Omega-3 fatty acids for depression in adults

Omega-3 fatty acid supplementation for depression in children and adolescents

BACKGROUND

Mental health disorders including major depressive disorder (MDD) are well recognized as major contributors to the global burden of disease among adolescents. The prevalence of adolescent depression is estimated to have increased by at least 25% during the COVID-19 pandemic, compounding the already challenging problem of insufficient mental health service and service accessibility that existed prepandemic. Omega-3 polyunsaturated fatty acid (PUFA) supplementation is currently recommended as a preventive treatment for depression in high-risk adults as well as a second-line monotherapy for adults with mild to moderate MDD, and adjunctive to antidepressants for adults with moderate to severe MDD. The benefits of omega-3 PUFA intake on depressive illness have been hypothesized to occur as a result of their effect on neurotransmission, maintenance of membrane fluidity, and anti-inflammatory action. A comprehensive synthesis and quantification of the existing evidence on omega-3 PUFA's efficacy in treating depression among children and adolescents is essential for clinicians to provide informed guidance to young people and their families, especially considering the absence of current guidelines for this age group.

OBJECTIVES

Primary objective To determine the impact of omega-3 PUFA supplementation versus a comparator (e.g. placebo, wait list controls, no treatment/supplementation, or standard care) on clinician-diagnosed depression or self-reported depression symptoms in children and adolescents. Secondary objectives To estimate the size of the effect of omega-3 PUFAs on depression symptoms. To estimate the effect of each type of omega-3 PUFA (EPA or DHA), compared with placebo, on depression. To determine if the effect is modified by dosage, format (capsule or liquid), sex, or age. To determine compliance and attrition for omega-3 PUFAs as an intervention for depression in children and adolescents. To determine the safety of omega-3 PUFAs as an intervention for depression in children and adolescents.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, three other databases, reference lists of included studies, grey literature, and relevant reviews. The latest search date was 18 May 2023.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) involving males and females aged 19 years or younger with diagnosed depression comparing omega-3 PUFA supplementation to placebo, wait list control, no treatment/supplementation, or standard care.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were self-reported depression symptoms and clinically diagnosed resolution of depression. Our secondary outcomes were attrition, adverse effects, and compliance with the intervention. We used GRADE to assess the certainty of evidence for key outcomes.

MAIN RESULTS

We included five trials with 228 participants in our meta-analysis. All trials used a placebo comparator; intervention duration ranged from 10 to 16 weeks (median: 12 weeks). Omega-3 PUFA supplementation compared to placebo may reduce self-reported depression symptoms, but the evidence is very uncertain (standardized mean difference [SMD] -0.34, 95% confidence interval [CI] -0.85 to 0.17; lower SMD means greater improvement in depression due to omega-3 PUFA; 5 trials, 185 participants; very low-certainty evidence). Omega-3 PUFA supplementation may have little to no effect on remission of depression symptoms compared to placebo, but the evidence is very uncertain (omega-3 PUFA versus placebo: 50% versus 48%; odds ratio [OR] 1.11, 95% CI 0.45 to 2.75; 4 trials, 127 participants; very low-certainty evidence). Omega-3 PUFA supplementation may result in little to no difference in attrition (dropouts) compared to placebo (omega-3 PUFA versus placebo: 18% versus 19%; OR 0.94, 95% CI 0.46 to 1.90; 5 trials, 228 participants; low-certainty evidence). Omega-3 PUFA supplementation may result in little to no difference in adverse effects, with one study reporting more muscle cramps in the fish oil group (13/27 participants) compared to the placebo group (6/29 participants); one study reported more frequent defecation in the omega-3 group (1/29 participants) and one study identified mild skin rash and unusual/manic behavior in the placebo group (2/27 participants). None of the included studies reported serious adverse effects.

AUTHORS' CONCLUSIONS

Based on five small studies, omega-3 PUFA supplementation may reduce self-reported depression symptoms, but the evidence is very uncertain. Omega-3 PUFA supplementation may have little to no effect on depression remission compared to placebo, but the evidence is very uncertain. Omega-3 PUFA supplementation may result in little to no difference in attrition or adverse effects. The studies observed no serious adverse effects. This review highlights early-stage research on omega-3 PUFA and depression in young people. The evidence on the effects of omega-3 PUFA supplementation in improving self-reported depression symptoms or achieving depression remission in children and adolescents is very uncertain. While no harms are evident, more data are needed to confirm potential risks. Addressing current limitations in the evidence base through the design and conduct of methodologically rigorous studies - larger sample sizes, varied dosages, eicosapentaenoic acid/docosahexaenoic acid ratios, treatment durations, and safety profiles - is crucial to advance our understanding of the role of omega-3 PUFA supplementation for depression in children and adolescents.

Genetic Associations of Anhedonia: Insights into Overlap of Mental and Somatic Disorders

BACKGROUND

Anhedonia is characterized by a reduced ability to anticipate, experience, and/or learn about pleasure. This phenomenon has a transdiagnostic nature and is one of the key symptoms of mood disorders, schizophrenia, addictions, and somatic conditions.

AIM

To evaluate the genetic architecture of anhedonia and its overlap with other mental disorders and somatic conditions.

METHODS

We performed a genome-wide association study of anhedonia on a sample of 4,520 individuals from a Russian non-clinical population. Using the available summary statistics, we calculated polygenic risk scores (PRS) to investigate the genetic relationship between anhedonia and other psychiatric or somatic phenotypes.

RESULTS

No variants with a genome-wide significant association were identified. PRS for major depression, bipolar disorder, and schizophrenia were significantly associated with anhedonia. Conversely, no significant associations were found between PRS for anxiety and anhedonia, which aligns well with existing clinical evidence. None of the PRS for somatic phenotypes attained a significance level after correction for multiple comparisons. A nominal significance for the anhedonia association was determined for omega-3 fatty acids, type 2 diabetes mellitus, and Crohn's disease.

CONCLUSION

Anhedonia has a complex polygenic architecture, and its presence in somatic diseases or normal conditions may be due to a genetic predisposition to mood disorders or schizophrenia.

