Eicosapentaenoic acid appears to be the key omega-3 fatty acid component associated with efficacy in major depressive disorder: a critique of Bloch and Hannestad and updated meta-analysis

Clinical impacts of n-3 fatty acids supplementation on depression symptoms: an umbrella review of meta-analyses

Several meta-analyses investigating the efficacy of n-3 PUFA in alleviating depression symptoms have reported conflicting findings. In the present study, we aimed to perform an umbrella meta-analysis to provide a definite conclusion. A comprehensive systematic search of PubMed, Scopus, Embase, Web of Science and Cochrane Central Library was performed up to June 2021. Meta-analysis studies evaluating the effects of n-3 PUFA on depression symptoms were included. The quality of the included meta-analyses was assessed using AMSTAR questionnaire. Out of 101 studies, twenty-two studies with twenty-six effect sizes (ES) were eligible for inclusion. Sixteen ES showed significant improving effect of n-3 supplementation on depression symptoms among which eleven ES had small ES. The other studies observed no significant effect. Available evidence suggests that n-3 PUFA (EPA, DHA) supplementation could be considered as an effective add-on therapeutic approach in relieving depression symptoms.

The role of polyunsaturated fatty acids in the neurobiology of major depressive disorder and suicide risk

Long-chain polyunsaturated fatty acids (LC-PUFAs) are obtained from diet or derived from essential shorter-chain fatty acids, and are crucial for brain development and functioning. Fundamentally, LC-PUFAs' neurobiological effects derive from their physicochemical characteristics, including length and double bond configuration, which differentiate LC-PUFA species and give rise to functional differences between n(omega)-3 and n-6 LC-PUFAs. LC-PUFA imbalances are implicated in psychiatric disorders, including major depression and suicide risk. Dietary intake and genetic variants in enzymes involved in biosynthesis of LC-PUFAs from shorter chain fatty acids influence LC-PUFA status. Domains impacted by LC-PUFAs include 1) cell signaling, 2) inflammation, and 3) bioenergetics. 1) As major constituents of lipid bilayers, LC-PUFAs are determinants of cell membrane properties of viscosity and order, affecting lipid rafts, which play a role in regulation of membrane-bound proteins involved in cell-cell signaling, including monoaminergic receptors and transporters. 2) The n-3:n-6 LC-PUFA balance profoundly influences inflammation. Generally, metabolic products of n-6 LC-PUFAs (eicosanoids) are pro-inflammatory, while those of n-3 LC-PUFAs (docosanoids) participate in the resolution of inflammation. Additionally, n-3 LC-PUFAs suppress microglial activation and the ensuing proinflammatory cascade. 3) N-3 LC-PUFAs in the inner mitochondrial membrane affect oxidative stress, suppressing production of and scavenging reactive oxygen species (ROS), with neuroprotective benefits. Until now, this wealth of knowledge about LC-PUFA biomechanisms has not been adequately tapped to develop translational studies of LC-PUFA clinical effects in humans. Future studies integrating neurobiological mechanisms with clinical outcomes may suggest ways to identify depressed individuals most likely to respond to n-3 LC-PUFA supplementation, and mechanistic research may generate new treatment strategies.

Omega-3 as an adjuvant in the treatment eating and psychological symptoms in patients with anorexia nervosa: a systematic review and meta-analyses

BACKGROUND

This study was carried out to assess the effects of omega-3 supplementation as an adjunct treatment for eating and psychological symptoms in patients with anorexia nervosa.

METHODS

We conducted a systematic review of the literature using the terms 'anorexia nervosa' AND 'Fatty Acids, Omega-3'. Five randomised controlled trials with a total of 144 participants, published between 2003 and 2022, were included.

RESULTS

The effects of supplementation of omega-3 on anxiety were standardised mean difference (SMD) 0.79, 95% confidence interval (CI) -0.08 to 1.66; p = 0.08; I² = 3%; two studies, 33 participants; moderate quality of evidence. For depression, the supplementation of omega-3 was SMD: 0.22, 95% CI: -0.50 to 0.93; p = 0.18; I² = 45%; two studies, 33 participants; moderate quality of evidence. For obsessive-compulsive disorder, the supplementation of omega-3 was SMD: -0.22, 95% CI: -0.70 to 2.25; p = 0.36; I² = 0%; three studies, 32 participants; low quality of evidence.

CONCLUSION

This research showed that regardless of dose, time or, if associated with other components, the use of omega-3 supplementations as an adjuvant treatment showed no evidence of effect in eating and psychological symptoms in patients with anorexia nervosa.

Anti-Inflammatory Treatment Efficacy in Major Depressive Disorder: A Systematic Review of Meta-Analyses

PURPOSE

Immune imbalances in major depressive disorder (MDD) have been targeted by anti-inflammatory treatment approaches in clinical trials to increase responsiveness to therapy. However, even after several meta-analyses, no translation of evidence into clinical practice has taken place. We performed a systematic review to evaluate meta-analytic evidence of randomized controlled trials on the use of anti-inflammatory agents for MDD to summarize efficacy estimates and elucidate shortcomings.

METHODS

Pooled effect estimates and heterogeneity indices were primary outcomes. Characteristics of the included meta-analyses were extracted. Scientific quality of meta-analyses was assessed using the Revised Assessment of Multiple Systematic Reviews (R-AMSTAR).

RESULTS

N=20 meta-analyses met the eligibility criteria. Study characteristics like outcome scales, composition of patient populations, and add-on or monotherapy regimen varied very little for celecoxib studies, varied little for minocycline studies, and were rather variable for omega 3 fatty acids studies. R-AMSTAR scores ranged from 26 to 39 out of 44 points indicating variable quality, where a comprehensive literature search was the strongest and the consideration of scientific quality in the conclusions was the weakest domain across all meta-analyses. For minocycline and celecoxib, superiority was demonstrated with medium to large effect size with substantial heterogeneity and with large to very large effect size with negligible heterogeneity, respectively. For omega 3 fatty acids, superiority was also demonstrated with mainly small and medium effect sizes with substantial heterogeneity. However, for minocycline and omega 3 fatty acids, non-significant meta-analyses were found also.

CONCLUSION

Even in our synthesized approach, no clear recommendations could be derived on the use of anti-inflammatory treatment for MDD due to several critical aspects like heterogeneity, diversity of patient populations, treatment regimen, and outcomes, and limited scientific quality. However, we observed clear inter-substance differences with meta-analytic evidence being strongest for celecoxib and weakest for omega 3 fatty acids.

