Investigating the inflammatory phenotype of major depression: focus on cytokines and polyunsaturated fatty acids

Abnormal erythrocyte fatty acid composition in first-diagnosed, drug-naïve patients with depression

BACKGROUND & AIMS

The correlation between fatty acids (FAs) and depression is not yet conclusive. This study examined the relationship of FAs composition with the presence and clinical characteristics of first-diagnosed, drug-naïve patients with depression.

METHODS

A total of 139 first-diagnosed, drug-naïve patients with depression and 55 healthy controls (HCs) were included in the cross-sectional study. The levels of erythrocyte membrane FAs were compared and then the correlation between clinical symptoms and fatty acid levels in depression was investigated.

RESULTS

Compared to HCs, patients with depression had higher C18:1n9t (z = -2.033, p = 0.042), C20:4n6 (z = -2.104, p = 0.035), C20:3n6 (z = -2.104, p = 0.035) and n-6 polyunsaturated fatty acids (PUFAs) (z = -2.127, p = 0.033), whereas the levels of C18:1n9c (z = -3.348, p = 0.001) were significantly lower. Higher C20:3n6, C20:4n6, C18:1n9t and n-6 PUFAs levels were associated with higher severity of depressive and anxiety symptoms in patients with depression, and the correlation remained after adjusting for the related confounding factors (p < 0.05).

CONCLUSIONS

Patients with first-diagnosed, drug-naïve depression show abnormal erythrocyte fatty acid composition. Trans fatty acids (TFAs) and n-6 PUFAs levels are closely related to clinical characteristics of depression. This study indicated that increased n-6 PUFAs and TFAs are characteristic changes of first-diagnosed, drug-naïve depression.

Low omega-3 polyunsaturated fatty acids predict reduced response to standard antidepressants in patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is characterized by a high rate of treatment resistance. Omega (ω)-3 polyunsaturated fatty acids (PUFAs) were shown to correlate with depressive phenotype both in rodents and in humans. However, few studies to date have investigated the role of PUFAs in antidepressant response. The primary aim of this study was to assess the link between baseline PUFA composition and changes in depressive symptoms as well as antidepressant response in a multicenter study of depressed patients.

METHODS

Sixty depressed adults who met criteria for MDD according to DSM-IV-TR were recruited. Neuropsychiatric evaluations occurred at baseline and after 4 and 8 weeks of treatment with standard antidepressants, including escitalopram (N = 45), sertraline (N = 13) and venlafaxine (N = 2). At study endpoint, patients were stratified into responders (R) or non-responders (NR) based on their MADRS (Montgomery-Åsberg Depression Rating Scale) score. Baseline PUFA levels were assessed and their association with clinical response was determined.

RESULTS

Lower ω-3 PUFA levels were associated to worse baseline symptomatology. Baseline levels of PUFAs were significantly different between R and NR, with R exhibiting lower docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and ω-3 index; and higher ω-6/ω-3 ratio than NR before the start of antidepressant treatment. DHA levels as well as the ω-3 index and ω-6/ω-3 ratio significantly predicted response to antidepressants at study endpoint.

CONCLUSIONS

These results show that baseline levels of PUFAs predict later response to standard antidepressants in depressed subjects. They suggest that PUFA intake and/or metabolism represent a novel modifiable tool for the management of unresponsive depressed patients.

Investigating the potential of fish oil as a nutraceutical in an animal model of early life stress

Background: Early life stress is a key predisposing factor for depression and anxiety disorders. Selective serotonin re-uptake inhibitors (SSRI) are frequently used as the first line of pharmacology treatment for depression but have several negative qualities, i.e. a delay or absence of effectiveness and negative side-effects. Therefore, there is a growing need for new nutraceutical-based strategies to blunt the effects of adverse-life events.Objectives: This study aimed to use the maternal separation model in rats to test the efficacy of fish oil dietary supplementation, on its own and in conjunction with the SSRI anti-depressant fluoxetine, as a treatment for depressive and anxiety-like symptoms associated with early life stress.Methods: Behavioural tests (open field test, elevated plus maze test and forced swim test) and biochemical markers (corticosterone, BDNF, brain fatty acids and short chain fatty acids) were used to analyse the effects of the dietary treatments. Gut microbial communities and relating metabolites (SCFA) were analysed to investigate possible changes in the microbiota-gut-brain axis.Results: Maternally separated rats showed depressive-like behaviours in the forced swim and open field tests. These behaviours were prevented significantly by fluoxetine administration and in part by fish oil supplementation. Associated biochemical changes reported include altered brain fatty acids, significantly lower plasma corticosterone levels (AUC) and reduced brain stem serotonin turnover, compared to untreated, maternally separated (MS) rats. Untreated MS animals had significantly lower ratios of SCFA producers such as Caldicoprobacteraceae, Streptococcaceae, Rothia, Lachnospiraceae_NC2004_group, and Ruminococcus_2, along with significantly reduced levels of total SCFA compared to non-separated animals. Compared to untreated MS animals, animals fed fish oil had significantly higher Bacteroidetes and Prevotellaceae and reduced levels of butyrate, while fluoxetine treatment resulted in significantly higher levels of Neochlamydia, Lachnoclostridium, Acetitomaculum and Stenotrophomonas and, acetate and propionate.Conclusion: Despite the limitations in extrapolating from animal behavioural data and the notable differences in pharmacokinetics between rodents and humans, the results of this study provide a further advancement into the understanding of some of the complex systems within which nutraceuticals and pharmaceuticals effect the microbiota-gut-brain axis.

A systematic review and meta-analysis of lipid metabolomic signatures of Major Depressive Disorder

The aim of this meta-analysis was to provide a comprehensive synthesis of the evidence examining biomarker signatures in MDD patients including lipids, lipid regulatory proteins (LRP), and polyunsaturated fatty acid (PUFA) as compared to healthy individuals. We performed meta-analyses and meta-regression of the studies comparing lipid, LRP, and PUFA levels between MDD patients and healthy individuals by searching Embase, Ovid Medline, Scopus, PsycINFO, PubMed, and Cochrane databases. Search was performed in these databases up to September 2019 and 29 studies were included. Levels of lipid parameter triglyceride (TG) (SMD 0.55, 95% CI 0.30-0.80, p < 0.0001) were higher while total cholesterol (TC) (SMD = -0.46, 95%CI -0.93 to -0.001, p = 0.04) and very low-density lipoprotein (VLDL) (SMD = -0.46, 95%CI -0.71 to -0.20, p = 0.02) were lower in MDD patients than controls. Subgroup analysis for age showed that the levels of high-density lipoprotein (HDL) were lower in ≥40-year age group (SMD = -0.38, 95%CI -0.70 to -0.06, p = 0.01) and levels of TC was lower in MDD patients in studies from Asian countries (SMD = -0.74, 95%CI -1.37 to -0.10, p = 0.02). TG levels were found to be high all subgroups in MDD patients than controls. A negative association between TC levels and use of lipid lowering medications and a positive association between smoking and LDL levels was found using meta-regression analysis. This study will be useful for physicians when considering the assessment of lipidand LRP profiles in MDD patients to reduce the cardiovascular morbidity and mortality.

Understanding Why Post-Stroke Depression May Be the Norm Rather Than the Exception: The Anatomical and Neuroinflammatory Correlates of Post-Stroke Depression

Ischemic Stroke precedes depression. Post-stroke depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. In this systematic review, we analysed the inflammatory basis of post-stroke depression, which involves bioenergetic failure, deranged iron homeostasis (calcium influx, Na influx, potassium efflux etc), excitotoxicity, acidotoxicity, disruption of the blood brain barrier, cytokine-mediated cytotoxicity, reactive oxygen mediated toxicity, activation of cyclooxygenase pathway and generation of toxic products. This process subsequently results in cell death, maladapted, persistent neuro-inflammation and deranged neuronal networks in mood-related brain regions. Furthermore, an in-depth review likewise reveals that anatomic structures related to post-stroke depression may be localized to complex circuitries involving the cortical and subcortical regions.