Association of serum fatty acid pattern with depression in U.S. adults: analysis of NHANES 2011-2012

BACKGROUND

Exposure to different concentration levels of fatty acids (FAs) may have an impact on depression. However, previous studies using individual FAs may not reflect the performance of mixtures of various FAs, and the associations of FA patterns with depression remain unclear.

METHODS

We conducted the cross-sectional analysis in 792 adults aged 18 and older with available serum FAs and depression screening data in the National Health and Nutrition Examination Survey (NHANES) 2011-2012. The serum concentrations of thirty FAs were measured using gas chromatography-mass spectrometry and their percentage compositions were subsequently calculated. Depression was defined as the Patient Health Questionnaire-9 score ≥ 10. We employed principal component analysis to derive serum FA patterns. We examined the association between these patterns and depression in the overall population and various subgroups through survey-weighted logistic regression.

RESULTS

Four distinct patterns of serum FAs were identified: 'high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); low docosatetraenoic acid (DTA) and docosapentaenoic acid (DPA) n-6', 'high long-chain saturated FA and long chain FA', 'low median-chain saturated FA and myristoleic acid' and 'low capric acid and lauric acid; high gamma-linolenic acid (GLA) and stearidonic acid (SDA)' pattern. Individuals in the high tertile of 'high EPA and DHA; low DTA and DPA n-6' pattern score had 0.46 (95% CI: 0.22, 0.93) lower odds of developing depression compared to individuals in the lowest tertile after adjusting for confounders such as age, sex, physical activity and total energy intake, etc. The odds ratio (OR) of depression was increased in the population with the highest tertile of 'low capric acid and lauric acid; high GLA and SDA' pattern (OR: 2.45, 95% CI: 1.24, 4.83). In subgroup analyses, we observed that the association between 'high EPA and DHA; low DTA and DPA n-6' and depression persisted among specific demographic and lifestyle subgroups, including females, non-Mexican Americans, non-obese, those aged over 60 years, smokers and drinkers. Similarly, 'low capric acid and lauric acid; high GLA and SDA' showed stable associations in female, non-Mexican Americans and smokers.

CONCLUSIONS

Serum FA patterns are associated with depression, and their relationships vary across sex, race, BMI, age, smoking and drinking subgroups, highlighting the importance of considering specific FA patterns within these demographic and lifestyle categories. Utilization of combined FA administration may serve as a mitigation measure against depression in these specific populations.

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.

Biotechnological production of omega-3 fatty acids: current status and future perspectives

Omega-3 fatty acids, including alpha-linolenic acids (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), have shown major health benefits, but the human body's inability to synthesize them has led to the necessity of dietary intake of the products. The omega-3 fatty acid market has grown significantly, with a global market from an estimated USD 2.10 billion in 2020 to a predicted nearly USD 3.61 billion in 2028. However, obtaining a sufficient supply of high-quality and stable omega-3 fatty acids can be challenging. Currently, fish oil serves as the primary source of omega-3 fatty acids in the market, but it has several drawbacks, including high cost, inconsistent product quality, and major uncertainties in its sustainability and ecological impact. Other significant sources of omega-3 fatty acids include plants and microalgae fermentation, but they face similar challenges in reducing manufacturing costs and improving product quality and sustainability. With the advances in synthetic biology, biotechnological production of omega-3 fatty acids via engineered microbial cell factories still offers the best solution to provide a more stable, sustainable, and affordable source of omega-3 fatty acids by overcoming the major issues associated with conventional sources. This review summarizes the current status, key challenges, and future perspectives for the biotechnological production of major omega-3 fatty acids.

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.

Biochemical and behavioral effects of decreasing dietary linoleic acid and increasing eicosapentaenoic acid and docosahexaenoic acid in a rat chronic monoarthrits model

Clinical studies have demonstrated that decreasing linoleic acid (LA) while increasing eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in diets evokes an analgesic effect in headache sufferers. We utilized a rat chronic monoarthritis model to determine if these analgesic effects can be reproduced in rats and to and further probe potential analgesic mechanisms. We fed 8 rats a control diet (with fatty acid levels similar to standard US diets) and 8 rats a low LA diet with added EPA and DHA (H3L6 diet) and after 10 weeks, performed a unilateral intraarticular injection of Complete's Freund Adjuvant (CFA). We evaluated thermal and mechanical sensitivity as well as hind paw weight bearing prior to and at 4 and 20 days post CFA injection. At 28 days post CFA injection rats were euthanized and tissue collected. H3L6 diet fed rats had higher concentrations of EPA and DHA, as well as higher concentrations of oxidized lipids derived from these fatty acids, in hind paw and plasma, compared to control fed rats. LA and oxidized LA metabolites were lower in the plasma and hind paw of H3L6 compared to control fed rats. Diet did not affect thermal or mechanical sensitivity, nor did it affect hind paw weight bearing. In conclusion, the H3L6 diet evoked biochemical changes in rats but did not impact pain related behavioral measures in this chronic monoarthritis model.

n-3 polyunsaturated fatty acids improve depression-like behavior by inhibiting hippocampal neuroinflammation in mice via reducing TLR4 expression

INTRODUCTION

n-3 polyunsaturated fatty acids (PUFAs) are believed to be implicated in the pathogenesis of many inflammation-related diseases, including depression.

METHODS

The mouse model of depression was established through chronic unpredictable mild stress (CUMS), the mice were intervened with n-3 PUFAs, and then the expression of toll-like receptor 4 (TLR4) was stimulated with lipopolysaccharides (LPS). Tail suspension test (TST), forced swimming test (FST) and sucrose preference test were performed to monitor the depression behavior of mice. Microglia activation was detected by Iba1 immunofluorescence, and neuronal injury was detected by Nissl staining. Concentrations of tumor necrosis factor (TNF)-α, Interleukin (IL)-6 and IL-1β in the hippocampus were assessed via enzyme linked immunosorbent assay (ELISA). Quantitative real time polymerase chain reaction was used to detect IL-6, IL-1β and TNF-α messenger RNA levels. Western blot was utilized for detection of TLR4 protein expression.

RESULTS

CUMS significantly reduced the sucrose preference in mice, while increased the immobility time in FST and TST. Moreover, CUMS significantly aggravated microglia activation and neuronal damage in mice and increased the levels of IL-6, IL-1β and TNF-α in hippocampal tissues, however, intervention with n-3 PUFAs could improve the above effects. Further, the increased TLR4 induced by LPS partially reversed the inhibition of n-3 PUFAs on depression-like behaviors, microglial activation and inflammatory injury of hippocampal neurons.