Omega-3 Polyunsaturated Fatty Acids Supplementation Alleviate Anxiety Rather Than Depressive Symptoms Among First-Diagnosed, Drug-Naïve Major Depressive Disorder Patients: A Randomized Clinical Trial

Background

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) augmentation of antidepressants has shown great potential in the prevention and treatment of major depressive disorders (MDD).

Objective

To investigate the effect of n-3 PUFAs plus venlafaxine in patients with first-diagnosed, drug-naïve depression.

Method

A total of 72 outpatients with first-diagnosed depression were recruited. The daily dose of 2.4 g/day n-3 PUFAs or placebo plus venlafaxine was used for over 12 weeks. The outcomes were assessed by the Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), Beck depression inventory (BDI), and Self-rating anxiety scale (SAS).

Results

Both groups exhibited improvement on clinical characteristics at week 4 and week 12 compared with baseline. The rate of responders for anxiety in n-3 PUFAs group (44.44%) was significantly higher than that in placebo group (21.21%) at week 4 (χ² = 4.182, p = 0.041), while week 12 did not show a difference (χ² = 0.900, p = 0.343). The rate of responders for depression at both week 4 (χ² = 0.261, p = 0.609) and week 12 (χ² = 1.443, p = 0.230) showed no significant difference between two groups. Further analysis found that Childhood Trauma Questionnaire (CTQ) had positive correlation with HAMA (r = 0.301, p = 0.012), SAS (r = 0.246, p = 0.015), HAMD (r = 0.252, p = 0.038) and BDI (r = 0.233, p = 0.022) with Pearson correlation analysis. Social Support Rating Scale (SSRS) had negative correlation with SAS (r = -0.244, p = 0.015) and BDI (r = -0.365, p = 0.000).

Conclusion

This trial found that n-3 PUFAs supplementation in favor of venlafaxine alleviated the anxiety symptoms rather than depressive symptoms at the early stage of treatment (4 weeks) for first-diagnosed, drug-naïve depressed patients. However, the advantage disappeared in long-term treatment. Furthermore, childhood abuse and social support are closely related to the clinical and biological characteristics of depression. Both childhood trauma and lack of social support might be predictors of poor prognosis in depression.

Clinical Trial Registration

[clinicaltrials.gov], identifier [NCT03295708].

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.

Effects of n-3 Polyunsaturated Fatty Acid Supplementation in the Prevention and Treatment of Depressive Disorders-A Systematic Review and Meta-Analysis

N-3 polyunsaturated fatty acids (PUFAs) have been suggested to affect depressive disorders. This review aims to determine the effect of n-3 PUFAs on depressive symptoms in people with or without diagnosed depression. Medline, PsycINFO, and Cochrane CENTRAL databases were searched for randomized controlled trials (RCTs) assessing the association between n-3 PUFAs and depressive symptoms or disorders as outcomes. A random-effects meta-analysis of standardized mean difference (SMD) with 95% confidence intervals (CI) was performed. Twenty-five studies (7682 participants) were included. Our meta-analysis (20 studies) indicated that n-3 PUFA supplementation lowered depressive symptomology as compared with placebo: SMD = −0.34, 95% CI: −0.55, −0.12, I² = 86%, n = 5836, but a possible publication bias cannot be ruled out. Subgroup analyses indicated no statistically significant difference by treatment duration of <12 vs. ≥12 weeks, presence of comorbidity, or severity of depressive symptoms. Nevertheless, beneficial effects were seen in the subgroups of studies with longer treatment duration and with no depression and mild to moderate depression. Subgroup analysis by eicosapentaenoic acid (EPA) dosage revealed differences in favor of the lower EPA dosage. Sensitivity analysis including studies with low risk of bias seems to confirm the overall result. Supplementation of n-3 PUFA appears to have a modest beneficial effect on depressive symptomology, although the quality of evidence is still insufficient.

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.

Effect of Supplemental Enteral Fish Oil on the Development of Psychological Complications in Critically Ill Multiple-Trauma Patients: 6 Months' Follow-Up

BACKGROUND

Posttraumatic stress disorder (PTSD) is common in intensive care unit (ICU) patients. Defic it intake of ω-3 polyuns aturated fatty ac ids (PUFAs) may be as sociated with developm ent of PTSD.

METHODS

This study randomized mechanically ventilated patients suffering from multiple trauma (n = 150) into 2 groups: a study and a control group that received enteral feeding with or without fish oil. Fifty-one patients were interviewed 6 months after discharge from the ICU. Psychometric parameters of PTSD were assessed by questionnaires. The fatty acid composition of erythrocyte membranes was performed by homogenization of the cells in hexane-isopropanol.

RESULTS

No differences were found in baseline characteristics between the groups. Erythrocyte membrane composition showed significantly higher concentrations of ω-3 fatty acids in the study group. Anxiety and depression symptoms were correlated with an increase in eicosapentaenoic acid (EPA) on days 4 and 8 for depression and EPA on day 4 and docosahexaenoic acid (DHA) on day 8 for anxiety. Total ω-3 content was positively correlated with anxiety and depression as well. An inverse correlation was found between DHA and EPA in the treatment group and with the total ω-3 and DHA in the control group for the Brief Illness Perceptions Questionnaire.

CONCLUSION

Administration of an ω-3 PUFA-enriched diet during the ICU stay did not prevent development of PTSD in trauma patients 6 months after discharge from ICU.

Diet, Stress and Mental Health

Introduction: There has long been an interest in the effects of diet on mental health, and the interaction of the two with stress; however, the nature of these relationships is not well understood. Although associations between diet, obesity and the related metabolic syndrome (MetS), stress, and mental disorders exist, causal pathways have not been established. Methods: We reviewed the literature on the relationship between diet, stress, obesity and psychiatric disorders related to stress. Results: Diet and obesity can affect mood through direct effects, or stress-related mental disorders could lead to changes in diet habits that affect weight. Alternatively, common factors such as stress or predisposition could lead to both obesity and stress-related mental disorders, such as depression and posttraumatic stress disorder (PTSD). Specific aspects of diet can lead to acute changes in mood as well as stimulate inflammation, which has led to efforts to assess polyunsaturated fats (PUFA) as a treatment for depression. Bidirectional relationships between these different factors are also likely. Finally, there has been increased attention recently on the relationship between the gut and the brain, with the realization that the gut microbiome has an influence on brain function and probably also mood and behavior, introducing another way diet can influence mental health and disorders. Brain areas and neurotransmitters and neuropeptides that are involved in both mood and appetite likely play a role in mediating this relationship. Conclusions: Understanding the relationship between diet, stress and mood and behavior could have important implications for the treatment of both stress-related mental disorders and obesity.