Genome-scale metabolic modelling predicts biomarkers and therapeutic targets for neuropsychiatric disorders

Distinguishing neuropsychiatric disorders is challenging due to the overlap in symptoms and genetic risk factors. People suffering from these disorders face personal and professional challenges. Understanding the dysregulation of brain metabolism under disease condition can aid in effective diagnosis and in developing treatment strategies based on the metabolism. In this study, we reconstructed the metabolic network of three major neuropsychiatric disorders, schizophrenia (SCZ), bipolar disorder (BD) and major depressive disorder (MDD) using transcriptomic data and constrained based modelling approach. We integrated brain transcriptomic data from six independent studies with a recent comprehensive genome-scale metabolic model Recon3D. The analysis of the reconstructed network revealed the flux-level alterations in the peroxisome-mitochondria-golgi axis in neuropsychiatric disorders. We also extracted reporter metabolites and pathways that distinguish these three neuropsychiatric disorders. We found differences with respect to fatty acid oxidation, aromatic and branched chain amino acid metabolism, bile acid synthesis, glycosaminoglycans synthesis and modifications, and phospholipid metabolism. Further, we predicted network perturbations that transform the disease metabolic state to a healthy metabolic state for each disorder. These analyses provide local and global views of the metabolic changes in SCZ, BD and MDD, which may have clinical implications.

Inflammatory markers in depression: A meta-analysis of mean differences and variability in 5,166 patients and 5,083 controls

IMPORTANCE

The magnitude and variability of cytokine alterations in depression are not clear.

OBJECTIVE

To perform an up to date meta-analysis of mean differences of immune markers in depression, and to quantify and test for evidence of heterogeneity in immune markers in depression by conducting a meta-analysis of variability to ascertain whether only a sub-group of patients with depression show evidence of inflammation.

DATA SOURCES

Studies that reported immune marker levels in peripheral blood in patients with depression and matched healthy controls in the MEDLINE database from inception to August 29th 2018 were examined.

STUDY SELECTION

Case-control studies that reported immune marker levels in peripheral blood in patients with depression and healthy controls were selected.

DATA EXTRACTION AND SYNTHESIS

Means and variances (SDs) were extracted for each measure to calculate effect sizes, which were combined using multivariate meta-analysis.

MAIN OUTCOMES AND MEASURES

Hedges g was used to quantify mean differences. Relative variability of immune marker measurements in patients compared with control groups as indexed by the coefficient of variation ratio (CVR).

RESULTS

A total of 107 studies that reported measurements from 5,166 patients with depression and 5,083 controls were included in the analyses. Levels of CRP (g = 0.71; 95%CI: 0.50-0.92; p < 0.0001); IL-3 (g = 0.60; 95%CI: 0.31-0.89; p < 0.0001); IL-6 (g = 0.61; 95%CI: 0.39-0.82; p < 0.0001); IL-12 (g = 1.18; 95%CI: 0.74-1.62; p < 0.0001); IL-18 (g = 1.97; 95%CI: 1.00-2.95; p < 0.0001); sIL-2R (g = 0.71; 95%CI: 0.44-0.98; p < 0.0001); and TNFα (g = 0.54; 95%CI: 0.32-0.76; p < 0.0001) were significantly higher in patients with depression. These findings were robust to a range of potential confounds and moderators. Mean-scaled variability, measured as CVR, was significantly lower in patients with depression for CRP (CVR = 0.85; 95%CI: 0.75-0.98; p = 0.02); IL-12 (CVR = 0.61; 95%CI: 0.46-0.80; p < 0.01); and sIL-2R (CVR = 0.85; 95%CI: 0.73-0.99; p = 0.04), while it was unchanged for IL-3, IL-6, IL-18, and TNF α.

CONCLUSIONS AND RELEVANCE

Depression is confirmed as a pro-inflammatory state. Some of the inflammatory markers elevated in depression, including CRP and IL-12, show reduced variability in patients with depression, therefore supporting greater homogeneity in terms of an inflammatory phenotype in depression. Some inflammatory marker elevations in depression do not appear due to an inflamed sub-group, but rather to a right shift of the immune marker distribution.

Resolvin D1 Prevents the Impairment in the Retention Memory and Hippocampal Damage in Rats Fed a Corn Oil-Based High Fat Diet by Upregulation of Nrf2 and Downregulation and Inactivation of p66Shc

This study investigated the effect of a high-fat diet rich in corn oil (CO-HFD) on the memory retention and hippocampal oxidative stress, inflammation, and apoptosis in rats, and examined if the underlying mechanisms involve modulating Resolvin D1 (RvD1) levels and activation of p⁶⁶Shc. Also, we tested if co-administration of RvD1 could prevent these neural adverse effects induced by CO-HFD. Adult male Wistar rats were divided into 4 groups (n = 18/each) as control fed standard diet (STD) (3.82 kcal/g), STD + RvD1 (0.2 µg/Kg, i.p/twice/week), CO-HFD (5.4 kcal/g), and CO-HFD + RvD1. All treatments were conducted for 8 weeks. With normal fasting glucose levels, CO-HFD induced hyperlipidemia, hyperinsulinemia, increased HOMA-IRI and reduced the rats' memory retention. In parallel, CO-HFD increased levels of reactive oxygen species (ROS), malondialdehyde (MDA), cytoplasmic cytochrome-c, and cleaved caspase-3 and significantly decreased levels of glutathione (GSH), Bcl-2, and manganese superoxide dismutase (MnSOD) in rats' hippocampi. Besides, CO-HFD significantly reduced hippocampal levels of docosahexaenoic acid (DHA) and RvD1, as well as total protein levels of Nrf2 and significantly increased nuclear protein levels of p-NF-κB. Concomitantly, CO-HFD increased hippocampal protein levels of p-JNK, p53, p⁶⁶Shc, p-p⁶⁶Shc, and NADPH oxidase. However, without altering plasma and serum levels of glucose, insulin, and lipids, co-administration of RvD1 to CO-HFD completely reversed all these events. It also resulted in similar effects in the STD fed-rats. In conclusion, CO-HFD impairs memory function and induces hippocampal damage by reducing levels of RvD1 and activation of JNK/p53/p⁶⁶Shc/NADPH oxidase, effects that are prevented by co-administration of RvD1.

Impact, Diagnosis, Phenomenology, and Biology

This section provides summaries of the epidemiology, phenomenology, nosology, and the suspected biological substrates of the depressive disorders. It particularly emphasizes the historical evolution of the pertinent diagnostic constructs and the prognostic import both of the various diagnostic groupings and of the individual symptoms and symptom clusters.

Association between the ratio of serum arachidonic acid to eicosapentaenoic acid and the presence of depressive symptoms in a general Japanese population: the Hisayama Study

BACKGROUND

Epidemiological evidence suggests that fish consumption and intake of n-3 polyunsaturated fatty acids (PUFA)-namely, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)-confer protection against depression. However, few studies have addressed the influence of the balance between n-3 PUFA and n-6 PUFA in the human body on depression.

METHODS

A total of 2,529 community-dwelling Japanese residents aged ≥ 40 years were assessed for depressive symptoms (defined as a score of 16 points or more on the Center for Epidemiologic Studies Depression Scale [CES-D]) in 2007. The serum arachidonic acid (AA) /EPA ratio and AA/DHA ratio were measured in frozen samples collected in 2002 and categorized into quartiles. The odds ratios (ORs) for the presence of depressive symptoms were calculated using a logistic regression model.

