Omega-3 polyunsaturated fatty acids for major depressive disorder

How fish consumption prevents the development of Major Depressive Disorder? A comprehensive review of the interplay between n-3 PUFAs, LTP and BDNF

MDD (major depressive disorder) is a highly prevalent mental disorder with a complex etiology involving behavioral and neurochemical factors as well as environmental stress. The interindividual variability in response to stress stimuli may be explained by processes such as long-term potentiation (LTP) and long-term depression (LTD). LTP can be described as the strengthening of synaptic transmission, which translates into more efficient cognitive performance and is regulated by brain-derived neurotrophic factor (BDNF), a protein responsible for promoting neural growth. It is found in high concentrations in the hippocampus, a part of the limbic system which is far less active in people with MDD. Omega-3 fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) not only contribute to structural and antioxidative functions but are essential for the maintenance of LTP and stable BDNF levels. This review explores the mechanisms and potential roles of omega-3 fatty acids in the prevention of MDD.

Krill oil treatment ameliorates lipid metabolism imbalance in chronic unpredicted mild stress-induced depression-like behavior in mice

The pathology of depression involves various factors including the interaction between genes and the environment. The deficiency of n-3 polyunsaturated fatty acids (n-3 PUFAs) in the brain and depressive symptoms are closely related. Krill oil contains abundant amounts of n-3 PUFAs incorporated in phosphatidylcholine. However, the effect of krill oil treatment on depression-like behaviors induced by chronic stress and its molecular mechanism in the brain remain poorly understood. Here, we used a chronic unpredictable mild stress (CUMS) model to evaluate the effect of krill oil on depression-like behaviors and explored its molecular mechanism through lipid metabolomics and mRNA profiles in the whole brain. We observed that CUMS-induced depression-like behaviors were ameliorated by krill oil supplementation in mice. The metabolism of glycerophospholipids and sphingolipids was disrupted by CUMS treatment, which were ameliorated after krill oil supplementation. Further analysis found that differently expressed genes after krill oil supplementation were mainly enriched in the membrane structures and neuroactive ligand-receptor interaction pathway, which may be responsible for the amelioration of CUMS-induced depression-like behaviors. Altogether, our results uncovered the relationship between lipid metabolism and CUMS, and provided new strategies for the prevention and treatment of depression.

Omega-3 fatty acids and blood-based biomarkers in Alzheimer's disease and mild cognitive impairment: A randomized placebo-controlled trial

BACKGROUND

Increased serum levels of pro-inflammatory biomarkers are consistently associated with cognitive decline. The omega-3 unsaturated fatty acids (n-3 PUFAs) had been linked to slowing cognitive decline due to their potential anti-inflammatory effects. To our knowledge, the different regiments of pure DHA, pure EPA, and their combination on various associated symptoms of dementia, including a mild form of cognitive impairment (MCI) and Alzheimer's disease (AD), have never been studied.

METHODS

This multisite, randomized, double-blind, placebo-controlled trial was conducted at two veteran's retirement centers and one medical center in central Taiwan between 2013 and 2015. 163 MCI or AD patients were randomly assigned to placebo (n = 40), docosahexaenoic acid (DHA, 0.7 g/day, n = 41), eicosapentaenoic acid (EPA, 1.6 g/day, n = 40), or EPA (0.8 g/day) + DHA (0.35 g/day) (n = 42) group for 24 months. The results were measured as the cognitive and functional abilities, biochemical, and inflammatory cytokines profiles. Chi-square tests, two-sample t-test, ANOVA, and linear mixedeffects models were conducted with p < 0.05.

RESULTS

131 (80%) participants had completed the trial with all cognitive, functional, and mood status assessments. The statistically significant difference between the placebo and treatment groups was not determined, concerning the changes in cognitive, functional, and mood status scores, the biochemical profiles, and inflammatory cytokines levels. However, EPA was found to reduce the C-C motif ligands 4 (CCL4) level (p < 0.001). Additionally, EPA could reduce the constructional praxis (p < 0.05) and spoken language ability scores (p < 0.01), and DHA also reduced the spoken language ability score (p < 0.05).

CONCLUSION

Overall, n-3 PUFAs supplements did not reduce cognitive, functional, and depressive symptom outcomes, but spoken language ability and constructional praxis subitems of ADAS-cog. These findings show that attention to clinical heterogeneity in dementia is crucial when studying nutrients interventions, such as n-3 PUFAs. In addition, with small effect size CCL4 is a better indicator than other inflammatory cytokines for EPA treatment response.