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.

Bidirectional longitudinal associations of omega-3 polyunsaturated fatty acid plasma levels with depressive disorders

BACKGROUND

Temporality of the association of low omega-3 polyunsaturated fatty acid (n-3 PUFA) plasma levels with depression remains questionable. To determine the underlying nature of these associations, this study examined the bidirectional longitudinal associations of n-3 PUFA plasma levels with (presence, onset and course of) depressive disorders and symptoms.

METHODS

Baseline (n = 2912, 28.6% with current depressive disorder) and 6-year follow-up data (n = 1966, 13.0% with current depressive disorder) of the Netherlands Study of Depression and Anxiety (NESDA) were used. Depression diagnoses and symptoms were based on psychiatric interviews and self-report questionnaires. N-3 PUFA levels (ratio of total fatty acids (mmol%)), were assessed using nuclear magnetic resonance.

RESULTS

Using two waves of data, n-3 PUFA levels were lower among depressed persons, as compared to healthy controls (Beta = -0.047, SE = 0.011, p < .001). Nevertheless, baseline n-3 PUFA levels were not consistently associated with subsequent change in depressive symptoms, onset or remission of depressive disorders over 6 years. Furthermore, the difference in n-3 PUFA levels detected at baseline between depressed and non-depressed participants tended to dissipate over 6 years (depression-by-time estimate: p = .011). Finally, subjects depressed both at baseline and at 6-year follow up had consistently lower n-3 PUFA levels over the entire follow-up as compared to those who had never been depressed. Change in depressive disorders across waves was not consistently accompanied by change in n-3 PUFA levels over time.

LIMITATIONS

No data on intermediate time points and EPA levels were available.

CONCLUSIONS

Despite significant cross-sectional associations between n-3 PUFA plasma levels and depressive disorders and severity, this 6-year longitudinal study could not confirm an uni- or bidirectional association over time. The association between depression and n-3 PUFA plasma levels is unlikely to be causal.

Omega-3 fatty-acids modulate symptoms of depressive disorder, serum levels of omega-3 fatty acids and omega-6/omega-3 ratio in children. A randomized, double-blind and controlled trial

Omega-3 fatty acids (FA) are a promising adjuvant therapy for depressive disorder (DD) in adults. The objective of this single-centre, randomized, double-blind and controlled study was to compare the efficacy of an omega-3 FA fish oil emulsion with a control oil emulsion alongside the standard treatment for depression in children and adolescents suffering from DD or mixed anxiety depressive disorder (MADD) and to analyse serum fatty acid levels and omega-6/omega-3 FA ratio before and after the intervention. 60 children were randomised 1:1 to the intervention (Om3) or active comparator (Om6) groups. Children's Depression Inventory (CDI) ratings were performed at the baseline, every 2 weeks for a 12-week intervention period. Significant reductions in CDI scores were observed after 6 and 12 weeks of intervention in the Om3 group and in the DD subgroup compared to the Om6 and MADD subgroup. Ratio of omega-6/omega-3 decreased in Om3 but not in Om6 from 24.2/1 to 7.6/1 after 6 weeks, EPA, omega-6/omega-3 ratio, but not DHA, correlated with severity symptoms at the baseline. An omega-3 fatty acid rich fish oil emulsion may be an effective adjuvant supplement during the treatment of depressive disorders in children. Trial registration: ISRCTN 81655012.

Brain eicosapentaenoic acid metabolism as a lead for novel therapeutics in major depression

The results of several meta-analyses suggest that eicosapentaenoic acid (EPA) supplementation is therapeutic in managing the symptoms of major depression. It was previously assumed that because EPA is extremely low in the brain it did not cross the blood-brain barrier and any therapeutic effects it exerted would be via the periphery. However, more recent studies have established that EPA does enter the brain, but is rapidly metabolised following entry. While EPA does not accumulate within the brain, it is present in microglia and homeostatic mechanisms may regulate its esterification to phospholipids that serve important roles in cell signaling. Furthermore, a variety of signaling molecules from EPA have been described in the periphery and they have the potential to exert effects within the brain. If EPA is confirmed to be therapeutic in major depression as a result of adequately powered randomized clinical trials, future research on brain EPA metabolism could lead to the discovery of novel targets for treating or preventing major depression.

Plasma estradiol levels and antidepressant effects of omega-3 fatty acids in pregnant women

BACKGROUND

Omega-3 polyunsaturated fatty acids (PUFAs) reduce depressive symptoms through an anti-inflammatory effect, and injection of both omega-3 PUFAs and estradiol (E2) induces antidepressant-like effects in rats by regulating the expression of inflammatory cytokines. The aims of this study were to examine the association of increased E2 during pregnancy with depressive symptoms and with inflammatory cytokines in women who were and were not supplemented with omega-3 PUFAs.

METHODS

Pregnant women with Edinburgh Postnatal Depression Scale scores ≥9 were recruited at 12-24 weeks of gestation. The participants were randomly assigned to receive 1800 mg omega-3 fatty acids (containing 1206 mg eicosapentaenoic acid [EPA]) or placebo for 12 weeks. E2, omega-3 PUFAs, high-sensitivity C-reactive protein, interleukin-6, and adiponectin were measured at baseline and at the 12-week follow-up. Multivariable regression analyses were conducted to examine the association of the changes of E2 and omega-3 PUFAs with the changes in depressive symptoms and with the changes of inflammatory cytokines at follow-up by intervention group.

RESULTS

Of the 108 participants in the trial, 100 (92.6%) completed the follow-up assessment including blood sampling. Multivariable regression analyses revealed that the increase of EPA and E2 was significantly associated with a decrease in depressive symptoms among the participants assigned to the omega-3 group, but not among those assigned to the placebo group. Neither E2 nor any PUFAs were associated with a change in inflammatory cytokines.

CONCLUSION

Supplementation with EPA and increased levels of E2 during pregnancy might function together to alleviate antenatal depression through a mechanism other than anti-inflammation.