RESULTS

The prevalence of depressive symptoms was 4.3%. There was no significant association between either the serum AA/EPA ratio or AA/DHA ratio and the presence of depressive symptoms. However, subjects with the highest serum AA/EPA ratios (range: 3.28-13.3) had a 4.10 times (95%CI: 1.13-19.80) greater OR for the presence of depressive symptoms than those with the lowest ratios (0.30-1.65) after adjusting for confounding factors in the subgroup with high-sensitivity C-reactive protein (hs-CRP) ≥ 1.0 mg/L, while no clear association was observed in the subgroup with hs-CRP < 1.0 mg/L.

LIMITATIONS

Reverse causality is possible due to the cross-sectional study design.

CONCLUSIONS

Our findings suggest that a higher serum AA/EPA ratio is associated with a greater likelihood of depressive symptoms in subjects with systemic inflammation in the general Japanese population.

How lipids may affect risk for suicidal behavior

Suicide and nonfatal suicidal behaviors are major causes of mortality and morbidity worldwide. Variability in rates of suicide and suicidal behaviors within and between countries has been attributed to population and individual risk factors, including economic status and cultural differences, both of which can have suicide risk effects mediated through a variety of factors, of which perhaps the least understood is the role of diet. We therefore review the scientific literature concerning two major dietary lipid classes, cholesterol and polyunsaturated fatty acids (PUFAs), that have been associated with higher risk of suicide attempts and suicide. We consider potential mechanistic intermediates including serotonin transporters and receptors, toll-like receptors (TLRs), nuclear factor kappa-light-chain-enhancer of activated B cells (NFκB), and peroxisome proliferator activated receptors (PPARs). Based on this review, we describe a theoretical model linking cholesterol and PUFA status to suicide risk, taking into account the effects of cholesterol-lowering interventions on PUFA balance, membrane lipid microdomains (rafts) as a nexus of interaction between cholesterol and omega-3 PUFAs, and downstream effects on serotonergic neurotransmission and specific inflammatory pathways.

Focus on fatty acids in the neurometabolic pathophysiology of psychiatric disorders

Continuous research into the pathophysiology of psychiatric disorders, such as major depressive disorder (MDD), posttraumatic stress disorder (PTSD), and schizophrenia, suggests an important role for metabolism. This narrative review will provide an up-to-date summary of how metabolism is thought to be involved in the pathophysiology of these psychiatric disorders. We will focus on (I) the important role of fatty acids in these metabolic alterations, (II) whether fatty acid alterations represent epiphenomena or risk factors, and (III) similarities and dissociations in fatty acid alterations between different psychiatric disorders. (Historical) epidemiological evidence links fatty acid intake to psychiatric disorder prevalence, corroborated by altered fatty acid concentrations measured in psychiatric patients. These fatty acid alterations are connected with other concomitant pathophysiological mechanisms, including biological stress (hypothalamic-pituitary-adrenal (HPA)-axis and oxidative stress), inflammation, and brain network structure and function. Metabolomics and lipidomics studies are underway to more deeply investigate this complex network of associated neurometabolic alterations. Supplementation of fatty acids as disease-modifying nutraceuticals has clinical potential, particularly add-on eicosapentaenoic acid (EPA) in depressed patients with markers of increased inflammation. However, by interpreting the observed fatty acid alterations as partly (mal)adaptive phenomena, we attempt to nuance translational expectations and provide new clinical applications for these novel neurometabolic insights, e.g., to predict treatment response or depression recurrence. In conclusion, placing fatty acids in context can contribute to further understanding and optimized treatment of psychiatric disorders, in order to diminish their overwhelming burden of disease.

Biological profiling of prospective antidepressant response in major depressive disorder: Associations with (neuro)inflammation, fatty acid metabolism, and amygdala-reactivity

BACKGROUND

A better understanding of factors underlying antidepressant non-response may improve the prediction of which patients will respond to what treatment. Major depressive disorder (MDD) is associated with alterations in fatty acid metabolism, (neuro)inflammation and amygdala-reactivity. However, their mutual relations, and the extent to which they are associated with prospective antidepressant-response, remain unknown.

PURPOSE

To test (I) alterations in (neuro)inflammation and its associations with fatty acid metabolism and amygdala-reactivity in MDD-patients compared to controls, and (II) whether these alterations are associated with prospective paroxetine response.

METHODS

We compared 70 unmedicated MDD-patients with 51 matched healthy controls at baseline, regarding erythrocyte membrane omega-6 arachidonic acid (AA), inflammation [serum (high-sensitivity) C-reactive protein (CRP)], and in a subgroup amygdala-reactivity to emotional faces using functional magnetic resonance imaging (fMRI) (N=42). Subsequently, we treated patients with 12 weeks paroxetine, and repeated baseline measures after 6 and 12 weeks to compare non-responders, early-responders (response at 6 weeks), and late-responders (response at 12 weeks).

RESULTS

Compared to controls, MDD-patients showed higher CRP (p=0.016) and AA (p=0.019) after adjustment for confounders at baseline. AA and CRP were mutually correlated (p=0.043). In addition, patients showed a more negative relation between AA and left amygdala-reactivity (p=0.014). Moreover, AA and CRP were associated with antidepressant-response: early responders showed lower AA (p=0.018) and higher CRP-concentrations (p=0.008) than non-responders throughout the study.

CONCLUSION

Higher observed CRP and AA, their mutual association, and relation with amygdala-reactivity, are corroborative with a role for (neuro)inflammation in MDD. In addition, observed associations of these factors with prospective antidepressant-response suggest a potential role as biomarkers. Future studies in independent samples are needed to replicate and test the clinical applicability of these biological predictors for treatment response to result in a precision/personalized medicine approach for treatment.

Serum x03C9;-3 and x03C9;-6 Fatty Acids Are Not Associated with Personality Traits in Healthy Japanese Young People

BACKGROUND

Recent studies have reported that polyunsaturated fatty acids (PUFAs) are associated with mood and behaviors including depression and suicide risk. The aim of this study was to examine the relationship between PUFAs and personality traits in healthy subjects.

METHODS

A total of 279 subjects completed the Temperament and Character Inventory and Beck Depression Inventory. Serum levels of the PUFAs eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), the x03C9;-6 fatty acid arachidonic acid (AA), and dihomo-x03B3;-linolenic acid were measured.

RESULTS

Pearson's correlation analysis showed a positive correlation between DHA and cooperativeness scores. In the multiple regression analysis, harm avoidance scores were positively associated with AA, and a negative association was found between the EPA/AA ratio and reward dependence scores. However, these associations were nonsignificant after a Bonferroni correction.

CONCLUSION

The results of the present study suggest that the blood levels of PUFAs are not likely to be associated with personality traits.

Fatty acid metabolism and its longitudinal relationship with the hypothalamic-pituitary-adrenal axis in major depression: Associations with prospective antidepressant response

BACKGROUND

Metabolism of dietary fatty acids (FAs), and its relationship with the hypothalamic-pituitary-adrenal (HPA)-axis, have been found to be altered in major depressive disorder (MDD). Moreover, indications exist that these factors are associated with antidepressant-response. If we better understand these associations, we might identify novel targets for add-on therapy to increase antidepressant-response, and/or early indicators to improve response prediction.

OBJECTIVE

To determine whether alterations in FA-metabolism, and their relationship with the HPA-axis, are associated with prospective response to the antidepressant paroxetine in MDD.

DESIGN

We first compared 70 initially unmedicated MDD-patients with 51 age- and gender-matched controls at study-entry, regarding salivary cortisol and erythrocyte membrane FAs [omega-3 docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), FA-chain length, -unsaturation and -peroxidizability]. Subsequently, we treated patients with 6 weeks 20mg/day selective serotonin reuptake inhibitor paroxetine. After 6 weeks, we continued this treatment in responders (i.e. showing ≥50% decrease in Hamilton depression rating scale-score), and randomized non-responders to a 6-week, double-blind, placebo-controlled dose-escalation up to 50mg/day. We repeated cortisol and FA-measures in patients after 6 and 12 weeks.