CONCLUSION

n-3 PUFAs may ameliorate depression-like behaviors via reducing hippocampal neuroinflammation in CUMS-induced mice by regulating TLR4 expression, suggesting that n-3 PUFAs may be an effective antidepressant, which provides evidence for future treatment of depression.

Health Benefits, Food Applications, and Sustainability of Microalgae-Derived N-3 PUFA

Today's consumers are increasingly aware of the beneficial effects of n-3 PUFA in preventing, delaying, and intervening various diseases, such as coronary artery disease, hypertension, diabetes, inflammatory and autoimmune disorders, neurodegenerative diseases, depression, and many other ailments. The role of n-3 PUFA on aging and cognitive function is also one of the hot topics in basic research, product development, and clinical applications. For decades, n-3 PUFA, especially EPA and DHA, have been supplied by fish oil and seafood. With the continuous increase of global population, awareness about the health benefits of n-3 PUFA, and socioeconomic improvement worldwide, the supply chain is facing increasing challenges of insufficient production. In this regard, microalgae have been well considered as promising sources of n-3 PUFA oil to mitigate the supply shortages. The use of microalgae to produce n-3 PUFA-rich oils has been explored for over two decades and some species have already been used commercially to produce n-3 PUFA, in particular EPA- and/or DHA-rich oils. In addition to n-3 PUFA, microalgae biomass contains many other high value biomolecules, which can be used in food, dietary supplement, pharmaceutical ingredient, and feedstock. The present review covers the health benefits of n-3 PUFA, EPA, and DHA, with particular attention given to the various approaches attempted in the nutritional interventions using EPA and DHA alone or combined with other nutrients and bioactive compounds towards improved health conditions in people with mild cognitive impairment and Alzheimer's disease. It also covers the applications of microalgae n-3 PUFA in food and dietary supplement sectors and the economic and environmental sustainability of using microalgae as a platform for n-3 PUFA-rich oil production.

Risk factors for depression in the elderly: An umbrella review of published meta-analyses and systematic reviews

BACKGROUND

Depression has been identified as one of the leading causes of the disease burden worldwide. Identification of the potential factors that increased or decreased the risk of depression could be important to provide prevention strategies. We aimed to conduct an umbrella review of risk factors for depression in the elderly and assessed the credibility of evidence of the association between each factor and depression.

METHODS

We searched PubMed and Web of Science from 1990 to April 11, 2021 for articles investigating associations between potential factors and depression. For each association, we recalculated the summary effect size and 95% confidence intervals using random effects models. The 95% prediction interval and between-heterogeneity were also reported. For publication bias, small-study effect and excess of significance bias were assessed.

RESULTS

Twenty-five publications met the inclusion criteria, including twenty-two meta-analyses and three qualitative systematic reviews. Approximately 1,199,927 participants and 82 unique factors were reported. Two factors were rated as convincing evidence and four factors showed highly suggestive evidence. These risk factors were aspirin use, individuals aged 80 years and above, sleep disturbances and persistent sleep disturbances, hearing problem, poor vision, and cardiac disease.

LIMITATIONS

Most studies that we included were of low quality.

CONCLUSIONS

We found several risk factors for depression with different levels of evidence, in which aspirin use and individuals aged 80 years and above presented the strongest evidence. Further research is warranted to support other findings from this umbrella review using a large, well-designed cohort study.

The Problem of Malnutrition Associated with Major Depressive Disorder from a Sex-Gender Perspective

Major depressive disorder (MDD) is an incapacitating condition characterized by loss of interest, anhedonia and low mood, which affects almost 4% of people worldwide. With rising prevalence, it is considered a public health issue that affects economic productivity and heavily increases health costs alone or as a comorbidity for other pandemic non-communicable diseases (such as obesity, cardiovascular disease, diabetes, inflammatory bowel diseases, etc.). What is even more noteworthy is the double number of women suffering from MDD compared to men. In fact, this sex-related ratio has been contemplated since men and women have different sexual hormone oscillations, where women meet significant changes depending on the age range and moment of life (menstruation, premenstruation, pregnancy, postpartum, menopause…), which seem to be associated with susceptibility to depressive symptoms. For instance, a decreased estrogen level promotes decreased activation of serotonin transporters. Nevertheless, sexual hormones are not the only triggers that alter neurotransmission of monoamines and other neuropeptides. Actually, different dietary habits and/or nutritional requirements for specific moments of life severely affect MDD pathophysiology in women. In this context, the present review aims to descriptively collect information regarding the role of malnutrition in MDD onset and course, focusing on female patient and especially macro- and micronutrient deficiencies (amino acids, ω3 polyunsaturated fatty acids (ω3 PUFAs), folate, vitamin B12, vitamin D, minerals…), besides providing evidence for future nutritional intervention programs with a sex-gender perspective that hopefully improves mental health and quality of life in women.

Nutraceuticals and Physical Activity as Antidepressants: The Central Role of the Gut Microbiota

Major depressive disorder (MDD) is a common mental illness. Evidence suggests that the gut microbiota play an essential role in regulating brain functions and the pathogenesis of neuropsychiatric diseases, including MDD. There are numerous mechanisms through which the gut microbiota and brain can exchange information in a continuous, bidirectional communication. Current research emphasizes the interexchange of signals influenced by the gut microbiota that are detected and transduced in information from the gut to the nervous system involving neural, endocrine, and inflammatory mechanisms, suggesting a relationship between oxidative stress and the pathophysiology of MDD via the hyperactivation of inflammatory responses. Potential sources of inflammation in the plasma and hippocampus of depressed individuals could stem from increases in intestinal permeability. Some nutraceuticals, such as specific probiotics, namely psychobiotics, polyphenols, carotenoids, butyrate, and prebiotics, have been demonstrated to exert an antidepressant activity, but most of them need to be metabolized and activated by gut microorganisms. By inducing changes in the gut microbiota composition, physical exercise might also exert a role in alleviating depression-like symptoms. The mutual relationships among nutraceuticals, exercise, and depression will be discussed, and the potential role of the gut microbiota as a therapeutic target to treat depression will be explored.