Role of n-3 long-chain polyunsaturated fatty acids in human nutrition and health: review of recent studies and recommendations

Long-chain (LC) n-3 polyunsaturated fatty acids (n-3 PUFAs), in particular docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are nutrients involved in many metabolic and physiological processes, and are referred to as n-3 LCPUFA. They have been extensively studied for their effects in human nutrition and health. This paper provides an overview on metabolism, sources, dietary intake, and status of n-3 LCPUFA. A summary of the dietary recommendations for n-3 LCPUFAs for different age groups as well as specific physiological conditions is provided. Evidence for n-3 LCPUFA in cardiovascular diseases, including new studies, is reviewed. Expert recommendations generally support a beneficial effect of n-3 LCPUFA on cardiovascular health and recommend a daily intake of 500 mg as DHA and EPA, or 1-2 servings of fish per week. The role of n-3 LCPUFA on brain health, in particular neurodegenerative disorders and depression, is reviewed. The evidence for beneficial effects of n-3 LCPUFA on neurodegenerative disorders is non-conclusive despite mechanistic support and observational data. Hence, no definite n-3 LCPUFA expert recommendations are made. Data for the beneficial effect of n-3 LCPUFA on depression are generally compelling. Expert recommendations have been established: 200-300 mg/day for depression; up to 1-2 g/day for major depressive disorder. Recent studies support a beneficial role of n-3 LCPUFAs in reducing the risk for premature birth, with a daily intake of 600-800 mg of DHA during pregnancy. Finally, international experts recently reviewed the scientific evidence on DHA and arachidonic acid (ARA) in infant nutrition and concluded that the totality of data support that infant and follow-on formulas should provide both DHA and ARA at levels similar to those in breast milk. In conclusion, the available scientific data support that dietary recommendations for n-3 LCPUFA should be established for the general population and for subjects with specific physiological conditions.

Brain Responses to Emotional Stimuli after Eicosapentaenoic Acid and Docosahexaenoic Acid Treatments in Major Depressive Disorder: Toward Personalized Medicine with Anti-Inflammatory Nutraceuticals

N-3 polyunsaturated fatty acid supplements improve the symptoms of major depressive disorder (MDD) in randomized-controlled trials and meta-analyses, with the higher efficacy from anti-inflammatory eicosapentaenoic acid (EPA) than brain-dominant docosahexaenoic acid (DHA). To investigate the specific brain mechanisms of the anti-inflammatory anti-depressant nutraceutical compounds, we recruited 24 MDD subjects in this double-blind, head-to-head study with a 12-week EPA or DHA treatment (clinical trial registration number: NCT03871088). The depression severity was assessed by Hamilton depression rating scale (HAM-D). Brain responses to emotional stimuli were measured by a 3-Tesla MRI. The correlation between HAM-D scores and brain responses also were tested. Compared to 18 healthy controls, the brain responses of untreated 24 MDD patients mainly revealed hypoactivity in the regions associated with emotion perception and emotion control when processing positive emotion. After treatment, more remitted MDD patients have been observed in the EPA as compared to the DHA groups. In addition, the EPA, but not DHA, treatment revealed increased activity in the regions associated with emotion perception and cognitive control when processing positive emotion. The correlation analysis further revealed negative correlation between HAM-D scores and brain responses in cognitive control regions. The results of this study may imply the compensatory brain responses of cognitive and emotion controls by EPA but not DHA and underpin personalized medicine with anti-inflammatory nutraceuticals toward depression treatments.

International Society for Nutritional Psychiatry Research Practice Guidelines for Omega-3 Fatty Acids in the Treatment of Major Depressive Disorder

Major depressive disorder (MDD) is a complex mental illness with unmet therapeutic needs. The antidepressant effects of ω-3 polyunsaturated fatty acids (n-3 PUFAs) have been widely reported. The subcommittee of the International Society for Nutritional Psychiatry Research organized an expert panel and conducted a literature review and a Delphi process to develop a consensus-based practice guideline for clinical use of n-3 PUFAs in MDD. The guideline focuses on 5 thematic areas: general concepts, acute treatment strategy, depression recurrence monitoring and prevention, use in special populations, and potential safety issues. The key practice guidelines contend that: (1) clinicians and other practitioners are advised to conduct a clinical interview to validate clinical diagnoses, physical conditions, and measurement-based psychopathological assessments in the therapeutic settings when recommending n-3 PUFAs in depression treatment; (2) with respect to formulation and dosage, both pure eicosapentaenoic acid (EPA) or an EPA/docosahexaenoic acid (DHA) combination of a ratio higher than 2 (EPA/DHA >2) are considered effective, and the recommended dosages should be 1-2 g of net EPA daily, from either pure EPA or an EPA/DHA (>2:1) formula; (3) the quality of n-3 PUFAs may affect therapeutic activity; and (4) potential adverse effects, such as gastrointestinal and dermatological conditions, should be monitored, as well as obtaining comprehensive metabolic panels. The expert consensus panel has agreed on using n-3 PUFAs in MDD treatment for pregnant women, children, and the elderly, and prevention in high-risk populations. Personalizing the clinical application of n-3 PUFAs in subgroups of MDD with a low Omega-3 Index or high levels of inflammatory markers might be regarded as areas that deserve future research.

Diet and Neurocognition in Mood Disorders - An Overview of the Overlooked

Bipolar disorder and major depression are associated with significant disability, morbidity, and reduced life expectancy. People with mood disorders have shown higher ratios of unhealthy lifestyle choices, including poor diet quality and suboptimal nutrition. Diet and nutrition impact on brain /mental health, but cognitive outcomes have been less researched in psychiatric disorders. Neurocognitive dysfunction is a major driver of social dysfunction and a therapeutic target in mood disorders, although effective cognitive-enhancers are currently lacking. This narrative review aimed to assess the potential cognitive benefits of dietary and nutritional interventions in subjects diagnosed with mood disorders. Eight clinical trials with nutrients were identified, whereas none involved dietary interventions. Efficacy to improve select cognitive deficits has been reported, but results are either preliminary or inconsistent. Methodological recommendations for future cognition trials in the field are advanced. Current evidence and future views are discussed from the perspectives of precision medicine, clinical staging, nutritional psychiatry, and the brain-gut-microbiota axis.