RESULTS

Compared to controls, patients showed higher FA-chain length, FA-unsaturation and FA-peroxidation, and more negative relationships of FA-unsaturation and FA-peroxidation with cortisol. Moreover, these negative relationships were associated with paroxetine nonresponse. Nonresponse was also associated with low DHA, which was related to low fatty fish intake. Furthermore, early responders showed initial low FA-chain length, FA-peroxidation and EPA that increased during the study, while non-responders exhibited opposite patterns.

CONCLUSIONS

FA-metabolism alterations, and their relationship with cortisol, are associated with prospective paroxetine response in MDD, and may therefore form an early indicator of treatment effectiveness. Moreover, dietary fatty fish intake may improve antidepressant response through an effect on FA-metabolism.

A review of recent evidence in human studies of n-3 and n-6 PUFA intake on cardiovascular disease, cancer, and depressive disorders: does the ratio really matter?

Polyunsaturated fatty acids (PUFAs) have been considered of great interest for human health due to their potential anti-inflammatory action that may protect from a number of chronic-degenerative diseases with an inflammatory pathogenesis. This review aimed to report the most updated evidence of both n-3 and n-6 PUFAs effect on cardiovascular disease, cancer, and depression in humans. Attention has been also paid to those studies exploring the effects of the ratio intake. Results from pooled analyses of human studies reported a general positive effect of n-3 PUFAs intake on all outcomes considered. In contrast, the role of n-6 PUFAs on human health needs to be better assessed in order to clearly identify which compound exerts beneficial/harmful effects. Only a limited number of clinical studies considered the n-3:n-6 PUFAs ratio, rather reporting contrasting results. A number of limitations when considering the ratio between these two families of PUFAs have risen.

Potential role of dietary lipids in the prophylaxis of some clinical conditions

An imbalance of dietary lipids may potentially have a significant role in the pathobiology of some chronic diseases. Public health dietary fat recommendations have emphasized that low saturated fat, high monounsaturated fat, and high polyunsaturated fat with a lower ω-6 to ω-3 fatty acid ratio intake are necessary for normal health. However, such universal recommendations are likely to be hazardous, since the outcome of recommended lipid intake may depend on the consumption of other important dietary constituents that have an important role in the metabolism of lipids. In addition, consumption of fatty acids as per the individually tailored specific requirements in the context of other nutritional factors may have the potential to stabilize hormones, mood and sleep, and minimize adverse events. In support of this proposal, we review various factors that influence fatty acid metabolism, which need to be taken into consideration for appropriate utilization and consequently prevention of various diseases.

Decreased serum levels of polyunsaturated fatty acids and folate, but not brain-derived neurotrophic factor, in childhood and adolescent females with depression

Evidence from observational studies suggests that there is an association among depression and brain-derived neurotrophic factor (BDNF), polyunsaturated fatty acids (PUFAs), and folate; however, this association has yet to be examined in childhood and adolescent depression. The objective was to determine whether the BDNF, PUFAs, and folate in serum differ between first-episode childhood and adolescent depressed patients and healthy controls. We measured the serum levels of BDNF, PUFAs, and folate of cases admitted to the hospital for depression (n=24) and compared it to that of controls (n=26). Subjects and their parents were informed about the nature and the purpose of this study, and a consent form was signed by parents. The ethics committee of Hirosaki University Graduate School of Medicine approved the study protocol. There were significant differences in the docosahexanoic acid (DHA), arachidonic acid (AA), and folate levels between cases and controls. Serum levels of DHA, AA, and folate levels in the patients group were statistically lower than those in the control group, while serum levels of BDNF were not different between cases and controls. These results are in line with findings of previous studies involving adult and elderly subjects, demonstrating lower levels of PUFAs and folate in patients with depression than healthy controls. However, further studies using larger sample size are warranted.

A meta-analysis of lipid peroxidation markers in major depression

BACKGROUND

Major depressive disorder (MDD) may be associated with oxidative damage to lipids, which can potentially affect mood-regulating pathways. This meta-analysis summarizes current knowledge regarding lipid peroxidation markers in clinical samples of MDD and the effects of antidepressant pharmacotherapy on those markers.

METHODS

MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Collaboration were searched for original, peer-reviewed articles measuring markers of lipid peroxidation in patients with MDD and nondepressed healthy controls up to April 2015. Standardized mean differences (SMDs) were generated from random effects models summarizing mean (± standard deviations) concentrations of selected markers.

RESULTS

Lipid peroxidation was greater in MDD than in controls (studies =17, N=857 MDD/782 control, SMD =0.83 [0.56-1.09], z=6.11, P<0.01, I (2)=84.0%) and was correlated with greater depressive symptom severity (B=0.05, df=8, P<0.01). Antidepressant treatment was associated with a reduction in lipid peroxidation in MDD patients (studies=5, N=222, SMD=0.71 [0.40-0.97], P<0.01; I (2)=42.5%).

LIMITATIONS

Lipid peroxidation markers were sampled from peripheral blood, included studies comparing MDD to controls were all cross-sectional, and only five antidepressant treatment studies were eligible for inclusion.

CONCLUSION

Increased lipid peroxidation was associated with MDD and may be normalized by antidepressants. Continued investigation of lipid peroxidation in MDD is warranted.

The effect of omega-3 fatty acids on depressive symptoms and inflammatory markers in maintenance hemodialysis patients: a randomized, placebo-controlled clinical trial

PURPOSE

This study was designed to investigate the effects of omega-3 fatty acids on depression and chronic inflammation in hemodialysis patients.

METHOD

Fifty-four maintenance hemodialysis patients were randomized to ingest two omega-3 (each containing 180 mg eicosapentaenoic acid and 120 mg docosahexaenoic acid) or placebo capsules, three times daily for 4 months.

MAIN OUTCOME MEASURES

Beck Depression Inventory (BDI) score and serum levels of C-reactive protein (CRP), interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, ferritin, intact parathyroid hormone (iPTH), and ratios of IL-10 to IL-6 and IL-10 to TNF-α were measured at baseline and at the end of the study.

RESULTS

Omega-3 supplement lowered BDI score significantly after 4 months of intervention. Among pro- and anti-inflammatory mediators, only serum ferritin level and IL-10 to IL-6 ratio showed significant changes in favor of omega-3 supplement during the study. In linear regression model adjusted for baseline values, omega-3 treatment was a significant predictor of reduced serum CRP, ferritin, and iPTH levels, and increased IL-10 to IL-6 ratio. No significant association was found between the anti-inflammatory and anti-depressant effects of omega-3 supplement.

CONCLUSIONS

Supplemental use of omega-3 fatty acids decreases depressive symptoms in hemodialysis patients apart from their anti-inflammatory effects.

Common biological pathways underlying the psychoneurological symptom cluster in cancer patients

BACKGROUND

A symptom cluster is a group of symptoms that occur together and are interrelated. The clinical implication of symptom cluster research is to use the clustering patterns of symptoms to understand the mechanisms for these symptoms and develop management strategies targeted at multiple symptoms.

OBJECTIVE

The purposes of this review were to summarize the evidence for a psychoneurological symptom cluster in cancer patients, to provide information regarding the underlying biological mechanisms for each of the psychoneurological symptoms within the cluster, and to propose possible common biological pathways that may underlie this cluster.

METHODS

A systematic review of the literature was conducted.

RESULTS

Empirical evidence exists to support a cluster of psychoneurological symptoms (ie, depressive symptoms, cognitive disturbance, fatigue, sleep disturbance, pain). At a molecular level, common biological pathways (ie, proinflammatory cytokines, hypothalamic-pituitary-adrenal axis, and monoamine neurotransmission system) may underlie the development of symptoms within this cluster. Activation of proinflammatory cytokines is proposed as a first stage of mechanistic pathway. However, other biological factors, such as lowered estrogen or hemoglobin levels, may influence psychoneurological cluster.

