in relation to ADHD. Study 2 examined a larger sample of randomized intervention trials than previously reported.

RESULTS

Study 1 included 9 studies (n=586) and found lower overall blood levels of n-3 in individuals with ADHD versus controls (g=0.42, 95% CI=0.26-0.59; p<.001). Study 2 included 16 studies (n=1408) and found that n-3 supplementation improved ADHD composite symptoms; using the best available rating and reporter (g=0.26, 95% CI=0.15-0.37; p<.001). Supplementation showed reliable effects on hyperactivity by parent and teacher report, but reliable effects for inattention only by parent report.

CONCLUSIONS

Omega-3 levels are reduced in children with ADHD. Dietary supplementation appears to create modest improvements in symptoms. There is sufficient evidence to consider omega-3 fatty acids as a possible supplement to established therapies. However it remains unclear whether such intervention should be confined to children with below normal blood levels.

Fatty acid correlates of temperament in adolescent boys with attention deficit hyperactivity disorder

Atypical fatty acid metabolism has been reported in attention deficit hyperactivity disorder (ADHD), however, its relationship with temperament in this population is unclear. The current study investigated the association between blood levels of fatty acids implicated in brain structure and function (omega-3, omega-6, omega-9) and personality traits of stability (neuroticism, conscientiousness and agreeableness) and plasticity (extraversion and openness). Twenty right-handed adolescent boys with ADHD completed a self-report NEO-FFI personality questionnaire, and had fatty acid content assessed from red blood using gas chromatography. Pearson's correlations showed no significant associations between omega-3 levels and personality. After correction for multiple comparisons, Adrenic Acid (C22:4n6) was inversely associated with stability. Oleic acid (C18:1n9) was positively associated with plasticity. Results are in line with a role of fatty acids in brain function. They suggest that those fatty acids that are involved in myelination (Adrenic, Oleic) have the strongest associations with temperament in adolescents with ADHD.

Omega-3 fatty acids are related to abnormal emotion processing in adolescent boys with attention deficit hyperactivity disorder

BACKGROUND

In addition to the core symptoms, attention deficit hyperactivity disorder (ADHD) is associated with poor emotion regulation. There is some evidence that children and young adults with ADHD have lower omega-3 levels and that supplementation with omega-3 can improve both ADHD and affective symptoms. We therefore investigated differences between ADHD and non-ADHD children in omega-3/6 fatty acid plasma levels and the relationship between those indices and emotion-elicited event-related potentials (ERPs).

METHODS

Children/adolescents with (n=31) and without ADHD (n=32) were compared in their plasma omega-3/6 indices and corresponding ERPs during an emotion processing task.

RESULTS

Children with ADHD had lower mean omega-3/6 and ERP abnormalities in emotion processing, independent of emotional valence relative to control children. ERP abnormalities were significantly associated with lower omega-3 levels in the ADHD group.

CONCLUSIONS

The findings reveal for the first time that lower omega-3 fatty acids are associated with impaired emotion processing in ADHD children.

Altered serum mono- and polyunsaturated fatty acid levels in adults with ADHD

Other than in children diagnosed with attention deficit hyperactivity disorder (ADHD), the connection between ADHD and lipids has not been sufficiently investigated so far in adults. Blood serum lipoproteins and fatty acids (FA) composition were measured and analyzed by colorimetry and gaschromatography in eight male and seven female adults diagnosed with ADHD as well as in 15 age- and gender-matched healthy control subjects. In ADHD patients, polyunsaturated FAs [docosahexaenoic, arachidonic and dihomogammalinolenic acid (p = 0.048; 0.003; 0.012)] showed lower concentrations, while monounsaturated acids (palmitoleic and oleic acid) as well as total and LDL cholesterol showed higher concentrations (p = 0.011; 0.005). ADHD scores positively correlated with palmitoleic (R = -0.56; p = 0.032), stearic (R = 0.53; p = 0.044), eicosapentaenoic (R = 0.62; p = 0.014), docosahexaenoic (R = 0.51; p = 0.050), gammalinolenic (R = 0.62; p = 0.018) and alphalinolenic acid (R = 0.56; p = 0.031) concentration. Even though the total and LDL cholesterol concentrations in blood serum were significantly higher among the ADHD patients than in controls, none of the ADHD symptom scores were significantly associated with any of the lipoproteine measures. We could demonstrate that a lack of polyunsaturated FAs in blood serum of subjects with ADHD persists into adulthood. Furthermore, we could show that adult ADHD symptomatology positively correlates with elevated levels of saturated stearic and monounsaturated FAs.

