Serum pro-BDNF/BDNF as a treatment biomarker for response to docosahexaenoic acid in traumatized people vulnerable to developing psychological distress: a randomized controlled trial

A systematic review and meta-analysis of the omega-3 fatty acids effects on brain-derived neurotrophic factor (BDNF)

BACKGROUND

Omega-3 fatty acids (omega-3 FAs) have attracted the attention of researchers because of their influence on circulatory levels of brain-derived neurotrophic factor (BDNF). Our objective was to review systematically and Meta-analyze randomized controlled trials (RCTs) to assess the effects of omega-3 FAs supplementation on serum BDNF concentration.

METHODS

Scopus, PubMed, Web of Science, and Cochrane Library were systematically searched until April 2023. The Cochrane risk of bias assessment tool was utilized to evaluate the quality of the studies. A random-effects model was employed to estimate the overall effect size of BDNF levels, using the Standard Mean Difference (SMD) and a 95% confidence interval (CI). The heterogeneity among the studies was assessed using chi-squared and I2 statistics.

RESULTS

A total of 12 studies involving 587 subjects were included. The supplementation of PUFA was found to be associated with a significant increase in serum levels of BNDF in the group receiving the supplements, as compared to the placebo group (SMD: 0.72 pg/mL, 95% CI: 0.28, 1.15; P < 0.001) (I2 = 84.39%, P < 0.001). Sub-group analyses revealed similar findings in trials with fewer than 10 weeks, which utilized both animal (fish oil) and herbal (flaxseed) forms of omega-3 supplements with a high daily dosage of 2000mg.

CONCLUSION

The present systematic review and meta-analysis indicate the efficacy of omega-3 FAs in increasing the serum concentration of BDNF. Therefore, omega-3 FAs should be prioritized as agents for increasing BDNF in interventions.

Early pharmacological interventions for prevention of post-traumatic stress disorder (PTSD) in individuals experiencing acute traumatic stress symptoms

BACKGROUND

Acute traumatic stress symptoms may develop in people who have been exposed to a traumatic event. Although they are usually self-limiting in time, some people develop post-traumatic stress disorder (PTSD), a severe and debilitating condition. Pharmacological interventions have been proposed for acute symptoms to act as an indicated prevention measure for PTSD development. As many individuals will spontaneously remit, these interventions should balance efficacy and tolerability.

OBJECTIVES

To assess the efficacy and acceptability of early pharmacological interventions for prevention of PTSD in adults experiencing acute traumatic stress symptoms.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trial Register (CCMDCTR), CENTRAL, MEDLINE, Embase and two other databases. We checked the reference lists of all included studies and relevant systematic reviews. The search was last updated on 23 January 2023.

SELECTION CRITERIA

We included randomised controlled trials on adults exposed to any kind of traumatic event and presenting acute traumatic stress symptoms, without restriction on their severity. We considered comparisons of any medication with placebo, or with another medication. We excluded trials that investigated medications as an augmentation to psychotherapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. Using a random-effects model, we analysed dichotomous data as risk ratios (RR) and calculated the number needed to treat for an additional beneficial/harmful outcome (NNTB/NNTH). We analysed continuous data as mean differences (MD) or standardised mean differences (SMD). Our primary outcomes were PTSD severity and dropouts due to adverse events. Secondary outcomes included PTSD rate, functional disability and quality of life.

MAIN RESULTS

We included eight studies that considered four interventions (escitalopram, hydrocortisone, intranasal oxytocin, temazepam) and involved a total of 779 participants. The largest trial contributed 353 participants and the next largest, 120 and 118 participants respectively. The trials enrolled participants admitted to trauma centres or emergency departments. The risk of bias in the included studies was generally low except for attrition rate, which we rated as high-risk. We could meta-analyse data for two comparisons: escitalopram versus placebo (but limited to secondary outcomes) and hydrocortisone versus placebo. One study compared escitalopram to placebo at our primary time point of three months after the traumatic event. There was inconclusive evidence of any difference in terms of PTSD severity (mean difference (MD) on the Clinician-Administered PTSD Scale (CAPS, score range 0 to 136) -11.35, 95% confidence interval (CI) -24.56 to 1.86; 1 study, 23 participants; very low-certainty evidence), dropouts due to adverse events (no participant left the study early due to adverse events; 1 study, 31 participants; very low-certainty evidence) and PTSD rates (RR 0.59, 95% CI 0.03 to 13.08; NNTB 37, 95% CI NNTB 15 to NNTH 1; 1 study, 23 participants; very low-certainty evidence). The study did not assess functional disability or quality of life. Three studies compared hydrocortisone to placebo at our primary time point of three months after the traumatic event. We found inconclusive evidence on whether hydrocortisone was more effective in reducing the severity of PTSD symptoms compared to placebo (MD on CAPS -7.53, 95% CI -25.20 to 10.13; I2 = 85%; 3 studies, 136 participants; very low-certainty evidence) and whether it reduced the risk of developing PTSD (RR 0.47, 95% CI 0.09 to 2.38; NNTB 14, 95% CI NNTB 8 to NNTH 5; I2 = 36%; 3 studies, 136 participants; very low-certainty evidence). Evidence on the risk of dropping out due to adverse events is inconclusive (RR 3.19, 95% CI 0.13 to 75.43; 2 studies, 182 participants; low-certainty evidence) and it is unclear whether hydrocortisone might improve quality of life (MD on the SF-36 (score range 0 to 136, higher is better) 19.70, 95% CI -1.10 to 40.50; 1 study, 43 participants; very low-certainty evidence). No study assessed functional disability.