Mitochondrial Bioenergetics in Brain Following Ozone Exposure in Rats Maintained on Coconut, Fish and Olive Oil-Rich Diets

Dietary supplementation with omega-3 and omega-6 fatty acids offer cardioprotection against air pollution, but these protections have not been established in the brain. We tested whether diets rich in omega-3 or -6 fatty acids offered neuroprotective benefits, by measuring mitochondrial complex enzyme I, II and IV activities and oxidative stress measures in the frontal cortex, cerebellum, hypothalamus, and hippocampus of male rats that were fed either a normal diet, or a diet enriched with fish oil olive oil, or coconut oil followed by exposure to either filtered air or ozone (0.8 ppm) for 4 h/day for 2 days. Results show that mitochondrial complex I enzyme activity was significantly decreased in the cerebellum, hypothalamus and hippocampus by diets. Complex II enzyme activity was significantly lower in frontal cortex and cerebellum of rats maintained on all test diets. Complex IV enzyme activity was significantly lower in the frontal cortex, hypothalamus and hippocampus of animals maintained on fish oil. Ozone exposure decreased complex I and II activity in the cerebellum of rats maintained on the normal diet, an effect blocked by diet treatments. While diet and ozone have no apparent influence on endogenous reactive oxygen species production, they do affect antioxidant levels in the brain. Fish oil was the only diet that ozone exposure did not alter. Microglial morphology and GFAP immunoreactivity were assessed across diet groups; results indicated that fish oil consistently decreased reactive microglia in the hypothalamus and hippocampus. These results indicate that acute ozone exposure alters mitochondrial bioenergetics in brain and co-treatment with omega-6 and omega-3 fatty acids alleviate some adverse effects within the brain.

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.

Genetic polymorphisms of FADS1, FADS2, and FADS3 and fatty acid profiles in subjects received methadone maintenance therapy

Abnormal fatty acid metabolism and the related enzymes had been observed to be associated with psychiatric disorders. We investigated FADS gene family genetic polymorphisms and variations of lipid profiles in patients with heroin dependence receiving 6-month methadone maintenance therapy (MMT). We recruited 89 MMT drug abusers and analyzed 3 tag single nucleotide polymorphisms (SNPs) from Fatty acid desaturases (FADS), FADS1, FADS2 and FADS3. The fatty acid profiles of erythrocyte membranes were analyzed based on genetic variations. Six-month MMT therapy were significantly associated with decreased C20: 5n3 and C22:4n6 levels in the whole group of drug abusers. The decreases of C22: 6n3 after MMT therapy were associated with specific genetic variations, including FADS1 C/C, FADS2 T/T and FADS3 C/C genotypes. The variations on n3 and n6 PUFA composition were significantly shown in different alleles of FADS in MMT drug abusers. Further studies are needed to elucidate the role of fatty acid metabolism on rehabilitation by MMT.

Five potential therapeutic agents as antidepressants: a brief review and future directions

Despite the availability of numerous antidepressants, many patients with depression do not show adequate response. The therapeutic lag between drug administration and onset of clinical improvement observed with conventional antidepressants has led to a need for antidepressants with a novel mechanism of action. Recently, five such agents, including acetyl-L-carnitine, scopolamine, ω-3 polyunsaturated fatty acids, ketamine, and selective 5-HT7 serotonin receptor antagonists, have gained interest as potential antidepressants with enhanced symptom control, improved tolerability, and faster onset of action compared to conventional antidepressants. This review provides an update and critical examination of these five novel therapeutic agents as potential antidepressants.

Safety and tolerability of prescription omega-3 fatty acids: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Omega-3 fatty acids [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] are widely recommended for health promotion. Over the last decade, prescription omega-3 fatty acid products (RxOME3FAs) have been approved for medical indications. Nonetheless, there is no comprehensive analysis of safety and tolerability of RxOME3FAs so far.

METHODS

A systematic review of randomized controlled trials (RCTs) was carried out based on searches in six electronic databases. The studies involving marketed RxOME3FA products were included, and adverse-effect data were extracted for meta-analysis. Subgroup analysis and meta-regression were conducted to explore the sources of potential heterogeneity.

RESULTS

Among the 21 included RCTs (total 24,460 participants; 12,750 from RxOME3FA treatment cohort and 11,710 from control cohort), there was no definite evidence of any RxOME3FA-emerging serious adverse event. Compared with the control group, RxOME3FAs were associated with more treatment-related dysgeusia (fishy taste; p = 0.011) and skin abnormalities (eruption, itching, exanthema, or eczema; p < 0.001). Besides, RxOME3FAs had mild adverse effects upon some non-lipid laboratory measurements [elevated fasting blood sugar (p = 0.005); elevated alanine transaminase (p = 0.022); elevated blood urea nitrogen (p = 0.047); decreased hemoglobin (p = 0.002); decreased hematocrit (p = 0.009)]. Subgroup analysis revealed that EPA/DHA combination products were associated with more treatment-related gastrointestinal adverse events [eructation (belching; p = 0.010); nausea (p = 0.044)] and low-density lipoprotein cholesterol elevation (p = 0.009; difference in means = 4.106mg/dL).