Psychological and pharmacological interventions for depression in patients with coronary artery disease

BACKGROUND

Depression occurs frequently in individuals with coronary artery disease (CAD) and is associated with a poor prognosis.

OBJECTIVES

To determine the effects of psychological and pharmacological interventions for depression in CAD patients with comorbid depression.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, PsycINFO, and CINAHL databases up to August 2020. We also searched three clinical trials registers in September 2021. We examined reference lists of included randomised controlled trials (RCTs) and contacted primary authors. We applied no language restrictions.

SELECTION CRITERIA

We included RCTs investigating psychological and pharmacological interventions for depression in adults with CAD and comorbid depression. Our primary outcomes included depression, mortality, and cardiac events. Secondary outcomes were healthcare costs and utilisation, health-related quality of life, cardiovascular vital signs, biomarkers of platelet activation, electrocardiogram wave parameters, non-cardiac adverse events, and pharmacological side effects.

DATA COLLECTION AND ANALYSIS

Two review authors independently examined the identified papers for inclusion and extracted data from the included studies. We performed random-effects model meta-analyses to compute overall estimates of treatment outcomes.

MAIN RESULTS

Thirty-seven trials fulfilled our inclusion criteria. Psychological interventions may result in a reduction in end-of-treatment depression symptoms compared to controls (standardised mean difference (SMD) -0.55, 95% confidence interval (CI) -0.92 to -0.19, I² = 88%; low certainty evidence; 10 trials; n = 1226). No effect was evident on medium-term depression symptoms one to six months after the end of treatment (SMD -0.20, 95% CI -0.42 to 0.01, I² = 69%; 7 trials; n = 2654). The evidence for long-term depression symptoms and depression response was sparse for this comparison. There is low certainty evidence that psychological interventions may result in little to no difference in end-of-treatment depression remission (odds ratio (OR) 2.02, 95% CI 0.78 to 5.19, I² = 87%; low certainty evidence; 3 trials; n = 862). Based on one to two trials per outcome, no beneficial effects on mortality and cardiac events of psychological interventions versus control were consistently found. The evidence was very uncertain for end-of-treatment effects on all-cause mortality, and data were not reported for end-of-treatment cardiovascular mortality and occurrence of myocardial infarction for this comparison. In the trials examining a head-to-head comparison of varying psychological interventions or clinical management, the evidence regarding the effect on end-of-treatment depression symptoms is very uncertain for: cognitive behavioural therapy compared to supportive stress management; behaviour therapy compared to person-centred therapy; cognitive behavioural therapy and well-being therapy compared to clinical management. There is low certainty evidence from one trial that cognitive behavioural therapy may result in little to no difference in end-of-treatment depression remission compared to supportive stress management (OR 1.81, 95% CI 0.73 to 4.50; low certainty evidence; n = 83). Based on one to two trials per outcome, no beneficial effects on depression remission, depression response, mortality rates, and cardiac events were consistently found in head-to-head comparisons between psychological interventions or clinical management. The review suggests that pharmacological intervention may have a large effect on end-of-treatment depression symptoms (SMD -0.83, 95% CI -1.33 to -0.32, I² = 90%; low certainty evidence; 8 trials; n = 750). Pharmacological interventions probably result in a moderate to large increase in depression remission (OR 2.06, 95% CI 1.47 to 2.89, I² = 0%; moderate certainty evidence; 4 trials; n = 646). We found an effect favouring pharmacological intervention versus placebo on depression response at the end of treatment, though strength of evidence was not rated (OR 2.73, 95% CI 1.65 to 4.54, I² = 62%; 5 trials; n = 891). Based on one to four trials per outcome, no beneficial effects regarding mortality and cardiac events were consistently found for pharmacological versus placebo trials, and the evidence was very uncertain for end-of-treatment effects on all-cause mortality and myocardial infarction. In the trials examining a head-to-head comparison of varying pharmacological agents, the evidence was very uncertain for end-of-treatment effects on depression symptoms. The evidence regarding the effects of different pharmacological agents on depression symptoms at end of treatment is very uncertain for: simvastatin versus atorvastatin; paroxetine versus fluoxetine; and escitalopram versus Bu Xin Qi. No trials were eligible for the comparison of a psychological intervention with a pharmacological intervention.

AUTHORS' CONCLUSIONS

In individuals with CAD and depression, there is low certainty evidence that psychological intervention may result in a reduction in depression symptoms at the end of treatment. There was also low certainty evidence that pharmacological interventions may result in a large reduction of depression symptoms at the end of treatment. Moderate certainty evidence suggests that pharmacological intervention probably results in a moderate to large increase in depression remission at the end of treatment. Evidence on maintenance effects and the durability of these short-term findings is still missing. The evidence for our primary and secondary outcomes, apart from depression symptoms at end of treatment, is still sparse due to the low number of trials per outcome and the heterogeneity of examined populations and interventions. As psychological and pharmacological interventions can seemingly have a large to only a small or no effect on depression, there is a need for research focusing on extracting those approaches able to substantially improve depression in individuals with CAD and depression.

Omega-3 fatty acids for depression in adults

BACKGROUND

Major depressive disorder (MDD) is highly debilitating, difficult to treat, has a high rate of recurrence, and negatively impacts the individual and society as a whole. One potential treatment for MDD is n-3 polyunsaturated fatty acids (n-3PUFAs), also known as omega-3 oils, naturally found in fatty fish, some other seafood, and some nuts and seeds. Various lines of evidence suggest a role for n-3PUFAs in MDD, but the evidence is far from conclusive. Reviews and meta-analyses clearly demonstrate heterogeneity between studies. Investigations of heterogeneity suggest different effects of n-3PUFAs, depending on the severity of depressive symptoms, where no effects of n-3PUFAs are found in studies of individuals with mild depressive symptomology, but possible benefit may be suggested in studies of individuals with more severe depressive symptomology. Hence it is important to establish their effectiveness in treating MDD. This review updates and incorporates an earlier review with the same research objective (Appleton 2015).