AUTHORS' CONCLUSIONS

This review provides uncertain evidence regarding the use of escitalopram, hydrocortisone, intranasal oxytocin and temazepam for people with acute stress symptoms. It is therefore unclear whether these pharmacological interventions exert a positive or negative effect in this population. It is important to note that acute traumatic stress symptoms are often limited in time, and that the lack of data prevents the careful assessment of expected benefits against side effects that is therefore required. To yield stronger conclusions regarding both positive and negative outcomes, larger sample sizes are required. A common operational framework of criteria for inclusion and baseline assessment might help in better understanding who, if anyone, benefits from an intervention. As symptom severity alone does not provide the full picture of the impact of exposure to trauma, assessment of quality of life and functional impairment would provide a more comprehensive picture of the effects of the interventions. The assessment and reporting of side effects may facilitate a more comprehensive understanding of tolerability.

Changes in serum brain-derived neurotrophic factor following supplementation of omega 3 fatty acids: A systematic review and Meta-Regression analysis

BACKGROUND & AIMS

This study aimed to comprehensively investigate the effects of omega 3 supplementation on BDNF.

METHODS

Original databases were searched using standard keywords to identify all controlled trials that investigating the BDNF effects of omega 3 supplementation. Pooled weighted mean difference and 95% confidence intervals were achieved by random-effects model analysis for the best estimation of outcomes.

RESULTS

According to the results of a random-effects meta-analysis, omega 3 supplementation significantly raised BDNF levels compared to the control group (pooled WMD of 1.01 μmol/L; 95% confidence interval [CI] 0.35 to 1.67; P = 0.003) and this increase was even more pronounced for interventions >10 weeks and doses ≤1500 mg/day. Additionally, in individuals under 50 years of age, a greater increase in the effects of omega-3 supplements on this brain factor was observed.

CONCLUSIONS

The present comprehensive review and meta-regression analysis generally showed that omega-3 supplementation can statistically significantly increase BDNF levels.

Oxidative Stress in Traumatic Brain Injury

Traumatic Brain Injury (TBI) remains a major cause of disability worldwide. It involves a complex neurometabolic cascade, including oxidative stress. The products of this manuscript is examining the underlying pathophysiological mechanism, including reactive oxygen species (ROS) and reactive nitrogen species (RNS). This process in turn leads to secondary injury cascade, which includes lipid peroxidation products. These reactions ultimately play a key role in chronic inflammation and synaptic dysfunction in a synergistic fashion. Although there are no FDA approved antioxidant therapy for TBI, there is a number of antioxidant therapies that have been tested and include free radical scavengers, activators of antioxidant systems, inhibitors of free radical generating enzymes, and antioxidant enzymes. Antioxidant therapies have led to cognitive and functional recovery post TBI, and they offer a promising treatment option for patients recovering from TBI. Current major challenges in treatment of TBI symptoms include heterogenous nature of injury, as well as access to timely treatment post injury. The inherent benefits of antioxidant therapies include minimally reported side effects, and relative ease of use in the clinical setting. The current review also provides a highlight of the more studied anti-oxidant regimen with applicability for TBI treatment with potential use in the real clinical setting.

Oxidative stress and mitochondrial dysfunction following traumatic brain injury: From mechanistic view to targeted therapeutic opportunities

Traumatic brain injury (TBI) is one of the most prevalent causes of permanent physical and cognitive disabilities. TBI pathology results from primary insults and a multi-mechanistic biochemical process, termed as secondary brain injury. Currently, there are no pharmacological agents for definitive treatment of patients with TBI. This article is presented with the purpose of reviewing molecular mechanisms of TBI pathology, as well as potential strategies and agents against pathological pathways. In this review article, materials were obtained by searching PubMed, Scopus, Elsevier, Web of Science, and Google Scholar. This search was considered without time limitation. Evidence indicates that oxidative stress and mitochondrial dysfunction are two key mediators of the secondary injury cascade in TBI pathology. TBI-induced oxidative damage results in the structural and functional impairments of cellular and subcellular components, such as mitochondria. Impairments of mitochondrial electron transfer chain and mitochondrial membrane potential result in a vicious cycle of free radical formation and cell apoptosis. The results of some preclinical and clinical studies, evaluating mitochondria-targeted therapies, such as mitochondria-targeted antioxidants and compounds with pleiotropic effects after TBI, are promising. As a proposed strategy in recent years, mitochondria-targeted multipotential therapy is a new hope, waiting to be confirmed. Moreover, based on the available findings, biologics, such as stem cell-based therapy and transplantation of mitochondria are novel potential strategies for the treatment of TBI; however, more studies are needed to clearly confirm the safety and efficacy of these strategies.

Early pharmacological interventions for universal prevention of post-traumatic stress disorder (PTSD)

BACKGROUND

Post-traumatic stress disorder (PTSD) is a severe and debilitating condition. Several pharmacological interventions have been proposed with the aim to prevent or mitigate it. These interventions should balance efficacy and tolerability, given that not all individuals exposed to a traumatic event will develop PTSD. There are different possible approaches to preventing PTSD; universal prevention is aimed at individuals at risk of developing PTSD on the basis of having been exposed to a traumatic event, irrespective of whether they are showing signs of psychological difficulties.