CONCLUSION

RxOME3FAs are generally safe and well tolerated but not free of adverse effects. Post-marketing surveillance and observational studies are still necessary to identify long-term adverse effects and to confirm the safety and tolerability profiles of RxOME3FAs.

Eicosapentaenoic and docosahexaenoic acids have different effects on peripheral phospholipase A2 gene expressions in acute depressed patients

INTRODUCTION

Omega-3 polyunsaturated fatty acids (PUFAs) have been proven critical in the development and management of major depressive disorder (MDD) by a number of epidemiological, clinical and preclinical studies, but the molecular mechanisms underlying this therapeutic action are yet to be understood. Although eicosapentaenoic acid (EPA) seems to be the active component of omega-3 PUFAs' antidepressant effects, the biological research about the difference of specific genetic regulations between EPA and docosahexaenoic acid (DHA), the two main components of omega-3 PUFAs, is still lacking in human subjects.

METHODS

We conducted a 12-week randomized-controlled trial comparing the effects of EPA and DHA on gene expressions of phospholipase A2 (cPLA2) and cyclooxygenase-2 (COX2), serotonin transporter (5HTT), and Tryptophan hydroxylase 2 (TPH-2) in 27 MDD patients. In addition, the erythrocyte PUFA compositions and the candidate gene expressions were also compared between these 27 MDD patients and 22 healthy controls.

RESULTS

EPA was associated with a significant decrease in HAM-D scores (CI: -13 to -21, p<0.001) and significant increases in erythrocyte levels of EPA (CI: +1.0% to +2.9%, p=0.001) and DHA (CI: +2.9% to +5.6%, p=0.007). DHA treatment was associated with a significant decrease in HAM-D scores (CI: -6 to -14, p<0.001) and a significant increase in DHA levels (CI: +0.2% to +2.3%, p=0.047), but not of EPA levels. The cPLA2 gene expression levels were significantly increased in patients received EPA (1.9 folds, p=0.038), but not DHA (1.08 folds, p=0.92). There was a tendency for both EPA and DHA groups to decrease COX-2 gene expressions. The gene expressions of COX-2, cPLA2, TPH-2 and 5-HTT did not differ between MDD cases and healthy controls.

CONCLUSIONS

EPA differentiates from DHA in clinical antidepressant efficacy and in upregulating cPLA2 gene regulations, which supports the clinical observation showing the superiority of EPA's antidepressant effects.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02615405.

Polyunsaturated fatty acids and inflammatory markers in major depressive episodes during pregnancy

INTRODUCTION

Prenatal depression (PND) is a common psychiatric disorder in pregnant women and leads to psychosocial dysfunction, high suicidal rate, and adverse childcare. Patients with PND have omega-3 polyunsaturated fatty acid (omega-3 or n-3 PUFAs) deficits, which might link to chronic low-grade inflammatory process and the pathophysiological mechanisms of depression. In this case-control study, we examined the levels of PUFAs and inflammatory cytokines in PND.

METHOD

Blood samples were obtained and analyzed from 16 healthy controls and 17 depressed cases (PND group) diagnosed with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV). Independent sample t-test and correlation analysis were performed with Statistical Package for the Social Sciences (SPSS) logistics correlation analysis.

RESULTS

PND group had significantly lower levels of total n-3 (p=0.026), docosahexaenoic acid (DHA) (p=0.020) and eicosapentaenoic (EPA) (p=0.019) but a higher omega-6 (n-6)/n-3 PUFAs ratio (p=0.007) and tumor necrosis factor alpha (TNF-α) (p=0.016) level. Moreover, the duration of current PND episodes were also significantly correlated with DHA, EPA, n-3 PUFAs, n-6/n-3 ratio and TNF-α. In terms of PUFAs and cytokine levels, only DHA was inversely correlated with TNF-α.

CONCLUSION

PND is significantly associated with lower DHA, EPA, and total n-3 PUFAs levels and an increased n-6/n-3 PUFAs ratio, while the duration of PND is associated with lower levels of n-3 PUFAs, including DHA and EPA. The correlation of PUFAs levels with depression and TNF-α level grant further investigation into the inflammatory process underlying PND, mediated by PUFAs.

Efficacy of adding nutritional supplements in unipolar depression: A systematic review and meta-analysis

In this article, we aimed to assess the efficacy of adjunctive administration of nutritional supplements to antidepressants by means of a systematic review and meta-analysis. The supplements included were inositol, vitamin D, folic acid, vitamin B12, S-adenosyl-L-methionine (SAMe), omega-3 polyunsaturated fatty acids (n-3 PUFA) and zinc. A structured database search (MEDLINE, EBSCO, CENTRAL, Web of Science) was performed using terms for the respective substances in conjunction with terms for depression and the mode of treatment ("add-on" OR "adjunctive" OR "augmentation"). Meta-analyses, randomized controlled trials (RCTs) and non-randomized comparative studies that investigated the supplements as an add-on in the treatment of clinically diagnosed MDD were included. Agents had to be added to an existing antidepressant regime (augmentation) or started simultaneously with the antidepressant (acceleration). For n-3 PUFAs, folic acid and zinc, new meta-analyses were performed as part of this work. Our meta-analyses of 10 articles on n-3 PUFAs and four on zinc support their efficacy. For folic acid, our meta-analysis does not support efficacy. For n-3 PUFAs, sensitivity analysis showed no difference between acceleration and augmentation designs, but significant differences between individuals with or without comorbidities. For the remaining substances, only a few RCTs were available. The preliminary data on inositol was negative, while one RCT for vitamin D demonstrated positive results. For vitamin B12 one and for SAMe two RCTs and a few open trials are available reporting positive and mixed results. To summarize, for most of the substances, the available data is not yet sufficient or inconclusive.