Lipids and Suicide Risk

In the search for biomarkers and modifiable risk factors for suicide, lipid status has garnered considerable interest, although the lipid-suicide connection is not without controversy. Major categories of lipids that have been reported as germane to suicide include sterols and polyunsaturated fatty acids (PUFAs). Research concerning lipid effects on mood and suicide risk includes epidemiologic approaches, cohort studies, and clinical trials. In general, current evidence suggests that higher n-3 relative to n-6 PUFA intake may have beneficial effects on depression and suicide risk, particularly in women, while low cholesterol may be detrimental in both sexes. Additionally, low estrogen in women has been associated with suicide attempts, whereas high androgen loads may contribute to the higher suicide completion rate in men. Basic and translational research provides strong evidence for several potential mechanisms that have been implicated in depression and suicide. Firstly, PUFAs, cholesterol, and estrogen can interact to influence structure and function of membrane microdomains ("lipid rafts"), with potential regulatory effects on inflammation and signal transduction, including monoaminergic signaling. Secondly, PUFAs bind to and activate peroxisome proliferator-activated receptors (PPARs), nuclear receptors that regulate gene expression, with resultant effects on inflammation and bioenergetics. Thirdly, PUFAs are both a target for and a hormetic regulator of oxidative stress. Critical to a greater understanding of lipid status as a suicide risk predictor and treatment target will be studies that map genomic and phenotypic characteristics of individuals whose emotional state is affected most by lipid status. Also important will be a more nuanced understanding of lipid-lipid interactions and the differential roles of lipid subclasses on suicide risk.

Depression as an Immunometabolic Disorder: Exploring Shared Pharmacotherapeutics with Cardiovascular Disease

Modern times have seen depression and cardiovascular disease (CVD) become notorious public health concerns, corresponding to alarming proportions of morbidity, mortality, decreased quality of life, and economic costs. Expanding comprehension of the pathogenesis of depression as an immunometabolic disorder has identified numerous pathophysiologic phenomena in common with CVD, including chronic inflammation, insulin resistance, and oxidative stress. These shared components could be exploited to offer improved alternatives in the joint management of these conditions. Abundant preclinical and clinical data on the impact of established treatments for CVD in the management of depression have allowed for potential candidates to be proposed for the joint management of depression and CVD as immunometabolic disorders. However, a large proportion of the clinical investigation currently available exhibits marked methodological flaws which preclude the formulation of concrete recommendations in many cases. This situation may be a reflection of pervasive problems present in clinical research in psychiatry, especially pertaining to study homogeneity. Therefore, further high-quality research is essential in the future in this regard.

Activation of WNT and CREB signaling pathways in human neuronal cells in response to the Omega-3 fatty acid docosahexaenoic acid (DHA)

A subset of individuals with major depressive disorder (MDD) elects treatment with complementary and alternative medicines (CAMs), including the omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Previous studies in rodents suggest that DHA modulates neurodevelopmental processes, including adult neurogenesis and neuroplasticity, but the molecular and cellular mechanisms of DHA's potential therapeutic effect in the context of human neurobiology have not been well established. Here we sought to address this knowledge gap by investigating the effects of DHA using human iPSC-derived neural progenitor cells (NPCs) and post-mitotic neurons using pathway-selective reporter genes, multiplexed mRNA expression profiling, and a panel of metabolism-based viability assays. Finally, real-time, live-cell imaging was employed to monitor neurite outgrowth upon DHA treatment. Overall, these studies showed that DHA treatment (0-50 μM) significantly upregulated both WNT and CREB signaling pathways in human neuronal cells in a dose-dependent manner with 2- to 3-fold increases in pathway activation. Additionally, we observed that DHA treatment enhanced survival of iPSC-derived NPCs and differentiation of post-mitotic neurons with live-cell imaging, revealing increased neurite outgrowth with DHA treatment within 24 h. Taken together, this study provides evidence that DHA treatment activates critical pathways regulating neuroplasticity, which may contribute to enhanced neuronal cell viability and neuronal connectivity. The extent to which these pathways represent molecular mechanisms underlying the potential beneficial effects of omega-3 fatty acids in MDD and other brain disorders merits further investigation.

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

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

A Randomized Placebo-Controlled Trial of Omega-3 and Sertraline in Depressed Patients With or at Risk for Coronary Heart Disease

OBJECTIVE

Studies of depressed psychiatric patients have suggested that antidepressant efficacy can be increased by adding eicosapentaenoic acid (EPA), one of the omega-3 fatty acids found in fish oils. The purpose of this study was to determine whether the addition of EPA improves the response to sertraline in depressed patients with or at high risk for coronary heart disease (CHD).

METHODS

Between May 2014 and June 2018, 144 patients with DSM-5 major depressive disorder seen at the Washington University School of Medicine with or at high risk for CHD were randomized to receive either 50 mg/d of sertraline and 2 g/d of EPA or 50 mg/d of sertraline and corn oil placebo capsules for 10 weeks. The Beck Depression Inventory II (BDI-II) was the primary outcome measure.

RESULTS

After 10 weeks of treatment, there were no differences between the arms on the mean baseline-adjusted BDI-II (placebo, 10.3; EPA, 12.1; P = .22), the 17-item Hamilton Depression Rating Scale (placebo, 7.2; EPA, 8.0; P = .40), or the 10-week remission rate (BDI-II score ≤ 8: placebo, 50.6%; EPA, 46.7%; odds ratio = 0.85; 95% CI, 0.43 to 1.68; P = .63).

CONCLUSIONS

Augmentation of sertraline with 2 g/d of EPA for 10 weeks did not result in greater improvement in depressive symptoms compared to sertraline and corn oil placebo in patients with major depressive disorder and CHD or CHD risk factors. Identifying the characteristics of cardiac patients whose depression may benefit from omega-3 and clarifying the pathways linking omega-3 to improvement in depression symptoms are important directions for future research.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02021669; FDA IND registration number: 121107.

Relationship between polyunsaturated fatty acid and eating disorders: Systematic review and meta-analysis

OBJECTIVES

Eating disorders result in poor nutrition, poor physical conditions and even suicidality and mortality. Although polyunsaturated fatty acids (PUFAs) have attracted attention in the emerging field of nutritional psychiatry, their role in eating disorders remains unknown. This meta-analysis investigates the differences of PUFA levels between patients with eating disorders and healthy controls, and the potentially beneficial effects of PUFAs in such patients.

METHODS

We conducted a systematic literature search and meta-analysis under the random effects model.

RESULT

Eleven studies were included in the current meta-analysis. Compared with controls, 379 patients with eating disorders had significantly higher plasma levels of alpha-linolenic acid, eicosapentaenoic acid, stearidonic acid, osbond acid, palmitoleic acid, oleic acid, and total omega-3 fatty acids; and lower levels of total omega-6 fatty acids and omega-6/omega-3 ratio. Eating disorders were associated with significantly higher red blood cell membrane levels of palmitoleic acid and oleic acid and lower levels of adrenic acid, arachidonic acid, and total omega-6 fatty acids. In addition, PUFA supplements were associated with a benefit to body weight outcomes but not disease severity and mood symptoms in interventional trials.