OBJECTIVES

To assess the effects of n-3 polyunsaturated fatty acids (also known as omega-3 fatty acids) versus a comparator (e.g. placebo, antidepressant treatment, standard care, no treatment, wait-list control) for major depressive disorder (MDD) in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled trials (CENTRAL), Ovid MEDLINE, Embase and PsycINFO together with trial registries and grey literature sources (to 9 January 2021). We checked reference lists and contacted authors of included studies for additional information when necessary.

SELECTION CRITERIA

We included studies in the review if they: used a randomised controlled trial design; provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and were conducted in adults with MDD. Primary outcomes were depressive symptomology (continuous data collected using a validated rating scale) and adverse events. Secondary outcomes were depressive symptomology (dichotomous data on remission and response), quality of life, and non-completion of studies.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane. We assessed the certainty of the evidence using GRADE criteria.

MAIN RESULTS

The review includes 35 relevant studies: 34 studies involving a total of 1924 participants investigated the impact of n-3PUFA supplementation compared to placebo, and one study involving 40 participants investigated the impact of n-3PUFA supplementation compared to antidepressant treatment. For the placebo comparison, n-3PUFA supplementation resulted in a small to modest benefit for depressive symptomology, compared to placebo: standardised mean difference (SMD) (random-effects model) -0.40 (95% confidence interval (CI) -0.64 to -0.16; 33 studies, 1848 participants; very low-certainty evidence), but this effect is unlikely to be clinically meaningful. An SMD of 0.40 represents a difference between groups in scores on the HDRS (17-item) of approximately 2.5 points (95% CI 1.0 to 4.0), where the minimal clinically important change score on this scale is 3.0 points. The confidence intervals include both a possible clinically important effect and a possible negligible effect, and there is considerable heterogeneity between studies. Sensitivity analyses, funnel plot inspection and comparison of our results with those of large well-conducted trials also suggest that this effect estimate may be biased towards a positive finding for n-3PUFAs. Although the numbers of individuals experiencing adverse events were similar in intervention and placebo groups (odds ratio (OR) 1.27, 95% CI 0.99 to 1.64; 24 studies, 1503 participants; very low-certainty evidence), the confidence intervals include a small decrease to a modest increase in adverse events with n-3PUFAs. There was no evidence for a difference between n-3PUFA and placebo groups in remission rates (OR 1.13, 95% CI 0.74 to 1.72; 8 studies, 609 participants, low-certainty evidence), response rates (OR 1.20, 95% CI 0.80 to 1.79; 17 studies, 794 participants; low-certainty evidence), quality of life (SMD -0.38 (95% CI -0.82 to 0.06), 12 studies, 476 participants, very low-certainty evidence), or trial non-completion (OR 0.92, 95% CI 0.70 to 1.22; 29 studies, 1777 participants, very low-certainty evidence). The evidence on which these results are based was also very limited, highly heterogeneous, and potentially biased. Only one study, involving 40 participants, was available for the antidepressant comparison. This study found no differences between treatment with n-3PUFAs and treatment with antidepressants in depressive symptomology (mean difference (MD) -0.70, 95% CI -5.88 to 4.48), rates of response to treatment (OR 1.23, 95% CI 0.35 to 4.31), or trial non-completion (OR 1.00, 95% CI 0.21 to 4.71). Confidence intervals are however very wide in all analyses, and do not rule out important beneficial or detrimental effects of n-3PUFAs compared to antidepressants. Adverse events were not reported in a manner suitable for analysis, and rates of depression remission and quality of life were not reported.

AUTHORS' CONCLUSIONS

At present, we do not have sufficient high-certainty evidence to determine the effects of n-3PUFAs as a treatment for MDD. Our primary analyses may suggest a small-to-modest, non-clinically beneficial effect of n-3PUFAs on depressive symptomology compared to placebo; however the estimate is imprecise, and we judged the certainty of the evidence on which this result is based to be low to very low. Our data may also suggest similar rates of adverse events and trial non-completion in n-3PUFA and placebo groups, but again our estimates are very imprecise. Effects of n-3PUFAs compared to antidepressants are very imprecise and uncertain. More complete evidence is required for both the potential positive and negative effects of n-3PUFAs for MDD.

Unbiased Metabolomics Links Fatty Acid Pathways to Psychiatric Symptoms in People Living with HIV

Psychiatric symptoms are prevalent in people living with HIV (PLWH), especially depression, anxiety, impulsivity, and substance use. Various biological mechanisms might play a role in the occurrence of psychiatric symptoms in this population. A hypothesis free, data-driven metabolomics approach can further our understanding of these mechanisms. In this study, we identified metabolic pathways associated with impulsivity, depression and substance use in 157 PLWH. First, Spearman’s rank correlations between metabolite feature intensities and psychiatric symptom levels were calculated, while controlling for age, gender and body mass index. Subsequently, a mummichog pathway analysis was performed. Finally, we analyzed which individual metabolites drove the observed effects. In our cohort of PLWH, fatty acid-related pathways were associated with both depressive as well as impulsive symptomatology. Substance use showed most extensive metabolic associations, and was positively associated with short chain fatty acids (SCFA’s), and negatively associated with glutamate levels. These findings suggest that PUFA metabolism might be associated with both internalising and externalising symptomatology in PLWH. Furthermore, glutamate and SCFA’s—microbiome derivatives with known neuroactive properties—might be involved in substance use in these patients. Future studies should explore potential causal mechanisms involved and whether these findings are HIV-specific.