Polyunsaturated Fatty Acids in Perinatal Depression: A Systematic Review and Meta-analysis

BACKGROUND

Omega-3 (or n-3) polyunsaturated fatty acids (PUFAs) are promising antidepressant treatments for perinatal depression (PND) because of supporting evidence from clinical trials, the advantage in safety, and their anti-inflammatory and neuroplastic effects. Although several observational studies have shown n-3 PUFA deficits in women with PND, the results of individual PUFAs from different studies were inconsistent.

METHODS

This systematic review and meta-analysis aims to compare the levels of PUFA indices, including eicosapentaenoic acid, docosahexaenoic acid, arachidonic acid, total n-3, total n-6, and the n-6/n-3 ratio between women with PND and healthy control subjects. The meta-analysis included 12 eligible studies available as of December 2016. The effect sizes were synthesized by using a random effects model. In addition, we performed subgroup analysis for the PUFA levels in patients with prenatal and postnatal depression, both of which were compared with healthy control subjects.

RESULTS

There were significantly lower levels of total n-3 PUFAs and docosahexaenoic acid and significantly increased n-6/n-3 ratios in PND patients. In the subgroup analyses, there were significantly lower levels of n-3 PUFAs, eicosapentaenoic acid, and docosahexaenoic acid in women with prenatal depression. The n-6/n-3 ratio was significantly increased in both prenatal and postnatal depression subgroups.

CONCLUSIONS

Our meta-analysis consolidates the important role of n-3 PUFAs in PND. Nutritional medicine is an important strategy to improve the effectiveness of treatment for depression, and our findings provide the strong rationale to conduct clinical trials to test the therapeutic and prophylactic effects of n-3 PUFAs in PND.

Polyunsaturated fatty acids levels and initial presentation of somatic symptoms induced by interferon-alpha therapy in patients with chronic hepatitis C viral infection

OBJECTIVES

Somatic symptoms are common in depressive disorder and are similar to sickness behaviors due to inflammatory activation after cytokine administration. Omega-3 polyunsaturated fatty acids (PUFAs) are natural anti-inflammatory agents and may reduce inflammation-induced behavioral changes. The aim of this study was to investigate the role of PUFAs on the development of somatic symptoms and depression in patients of hepatitis C virus infection (HCV) receiving interferon-alpha therapy (IFN-α) in a prospective manner.

METHODS

In this 24-week, prospective cohort study, 43 patients with chronic HCV ongoing IFN-α therapy were assessed with the mini-international neuropsychiatric interview for major depressive episodes and neurotoxicity rating scale (NRS) for somatic symptoms.

RESULTS

One-third later developed IFN-α-induced depression (depression (DEP) group). As compared to subjects without depression, DEP group had higher NRS scores (P < 0.001), lower eicosapentaenoic acid (EPA) levels (P = 0.038) at week 2. Somatic symptoms, regardless of painful/non-painful characteristics, had positive association with arachidonic acid (P < 0.05), and negative association with EPA (P < 0.05).

CONCLUSION

This study implies that early intervention with omega-3 PUFAs might be a promising strategy to prevent depression and somatic symptoms in patients receiving cytokine therapy.

Serum n-3 polyunsaturated fatty acids are inversely associated with longitudinal changes in depressive symptoms during pregnancy

BACKGROUNDS

N-3 polyunsaturated fatty acids (PUFAs) have been hypothesised to be protective for depression during pregnancy. However, there are few data and no consensus regarding this association. In this line, we aim to evaluate if the concentration of n-3 and n-6 PUFAs, and their ratio, are associated with depressive symptoms throughout pregnancy.

METHOD

A prospective cohort of 172 Brazilian women was followed at 5-13th, 20-26th and 30-36th weeks of gestation. The presence of depressive symptoms was evaluated using the Edinburgh Postnatal Depression Scale (EPDS) at each pregnancy trimester. Depression was defined as an EPDS score ≥11. The concentrations of n-3 [α-linolenic acid; eicosapentaenoic acid (EPA); docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA)] and n-6 PUFAs [linoleic acid; γ linolenic acid; eicosadienoic acid; eicosatrienoic acid; arachidonic acid; docosatetraenoic acid and docosapentaenoic acid] were expressed as absolute (μg/ml) values. The total n-6/n-3 ratio was calculated. Statistical analyses were performed using univariate and adjusted random intercept logistic model for each fatty acid (FA) considering the longitudinal nature of data. Covariates were selected as potential confounders based on their biological plausibility of having an association with the concentration of FA and depressive symptoms during pregnancy.