DISCUSSION

This meta-analysis indicates abnormal levels of PUFAs in peripheral blood tissues in patients with eating disorders. The relationship between PUFAs and eating disorders should be interpreted cautiously considering the specific lipid metabolism under starvation state. To investigate the role of PUFAs on psychopathological and therapeutic effects in eating disorders, further larger clinical studies are warranted.

Relationship Between Polyunsaturated Fatty Acids and Psychopathology in the NEURAPRO Clinical Trial

Background: Deficiencies in membrane polyunsaturated fatty acids (PUFA) such as omega-3 (n-3) fatty acids are thought to contribute to the pathophysiological processes underlying psychotic disorders. Emerging evidence suggests that the levels of PUFA are related to clinical symptoms but significant heterogeneity exists between studies. Here, we investigated associations of membrane PUFA with clinical symptoms and functioning in a large sample of individuals at ultra-high risk (UHR) for psychosis. Methods: A total of 285 participants of the NEURAPRO clinical trial were investigated for erythrocyte PUFA levels, including the n-3 index, n-6/n-3 PUFA ratio, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Severity of general psychopathology [Brief Psychiatric Rating Scale (BPRS)], psychotic symptoms (BPRS psychosis subscale), negative symptoms [Scale for the Assessment of Negative Symptoms (SANS)], manic symptoms [Young Mania Rating Scale (YMRS)], depressive symptoms [Montgomery Asberg Depression Rating Scale (MADRS)], and functioning [Social and Occupational Functioning Scale (SOFAS), Global Functioning Social (GF-S) and Role (GF-R) scales] were assessed concurrently. Partial correlation taking into account the effects of gender, age, and smoking was used to examine the relationship between PUFAs and symptoms severity. Results: The n-3 index negatively correlated with the severity of general psychopathology, psychotic symptoms, depressive symptoms, and manic symptoms. The n-6/n-3 PUFA ratio positively correlated with severity of psychotic and depressive symptoms. The n-3 PUFA DHA negatively correlated with the severity of general psychopathology, positive, manic, and depressive symptoms. EPA negatively correlated with manic symptoms. Nervonic acid, an n-9 monounsaturated fatty acid, positively correlated with general psychopathology, positive and negative symptoms, depressive symptoms, and manic symptoms. The long-chain saturated fatty acid tetracosanoic acid positively correlated with general psychopathology, positive, manic, and depressive symptoms. Conclusions: Partially consistent with a previous study, psychotic symptoms, depressive symptoms, and symptoms of mania were associated with several classes of FAs in the present study. These findings support the relevance of membrane fatty acids for the onset of psychotic symptoms and indicate that FAs should be further evaluated as biomarkers in the UHR for psychosis group. Clinical Trial Registration: ANZCTR, identifier: 12608000475347.

Regulation of monoamine transporters and receptors by lipid microdomains: implications for depression

Lipid microdomains ("rafts") are dynamic, nanoscale regions of the plasma membrane enriched in cholesterol and glycosphingolipids, that possess distinctive physicochemical properties including higher order than the surrounding membrane. Lipid microdomain integrity is thought to affect neurotransmitter signaling by regulating membrane-bound protein signaling. Among the proteins potentially affected are monoaminergic receptors and transporters. As dysfunction of monoaminergic neurotransmission is implicated in major depressive disorder and other neuropsychiatric conditions, interactions with lipid microdomains may be of clinical importance. This systematic review evaluates what is known about the molecular relationships of monoamine transporter and receptor regulation to lipid microdomains. The PubMed/MeSH database was searched for original studies published in English through August 2017 concerning relationships between lipid microdomains and serotonin, dopamine and norepinephrine transporters and receptors. Fifty-seven publications were identified and assessed. Strong evidence implicates lipid microdomains in the regulation of serotonin and norepinephrine transporters; serotonin 1A, 2A, 3A, and 7A receptors; and dopamine D1 and β2 adrenergic receptors. Results were conflicting or more complex regarding lipid microdomain associations with the dopamine transporter, D2, D3, and D5 receptors; and negative with respect to β1 adrenergic receptors. Indirect evidence suggests that antidepressants, lipid-lowering drugs, and polyunsaturated fatty acids may exert effects on depression and suicide by altering the lipid milieu, thereby affecting monoaminergic transporter and receptor signaling. The lipid composition of membrane subdomains is involved in localization and trafficking of specific monoaminergic receptors and transporters. Elucidating precise mechanisms whereby lipid microdomains modulate monoamine neurotransmission in clinical contexts can have critical implications for pharmacotherapeutic targeting.

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.

Food for Mood: Relevance of Nutritional Omega-3 Fatty Acids for Depression and Anxiety

The central nervous system (CNS) has the highest concentration of lipids in the organism after adipose tissue. Among these lipids, the brain is particularly enriched with polyunsaturated fatty acids (PUFAs) represented by the omega-6 (ω6) and omega-3 (ω3) series. These PUFAs include arachidonic acid (AA) and docosahexaenoic acid (DHA), respectively. PUFAs have received substantial attention as being relevant to many brain diseases, including anxiety and depression. This review addresses an important question in the area of nutritional neuroscience regarding the importance of ω3 PUFAs in the prevention and/or treatment of neuropsychiatric diseases, mainly depression and anxiety. In particular, it focuses on clinical and experimental data linking dietary intake of ω3 PUFAs and depression or anxiety. In particular, we will discuss recent experimental data highlighting how ω3 PUFAs can modulate neurobiological processes involved in the pathophysiology of anxiety and depression. Potential mechanisms involved in the neuroprotective and corrective activity of ω3 PUFAs in the brain are discussed, in particular the sensing activity of free fatty acid receptors and the activity of the PUFAs-derived endocannabinoid system and the hypothalamic-pituitary-adrenal axis.

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.

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

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

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.

Immune-based strategies for mood disorders: facts and challenges

INTRODUCTION

Inflammation seems to play a role in the pathophysiology of mood disorders, including major depressive disorder (MDD) and bipolar disorder (BD). In the last years several studies have shown increased levels of inflammatory and/or immune markers in patients with mood disorders. Accordingly, the immune system has become a target of interest for the development of biomarkers and therapeutics for mood disorders. Areas covered: Here, we review the evidence showing low-grade inflammation in mood disorders and the studies evaluating immune-based strategies for the treatment of these conditions. Expert commentary: Clinical trials with non-steroidal anti-inflammatory drugs, polyunsaturated acids, N-acetylcysteine, anti-cytokines, physical activity and probiotics have provided promising results in terms of antidepressant efficacy in patients with MDD and BD. Regarding stem cells, only studies with animal models have been performed so far with interesting pre-clinical results. Due to the preliminary nature of the results, most of the clinical studies need to be replicated and/or confirmed in larger clinical settings, embracing the highly heterogeneous pathophysiology of mood disorders.