OBJECTIVES

To assess the efficacy and acceptability of pharmacological interventions for universal prevention of PTSD in adults exposed to a traumatic event.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trial Register (CCMDCTR), CENTRAL, MEDLINE, Embase, two other databases and two trials registers (November 2020). We checked the reference lists of all included studies and relevant systematic reviews. The search was last updated on 13 November 2020.

SELECTION CRITERIA

We included randomised clinical trials on adults exposed to any kind of traumatic event. We considered comparisons of any medication with placebo or with another medication. We excluded trials that investigated medications as an augmentation to psychotherapy.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. In a random-effects model, we analysed dichotomous data as risk ratios (RR) and number needed to treat for an additional beneficial/harmful outcome (NNTB/NNTH). We analysed continuous data as mean differences (MD) or standardised mean differences (SMD).

MAIN RESULTS

We included 13 studies which considered eight interventions (hydrocortisone, propranolol, dexamethasone, omega-3 fatty acids, gabapentin, paroxetine, PulmoCare enteral formula, Oxepa enteral formula and 5-hydroxytryptophan) and involved 2023 participants, with a single trial contributing 1244 participants. Eight studies enrolled participants from emergency departments or trauma centres or similar settings. Participants were exposed to a range of both intentional and unintentional traumatic events. Five studies considered participants in the context of intensive care units with traumatic events consisting of severe physical illness. Our concerns about risk of bias in the included studies were mostly due to high attrition and possible selective reporting. We could meta-analyse data for two comparisons: hydrocortisone versus placebo, but limited to secondary outcomes; and propranolol versus placebo. No study compared hydrocortisone to placebo at the primary endpoint of three months after the traumatic event. The evidence on whether propranolol was more effective in reducing the severity of PTSD symptoms compared to placebo at three months after the traumatic event is inconclusive, because of serious risk of bias amongst the included studies, serious inconsistency amongst the studies' results, and very serious imprecision of the estimate of effect (SMD -0.51, 95% confidence interval (CI) -1.61 to 0.59; I² = 83%; 3 studies, 86 participants; very low-certainty evidence). No study provided data on dropout rates due to side effects at three months post-traumatic event. The evidence on whether propranolol was more effective than placebo in reducing the probability of experiencing PTSD at three months after the traumatic event is inconclusive, because of serious risk of bias amongst the included studies, and very serious imprecision of the estimate of effect (RR 0.77, 95% CI 0.31 to 1.92; 3 studies, 88 participants; very low-certainty evidence). No study assessed functional disability or quality of life.  Only one study compared gabapentin to placebo at the primary endpoint of three months after the traumatic event, with inconclusive evidence in terms of both PTSD severity and probability of experiencing PTSD, because of imprecision of the effect estimate, serious risk of bias and serious imprecision (very low-certainty evidence). We found no data on dropout rates due to side effects, functional disability or quality of life. For the remaining comparisons, the available data are inconclusive or missing in terms of PTSD severity reduction and dropout rates due to adverse events. No study assessed functional disability.

AUTHORS' CONCLUSIONS

This review provides uncertain evidence only regarding the use of hydrocortisone, propranolol, dexamethasone, omega-3 fatty acids, gabapentin, paroxetine, PulmoCare formula, Oxepa formula, or 5-hydroxytryptophan as universal PTSD prevention strategies. Future research might benefit from larger samples, better reporting of side effects and inclusion of quality of life and functioning measures.

PTSD as an Endothelial Disease: Insights From COVID-19

SARS-CoV-2 virus, the etiologic agent of COVID-19, has affected almost every aspect of human life, precipitating stress-related pathology in vulnerable individuals. As the prevalence rate of posttraumatic stress disorder in pandemic survivors exceeds that of the general and special populations, the virus may predispose to this disorder by directly interfering with the stress-processing pathways. The SARS-CoV-2 interactome has identified several antigens that may disrupt the blood-brain-barrier by inducing premature senescence in many cell types, including the cerebral endothelial cells. This enables the stress molecules, including angiotensin II, endothelin-1 and plasminogen activator inhibitor 1, to aberrantly activate the amygdala, hippocampus, and medial prefrontal cortex, increasing the vulnerability to stress related disorders. This is supported by observing the beneficial effects of angiotensin receptor blockers and angiotensin converting enzyme inhibitors in both posttraumatic stress disorder and SARS-CoV-2 critical illness. In this narrative review, we take a closer look at the virus-host dialog and its impact on the renin-angiotensin system, mitochondrial fitness, and brain-derived neurotrophic factor. We discuss the role of furin cleaving site, the fibrinolytic system, and Sigma-1 receptor in the pathogenesis of psychological trauma. In other words, learning from the virus, clarify the molecular underpinnings of stress related disorders, and design better therapies for these conditions. In this context, we emphasize new potential treatments, including furin and bromodomains inhibitors.