Role of dietary factors in the prevention and treatment for depression: an umbrella review of meta-analyses of prospective studies

The role of diet in depression is becoming increasingly acknowledged. This umbrella review aimed to summarize comprehensively the current evidence reporting the effects of dietary factors on the prevention and treatment of depression. PubMed, Embase, and the Cochrane Library were searched up to June 2021 to identify relevant meta-analyses of prospective studies. Twenty-eight meta-analyses, with 40 summary estimates on dietary patterns (n = 8), food and beverages (n = 19), and nutrients (n = 13) were eligible. The methodological quality of most meta-analyses was low (50.0%) or very low (25.0%). Quality of evidence was moderate for inverse associations for depression incidence with healthy diet [risk ratio (RR): 0.74, 95% confidential interval (CI), 0.48-0.99, I2 = 89.8%], fish (RR: 0.88, 95% CI, 0.79-0.97, I2 = 0.0%), coffee (RR: 0.89, 95% CI, 0.84-0.94, I2 = 32.9%), dietary zinc (RR: 0.66, 95% CI 0.50-0.82, I2 = 13.9%), light to moderate alcohol (<40 g/day, RR: 0.77, 95% CI, 0.74-0.83, I2 = 20.5%), as well as for positive association with sugar-sweetened beverages (RR: 1.05, 95% CI, 1.01-1.09, I2 = 0.0%). For depression treatment, moderate-quality evidence was identified for the effects of probiotic [standardized mean difference (SMD): -0.31, 95% CI, -0.56 to -0.07, I2 = 48.2%], omega-3 polyunsaturated fatty acid (SMD: -0.28, 95% CI, -0.47 to -0.09, I2 = 75.0%) and acetyl-L-carnitine (SMD: -1.10, 95% CI, -1.65 to -0.56, I2 = 86.0%) supplementations. Overall, the associations between dietary factors and depression had been extensively evaluated, but none of them were rated as high quality of evidence, suggesting further studies are likely to change the summary estimates. Thus, more well-designed research investigating more detailed dietary factors in association with depression is warranted.

Nutrition, Exercise, and Stress Management for Treatment and Prevention of Psychiatric Disorders. A Narrative Review Psychoneuroendocrineimmunology-Based

Psychoneuroendocrineimmunology (PNEI) brings together knowledge acquired since the 1930s from endocrinology, immunology, neuroscience, and psychology. With PNEI, a model of research and interpretation of health and disease is emerging, which sees the human body as a structured and interconnected unit, where the psychological and biological systems are mutually coordinated. In the PNEI view, many factors could influence mental health, with the endocrine system involved in mediating the effects of environmental stress on mental health and inflammation in the onset and course of psychiatric disorders as a result of individual and collective conditions and behaviors. Among these, nutrition is one way by which the environment impacts physiology: indeed, many pieces of research showed that several elements (e.g., probiotics, fish oil, zinc) have a positive effect on mental disorders thus being potentially augmentation agents in treatment. Still, physical activity can moderate depressive symptoms, while prolonged stress increases the risk of psychopathology. Taken together, the PNEI-based approach may inform prevention and treatment strategies, also in the field of mental health care.

Depression

Most psychiatric care is delivered in primary care settings, where depression is the most common presenting psychiatric symptom. Given the high prevalence of depression worldwide and the well-established consequences of untreated depression, the ability of primary care clinicians to effectively diagnose and treat it is critically important. This article offers up-to-date guidance for the diagnosis and treatment of major depressive disorder, including practical considerations for delivering optimal and efficient care for these patients.

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.

From Fish Waste to Value: An Overview of the Sustainable Recovery of Omega-3 for Food Supplements

The disposal of food waste is a current and pressing issue, urging novel solutions to implement sustainable waste management practices. Fish leftovers and their processing byproducts represent a significant portion of the original fish, and their disposal has a high environmental and economic impact. The utilization of waste as raw materials for the production of different classes of biofuels and high-value chemicals, a concept known as "biorefinery", is gaining interest in a vision of circular economy and zero waste policies. In this context, an interesting route of valorization is the extraction of omega-3 fatty acids (ω-3 FAs) for nutraceutical application. These fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have received attention over the last decades due to their beneficial effects on human health. Their sustainable production is a key process for matching the increased market demand while reducing the pressure on marine ecosystems and lowering the impact of waste production. The high resale value of the products makes this waste a powerful tool that simultaneously protects the environment and benefits the global economy. This review aims to provide a complete overview of the sustainable exploitation of fish waste to recover ω-3 FAs for food supplement applications, covering composition, storage, and processing of the raw material.

Inflammatory Depression-Mechanisms and Non-Pharmacological Interventions

Treatment of depression is hampered by the failure to identify distinct symptom profiles with distinct pathophysiologies that differentially respond to distinct treatments. We posit that inflammatory depression is a meaningful depression subtype associated with specific symptoms and biological abnormalities. We review several upstream, potentially causative, mechanisms driving low-grade inflammation in this subtype of depression. We also discuss downstream mechanisms mediating the link between inflammation and symptoms of depression, including alterations in dopaminergic neurotransmission and tryptophan metabolism. Finally, we review evidence for several non-pharmacological interventions for inflammatory depression, including probiotics, omega-3 fatty acids, and physical exercise interventions. While some evidence suggests that these interventions may be efficacious in inflammatory depression, future clinical trials should consider enriching patient populations for inflammatory markers, or stratify patients by inflammatory status, to confirm or refute this hypothesis.

The Potential of Cryptophyte Algae in Biomedical and Pharmaceutical Applications

Microalgae produce a variety of bioactive components that provide benefits to human and animal health. Cryptophytes are one of the major groups of microalgae, with more than 20 genera comprised of 200 species. Recently, cryptophytes have attracted scientific attention because of their characteristics and biotechnological potential. For example, they are rich in a number of chemical compounds, such as fatty acids, carotenoids, phycobiliproteins and polysaccharides, which are mainly used for food, medicine, cosmetics and pharmaceuticals. This paper provides a review of studies that assess protective algal compounds and introduce cryptophytes as a remarkable source of bioactive components that may be usable in biomedical and pharmaceutical sciences.

Efficacy of omega-3 supplementation on sertraline continuous therapy to reduce depression or anxiety symptoms: A systematic review and meta-analysis

We aimed to synthesize the evidence from randomized controlled trials (RCTs) that determined the efficacy of adding omega-3 supplementation to the continuous sertraline therapy in adults with depression. Meta-analyses were performed using random effects. We used the Revised Cochrane risk of bias tool for randomized trials version 2.0. to assess the risk of bias. Four RCTs were included. The follow-up ranged from eight to 12 weeks. Regarding the Beck Depression Inventory, the pooled SMD was 0.50 (95% CI: -0.51, 1.50; I²: 94.1%). A subgroup analysis was performed regarding the presence of coronary disease: SMD -0.17 (95% CI: -0.41, 0.07; I²: 0.0%). Regarding the Beck Anxiety Inventory, the pooled MD was 0.03 (95% CI: -2.22, 2.28; I²: 0.0%). Regarding the Hamilton Depression Rating Scale, the pooled MD was 0.42 (95% CI: -1.44, 2.29; I²: 35.7%). All pooled outcomes presented a very low certainty of the evidence. Three RCTs presented a low risk of bias in all domains; however, one study presented some concerns in two domains. No essential reductions in the outcomes were found. A subgroup analysis suggested that may be better not to provide the supplementation in patients with coronary disease. The evidence is not enough to make recommendations.