Fish consumption and severely depressed mood, findings from the first national nutrition follow-up study

The evidence obtained from prospective studies to support the hypothesis that fish consumption may improve mental status remains limited. The current study prospectively assessed a low frequency of fish consumption as a risk factor for depressed mood. Included were 5068 adults aged 25-74 years examined in 1971-1975 as the baseline of the First National Health and Nutrition Examination Survey Follow-up Study. Frequency of eating fish at baseline was obtained using a 3-month food frequency questionnaire. Severely depressed mood (SDM) was defined as the Center for Epidemiologic Studies Depression Scale scores ≥22 or taking anti-depressants. After an average of 10.6 years of follow-up, among men (n=2039), the percentage of individuals with SDM was 11.7%. Compared with frequent consumers (more than once a week), the odds ratios (ORs) were 1.43 (95%CI=0.66-3.11) and 2.08 (1.08-4.09) respectively for the men eating fish once a week and less than once a week (p for trend=0.03). Among women (n=3029), the percentage of individuals with SDM was 17.89%. The ORs were 1 (reference), 0.91 (0.68-1.22) and 1.15 (0.83-1.59) respectively for the women eating fish more than once, once, and less than once a week. These estimates were obtained after adjustment for indicators of social deprivation and major physical diseases. The study concluded that independently from social deprivation and physical diseases, low fish consumption was a risk factor for SDM among men. Further studies are needed to confirm these findings and elucidate mechanisms for the difference between men and women.

EPA supplementation improves teacher-rated behaviour and oppositional symptoms in children with ADHD

AIM

Measure efficacy of eicosapentaenoic acid (EPA) in children with attention deficit hyperactivity disorder (ADHD).

METHODS

Randomized controlled trial (RCT) of 0.5 g EPA or placebo (15 weeks) in 92 children (7-12 years) with ADHD. Efficacy measure was Conners' Parent/Teacher Rating Scales (CPRS/CTRS). Fatty acids were analysed in serum phospholipids and red blood cell membranes (RBC) at baseline and endpoint with gas chromatography.

RESULTS

EPA improved CTRS inattention/cognitive subscale (p = 0.04), but not Conners' total score. In oppositional children (n = 48), CTRS total score improved ≥25% in 48% of the children receiving EPA vs. 9% for placebo [effect size (ES) 0.63, p = 0.01]. In less hyperactive/impulsive children (n = 44), ≥25% improvement was seen in 36% vs. 18% (ES 0.41, n.s.), and with both these types of symptoms 8/13 with EPA vs. 1/9 for placebo improved ≥25% (p = 0.03). Children responding to treatment had lower EPA concentrations (p = 0.02), higher AA/EPA (p = 0.005) and higher AA/DHA ratios (p = 0.03) in serum at baseline. Similarly, AA/EPA (p = 0.01), AA/DHA (p = 0.038) and total omega-6/omega-3 ratios (p = 0.028) were higher in RBC, probably because of higher AA (p = 0.011).

CONCLUSION

Two ADHD subgroups (oppositional and less hyperactive/impulsive children) improved after 15-week EPA treatment. Increasing EPA and decreasing omega-6 fatty acid concentrations in phospholipids were related to clinical improvement.

A meta-analysis of blood fatty acids in people with learning disorders with particular interest in arachidonic acid

Small individual studies report that people with learning disorders have lower than normal blood concentrations of docosahexaenoic acid and arachidonic acid. The origin and consequence of the subnormal docosahexaenoic acid have been much speculated. However, relatively little attention has been paid to the significance of the low arachidonic acid concentration. Studies were identified through a literature search including subjects with various learning disorders or symptoms thereof and age-matched controls. A meta-analysis of pooled data from the red blood cell and plasma/serum showed that red blood cell arachidonic acid and docosahexanoic acid concentrations were significantly lower than normal [-3.93 and -18.92, respectively (weighted mean difference as a % of weighted mean control)]. Plasma/serum arachidonic acid and docosahexaenoic acid concentrations were also significantly lower than normal [-6.99 and -15.66, respectively (weighted mean difference as a % of weighted mean control)]. However, in absolute amounts the arachidonic acid was as severely depressed as docosahexanoic acid within red blood cells 0.57mg/100mg of fatty acid below normal verses 0.59mg/100mg for docosahexaenoic acid. Plasma/serum arachidonic acid was even lower; 0.71mg/100mg of fatty acid below normal verses 0.34mg/100mg for docosahexaenoic acid. The origin, consequences and relative importance of subnormal arachidonic acid to brain function bears further investigation.

Resting state electroencephalographic correlates with red cell long-chain fatty acids, memory performance and age in adolescent boys with attention deficit hyperactivity disorder

Abnormal fatty acid status has been implicated in the aetiology of attention deficit hyperactivity disorder (ADHD). Delayed maturation in ADHD may result in raised frontal low frequency (theta) electroencephalographic activity (EEG) and a reduction in posterior high frequency (beta, alpha) activity. The current study used sequential linear regression to investigate the association between age, resting-state EEG and levels of long-chain polyunsaturated omega-3 and omega-6 fatty acids in red blood cells in 46 adolescent boys with ADHD symptoms. Docosahexaenoic acid (DHA) levels were positively associated with fast frequency activity: alpha during eyes-open and beta during eyes-closed conditions. Frontal theta activity during both eyes-open and eyes-closed conditions was inversely associated with age and positively associated with eicosapentaenoic acid (EPA) levels. Alpha activity correlated positively with performance on fluency for categories (semantic memory). Theta activity correlated inversely with performance on delayed (25 min) verbal memory (recall + recognition/2). No associations were observed between long-chain omega-6 and EEG measures. Results support differential associations for DHA and EPA with fast and slow EEG activity respectively. Results support EEG activity as an objective biomarker of neural function associated with long-chain omega-3 fatty acids in ADHD.