Effects of nutritional interventions on BDNF concentrations in humans: a systematic review

Objectives: Brain-derived neurotrophic factor (BDNF) plays an essential role in brain and metabolic health. The fact that higher concentrations are associated with improved cognitive performance has resulted in numerous intervention trials that aim at elevating BDNF levels. This systematic review provides an overview of the relation between various nutritional factors and BDNF concentrations in controlled human intervention studies. Methods: A systematic search in May 2020 identified 48 articles that examined the effects of dietary patterns or foods (n = 3), diets based on energy intake (n = 7), vitamins and minerals (n = 7), polyphenols (n = 11), long-chain omega-3 polyunsaturated fatty acids (n = 5), probiotics (n = 8), and miscellaneous food supplements (n = 7). Results: In particular, studies with dietary patterns or foods showed increased peripheral BDNF concentrations. There are also strong indications that polyphenols tend to have a positive effect on BDNF concentrations. Four of the 11 included studies with a polyphenol intervention showed a significant increase in BDNF concentrations, one study showed an increase but this was not statistically analyzed, and two studies showed a trend to an increase. Discussion: The two polyphenol classes, phenolic acids, and other phenolic compounds were responsible for the significant effects. No clear effect was found for the other dietary factors, which might also be related to whether serum or plasma was used for BDNF analysis. More work is needed to understand the relation between peripheral and central BDNF concentrations.

Mechanism of Intermittent Theta-Burst Stimulation in Synaptic Pathology in the Prefrontal Cortex in an Antidepressant-Resistant Depression Rat Model

Intermittent theta-burst stimulation (iTBS), a form of repetitive transcranial magnetic stimulation, is considered a potential therapy for treatment-resistant depression. The synaptic mechanism of iTBS has long been known to be an effective method to induce long-term potentiation (LTP)-like plasticity in humans. However, there is limited evidence as to whether the antidepressant effect of iTBS is associated with change in synaptic function in the prefrontal cortex (PFC) in preclinical study. Hence, we applied an antidepressant (i.e., fluoxetine)-resistant depression rat model induced by severe foot-shocks to investigate the antidepressant efficacy of iTBS in the synaptic pathology. The results showed that iTBS treatment improved not only the impaired LTP, but also the aberrant long-term depression in the PFC of antidepressant-resistant depression model rats. Moreover, the mechanism of LTP improvement by iTBS involved downstream molecules of brain-derived neurotrophic factor, while the mechanism of long-term depression improvement by iTBS involved downstream molecules of proBDNF. The aberrant spine morphology was also improved by iTBS treatment. This study demonstrated that the mechanism of the iTBS paradigm is complex and may regulate not only excitatory but also inhibitory synaptic effects in the PFC.

Free Fatty Acids and Their Inflammatory Derivatives Affect BDNF in Stroke Patients

Objective

The neurotrophin brain-derived neurotrophic factor (BDNF) affects poststroke functional outcome, neurogenesis, neuroprotection, and neuroplasticity. Its level is related to the diet and nutritional status, and more specifically, it is free fatty acids (FFAs) and eicosanoids that can have an impact on the BDNF level. The aim of this study was to analyze the potential impact of FFAs and eicosanoids on the BDNF level in stroke patients. Material and Methods. Seventy-three ischemic stroke patients were prospectively enrolled in the study. Laboratory tests were performed in all subjects, including the levels of FFAs, eicosanoids, and BDNF. FFAs and inflammatory metabolites were determined by gas chromatography and liquid chromatography, while BDNF was evaluated by the immune-enzymatic method (ELISA).

Results

The plasma level of BDNF negatively correlated with C22:1n9 13 erucic acid, C18:3n3 linolenic acid (ALA), and lipoxin A4 15-epi-LxA4. A direct association was observed in relation to BDNF and C16:1 palmitoleic acid and C20:3n6 eicosatrienoic acid (dihomo-gamma-linolenic acid (DGLA)).

Conclusions

Saturated fatty acids and omega-3 and omega-9 erucic acids can affect signaling in the BDNF synthesis resulting in the decrease in BDNF. There is a beneficial effect of DGLA on the BDNF level, while the effect of ALA on BDNF can be inhibitory. Specialized proresolving lipid mediators can play a role in the BDNF metabolism. BDNF can interact with inflammation as the risk factor in the cardiovascular disorders, including stroke.

Peripheral blood levels of brain-derived neurotrophic factor in patients with post-traumatic stress disorder (PTSD): A systematic review and meta-analysis

BACKGROUND

Brain-derived neurotrophic factor (BDNF) plays a crucial role in the survival, differentiation, growth, and plasticity of the central nervous system (CNS). Post-traumatic stress disorder (PTSD) is a complex syndrome that affects CNS function. Evidence indicates that changes in peripheral levels of BDNF may interfere with stress. However, the results are mixed. This study investigates whether blood levels of BDNF in patients with post-traumatic stress disorder (PTSD) are different.

METHODS

We conducted a systematic search in the major electronic medical databases from inception through September 2019 and identified Observational studies that measured serum levels of BDNF in patients with PTSD compared to controls without PTSD.

RESULTS

20 studies were eligible to be included in the present meta-analysis. Subjects with PTSD (n = 909) showed lower BDNF levels compared to Non-PTSD controls (n = 1679) (SMD = 0.52; 95% confidence interval: 0.18 to 0.85). Subgroup meta-analyses confirmed higher levels of BDNF in patients with PTSD compared to non-PTSD controls in plasma, not serum, and in studies that used sandwich ELISA, not ELISA, for BDNF measurement. Meta-regressions showed no significant effect of age, gender, NOS, and sample size.