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.

Maternal dietary n-6 polyunsaturated fatty acid deprivation does not exacerbate post-weaning reductions in arachidonic acid and its mediators in the mouse hippocampus

OBJECTIVES

The present study examines how lowering maternal dietary n-6 polyunsaturated fatty acids (PUFA) (starting from pregnancy) compared to offspring (starting from post-weaning) affect the levels of n-6 and n-3 fatty acids in phospholipids (PL) and lipid mediators in the hippocampus of mice.

METHODS

Pregnant mice were randomly assigned to consume either a deprived or an adequate n-6 PUFA diet during pregnancy and lactation (maternal exposure). On postnatal day (PND) 21, half of the male pups were weaned onto the same diet as their dams, and the other half were switched to the other diet for 9 weeks (offspring exposure). At PND 84, upon head-focused high-energy microwave irradiation, hippocampi were collected for PL fatty acid and lipid mediator analyses.

RESULTS

Arachidonic acid (ARA) concentrations were significantly decreased in both total PL and PL fractions, while eicosapentaenoic acid (EPA) concentrations were increased only in PL fractions upon n-6 PUFA deprivation of offspring, regardless of maternal exposure. Several ARA-derived eicosanoids were reduced, while some of the EPA-derived eicosanoids were elevated by n-6 PUFA deprivation in offspring. There was no effect of diet on docosahexaenoic acid (DHA) or DHA-derived docosanoids concentrations under either maternal or offspring exposure.

DISCUSSION

These results indicate that the maternal exposure to dietary n-6 PUFA may not be as important as the offspring exposure in regulating hippocampal ARA and some lipid mediators. Results from this study will be helpful in the design of experiments aimed at testing the significance of altering brain ARA levels over different stages of life.

Omega-6 to omega-3 polyunsaturated fatty acid ratio and subsequent mood disorders in young people with at-risk mental states: a 7-year longitudinal study

While cross-sectional studies suggest that patients with mood disorders have a higher ratio of omega-6 to omega-3 polyunsaturated fatty acids (PUFAs) and lower levels of omega-3 PUFAs, it is unknown if a high n-6/3 ratio indicates vulnerability for depression. We tested this hypothesis in a 7-year follow-up study of young individuals with an ultra-high risk (UHR) phenotype. We conducted a secondary analysis of the Vienna omega-3 study, a longitudinal study of omega-3 PUFAs in individuals at UHR for psychosis (n=69). Levels of n-6 and n-3 PUFAs were measured in the phosphatidylethanolamine fraction of erythrocyte membranes at intake into the study. Mood disorder diagnosis was ascertained with the Structured Clinical Interview for DSM-IV-TR and confirmed by review of medical records and interviews of caregivers. A higher n-6/3 PUFA ratio at baseline predicted mood disorders in UHR individuals over a 7-year (median) follow-up (odds ratio=1.89, 95% CI=1.075-3.338, P=0.03). This association remained significant after adjustment for age, gender, smoking, severity of depressive symptoms at baseline and n-3 supplementation. Consistent results were obtained for individual PUFAs, including lower levels of eicosapentaenoic acid and docosahexaenoic acid. The predictive capacity of these findings was specific to mood disorders as no associations were found for any other psychiatric disorder. To our knowledge, our data provide the first prospective evidence that the n-6/3 PUFA ratio is associated with an increased risk for mood disorders in young people exhibiting an UHR phenotype. These findings may have important implications for treatment and risk stratification beyond clinical characteristics.

Emulsified omega-3 fatty-acids modulate the symptoms of depressive disorder in children and adolescents: a pilot study

BACKGROUND

The prevalence of mood disorders in children is a growing global concern. Omega-3 fatty acids (FA) are emerging as a promising adjuvant therapy for depressive disorder (DD) in paediatric patients. The primary objective of this pilot, single-centre, randomized, double-blind controlled study was to compare the efficacy of an Omega-3 FA fish oil emulsion with a control oil emulsion alongside standard treatment for depressive symptoms in children and adolescents suffering from depressive disorder (DD) and mixed anxiety depressive disorder (MADD).

METHODS

38 children (12 patients were treated and diagnosed for at least 1 month before enrolment, 26 patients were first-time diagnosed as DD) aged 11-17 years were randomised 1:1 to the intervention (Omega-3 FA, 19 patients) or active comparator (Omega-6 FA, 19 patients) groups. Children's depression inventory (CDI) ratings were performed at baseline, every 2 weeks for a 12-week intervention period and at 4-week post-intervention. 35 patients (17 in Omega-3 and 18 in Omega-6 groups) who completed the whole intervention period were evaluated. Patients from Omega-3 group were stratified according to diagnosis into two subgroups (DD-10/17 and mixed anxiety depressive disorder (MADD)-7/17 patients) and in the Omega-6 group into DD-10/18 and MADD-8/18 patients. Groups were evaluated separately. Differences between-groups were tested with the Student´s t test or non-parametric Mann-Whitney U test. Two-way ANOVA with repeated measures and Friedman test were used to analyse the Treatment effect for response in CDI score. p < 0.05 was considered significant in all statistical analyses.

RESULTS

Significant reductions in CDI scores in 35 analysed patients who completed 12 weeks intervention were observed after 12 weeks of intervention only in the Omega-3 group (p = 0.034). After stratification to depressive disorder and mixed anxiety depressive disorder subgroups, the DD subgroup receiving the Omega-3 FA fish oil showed statistically greater improvement (score reduction after 8 week treatment of -9.1 CDI, p = 0.0001) when compared to the MADD subgroup (score reduction after 8 week treatment -4.24 CDI, p = 0.271).

CONCLUSIONS

CDI scores were reduced in the Omega-3 group and the depression subgroup had greater improvement than the mixed depressive/anxiety group. An Omega-3 fatty acid rich fish oil emulsion may be an effective adjuvant supplement during the treatment of depressive disorders in children. Trial registration ISRCTN81655012.