Associations among Dietary Omega-3 Polyunsaturated Fatty Acids, the Gut Microbiota, and Intestinal Immunity

Omega-3 polyunsaturated fatty acids (omega-3 PUFAs), which are essential fatty acids that humans should obtain from diet, have potential benefits for human health. In addition to altering the structure and function of cell membranes, omega-3 PUFAs (docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), alpha-linolenic acid (ALA), and docosapentaenoic acid (DPA)) exert different effects on intestinal immune tolerance and gut microbiota maintenance. Firstly, we review the effect of omega-3 PUFAs on gut microbiota. And the effects of omega-3 PUFAs on intestinal immunity and inflammation were described. Furthermore, the important roles of omega-3 PUFAs in maintaining the balance between gut immunity and the gut microbiota were discussed. Additional factors, such as obesity and diseases (NAFLD, gastrointestinal malignancies or cancer, bacterial and viral infections), which are associated with variability in omega-3 PUFA metabolism, can influence omega-3 PUFAs–microbiome–immune system interactions in the intestinal tract and also play roles in regulating gut immunity. This review identifies several pathways by which the microbiota modulates the gut immune system through omega-3 PUFAs. Omega-3 supplementation can be targeted to specific pathways to prevent and alleviate intestinal diseases, which may help researchers identify innovative diagnostic methods.

Current Research on Complementary and Alternative Medicine (CAM) in the Treatment of Major Depressive Disorder: An Evidence-Based Review

Complementary and alternative medicine (CAM) encompasses a wide range of different non-mainstream therapies that have been increasingly used for treatment or adjunctive treatment of various ailments with mood disorders and "depressive difficulties" being two of the commonly CAM (self-)medicated conditions. We focus specifically on clinically diagnosed (in line with the standard criteria) depressive disorders, primarily major depressive disorder (MDD), and overview evidence of efficacy/safety of a range of CAM modalities addressing exclusively randomized controlled trials (RCTs) and systematic reviews/meta-analyses of RCTs. The list of addressed CAM interventions is not exhaustive: due to space limitation, addressed are interventions with at least a few conducted RCTs in the specific clinical conditions. We try to provide numerical and meaningful data as much as it is possible and to (a) indicate situations in which the reported data/estimates might have been "too enthusiastic" and (b) warn about heterogeneity of results that, together with other possible limitations (various biases and imprecision), results in uncertainty about the effects.

Low Omega-3 intake is associated with high rates of depression and preterm birth on the country level

Low circulating levels of long chain omega-3 polyunsaturated fatty acids (LC omega-3 PUFA) have been linked to major depressive disorder (MDD) and preterm birth (PTB), and prenatal depression associates with PTB. We therefore hypothesized that low Omega-3 intake would associate with higher MDD and PTB rates on the country-level. To test this hypothesis, we obtained country-level estimates for omega-3 intake, MDD prevalence, PTB rate, and per capita income for 184 countries in 2010. We then estimated the LC omega-3 PUFA levels that these intakes produce by accounting for direct consumption and the endogenous conversion of ingested plant-based precursors. Penalized splines indicated that MDD and PTB rates decreased linearly with increasing LC omega-3 PUFA, up to ~ 1000 mg/day for MDD and up to ~ 550 mg/day for PTB. Adjusted linear regression models below these thresholds revealed that a one standard deviation increase in LC omega-3 PUFA (380 mg/day) was associated with an MDD decrease of 5 cases/1000 people and a PTB decrease of 15 cases/1000 livebirths. In light of the extensive prior evidence on the individual-level, these findings indicate that low intake of LC omega-3 PUFA and its precursors may be elevating MDD and PTB rates in 85% of the countries studied.

Supplementation-induced increase in circulating omega-3 serum levels is not associated with a reduction in depressive symptoms: Results from the MooDFOOD depression prevention trial

BACKGROUND

There is ambiguity on how omega-3 (n-3) polyunsaturated fatty acids (PUFAs) are associated with depression, and what the temporality of the association might be. The present study aimed to examine whether (intervention-induced changes in) n-3 PUFA levels were associated with (changes in) depressive symptoms.

METHODS

Baseline, 6- and 12-month follow-up data on 682 overweight and subclinically depressed persons from four European countries that participated in the MooDFOOD depression prevention randomized controlled trial were used. Participants were allocated to four intervention groups: (a) placebos, (b) placebos and food-related behavioral activation therapy (F-BA), (c) multinutrient supplements (fish oil and multivitamin), and (d) multinutrient supplements and F-BA. Depressive symptoms were measured using the inventory of depressive symptomatology. PUFA levels (µmol/L) were measured using gas chromatography. Analyses were adjusted for sociodemographics, lifestyle, and somatic health.

RESULTS

Increases in n-3 PUFA, docosahexaenoic acid, and eicosapentaenoic acid levels over time were significantly larger in the supplement groups than in placebo groups. Change in PUFA levels was not significantly associated with the change in depressive symptoms (β = .002, SE = 0.003, p = .39; β = .003, SE = 0.005, p = .64; β = .005, SE = 0.005, p = .29; β = -.0002, SE = 0.0004, p = .69). Baseline PUFA levels did not modify the intervention effects on depressive symptoms.

CONCLUSIONS

In overweight and subclinical depressed persons, multinutrient supplements led to significant increases in n-3 PUFA levels over time, which were not associated with changes in depressive symptoms. Multinutrient supplements do not seem to be an effective preventive strategy in lowering depressive symptoms over time in these at-risk groups.

Time Course and Sex Effects of α-Linolenic Acid-Rich and DHA-Rich Supplements on Human Plasma Oxylipins: A Randomized Double-Blind Crossover Trial

BACKGROUND

Differences in health effects of dietary α-linolenic acid (ALA) and DHA are mediated at least in part by differences in their effects on oxylipins.