CONCLUSION

Additional studies are needed to confirm the roles of cytokines as well as other biological factors in the development of the psychoneurological cluster and to determine the biomarkers to identify the subgroups of cancer patients who are at greatest risk for this cluster.

IMPLICATIONS FOR PRACTICE

This information can be used by researchers and clinicians to guide the selection of symptom management strategies that are ideally targeted to the biological mechanisms that underlie this symptom cluster.

Omega-3 polyunsaturated fatty acid (PUFA) status in major depressive disorder with comorbid anxiety disorders

BACKGROUND

Although lower levels of omega-3 polyunsaturated fatty acids (PUFAs) are found in major depressive disorder, less is known about PUFA status and anxiety disorders.

METHOD

Medication-free participants with DSM-IV-defined major depressive disorder (MDD), with (n = 18) and without (n = 41) comorbid DSM-IV anxiety disorders, and healthy volunteers (n = 62) were recruited from October 2006 to May 2010 for mood disorder studies at the New York State Psychiatric Institute. Participants were 18-73 years of age (mean age, 35.8 ± 12.6 years). Depression and anxiety severity was assessed using depression and anxiety subscales from the 17-item Hamilton Depression Rating Scale. Plasma PUFAs eicosapentaenoic acid (EPA; 20:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) and the ratio of arachidonic acid (AA; 22:4n-6) to EPA (AA:EPA) were quantified. This secondary analysis employed analysis of variance with a priori planned contrasts to test for diagnostic group differences in log-transformed PUFA levels (logDHA, logEPA, and logAA:EPA).

RESULTS

Plasma levels of logDHA (F(2,118) = 4.923, P = .009), logEPA (F(2,118) = 6.442, P = .002), and logAA:EPA (F(2,118) = 3.806, P = .025) differed across groups. Participants with MDD had lower logDHA (t(118) = 2.324, P = .022) and logEPA (t(118) = 3.175, P = .002) levels and higher logAA:EPA levels (t(118) = -2.099, P = .038) compared with healthy volunteers. Lower logDHA (t(118) = 2.692, P = .008) and logEPA (t(118) = 2.524, P = .013) levels and higher logAA:EPA levels (t(118) = -2.322, P = .022) distinguished anxious from nonanxious MDD. Depression severity was not associated with PUFA plasma levels; however, anxiety severity across the entire sample correlated negatively with logDHA (r(p) = -0.22, P = .015) and logEPA (r(p) = -0.25, P = .005) levels and positively with logAA:EPA levels (r(p) = 0.18, P = .043).

CONCLUSIONS

The presence and severity of comorbid anxiety were associated with the lowest EPA and DHA levels. Further studies are needed to elucidate whether omega-3 PUFA supplementation may preferentially alleviate MDD with more severe anxiety.

Platelet activating factors in depression and coronary artery disease: a potential biomarker related to inflammatory mechanisms and neurodegeneration

The persistence of a depressive episode in coronary artery disease (CAD) patients not only heightens the risk of acute ischemic events, but it is also associated with accelerated cognitive decline. Antidepressant interventions for depression in CAD have only modest effects and novel approaches are limited by a poor understanding of etiological mechanisms. This review proposes that the platelet activating factor (PAF) family of lipids might be associated with the persistence of a depressive episode and related neurodegenerative pathology in CAD due to their association with leading etiological mechanisms for depression in CAD such as inflammation, oxidative and nitrosative stress, vascular endothelial dysfunction, and platelet reactivity. The evidence implicating PAFs in CAD, vascular pathology, and neurodegenerative processes is also presented. We also propose future directions for the investigation of PAFs as mediators of persistent depression. In summary, PAFs are implicated in leading mechanisms associated with depression in CAD. PAFs may therefore be associated with the persistence of depression in CAD and related to neurodegenerative and cognitive sequelae.

Experimental human endotoxemia enhances brain activity during social cognition

Acute peripheral inflammation with corresponding increases in peripheral cytokines affects neuropsychological functions and induces depression-like symptoms. However, possible effects of increased immune responses on social cognition remain unknown. Therefore, this study investigated the effects of experimentally induced acute inflammation on performance and neural responses during a social cognition task assessing Theory of Mind (ToM) ability. In this double-blind randomized crossover functional magnetic resonance imaging study, 18 healthy right-handed male volunteers received an injection of bacterial lipopolysaccharide (LPS; 0.4 ng/kg) or saline, respectively. Plasma levels of pro- and anti-inflammatory cytokines as well as mood ratings were analyzed together with brain activation during a validated ToM task (i.e. Reading the Mind in the Eyes Test). LPS administration induced pronounced transient increases in pro- (IL-6, TNF-α) and anti-inflammatory (IL-10, IL-1ra) cytokines as well as decreases in mood. Social cognition performance was not affected by acute inflammation. However, altered neural activity was observed during the ToM task after LPS administration, reflected by increased responses in the fusiform gyrus, temporo-parietal junction, superior temporal gyrus and precuneus. The increased task-related neural responses in the LPS condition may reflect a compensatory strategy or a greater social cognitive processing as a function of sickness.

Fish oil as a management component for mood disorders - an evolving signal

PURPOSE OF REVIEW

To overview the theoretical relevance of omega-3 and omega-6 fatty acids in the cause of mood disorders, and focus on evaluating the potential therapeutic role of omega-3 fatty acids.

RECENT FINDINGS

Numerous studies have documented low omega-3 fatty acid levels in those with depressive disorders, and there are plausible biological explanations as to why reduced omega-3 status may predispose to mood disorders as well as to a range of other conditions. Although early studies evaluating the role of omega-3 preparations as treatments of depression were generally positive, the rate of negative or nondifferential studies has increased in recent years. Recent meta-analyses provide an explanation in suggesting that docosahexaenoic acid-weighted preparations may be ineffective while finding support for eicosapentaenoic acid (EPA)-weighted preparations.

SUMMARY

There is sufficient indicative data favouring EPA-weighted omega-3 supplementation for those with a depressive mood disorder, particular when fish oil is viewed by patients as 'natural,' it has few side effects and is neuroprotective. Recent meta-analyses inform us that intervention studies should focus on EPA-weighted preparations.

Healthy and adverse effects of plant-derived functional metabolites: the need of revealing their content and bioactivity in a complex food matrix

In recent years, both food quality and its effect on human health have become a fundamental issue all over the world. As a consequence of this new and increased awareness, American, European, and Asian policymakers have strongly encouraged the research programs on food quality and safety thematic. Attempts to improve human health and to satisfy people's desire for healthcare without intake of pharmaceuticals, has led the food industry to focus attention on functional or nutraceutical food. For a long time, compounds with nutraceutical activity have been produced chemically, but the new demands for a sustainable life have gradually led the food industry to move towards natural compounds, mainly those derived from plants. Many phytochemicals are known to promote good health, but, sometimes, undesirable effects are also reported. Furthermore, several products present on the market show few benefits and sometimes even the reverse - unhealthy effects; the evidence of efficacy is often unconvincing and epidemiological studies are necessary to prove the truth of their claims. Therefore, there is a need for reliable analytical control systems to measure the bioactivity, content, and quality of these additives in the complex food matrix. This review describes the most widespread nutraceutics and an analytical control of the same using recently developed biosensors which are promising candidates for routine control of functional foods.