CONCLUSIONS

PTSD patients had increased serum BDNF levels compared to healthy controls. Our finding of higher BDNF levels in patients with PTSD supports the notion that PTSD is a neuroplastic disorder.

Plasma BDNF is a more reliable biomarker than erythrocyte omega-3 index for the omega-3 fatty acid enrichment of brain

Enriching brain DHA is believed to be beneficial for the prevention and treatment of several neurological diseases, including Alzheimer's disease. An impediment in assessing the effectiveness of the treatments is the lack of a reliable biomarker for brain DHA. The commonly used erythrocyte omega-3 index is not suitable for brain because of the involvement of unique transporter at the blood brain barrier (BBB). We recently showed that dietary lysophosphatidylcholine (LPC)-DHA significantly increases brain DHA, which results in increase of brain BDNF. Since there is bidirectional transport of BDNF through the BBB, we tested the hypothesis that plasma BDNF may be used as biomarker for brain DHA enrichment. We altered the brain DHA in rats and mice over a wide range using different dietary carriers of DHA, and the correlations between the increase in brain omega-3 index with the increases in plasma BDNF and the erythrocyte index were determined. Whereas the increase in brain omega-3 index positively correlated with the increase in plasma BDNF, it negatively correlated with the erythrocyte index. These results show that the plasma BDNF is more reliable than the erythrocyte index as biomarker for assessing the effectiveness of omega-3 supplements in improving brain function.

Antioxidant Therapies in Traumatic Brain Injury

Due to a multiplicity of causes provoking traumatic brain injury (TBI), TBI is a highly heterogeneous pathology, characterized by high mortality and disability rates. TBI is an acute neurodegenerative event, potentially and unpredictably evolving into sub-chronic and chronic neurodegenerative events, with transient or permanent neurologic, cognitive, and motor deficits, for which no valid standardized therapies are available. A vast body of literature demonstrates that TBI-induced oxidative/nitrosative stress is involved in the development of both acute and chronic neurodegenerative disorders. Cellular defenses against this phenomenon are largely dependent on low molecular weight antioxidants, most of which are consumed with diet or as nutraceutical supplements. A large number of studies have evaluated the efficacy of antioxidant administration to decrease TBI-associated damage in various animal TBI models and in a limited number of clinical trials. Points of weakness of preclinical studies are represented by the large variability in the TBI model adopted, in the antioxidant tested, in the timing, dosages, and routes of administration used, and in the variety of molecular and/or neurocognitive parameters evaluated. The analysis of the very few clinical studies does not allow strong conclusions to be drawn on the real effectiveness of antioxidant administration to TBI patients. Standardizing TBI models and different experimental conditions, as well as testing the efficacy of administration of a cocktail of antioxidants rather than only one, should be mandatory. According to some promising clinical results, it appears that sports-related concussion is probably the best type of TBI to test the benefits of antioxidant administration.

High-dose eicosapentaenoic acid (EPA) improves attention and vigilance in children and adolescents with attention deficit hyperactivity disorder (ADHD) and low endogenous EPA levels

No studies have examined the relationship between endogenous polyunsaturated fatty acids (PUFAs) levels and treatment response to PUFAs. We conducted a 12-week, double-blind, placebo-controlled trial comparing the effects of high-dose eicosapentaenoic acid (EPA, 1.2 g) and placebo on cognitive function (continuous performance test) in n = 92 youth (age 6-18-years-old) with Attention Deficit Hyperactivity Disorder (ADHD). Blood erythrocytes PUFAs were measured before and after treatment, to examine the effects of baseline endogenous EPA levels on treatment response and the effects of EPA treatment on PUFAs levels. Secondary measures included other ADHD symptoms, emotional symptoms, and levels of plasma high-sensitivity c-reactive protein (hs-CRP) and brain-derived neurotrophic factor (BDNF). Overall, EPA group improved more than placebo group on focused attention (variability, Effect size (ES) = 0.38, p = 0.041); moreover, within youth with the lowest baseline endogenous EPA levels, EPA group improved more than placebo group in another measure of focused attention (hit reaction time, HRT, ES = 0.89, p = 0.015) and in vigilance (HRT interstimulus interval changes, HRTISIC, ES = 0.83, p = 0.036). Interestingly, EPA group improved less than placebo group in impulsivity (commission errors), both overall and in youth with the highest baseline EPA levels, who also showed less improvement in other ADHD and emotional symptoms. EPA increased blood erythrocytes EPA by 1.6-fold but not DHA levels, and did not affect hs-CRP and BDNF plasma levels. In conclusion, EPA treatment improves cognitive symptoms in ADHD youth, especially if they have a low baseline endogenous EPA level, while youth with high EPA levels may be negatively affected by this treatment.

Does metabolic status affect serum levels of BDNF and MMP-9 in patients with schizophrenia?