RESULTS

The prevalence of depressive symptoms was high in all pregnancy trimesters (1st = 33.7%; 2nd = 18.9%; 3rd = 17.4%). We did not find differences in means FA concentrations by depressive symptom classification, for each follow-up visit. The women presented a 5% decrease in the odds of having depressive symptoms for each one-week increase in the gestational age. As individual women progressed through pregnancy, higher concentrations of EPA (odds ratio (OR) = 0.92; 95% CI: 0.86-0.99), DHA (OR = 0.96; 95% CI: 0.93-0.99), DPA (OR = 0.87; 95% CI: 0.77-0.99) and total n-3 (OR = 0.98; 95% CI: 0.96-0.99) were associated with a lower odds of depressive symptoms, while higher total n-6/n-3 ratio were associated with greater odds of depressive symptoms (OR = 1.40; 95% CI: 1.09-1.79). We detected a decrease in the probability of depressive symptoms as concentrations of total n-3 FA, α-linolenic acid, DPA, and DHA increased. We also observed a sharper decline for women with initial greater chance of depressive symptoms compared with those with lower chance of having these symptoms.

CONCLUSIONS

We found a high prevalence of depressive symptoms in low-income Brazilian pregnant women and no significant associations between n-6 FA and depressive symptoms. Lower serum concentrations of DHA, EPA and DPA and a higher n-6/n-3 ratio at each pregnancy trimester were associated with higher odds of depressive symptoms throughout pregnancy.

Fish oil supplementation attenuates neuroinflammation and alleviates depressive-like behavior in rats submitted to repeated lipopolysaccharide

PURPOSE

Depression is frequently associated with inflammation, whereas omega-3 polyunsaturated fatty acids (PUFAs) primarily found in fish oil possess anti-inflammatory properties. Although converging studies suggest an antidepressant effect of PUFAs, there is limited evidence directly linking the neuro-immune modulating features of PUFAs to the antidepressant actions.

METHODS

Therefore, we assessed the effects of fish oil (FO) supplementation on behavioral changes, inflammatory cytokine expression and oxidative reactions in frontal cortex and hippocampus of rats following repeated peripheral immune challenge by lipopolysaccharide (LPS) for 2 weeks (500 μg/kg every other day).

RESULTS

Repeated LPS administration induced the rats to a depressive-like state and increased mRNA expression of pro-inflammatory cytokines, including 1L-1β, 1L-6 and TNF-α, in frontal cortex and hippocampus. FO supplementation attenuated the LPS-induced abnormal behavior and brain inflammatory response. Concurrent with the antidepressant action, FO also reduced LPS-induced oxidative reactions and neural apoptosis in the rat brain, as evidenced by decreased malondialdehyde (MDA) production, increased catalase activities and inhibited pro-apoptotic protein Bax mRNA expression. In addition, FO inhibited activation of NF-κB and iNOS induced by LPS. Interestingly, we found FO suppressed the activation of the inflammasome NLRP3 and ionotropic purinergic receptor P2X7R evoked by LPS, suggesting a potential anti-inflammatory mechanism for PUFAs. Besides, FO also restored the LPS-induced neurochemical disturbance, especially the balance between serotonin and kynurenine branches of tryptophan metabolism, which is tightly associated with depression.

CONCLUSIONS

These findings provide novel insights into the antidepressant action of PUFAs and further strengthen the link between inflammation and depression.

The importance of n-6/n-3 fatty acids ratio in the major depressive disorder

This review aims to clarify the relation between the ratio of omega-6 to omega-3 fatty acids and the development of depression. It is explained how these fatty acids are involved in the production of eicosanoids and how these fatty acids can affect the membrane fluidity, by their incorporation into membrane phospholipids. In addition, it is described how omega-3 derivatives are shown to regulate gene transcription. In view of the pathophysiology of depression, the mechanisms of how an altered ratio of omega-6 to omega-3 could be involved in depression are discussed. Possible mechanisms could include an increased production of pro-inflammatory cytokines, which can activate the HPA axis and a changed membrane fluidity, which potentially affects membrane bound enzymes, ion channels, receptor activity and neurotransmitter binding. In view of clinical trials, it is also discussed whether omega-3 supplementation could have a beneficial effect in the treatment of depressive patient. There are strong indications that an increased ratio of membrane omega-6 to omega-3 is involved in the pathogenesis of depression and so far, omega-3 supplementation has shown positive effects in clinical trials.

Mapping inflammation onto mood: Inflammatory mediators of anhedonia

Evidence supports inflammatory involvement in mood and cognitive symptoms across psychiatric, neurological and medical disorders; however, inflammation is not a sensitive or specific characteristic of these diagnoses. The National Institute of Mental Health Research Domain Criteria (RDoC) ask for a shift away from symptom-based diagnoses toward a transdiagnostic neurobiological focus in the study of brain illnesses. The RDoC matrix may provide a useful framework for integrating the effects of inflammation on brain function. Based on preclinical and clinical findings, relevant relationships span negative and positive valence systems, cognitive systems, systems for social processes and arousal/regulatory systems. As an exemplar, we consider the psychopathological domain of anhedonia, conceptualizing the relevance of inflammation (e.g., cellular immunity) and downstream processes (e.g., indoleamine 2,3-dioxygenase activation and oxidative inactivation of tetrahydrobiopterin) across RDoC units of analysis (e.g., catecholamine neurotransmitter molecules, nucleus accumbens medium spiny neuronal cells, dopaminergic mesolimbic and mesocortical reward circuits, animal paradigms, etc.). We discuss implications across illnesses affecting the brain, including infection, major depressive disorder, stroke, Alzheimer's disease and type 2 diabetes.