Soluble epoxide hydrolase as a therapeutic target for pain, inflammatory and neurodegenerative diseases

Eicosanoids are biologically active lipid signaling molecules derived from polyunsaturated fatty acids. Many of the actions of eicosanoid metabolites formed by cyclooxygenase and lipoxygenase enzymes have been characterized, however, the epoxy-fatty acids (EpFAs) formed by cytochrome P450 enzymes are newly described by comparison. The EpFA metabolites modulate a diverse set of physiologic functions that include inflammation and nociception among others. Regulation of EpFAs occurs primarily via release, biosynthesis and enzymatic transformation by the soluble epoxide hydrolase (sEH). Targeting sEH with small molecule inhibitors has enabled observation of the biological activity of the EpFAs in vivo in animal models, greatly contributing to the overall understanding of their role in the inflammatory response. Their role in modulating inflammation has been demonstrated in disease models including cardiovascular pathology and inflammatory pain, but extends to neuroinflammation and neuroinflammatory disease. Moreover, while EpFAs demonstrate activity against inflammatory pain, interestingly, this action extends to blocking chronic neuropathic pain as well. This review outlines the role of modulating sEH and the biological action of EpFAs in models of pain and inflammatory diseases.

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.

Lipid correlates of antidepressant response to omega-3 polyunsaturated fatty acid supplementation: A pilot study

Low omega-3 polyunsaturated fatty acid (PUFA) levels are seen in major depression. We examined effects of six weeks of fish oil supplementation on clinical characteristics in 16 patients with symptomatic major depressive disorder, and tested plasma phospholipid levels of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) as correlates of clinical response. Depression symptoms improved after supplementation (p=0.007). The reduction in depression severity was not predicted by baseline PUFA levels but did exhibit a relationship with endpoint PUFAs, correlating negatively with DHA as a percentage of plasma phospholipids (DHA%; R²=0.60, p=0.004), adjusting for endpoint EPA%; and correlating positively with endpoint EPA% (R²=0.58, p=0.007), adjusting for endpoint DHA%. Thus, the higher the proportion of DHA to EPA, the greater the reduction in depression severity (r=-0.43, p=0.097). Five patients showed a decrease of >50% on the 17-item Hamilton Depression Rating Scale and a final score <7 and were thus not only responders but met standard criteria for remission, and were distinguished from non-responders by higher levels of DHA% (p=0.03). This pilot study suggests that post-supplementation DHA% levels may be a necessary target for antidepressant response to fish oil, and that this may depend to some extent on the efficacy of EPA conversion to DHA.

Inflammation in Depression and the Potential for Anti-Inflammatory Treatment

Accumulating evidence supports an association between depression and inflammatory processes, a connection that seems to be bidirectional. Clinical trials have indicated antidepressant treatment effects for anti-inflammatory agents, both as add-on treatment and as monotherapy. In particular, nonsteroidal anti-inflammatory drugs (NSAIDs) and cytokine-inhibitors have shown antidepressant treatment effects compared to placebo, but also statins, poly-unsaturated fatty acids, pioglitazone, minocycline, modafinil, and corticosteroids may yield antidepressant treatment effects. However, the complexity of the inflammatory cascade, limited clinical evidence, and the risk for side effects stress cautiousness before clinical application. Thus, despite proof-of-concept studies of anti-inflammatory treatment effects in depression, important challenges remain to be investigated. Within this paper, we review the association between inflammation and depression together with the current evidence on use of anti-inflammatory treatment in depression. Based on this, we address the questions and challenges that seem most important and relevant to future studies, such as timing, most effective treatment lengths and identification of subgroups of patients potentially responding better to different anti-inflammatory treatment regimens.

Inflammation and Immune Regulation as Potential Drug Targets in Antidepressant Treatment

Growing evidence supports a mutual relationship between inflammation and major depression. A variety of mechanisms are outlined, indicating how inflammation may be involved in the pathogenesis, course and treatment of major depression. In particular, this review addresses 1) inflammatory cytokines as markers of depression and potential predictors of treatment response, 2) findings that cytokines interact with antidepressants and non-pharmacological antidepressive therapies, such as electroconvulsive therapy, deep brain stimulation and physical activity, 3) the influence of cytokines on the cytochrome (CYP) p450-system and drug efflux transporters, and 4) how cascades of inflammation might serve as antidepressant drug targets. A number of clinical trials have focused on agents with immunmodulatory properties in the treatment of depression, of which this review covers nonsteroidal anti-inflammatory drugs (NSAIDs), cytokine inhibitors, ketamine, polyunsaturated fatty acids, statins and curcumin. A perspective is also provided on possible future immune targets for antidepressant therapy, such as toll-like receptor-inhibitors, glycogen synthase kinase-3 inhibitors, oleanolic acid analogs and minocycline. Concluding from the available data, markers of inflammation may become relevant factors for more personalised planning and prediction of response of antidepressant treatment strategies. Agents with anti-inflammatory properties have the potential to serve as clinically relevant antidepressants. Further studies are required to better define and identify subgroups of patients responsive to inflammatory agents as well as to define optimal time points for treatment onset and duration.

Are Dietary Patterns Associated with Depression in U.S. Adults?

Nutrition is one of the most important modifiable determinants for and consequences of both mental and physical heath. Depression has become an increasingly important public health issue. We tested whether dietary patterns derived from food group intake are associated with depression in U.S. adults in a cross-sectional study with national population. This study included 4180 men and 4196 women aged 20-79 years in the 2007-2010 National Health and Nutrition Examination Surveys (NHANES), with complete data of one 24-h dietary recall, sociodemographics, lifestyles, and Patient Health Questionnaires (PHQ-9) for screening depression. Two major dietary patterns identified by factor analysis were investigated for their associations with presence of depression (PHQ-9 score ≥10) by using linear and multivariate logistic regressions. One of two major patterns, labeled "Western" dietary pattern was characterized by high intakes of nonwhole grain, white potatoes, cheese, meat, discretionary oil and fat, and added sugar; the second dietary pattern that was labeled "Healthy" dietary pattern was characterized by high intakes of whole grains, vegetables, fruits, fish, nuts and seeds. The "Western" dietary pattern was not significantly associated with depression in both men and women. The "Healthy" dietary pattern scores were inversely associated with the PHQ-9 depression scores and odd ratios (ORs) of depression after adjustment for covariates in women but not in men. The OR of depression in women with the highest quintile of "Healthy" dietary pattern scores was 0.60 (95% confidence interval [CI]: 0.42-0.85, P < .001) compared to the lowest quintile as a reference. These findings warrant future interventions or clinical trials in elucidating causal and effect relations of depression and dietary patterns, an important public health concern.