The purpose of the article: Brain-derived neurotrophic factor (BDNF) and matrix metalloproteinase-9 (MMP-9) are involved in the processes of neurogenesis, synaptic plasticity, learning and memory. Growing number of studies shows a relationship between BDNF or MMP-9 and schizophrenia. Also, BDNF and MMP-9 levels may be affected by metabolic parameters, such as obesity or dyslipidemia. Our hypothesis is that alterations of BDNF or MMP-9 levels in schizophrenia might be secondary to metabolic abnormalities, often found among schizophrenia patients. Materials and methods: We have compared BDNF and MMP-9 between patients with schizophrenia (n = 64, age 49 ± 8.2 y) and healthy controls (n = 32, age 51 ± 8.9 y) in the context of cardio-metabolic parameters. Serum levels of BDNF and MMP-9 were measured using ELISA test, body composition parameters were determined using bioelectric impedance analysis. Results and conclusions: Our results showed significantly lowered serum BDNF concentration in the schizophrenia group (schizophrenia: 23.8 ± 7.83 ng/mL, control: 27.69 ± 8.11 ng/mL, p = 0.03). Serum MMP-9 concentration in schizophrenia group did not differ compared with the control group (schizophrenia: 456.8 ± 278.4 ng/mL, control: 341.5 ± 162.4 ng/mL, p = 0.07). After adjusting for age, all anthropometric parameters, body composition and laboratory tests BDNF were still significantly lower in the schizophrenia group. However, MMP-9 became significantly elevated in the schizophrenia group after adjusting for several anthropometric and body composition covariates. Our results confirmed reduced serum BDNF concentration in patients with schizophrenia. Also, this reduction seems to be independent of metabolic abnormalities. On the other hand, our hypothesis that MMP-9 level in schizophrenia is altered due to metabolic abnormalities might be true.

A cross-sectional study of fatty acids and brain-derived neurotrophic factor (BDNF) in human milk from lactating women following vegan, vegetarian, and omnivore diets

PURPOSE

Essential fatty acids are critical for brain growth and neurodevelopment in infancy. Maternal diet and supplement use have a significant impact on the fat composition of human milk. The objective of this study is to assess supplement utilization patterns and fatty acid and brain-derived neurotrophic factor (BDNF) concentrations in the breast milk of women following vegan, vegetarian, and omnivore diet patterns.

METHODS

This is a cross-sectional, observational study of 74 lactating women in the United States following a vegan (n = 26), vegetarian (n = 22), or omnivore (n = 26) diet pattern. A single breast milk sample was collected from each participant and assessed for fatty acids and BDNF.

RESULTS

Median unsaturated fatty acids in the breast milk of vegan, vegetarian, and omnivores, as a percentage of total fatty acids, was 66.0, 57.8, and 56.2%, respectively (p < 0.001). Total omega-3 percentages were 2.29% for vegans, 1.55% for vegetarians, and 1.46% for omnivores (p < 0.001). Docosahexaenoic acid percentages were not different by diet pattern, but over 80% of participants had milk concentrations below 0.30% of total fatty acids. Reports of omega-3 supplements use (10/74) and weekly seafood consumption (3/74) were limited. BDNF was not detectable in any samples.

CONCLUSIONS

Breast milk from vegans had significantly higher unsaturated fat and total omega-3 fats, and lower saturated fats, trans fats, and omega-6 to omega-3 ratios than their vegetarian and omnivore counterparts. Docosahexaenoic acid concentrations in breast milk were low regardless of maternal diet pattern, and were reflective of low seafood intake and supplement use.

LINK-A lncRNA is upregulated in metastatic non-small cell lung cancer and is associated with poor prognosis

Long intergenic non-coding RNA for kinase activation (LINK-A) has been characterized as an oncogenic long non-coding RNA (lncRNA) in triple-negative breast cancer. However, its involvement in non-small cell lung cancer (NSCLC) remains unknown. The aim of the present study was to investigate the involvement of LINK-A in NSCLC. Expression of LINK-A lncRNA in the plasma of patients with NSCLC collected on the day of admission and the day of discharge, and in the plasma of healthy controls, was detected by reverse transcription-quantitative PCR. Diagnostic values of plasma LINK-A for metastatic NSCLC were evaluated by receiver operating characteristic curve analysis. A LINK-A lncRNA expression vector was constructed and transfected into human NSCLC cell lines, and the effects on cell migration and invasion, and Akt activation were detected by Transwell and Matrigel assays, and western blotting, respectively. Plasma levels of LINK-A were found to be significantly higher in patients with different types of metastatic NSCLC than in patients with non-metastatic NSCLC and healthy controls. Plasma levels of LINK-A were lower in patients with metastatic NSCLC on the day of discharge than on the day of admission. Patients with high plasma LINK-A had a higher mortality rate and lower progression-free survival rate within 2 years of discharge. In conclusion, LINK-A is overexpressed in metastatic NSCLC, and may promote the migration and invasion of NSCLC by activating Akt signaling.

Hericium erinaceus Improves Mood and Sleep Disorders in Patients Affected by Overweight or Obesity: Could Circulating Pro-BDNF and BDNF Be Potential Biomarkers?