Nutrition, psychoneuroimmunology and depression: the therapeutic implications of omega-3 fatty acids in interferon-α-induced depression

The unmet need of current pharmacotherapy and the high occurrence of somatic symptoms and physical illness in depression imply that the ‘monoamine hypothesis’ is insufficient in approaching the aetiology of depression. Clinically, depressed patients manifest higher levels of inflammatory biomarkers, while proinflammatory cytokines induce neuropsychiatric symptoms (sickness behaviour) as well as major depressive episodes. Indeed, accumulating evidence suggests that inflammation dysregulation plays an important role in the pathophysiology of depression. Biological mechanisms that link inflammation to neuropsychiatric symptoms are vital in the understanding of the “mind-body” interface. IFN-α-induced depression is the most powerful support for the inflammation theory of depression. This clinical observation provides an excellent model for depression research. By comparing subjects with and without major depression induced by the cytokine treatment, statistical powers could be largely increased by reducing phenotypic variation (homogeneity in aetiological factors). In addition, the anti-inflammatory pathway has recently become an important topic in looking for new antidepressant therapies. For example, anti-inflammatory compounds, omega-3 polyunsaturated fatty acids (omega-3 PUFAs or n-3 PUFAs), have been found to be associated with the development and treatment for depression in human and animal models. Here I review recent epidemiological studies, cross-sectional and longitudinal case-controlled studies, interventional clinical trials, as well as basic animal and cellular studies to prove the linkage among omega-3 PUFAs, inflammation, and depression.

Omega-3 fatty acids and the treatment of depression: a review of scientific evidence

Depression is a condition in which an individual feels lethargic, irritable, and guilty, has difficulty and trouble, no enjoyment in life, mood swings, sometimes suicidal ideation and thoughts, and loss of pleasure in activities. There are hundreds of millions of individuals suffering from major depression disorder all over the world. This leads to a considerable portion of the economy going for treatment as large amounts of money are spent on drugs every year. Pharmaceutical drugs are not very effective and they also have side effects that compound the problem. There are number of studies which shows that omega-3 fatty acids are proving to be very effective against the treatment of major depression disorder and other psychiatric disorders. However, the data regarding the efficacy of omega-3 fatty acids in depression treatment are conflicted. This article reviews the recent research showing the relation between omega-3 fatty acids and depression. The roles of the omega-3 fatty acids in the treatment of depression are being studied with increased pace in the last decade due to heightened prevalence of depression. It is emphasized that omega-3 fatty acids have no record of associated side effects, which deserves greater attention for further research.

Omega-3 Polyunsaturated Fatty Acids in Prevention of Mood and Anxiety Disorders

Psychiatric disorders in general, and major depression and anxiety disorders in particular, account for a large burden of disability, morbidity and premature mortality worldwide. Omega-3 polyunsaturated fatty acids (PUFAs) have a range of neurobiological activities in modulation of neurotransmitters, anti-inflammation, anti-oxidation and neuroplasticity, which could contribute to psychotropic effects. Here we reviewed recent research on the benefits of omega-3 PUFA supplements in prevention against major depression, bipolar disorders, interferon-α-induced depression patients with chronic hepatitis C viral infection, and posttraumatic stress disorder. The biological mechanisms underlying omega-3 PUFAs'psychotropic effects are proposed and reviewed. Nutrition is a modifiable environmental factor that might be important in prevention medicine, which have been applied for many years in the secondary prevention of heart disease with omega-3 PUFAs. This review extends the notion that nutrition in psychiatry is a modifiable environmental factor and calls for more researches on prospective clinical studies to justify the preventive application of omega-3 PUFAs in daily practice.

Aripiprazole augmentation versus antidepressant switching for patients with major depressive disorder: A 6-week, randomized, rater-blinded, prospective study

No study has directly compared the efficacy and tolerability of aripiprazole augmentation (AA) and antidepressant switching (SW) in patients with major depressive disorder (MDD). This is the first 6-week, randomized, rater-blinded, direct comparison study between AA and SW in outpatients. An inadequate response to antidepressants was defined as a total score ≥ 14 on the Hamilton Depression Rating Scale-item 17 (HDRS-17) despite adequate antidepressant dosage for at least 6 weeks in the current depressive episode. The primary endpoint was change in the total score of the Montgomery-Åsberg Depression Rating Scale (MADRS) from baseline to the end of treatment. Secondary efficacy measures included the response and remission rates as priori defined at the end of treatment: changes in total scores of the HDRS-17, Iowa Fatigue Scale (IFS), and Sheehan Disability Scale (SDS) from baseline to the end of treatment and the proportion of patients who scored 1 or 2 on the Clinical Global Impression-Improvement Score (CGI-I) at the end of treatment. Tolerability was assessed with the Barnes Akathisia Rating Scale (BARS) and Arizona Sexual dysfunction scale (ASEX), and the numbers of adverse events were compared between the two groups. A total of 101 patients were randomized to either AA (n = 52) or SW (n = 49). The mean change in the MADRS score from baseline was significantly higher in the AA, with a difference in magnitude of -8.7 (p < 0.0001). The intergroup difference was first evident in week 2. The numbers of responders (p = 0.0086) and remitters (p = 0.0005) were also significantly higher in the AA (60% and 54%, respectively) compared with the SW (32.6% and 19.6%, respectively). On most secondary endpoints, AA showed better clinical outcomes compared to SW. The tolerability profiles were comparable between the two groups. Overall, AA yielded potentially beneficial clinical outcomes compared to SW. Given the methodological shortcomings of the present study, adequately powered, more rigorously controlled clinical trials are strongly warranted to confirm the present findings.