Health implications of high dietary omega-6 polyunsaturated Fatty acids

Omega-6 (n-6) polyunsaturated fatty acids (PUFA) (e.g., arachidonic acid (AA)) and omega-3 (n-3) PUFA (e.g., eicosapentaenoic acid (EPA)) are precursors to potent lipid mediator signalling molecules, termed "eicosanoids," which have important roles in the regulation of inflammation. In general, eicosanoids derived from n-6 PUFA are proinflammatory while eicosanoids derived from n-3 PUFA are anti-inflammatory. Dietary changes over the past few decades in the intake of n-6 and n-3 PUFA show striking increases in the (n-6) to (n-3) ratio (~15 : 1), which are associated with greater metabolism of the n-6 PUFA compared with n-3 PUFA. Coinciding with this increase in the ratio of (n-6) : (n-3) PUFA are increases in chronic inflammatory diseases such as nonalcoholic fatty liver disease (NAFLD), cardiovascular disease, obesity, inflammatory bowel disease (IBD), rheumatoid arthritis, and Alzheimer's disease (AD). By increasing the ratio of (n-3) : (n-6) PUFA in the Western diet, reductions may be achieved in the incidence of these chronic inflammatory diseases.

Neuroimmunological effects of physical exercise in depression

The search for an extended understanding of the causes of depression, and for the development of additional effective treatments is highly significant. Clinical and pre-clinical studies suggest stress is a key mediator in the pathophysiology of depression. Exercise is a readily available therapeutic option, effective as a first-line treatment in mild to moderate depression. In pre-clinical models exercise attenuates stress-related depression-like behaviours. Cellular and humoral neuroimmune mechanisms beyond inflammation and oxidative stress are highly significant in understanding depression pathogenesis. The effects of exercise on such mechanisms are unclear. When clinical and pre-clinical data is taken together, exercise may reduce inflammation and oxidation stress via a multitude of cellular and humoral neuroimmune changes. Astrocytes, microglia and T cells have an antiinflammatory and neuroprotective functions via a variety of mechanisms. It is unknown whether exercise has effects on specific neuroimmune markers implicated in the pathogenesis of depression such as markers of immunosenescence, B or T cell reactivity, astrocyte populations, self-specific CD4+ T cells, T helper 17 cells or T regulatory cells.

Adjunctive nutraceuticals with standard pharmacotherapies in bipolar disorder: a systematic review of clinical trials

OBJECTIVE

  Studies using augmentation of pharmacotherapies with nutraceuticals in bipolar disorder (BD) have been conducted and preliminary evidence in many cases appears positive. To date, however, no specialized systematic review of this area has been conducted. We present the first systematic review of clinical trials using nutrient-based nutraceuticals in combination with standard pharmacotherapies to treat BD. A subsequent aim of this report was to discuss posited underlying mechanisms of action.

METHODS

  PubMed, CINAHL, Web of Science, and Cochrane Library databases, and grey literature were searched during mid-2010 for human clinical trials in English using nutraceuticals such as omega-3, N-acetyl cysteine (NAC), inositol, and vitamins and minerals, in combination with pharmacotherapies to treat bipolar mania and bipolar depression. A review of the results including an effect size analysis (Cohen's d) was subsequently conducted.

RESULTS

  In treating bipolar depression, positive evidence with large effect sizes were found for NAC (d=1.04) and a chelated mineral and vitamin formula (d=1.70). On the outcome of bipolar mania, several nutraceuticals reduced mania with strong clinical effects: a chelated mineral formula (d=0.83), L-tryptophan (d=1.47), magnesium (d=1.44), folic acid (d=0.40), and branched-chain amino acids (d=1.60). Mixed, but mainly positive, evidence was found for omega-3 for bipolar depression, while no evidentiary support was found for use in mania. No significant effect on BD outcome scales was found for inositol (possibly due to small samples).

CONCLUSIONS

  BD treatment outcomes may potentially be improved by additional use of certain nutraceuticals with conventional pharmacotherapies. However, caution should be extended in interpreting the large effects of several isolated studies, as they have not yet been replicated in larger trials.

Marine omega-3 fatty acids and mood disorders--linking the sea and the soul. 'Food for Thought' I

OBJECTIVE

While there has long been interest in any nutritional contribution to the onset and treatment of mood disorders, there has been increasing scientific evaluation of several candidate nutritional and dietary factors in recent years. In this inaugural study of our 'Food for Thought' series, we will overview the evidence for any role of omega-3 fatty acids (FA) in regulating mood.

METHOD

Relevant literature was identified through online database searches and cross-referencing.

RESULTS

Plausible mechanisms exist by which omega-3 FA may influence neuronal function and mood. Cross-sectional studies demonstrate an association between omega-3 fatty acid deficiency and both depressive and bipolar disorders. Studies investigating the efficacy of omega-3 fatty acid supplementation for mood disorders have however provided inconsistent results. The proportion of treatment studies showing a significant advantage of omega-3 supplementation has dropped over the last 5 years. However, the vast heterogeneity of the trials in terms of constituent omega-3 FAs, dose and length of treatment makes comparisons of these studies difficult.

CONCLUSION

More research is required before omega-3 supplementation can be firmly recommended as an effective treatment for mood disorders. Whereas increased omega-3 FA intake may alleviate depressive symptoms, there is little evidence of any benefit for mania.

Labile anger during interferon alfa treatment is associated with a polymorphism in tumor necrosis factor alpha

OBJECTIVE

Inflammatory cytokines may influence both labile anger and depression. Both psychiatric conditions can occur during interferon alfa-based treatments. Evidence also indicates a central nervous system role for tumor necrosis factor alpha (TNF-alpha), whose expression may be increased by interferon alfa. A polymorphism in the promoter region of TNF-alpha has been associated with various inflammatory illnesses. We therefore hypothesized that this TNF-alpha polymorphism would influence susceptibility to psychiatric symptoms during interferon alfa therapy.

METHODS

One hundred five patients with hepatitis C, initially without active major depression (major depressive disorder), were treated with interferon alfa and then prospectively monitored using the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, the Beck Depression Inventory II, the Anger Irritability and Assault Questionnaire, and circulating TNF-alpha levels. The A-308G polymorphism (rs1800629) was determined using the 5'-nuclease assay. Repeated-measure mixed-effect analyses compared changes in symptoms over time.

RESULT

Beck Depression Inventory II score increased during interferon alfa therapy (F = 6.2; P < 0.001), with 27% developing MDD. The TNF-alpha A allele was associated with worsened labile anger (F = 2.5; P < 0.05) and fatigue (F = 2.9; P < 0.05) during treatment but not with major depression incidence (chi = 0.0; P = 0.99) or increased Beck Depression Inventory II (F = 1.2; P = 0.31). Labile anger was not predicted by the serotonin transporter polymorphism (F = 0.8; P = 0.59).

DISCUSSION

During treatment with an exogenous cytokine, vulnerability to worsening labile anger-distinct from major depression-is associated with genetic variability in TNF-alpha. This has implications both for patients being treated with interferon alfa and our understanding of genetic vulnerability for different subtypes of dysphoric and mood disorders.

N-3 (omega-3) Fatty acids in postpartum depression: implications for prevention and treatment

A growing body of clinical and epidemiological evidence suggests that low dietary intake and/or tissue levels of n-3 (omega-3) polyunsaturated fatty acids (PUFAs) are associated with postpartum depression. Low tissue levels of n-3 PUFAs, particularly docosahexaenoic acid (DHA), are reported in patients with either postpartum or nonpuerperal depression. Moreover, the physiological demands of pregnancy and lactation put childbearing women at particular risk of experiencing a loss of DHA from tissues including the brain, especially in individuals with inadequate dietary n-3 PUFA intake or suboptimal metabolic capabilities. Animal studies indicate that decreased brain DHA in postpartum females leads to several depression-associated neurobiological changes including decreased hippocampal brain-derived neurotrophic factor and augmented hypothalamic-pituitary-adrenal responses to stress. Taken together, these findings support a role for decreased brain n-3 PUFAs in the multifactorial etiology of depression, particularly postpartum depression. These findings, and their implications for research and clinical practice, are discussed.