Omega-3 Fatty Acids, Depressive Symptoms, and Cognitive Performance in Patients With Coronary Artery Disease: Analyses From a Randomized, Double-Blind, Placebo-Controlled Trial

This trial investigated the efficacy of omega-3 polyunsaturated fatty acid (n-3 PUFA) treatment for improving depressive symptoms and cognitive performance in patients with coronary artery disease (CAD) participating in cardiac rehabilitation. Patients with CAD aged 45 to 80 years were randomized to receive either 1.9-g/d n-3 PUFA treatment or placebo for 12 weeks. Depressive symptoms were measured using the Hamilton Depression Rating Scale (HAM-D, primary outcome) and the Beck Depression Inventory II (BDI-II). Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria were used to identify a depressive episode at baseline. Cognitive performance was measured using a standardized battery for vascular cognitive impairment. In 92 patients (age, 61.7 ± 8.7 y; 76% male, 40% depressed; HAM-D, 6.9 ± 5.9; BDI-II, 12.3 ± 10.9; n = 45 n-3 PUFA, n = 47 placebo), depression decreased (HAM-D, F3,91 = 2.71 and P = 0.049; BDI-II, F3,91 = 6.24 and P < 0.01), and cognitive performance improved (attention/processing speed, F1,91 = 5.57, P = 0.02; executive function, F1,91 = 14.64, P < 0.01; visuospatial memory, F1,91 = 4.01, P = 0.04) over cardiac rehabilitation. Omega-3 PUFA treatment increased plasma eicosapentaenoic acid (F1,29 = 33.29, P < 0.01) and docosahexaenoic acid (F1,29 = 15.29, P < 0.01) concentrations but did not reduce HAM-D (F3,91 = 1.59, P = 0.20) or BDI-II (F3,91 = 0.46, P = 0.50) scores compared with placebo. Treatment did not improve cognitive performance; however, n-3 PUFAs significantly increased verbal memory compared with placebo in a subgroup of nondepressed patients (F1,54 = 4.16, P = 0.04). This trial suggests that n-3 PUFAs do not improve depressive and associated cognitive symptoms in those with CAD. The possible benefits of n-3 PUFAs for verbal memory may warrant investigation in well-powered studies.

The synchronized trial on expectant mothers with depressive symptoms by omega-3 PUFAs (SYNCHRO): Study protocol for a randomized controlled trial

BACKGROUND

Maternal depression can be harmful to both mothers and their children. Omega-3 polyunsaturated fatty acid (PUFA) supplementation has been investigated as an alternative intervention for pregnant women with depressive symptoms because of the supporting evidence from clinical trials in major depression, the safety advantage, and its anti-inflammatory and neuroplasticity effects. This study examines the efficacy of omega-3 PUFA supplementation for pregnant women with depressive symptoms in Taiwan and Japan, to provide evidence available for Asia. The rationale and protocol of this trial are reported here.

METHODS

The Synchronized Trial on Expectant Mothers with Depressive Symptoms by Omega-3 PUFAs (SYNCHRO) is a multicenter, double-blind, parallel group, randomized controlled trial. Participants will be randomized to either the omega-3 PUFAs arm (1,200 mg eicosapentaenoic acid and 600 mg docosahexaenoic acid daily) or placebo arm. Primary outcome is total score on the Hamilton Rating Scale for Depression (HAMD) at 12 weeks after the start of the intervention. We will randomize 56 participants to have 90 % power to detect a 4.7-point difference in mean HAMD scores with omega-3 PUFAs compared with placebo. Because seafood consumption varies across countries and this may have a major effect on the efficacy of omega-3 PUFA supplementation, 56 participants will be recruited at each site in Taiwan and Japan, for a total number of 112 participants. Secondary outcomes include depressive symptoms at 1 month after childbirth, diagnosis of major depressive disorder, changes in omega-3 PUFAs concentrations and levels of biomarkers at baseline and at 12 weeks' follow-up, and standard obstetric outcomes. Data analyses will be by intention to treat. The trial was started in June 2014 and is scheduled to end in February 2018.

DISCUSSION

The trial is expected to provide evidence that can contribute to promoting mental health among mothers and children in Asian populations.

TRIAL REGISTRATION

Clinicaltrials.gov: NCT02166424 . Registered 15 June 2014; University Hospital Medical Information Network (UMIN) Center: UMIN000017979. Registered 20 May 2015.

Efficacy of omega-3 highly unsaturated fatty acids in the treatment of depression

BACKGROUND

Trials evaluating efficacy of omega-3 highly unsaturated fatty acids (HUFAs) in major depressive disorder report discrepant findings.

AIMS

To establish the reasons underlying inconsistent findings among randomised controlled trials (RCTs) of omega-3 HUFAs for depression and to assess implications for further trials.

METHOD

A systematic bibliographic search of double-blind RCTs was conducted between January 1980 and July 2014 and an exploratory hypothesis-testing meta-analysis performed in 35 RCTs including 6665 participants receiving omega-3 HUFAs and 4373 participants receiving placebo.

RESULTS

Among participants with diagnosed depression, eicosapentaenoic acid (EPA)-predominant formulations (>50% EPA) demonstrated clinical benefits compared with placebo (Hedge's G = 0.61, P<0.001) whereas docosahexaenoic acid (DHA)-predominant formulations (>50% DHA) did not. EPA failed to prevent depressive symptoms among populations not diagnosed for depression.

CONCLUSIONS

Further RCTs should be conducted on study populations with diagnosed or clinically significant depression of adequate duration using EPA-predominant omega-3 HUFA formulations.

Inflammatory insults and mental health consequences: does timing matter when it comes to depression?

It has become widely accepted that the immune system, and specifically increased levels of inflammation, play a role in the development of depression. However, not everyone with increased inflammation develops depression, and as with all other diseases, there are risk factors that may contribute to an increased vulnerability in certain individuals. One such risk factor could be the timing of an inflammatory exposure. Here, using a combination of PubMed, EMBASE, Ovid Medline and PsycINFO, we systematically reviewed whether exposure to medically related inflammation in utero, in childhood, and in adolescence, increases the risk for depression in adulthood. Moreover, we tried to determine whether there was sufficient evidence to identify a particular time point during the developmental trajectory in which an immune insult could be more damaging. While animal research shows that early life exposure to inflammation increases susceptibility to anxiety- and depressive-like behaviour, human studies surprisingly find little evidence to support the notion that medically related inflammation in utero and in adolescence contributes to an increased risk of developing depression in later life. However, we did find an association between childhood inflammation and later life depression, with most studies reporting a significantly increased risk of depression in adults who were exposed to inflammation as children. More robust clinical research, measuring direct markers of inflammation throughout the life course, is greatly needed to expand on, and definitively address, the important research questions raised in this review.