Epidemiological data indicate that subjects affected by obesity have an increased risk of developing mood disorders. The relationship between obesity and mood disorders is bidirectional. We assessed whether a Hericium erinaceus treatment improved depression, anxiety, sleep, and binge eating disorders after 8 weeks of supplementation in subjects affected by overweight or obesity under a low calorie diet regimen. Looking for a possible clinical biomarker, we assessed the serum balance between brain-derived neurotrophic factor (BDNF) and its precursor pro-BDNF before and after H. erinaceus supplementation. Seventy-seven volunteers affected by overweight or obesity were recruited at the offices of the Department of Preventive Medicine, Luigi Devoto Clinic of Work, Obesity Centre, at the IRCCS Foundation Policlinico Hospital of Milan (Italy). Patients were recruited only if they had a mood and/or sleep disorder and/or were binge eating as evaluated through self-assessment questionnaires. We used two different enzyme-linked immunosorbent assays kits to discriminate circulating levels of pro-BDNF and BDNF. Eight weeks of oral H. erinaceus supplementation decreased depression, anxiety, and sleep disorders. H. erinaceus supplementation improved mood disorders of a depressive-anxious nature and the quality of the nocturnal rest. H. erinaceus increased circulating pro-BDNF levels without any significant change in BDNF circulating levels.

Demographic and lifestyle correlates of brain-derived neurotrophic factor in a working population: The Furukawa Nutrition and Health Study

This study aimed to examine the cross-sectional association of demographic and lifestyle factors with serum brain-derived neurotrophic factor (BDNF) concentrations in a Japanese working population. Participants were 1678 men and 172 women aged 19-69 years who received health check-ups and participated in a nutrition and health survey. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Dietary intake was assessed using a validated self-administered diet history questionnaire. Serum BDNF concentrations were measured using a solid phase sandwich enzyme-linked immunosorbent assay. Multiple linear regression analysis was used to estimate the mean and 95% confidence interval of serum BDNF concentrations according to demographic and lifestyle factors. Higher body mass index (BMI) was significantly associated with higher circulating BDNF concentrations. Current smokers had significantly higher mean BDNF concentrations than never-smokers. BDNF concentrations were not associated with folate and 25-hydroxyvitamin D concentrations in serum, or dietary eicosapentaenoic acid and docosahexaenoic acid intake. Serum BDNF concentrations were not associated with depressive symptoms or CES-D score per se. In this study, higher BMI and smoking were associated with higher concentrations of serum BDNF, while nutrients that have been linked to depression were not associated with BDNF concentrations among Japanese workers.

An increase in plasma brain derived neurotrophic factor levels is related to n-3 polyunsaturated fatty acid efficacy in first episode schizophrenia: secondary outcome analysis of the OFFER randomized clinical trial

RATIONALE

N-3 polyunsaturated fatty acids (n-3 PUFA) influence multiple biochemical mechanisms postulated in the pathogenesis of schizophrenia that may influence BDNF synthesis.

OBJECTIVES

A randomized placebo-controlled study was designed to compare the efficacy of a 26-week intervention composed of either 2.2 g/day of n-3 PUFA or olive oil placebo, with regard to symptom severity in first-episode schizophrenia patients. The secondary outcome measure of the study was to describe the association between n-3 PUFA clinical effect and changes in peripheral BDNF levels.

METHODS

Seventy-one patients aged 16-35 were enrolled in the study and randomly assigned to the following study arms: 36 to the EPA + DHA group and 35 to the placebo group. Plasma BDNF levels were assessed three times, at baseline and at weeks 8 and 26 of the intervention. BDNF levels were determined in plasma samples using Quantikine Human BDNF ELISA kit. Plasma BDNF level changes were further correlated with changes in the severity of symptoms in different clinical domains.

RESULTS

A significantly greater increase in plasma BDNF levels was observed in the intervention compared to the placebo group (Cohen's d = 1.54). Changes of BDNF levels inversely correlated with change in depressive symptoms assessed using the Calgary Depression Rating Scale in Schizophrenia (Pearson's r = - 0.195; p = 0.018).

CONCLUSIONS

The efficacy of a six-month intervention with n-3 PUFA observed in first-episode schizophrenia may be related to an increase in BDNF levels, which may be triggered by the activation of intracellular signaling pathways including transcription factors such as cAMP-reactive element binding protein.

Pain with traumatic brain injury and psychological disorders

Traumatic brain injury (TBI) is the cause for long-term disability in more than 3 million patients in the US alone, with chronic pain being the most frequently reported complain. To date, predisposing mechanisms for chronic pain in TBI patients are largely unknown. Psychological disorders, including post-traumatic stress disorder, depression and anxiety following TBI are commonly reported comorbidities to post-traumatic pain. Long term consequences can be debilitating and affect quality of life even when the injury is mild. In this review, we present the most commonly reported chronic pain conditions across the spectrum of severity of TBI, mainly focusing on mild TBI. We discuss chronic post- traumatic headaches, widespread pain as well as post-traumatic central pain. We discuss pain in the context of injury severity and military versus civilian populations. We are only starting to understand the biological mechanisms behind post-traumatic pain and associated psychological distress following TBI, with genetic, biochemical and imaging studies pointing to the dopaminergic, neurotrophic factors and the role of Apolipoprotein. Physiological and neurological mechanisms are proposed to partially explain this interaction between post-traumatic pain and psychological distress. Nevertheless, the evidence for the role of structural brain damage remains incomplete and to a large extent debatable, as it is still difficult to establish clear causality between brain trauma and chronic pain. Finally, general aspects of management of chronic pain post-TBI are addressed.