A meta-analytic review of polyunsaturated fatty acid compositions in patients with depression

BACKGROUND

On the basis of evidence from studies showing the antidepressant effects of omega-3 polyunsaturated fatty acids and the inverse relation between fish consumption and the prevalence of depression, the phospholipid hypothesis seems promising in ascertaining the etiology and treatment of depression. Although several studies have shown lower levels of omega-3 (n-3) polyunsaturated fatty acids in depressive patients, the results of individual polyunsaturated fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and the omega-6 (n-6) polyunsaturated fatty acid arachidonic acid (AA), were inconsistent.

METHODS

We conducted the meta-analyses of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects. The effect size of each study was synthesized by using a random effects model.

RESULTS

Compared with control subjects, the levels of EPA, DHA, and total n-3 polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in AA or total n-6 polyunsaturated fatty acids.

CONCLUSIONS

The results showed lower levels of EPA, DHA, and total n-3 polyunsaturated fatty acids in patients with depression, thus implying that n-3 polyunsaturated fatty acids play a role in the pathogenesis of depression. Our findings provide further support to the phospholipid hypothesis of depression and a rationale for using n-3 polyunsaturated fatty acids as an alternative treatment for depression. With these results, future studies examining specific roles of DHA and EPA in different clusters of depressive symptoms are warranted.

Antidepressant pharmacotherapy: focus on sex differences in neuroimmunopharmacological crossroads

Major depression is a stress-related disorder that shows a clear female preponderance. Sex differences in antidepressant response have been documented in both the clinical and experimental settings. It is of interest that antidepressant drugs exert critical immunotropic influences, mediated by direct and/or compensatory routes; these effects are not completely understood but comprise a matter of intensive investigation. Even though human studies have found only a few sex-related differences in the immunotropic effects of antidepressants, recent experimental evidence in the chronic mild stress model of depression points towards a sexually dimorphic neuroimmune playground in view of chronic antidepressant treatment. Herein, we provide a concise review regarding the effects of antidepressant pharmacotherapy on neuroimmune manifestations by concentrating on intriguing sex differences.

Effects of eicosapentaenoic acid and fluoxetine on plasma cortisol, serum interleukin-1beta and interleukin-6 concentrations in patients with major depressive disorder

Treatment studies have suggested that omega-3 fatty acids (omega-3 FAs) as monotherapy or adjunctive treatment have therapeutic effects in depression. The authors recently reported a study in which fluoxetine and eicosapentaenoic acid (EPA), which is an omega-3 fatty acid, appeared to be equally effective in controlling depressive symptoms and their combination was superior to either of them alone. Regulation of hypothalamus-pituitary-adrenal (HPA) axis activity and reduction of inflammatory cytokines are among several biological mechanisms which potentially explain the impact of omega-3 FAs on depression. In the present study, plasma cortisol and serum interleukin-1beta (IL-1 beta) and interleukin-6 (Il-6) were measured in patients with a diagnosis of major depressive disorder (MDD) participating in aforementioned trial to determine the effects of 8 weeks of treatment of depression with 1000 mg EPA alone or in combination with 20 mg fluoxetine on HPA axis activity and inflammatory cytokine production and compare the changes in these variables with those of treating with 20 mg fluoxetine alone. Forty-two patients were included in analysis. Two-way repeated measures analysis of variance (ANOVA) showed that plasma cortisol decreased significantly after 8 weeks of intervention without significant difference among the groups. There was no interaction between group and response to treatment over time in the cortisol response based on three-way ANOVA. Serum concentrations of IL-1beta and IL-6 did not change significantly after intervention. In conclusion, EPA alone or in combination with fluoxetine, as well as fluoxetine alone decreased serum cortisol after 8 weeks of treatment in patients with major depression disorder (MDD) without any significant effect of response to treatment. Serum IL-1beta and IL-6 did not change significantly after intervention. These findings suggest that EPA may exert its therapeutic effects through reduction of cortisol.

Serum polyunsaturated fatty acids are not associated with the risk of severe depression in middle-aged Finnish men: Kuopio Ischaemic Heart Disease Risk Factor (KIHD) study

PURPOSE

The aim of this study is to investigate whether serum n - 3 polyunsaturated fatty acids (PUFAs) or n - 6 to n - 3 ratio is associated with risk of severe depression in middle-aged Finnish men.

METHODS

The association between the serum concentrations of fatty acids and depression was investigated in 2077 men aged 42-60 years at baseline in a prospective follow-up setting. The population-based Kuopio Ischaemic Heart Disease Risk Factor (KIHD) Study cohort was recruited between 1984 and 1989 and followed until the end of 2007. The baseline levels of serum total n - 3 PUFAs, n - 6 PUFAs and individual fatty acids were determined. Data on hospital treatments due to major depressive disorder were derived from the national hospital discharge register.

RESULTS

During the average follow-up time of 18 years, 46 men received a discharge diagnosis of depression. When the Cox proportional hazards model was adjusted for age, examination year, baseline socioeconomic status, alcohol consumption, smoking, maximal oxygen uptake and body mass index, there was no association between serum total n - 3 PUFAs and the risk of depression [relative risk (RR) in the highest compared to the lowest tertile 0.71, 95% confidence interval (CI): 0.38; 1.43]. Serum concentrations of n - 6 PUFAs, n6/n3 PUFA ratio, or individual fatty acids were not associated with the risk of severe depression, either.

CONCLUSIONS

We did not find evidence that serum n - 3 PUFA concentration or n - 6/n - 3 ratio would be associated with risk of severe depression in middle-aged Finnish men.

Do omega-6 and trans fatty acids play a role in complex regional pain syndrome? A pilot study

OBJECTIVES

The study aims to compare the omega-6 (n-6) and omega-3 (n-3) highly unsaturated fatty acids (HUFA), and trans fatty acid (trans FA) status of Complex Regional Pain Syndrome (CRPS) patients to pain-free controls.

DESIGN

Case control study. Setting. The setting was at a multidisciplinary rehabilitation center.

PATIENTS

Twenty patients that met the Budapest research diagnostic criteria for CRPS and 15 pain-free control subjects were included in this study. Outcome Measures. Fasting plasma fatty acids were collected from all participants. In CRPS patients, pain was assessed using the McGill Pain Questionnaire-Short Form. In addition, results from the perceived disability (Pain Disability Index), pain-related anxiety (Pain Anxiety Symptom Scale Short Form), depression (Center for Epidemiologic Studies Depression Scale Short Form), and quality of life (Short Form-36 [SF-36]) were evaluated.

RESULTS

Compared with controls, CRPS patients demonstrated elevated concentrations of n-6 HUFA and trans FA. No differences in n-3 HUFA concentrations were observed. Plasma concentrations of the n-6 HUFA docosatetraenoic acid were inversely correlated with the "vitality" section of the SF-36. Trans FA concentrations positively correlated with pain-related disability and anxiety.

CONCLUSION

These pilot data suggest that elevated n-6 HUFA and trans FA may play a role in CRPS pathogenesis. These findings should be replicated, and more research is needed to explore the clinical significance of low n-6 and trans FA diets with or without concurrent n-3 HUFA supplementation, for the management of CRPS.