Inflamed moods: a review of the interactions between inflammation and mood disorders

Mood disorders have been recognized by the World Health Organization (WHO) as the leading cause of disability worldwide. Notwithstanding the established efficacy of conventional mood agents, many treated individuals continue to remain treatment refractory and/or exhibit clinically significant residual symptoms, cognitive dysfunction, and psychosocial impairment. Therefore, a priority research and clinical agenda is to identify pathophysiological mechanisms subserving mood disorders to improve therapeutic efficacy. During the past decade, inflammation has been revisited as an important etiologic factor of mood disorders. Therefore, the purpose of this synthetic review is threefold: 1) to review the evidence for an association between inflammation and mood disorders, 2) to discuss potential pathophysiologic mechanisms that may explain this association and 3) to present novel therapeutic options currently being investigated that target the inflammatory-mood pathway. Accumulating evidence implicates inflammation as a critical mediator in the pathophysiology of mood disorders. Indeed, elevated levels of pro-inflammatory cytokines have been repeatedly demonstrated in both major depressive disorder (MDD) and bipolar disorder (BD) patients. Further, the induction of a pro-inflammatory state in healthy or medically ill subjects induces 'sickness behavior' resembling depressive symptomatology. Potential mechanisms involved include, but are not limited to, direct effects of pro-inflammatory cytokines on monoamine levels, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, pathologic microglial cell activation, impaired neuroplasticity and structural and functional brain changes. Anti-inflammatory agents, such as acetyl-salicylic acid (ASA), celecoxib, anti-TNF-α agents, minocycline, curcumin and omega-3 fatty acids, are being investigated for use in mood disorders. Current evidence shows improved outcomes in mood disorder patients when anti-inflammatory agents are used as an adjunct to conventional therapy; however, further research is needed to establish the therapeutic benefit and appropriate dosage.

Nutritional psychiatry research: an emerging discipline and its intersection with global urbanization, environmental challenges and the evolutionary mismatch

In 21st-century public health, rapid urbanization and mental health disorders are a growing global concern. The relationship between diet, brain function and the risk of mental disorders has been the subject of intense research in recent years. In this review, we examine some of the potential socioeconomic and environmental challenges detracting from the traditional dietary patterns that might otherwise support positive mental health. In the context of urban expansion, climate change, cultural and technological changes and the global industrialization and ultraprocessing of food, findings related to nutrition and mental health are connected to some of the most pressing issues of our time. The research is also of relevance to matters of biophysiological anthropology. We explore some aspects of a potential evolutionary mismatch between our ancestral past (Paleolithic, Neolithic) and the contemporary nutritional environment. Changes related to dietary acid load, advanced glycation end products and microbiota (via dietary choices and cooking practices) may be of relevance to depression, anxiety and other mental disorders. In particular, the results of emerging studies demonstrate the importance of prenatal and early childhood dietary practices within the developmental origins of health and disease concept. There is still much work to be done before these population studies and their mirrored advances in bench research can provide translation to clinical medicine and public health policy. However, the clear message is that in the midst of a looming global epidemic, we ignore nutrition at our peril.

A review of current evidence for acetyl-l-carnitine in the treatment of depression

Despite numerous antidepressants available, many patients with depression do not achieve adequate response rendering needs for novel antidepressants with different mechanism of actions. Acetyl-l-carnitine (ALC) is a potential antidepressant with novel mechanism of action because of its diverse functions related with neuroplasticity. Animal and cellular models suggest that ALC's neuroplasiticity effect, membrane modulation, and neurotransmitter regulation may play an important role in treatment of depression. Four randomized clinical studies (RCT) demonstrated the superior efficacy of ALC over placebo (PBO) in patients with depression. Two RCTs showed its superior efficacy over PBO in dysthymic disorder, and 2 other RCTs showed that it is equally effective as fluoxetine and amisulpride in treatment of dysthymic disorder. ALC was also effective in improving depressive symptoms in patients with fibromyalgia and minimal hepatic encephalopathy. It was also found to be equally tolerable to PBO and better tolerable than fluoxetine and amisulpride. In conclusion, ALC may be potentially effective and tolerable next treatment option with novel action mechanisms for patients with depression, in particular older population and patients with comorbid medical conditions who are vulnerable to adverse events from antidepressants. However, more clinical trial data with adequately-powered, well-designed and advanced methodology will be mandatory to conclude whether ALC as a monotherapy or augmentation agent may be efficacious and clinically beneficial for depression.