Integrative Therapy Approaches for Posttraumatic Stress Disorder: A Special Focus on Treating Veterans

Over the past decade, the use of integrative health modalities, such as mind-body interventions, art therapy, nutrition, and exercise, to treat stress-related mental health conditions, including posttraumatic stress disorder (PTSD), in military and veteran populations has been increasing. The use of integrative therapies for PTSD provides options for veterans who are not interested in traditional modalities, have limited access to traditional treatments, or are seeking a more comprehensive approach to managing their PTSD or subthreshold symptoms. These therapies show promise for improving overall well-being and comorbid conditions with PTSD, such as pain or migraines, but yield mixed data for PTSD symptoms. The aim of this article is to review the evidence for the most promising integrative health modalities for treating PTSD, with a special focus on the treatment of veterans, as well as to offer recommendations and suggestions for clinicians.

Fatty acid concentrations in patients with posttraumatic stress disorder compared to healthy controls

BACKGROUND

Although fatty acid (FA)-supplementation studies are currently being implemented, in fact little is known about FA-profiles in posttraumatic stress disorder (PTSD). Therefore, the present study aimed at comparing FA-concentrations between PTSD-patients and healthy controls.

METHODS

A cross-sectional study comparing a mixed-gender sample of 49 patients with PTSD due to civilian trauma to 46 healthy controls regarding erythrocyte FAs including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), arachidonic acid (AA), and nervonic acid (NA).

RESULTS

DHA was found to be significantly lower in PTSD-patients compared to controls after adjusting for sociodemographic and dietary factors (p =0.043). Additionally, exploratory analyses showed lower vaccenic acid (p =0.035) and eicosatrienoic acid (p =0.006), but higher erucic acid (p =0.032) in PTSD-patients. The effect of erucic acid remained after adjustment for sociodemographic factors (p =0.047); with the additional adjustment for dietary factors none of these FAs were found to be significant.

LIMITATIONS

Statistical power for differences with small effect sizes was limited, and dietary assessment could be optimized.

CONCLUSIONS

We found little evidence for a considerable role of FA-metabolism in PTSD. Apart from lower DHA after adjusting for confounders, no differences were observed in the hypothesized long-chained polyunsaturated FA-concentrations. Additionally, we found few alterations in the long-chained monounsaturated FAs, which may be explained by dietary factors. Nevertheless, the observed small effect sizes and limited extent of the alterations emphasize the importance of further investigating the assumed role of FA-metabolism and its underlying mechanisms in PTSD, before implementing further FA-supplementation studies.

Clinical correlates of plasma brain-derived neurotrophic factor in post-traumatic stress disorder spectrum after a natural disaster

Clinical correlates of plasma Brain-Derived Neurotrophic Factor (BDNF) have been investigated in a clinical population with Post Traumatic Stress Disorder (PTSD) symptoms and healthy control subjects who survived to the L'Aquila 2009 earthquake. Twenty-six outpatients and 14 control subjects were recruited. Assessments included: Structured Clinical Interview for DSM-IV Axis-I disorders Patient Version, Trauma and Loss Spectrum-Self Report (TALS-SR) for post-traumatic spectrum symptoms. Thirteen patients were diagnosed as Full PTSD and 13 as Partial PTSD. The subjects with full-blown PTSD showed lower BDNF level than subjects with partial PTSD and controls. Different relationship patterns of BDNF with post-traumatic stress spectrum symptoms have been reported in the three samples. Our findings add more insight on the mechanisms regulating BDNF levels in response to stress and further proofs of the utility of the distinction of PTSD into full and partial categories.

Brain-derived neurotrophic factor in mood disorders and antidepressant treatments

Levels of brain-derived neurotrophic factor (BDNF) are reduced in the brain and serum of depressed patients and at least the reduction in serum levels is reversible upon successful treatment. These data, together with a wealth of reports using different animal models with depression-like behavior or manipulation of expression of BDNF or its receptor TrkB have implicated BDNF in the pathophysiology of depression as well as in the mechanism of action of antidepressant treatments. Recent findings have shown that posttranslational processing of BDNF gene product can yield different molecular entities that differently influence signaling through BNDF receptor TrkB and the pan-neurotrophin receptor p75^NTR. We will here review these data and discuss new insights into the possible pathophysiological roles of those new BDNF subtypes as well as recent findings on the role of BDNF mediated neuronal plasticity in mood disorders and their treatments.

Peripheral Biomarker Candidates of Posttraumatic Stress Disorder

There is high variability in the manifestation of physical and mental health problems following exposure to trauma and disaster. Although most people may show a range of acute symptoms in the aftermath of traumatic events, chronic and persistent mental disorders may not be developed in all individuals who were exposed to traumatic events. The most common long-term pathological consequence after trauma exposure is posttraumatic stress disorder (PTSD). However, comorbid conditions including depression, anxiety disorder, substance use-related problems, and a variety of other symptoms may frequently be observed in individuals with trauma exposure. Post-traumatic syndrome (PTS) is defined collectively as vast psychosocial problems that could be experienced in response to traumatic events. It is important to predict who will continue to suffer from physical and mental health problems and who will recover following trauma exposure. However, given the heterogeneity and variability in symptom manifestations, it is difficult to find identify biomarkers which predict the development of PTSD. In this review, we will summarize the results of recent studies with regard to putative biomarkers of PTSD and suggest future research directions for biomarker discovery for PTSD.