Impact of administered bifidobacterium on murine host fatty acid composition

Recently, we reported that administration of Bifidobacteria resulted in increased concentrations of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in murine adipose tissue [1]. The objective of this study was to assess the impact of co-administration of Bifidobacterium breve NCIMB 702258 and the substrate for EPA, alpha-linolenic acid, on host fatty acid composition. alpha-Linolenic acid-supplemented diets (1%, wt/wt) were fed to mice (n = 8), with or without B. breve NCIMB 702258 (daily dose of 10(9) microorganisms) for 8 weeks. Two further groups received either supplement of B. breve alone or unsupplemented diet. Tissue fatty acid composition was assessed by gas liquid chromatography. Dietary supplementation of alpha-linolenic acid resulted in higher (P < 0.05) alpha-linolenic acid and EPA concentrations in liver and adipose tissue and lower (P < 0.05) arachidonic acid in liver, adipose tissue and brain compared with mice that did not receive alpha-linolenic acid. Supplementation with B. breve NCIMB 702258 in combination with alpha-linolenic acid resulted in elevated (P < 0.05) liver EPA concentrations compared with alpha-linolenic acid supplementation alone. Furthermore, the former group had higher (P < 0.05) DHA in brain compared with the latter group. These results suggest a role for interactions between fatty acids and commensals in the gastrointestinal tract. This interaction between administered microbes and fatty acids could result in a highly effective nutritional approach to the therapy of a variety of inflammatory and neurodegenerative conditions.

Marked elevations in pro-inflammatory polyunsaturated fatty acid metabolites in females with irritable bowel syndrome

Irritable bowel syndrome (IBS) is the most common functional gastrointestinal disorder referred to gastroenterologists. Although the pathophysiology remains unclear, accumulating evidence points to the presence of low-level immune activation both in the gut and systemically. Circulating polyunsaturated fatty acids (PUFA) have recently attracted attention as being altered in a variety of disease states. Arachidonic acid (AA), in particular, has been implicated in the development of a pro-inflammatory profile in a number of immune-related disorders. AA is the precursor of a number of important immunomodulatory eicosanoids, including prostaglandin E(2) (PGE(2)) and leukotriene B(4) (LTB(4)). We investigated the hypothesis that elevated plasma AA concentrations in plasma contribute to the proposed pro-inflammatory profile in IBS. Plasma AA and related PUFA were quantified by gas chromatography analysis in IBS patients and controls. Both PGE(2) and LTB(4) were measured in serum using commercially available ELISA assays. AA concentrations were elevated in our patient cohort compared with healthy controls. Moreover, we demonstrated that this disturbance in plasma AA concentrations leads to downstream elevations in eicosanoids. Together, our data identifies a novel proinflammatory mechanism in irritable bowel syndrome and also suggests that elevated arachidonic acid levels in plasma may serve as putative biological markers in this condition.

A critical review of human endotoxin administration as an experimental paradigm of depression

The syndrome called depression may represent the common final pathway at which different aetiopathogenic processes converge. One such aetiopathogenic process is innate immune system activation. Some depressed patients have increased levels of inflammatory cytokines and other immunologic abnormalities. It is not known whether immune system activation contributes to the pathogenesis of depressive symptoms. Supporting this possibility is the observation that in both rodents and humans, exogenous immune stimuli such as endotoxin can produce symptoms that resemble depression. A new approach to depression research would be to use immune stimuli to elicit depressive symptoms in humans. Here we review each of the symptoms elicited in humans by endotoxin administration, and compare this model to two other immune depression paradigms: interferon-alpha treatment and typhoid vaccine administration, to assess to what degree endotoxin administration represents a valid model of immune depression. We also review corresponding behavioral changes in rodents and the potential molecular pathways through which immune system activation produces each symptom.

Considerations regarding neuropsychiatric nutritional requirements for intakes of omega-3 highly unsaturated fatty acids

BACKGROUND

Adverse neurodevelopmental and neuropsychiatric outcomes have been established as signs of nutrient deficiencies and may be applicable to insufficient dietary intakes of omega-3 highly unsaturated fatty acids (n-3 HUFAs).

OBJECTIVE

Consider if statistical definitions for Daily Reference Intakes can be applied to n-3 HUFAs intakes during pregnancy for maternal and neurodevelopmental deficiencies.

DESIGN

Data were prospectively collected from women during pregnancy and children up to age 8 years participating in the Avon Longitudinal Study of Parents and Children (ALSPAC). Statistical analyses took social and lifestyle factors into account.

RESULTS

During pregnancy, n-3 HUFA intakes from seafood that putatively meet statistical definitions of an estimated average requirement ranged from 0.05 to 0.06 en% (111-139 mg/d/2000 Cal) for suboptimal fine motor control at 42 m and 0.065-0.08 en% (114-181 mg/d/2000 Cal) for suboptimal verbal IQ at age 8 years and 0.18-0.22 en% (389-486 mg/d/2000 Cal) for maternal depression at 32 weeks. Intakes of n-3 ranging from 0.2 to 0.41 en% (445-917 mg/d/2000 Cal) prevented both increased risk of maternal depression and adverse neurodevelopmental outcomes for children among 97.5% of the population. No upper limit for safety was found.

CONCLUSION

During pregnancy, a n-3 HUFA intake of 0.40 en% (900 mg/d/2000 Cal) from seafood is likely to meet the nutritional requirements for 97.5% of the mothers and children of this population. These considerations do not constitute DRI's for docosahexaenoic acid and n-3 HUFAs, but may contribute to their formulation.

Chain reactions: early-life stress alters the metabolic profile of plasma polyunsaturated fatty acids in adulthood

The rat maternal separation paradigm can be used to examine the biological consequences of early-life stress. Immunomodulatory polyunsaturated fatty acids (PUFAs) have recently attracted attention in the study of stress-related disorders. We established the plasma PUFA profile of maternally separated rodents compared to controls. Our results identify a proinflammatory PUFA profile as a persistent consequence of early-life stress and suggest new avenues of investigation in stress-related disorders.

Major depressive disorder and nutritional medicine: a review of monotherapies and adjuvant treatments

A literature review was conducted to examine the evidence for nutritional interventions in depression. It revealed a number of significant conclusions. Interestingly, more positive clinical trials were found to support adjuvant, rather than monotherapeutic, use of nutrients to treat depression. Much evidence exists in the area of adjuvant application of folic acid, S-adenosyl-methionine, omega-3, and L-tryptophan with antidepressants. Current evidence does not support omega-3 as an effective monotherapy to treat depression. However, this may be due, at least in part, to olive oil being used as the control intervention, some studies using docosahexaenoic acid alone or a higher docosahexaenoic acid to eicosapentaenoic acid ratio, and significant heterogeneity regarding depressive populations. Nevertheless, adjunctive prescription of omega-3 with antidepressants, or in people with dietary deficiency, may be beneficial. Inositol lacks evidence as an effective antidepressant and cannot be currently recommended. Evidence on the use of L-tryptophan for depression is inconclusive, and additional studies utilizing a more robust methodology are required.

Verapamil in treatment resistant depression: a role for the P-glycoprotein transporter?

INTRODUCTION

Verapamil is a calcium channel blocker that also inhibits the P-glycoprotein (Pgp) membrane transporter. We have found that administration of verapamil with a recognised antidepressant improves clinical outcome in previously treatment resistant cases despite the fact that verapamil does not possess inherent antidepressant activity. In this study we examined the hypothesis that the antidepressant-like effects of verapamil are mediated through its blockade of the Pgp transporter in the blood brain barrier (BBB).

METHODS

Following pre-treatment with verapamil (20 mg/kg) or a saline solution male Sprague Dawley rats were injected with imipramine (15 mg/kg). Two hours later, the animals were sacrificed, trunk blood collected and brain regions dissected out. High performance liquid chromatography (HPLC) was used to quantitate antidepressant drug concentrations in all samples.

RESULTS

Verapamil pre-treatment significantly elevated imipramine concentrations in all brain regions studied. The effect was most pronounced in the brainstem and frontal cortex where we observed in excess of a doubling in the brain region: serum ratios.

CONCLUSION

Our results verify inhibition of Pgp as a potential mechanism of action for verapamil during treatment resistant depression. The implications of these findings are discussed in the context of novel treatment strategies in depression.