OBJECTIVES

Time course and sex differences of plasma oxylipins in response to ALA- compared with DHA-rich supplements were examined.

METHODS

Healthy men and women, aged 19-34 y and BMI 18-28 kg/m2, were provided with capsules containing ∼4 g/d of ALA or DHA in a randomized double-blind crossover study with >6-wk wash-in and wash-out phases. Plasma PUFA and oxylipin (primary outcome) concentrations at days 0, 1, 3, 7, 14, and 28 of supplementation were analyzed by GC and HPLC-MS/MS, respectively. Sex differences, supplementation and time effects, and days to plateau were analyzed.

RESULTS

ALA supplementation doubled ALA concentrations, but had no effects on ALA oxylipins after 28 d, whereas DHA supplementation tripled both DHA and its oxylipins. Increases in DHA oxylipins were detected as early as day 1, and a plateau was reached by days 5-7 for 11 of 12 individual DHA oxylipins and for total DHA oxylipins. Nine individual DHA oxylipins reached a plateau in females with DHA supplementation, compared with only 4 in males. A similar time course and sex difference pattern occurred with EPA and its oxylipins with DHA supplementation. DHA compared with ALA supplementation also resulted in higher concentrations of 4 individual arachidonic acids, 1 linoleic acid, and 1 dihomo-γ-linolenic acid oxylipin, despite not increasing the concentrations of these fatty acids, further demonstrating that oxylipins do not always reflect their precursor PUFA.

CONCLUSIONS

DHA compared with a similar dose of ALA has greater effects on both n-3 and n-6 oxylipins in young, healthy adults, with differences in response to DHA supplementation occurring earlier and being greater in females. These findings can help explain differences in dietary effects of ALA and DHA.This study was registered at clinicaltrials.gov as NCT02317588.

Blues in the Brain and Beyond: Molecular Bases of Major Depressive Disorder and Relative Pharmacological and Non-Pharmacological Treatments

Despite the extensive research conducted in recent decades, the molecular mechanisms underlying major depressive disorder (MDD) and relative evidence-based treatments remain unclear. Various hypotheses have been successively proposed, involving different biological systems. This narrative review aims to critically illustrate the main pathogenic hypotheses of MDD, ranging from the historical ones based on the monoaminergic and neurotrophic theories, through the subsequent neurodevelopmental, glutamatergic, GABAergic, inflammatory/immune and endocrine explanations, until the most recent evidence postulating a role for fatty acids and the gut microbiota. Moreover, the molecular effects of established both pharmacological and non-pharmacological approaches for MDD are also reviewed. Overall, the existing literature indicates that the molecular mechanisms described in the context of these different hypotheses, rather than representing alternative ones to each other, are likely to contribute together, often with reciprocal interactions, to the development of MDD and to the effectiveness of treatments, and points at the need for further research efforts in this field.

Self-care for anxiety and depression: a comparison of evidence from Cochrane reviews and practice to inform decision-making and priority-setting

BACKGROUND

Self-care refers to a range of activities and approaches undertaken by an individual to maintain health and manage ill-health which may include various complementary or alternative approaches. The purpose of this study was to identify the self-care approaches used by the general public for depression and anxiety, assess the usefulness of Cochrane reviews for informing decisions on self-care and highlight any gaps in the evidence.

METHODS

Searches were carried out for surveys of self-care for anxiety and/or depression and for Cochrane reviews and protocols of interventions with potential for use in self-care. Data was extracted from each review and Plain Language Summaries assessed for content, consistency and readability. Interventions reported in surveys and in Cochrane reviews were compared and effectiveness of each assessed.

RESULTS

Surveys from 10 countries reported a variety of self-care interventions, 17 of which appeared in 2 or more surveys and which included dietary supplements, herbal medicines, mind-body therapies and various forms of exercise. Twenty-two reviews and 5 protocols on potential self-care interventions were identified, the majority in depression. Twelve interventions were judged effective or promising, most with small effect sizes. Readability of summaries was highly variable: half were written at college/university level. Several commonly used approaches were not covered by Cochrane reviews.

CONCLUSIONS

This study has revealed the interventions currently used by the general public which are judged effective or promising based on Cochrane reviews. Some disparity is highlighted between interventions used in practice and the availability of reliable evidence, and in the presentation of effectiveness and safety. Being able to direct patients to reliable, accessible information is a positive step in ensuring effective patient-centered, evidence-informed care. Addressing gaps, ensuring consistency and increasing usability of evidence intended for the general public will support this goal.

Association of a priori dietary patterns with depressive symptoms: a harmonised meta-analysis of observational studies

BACKGROUND

Review findings on the role of dietary patterns in preventing depression are inconsistent, possibly due to variation in assessment of dietary exposure and depression. We studied the association between dietary patterns and depressive symptoms in six population-based cohorts and meta-analysed the findings using a standardised approach that defined dietary exposure, depression assessment and covariates.

METHODS

Included were cross-sectional data from 23 026 participants in six cohorts: InCHIANTI (Italy), LASA, NESDA, HELIUS (the Netherlands), ALSWH (Australia) and Whitehall II (UK). Analysis of incidence was based on three cohorts with repeated measures of depressive symptoms at 5-6 years of follow-up in 10 721 participants: Whitehall II, InCHIANTI, ALSWH. Three a priori dietary patterns, Mediterranean diet score (MDS), Alternative Healthy Eating Index (AHEI-2010), and the Dietary Approaches to Stop Hypertension (DASH) diet were investigated in relation to depressive symptoms. Analyses at the cohort-level adjusted for a fixed set of confounders, meta-analysis used a random-effects model.

RESULTS

Cross-sectional and prospective analyses showed statistically significant inverse associations of the three dietary patterns with depressive symptoms (continuous and dichotomous). In cross-sectional analysis, the association of diet with depressive symptoms using a cut-off yielded an adjusted OR of 0.87 (95% confidence interval 0.84-0.91) for MDS, 0.93 (0.88-0.98) for AHEI-2010, and 0.94 (0.87-1.01) for DASH. Similar associations were observed prospectively: 0.88 (0.80-0.96) for MDS; 0.95 (0.84-1.06) for AHEI-2010; 0.90 (0.84-0.97) for DASH.

CONCLUSION

Population-scale observational evidence indicates that adults following a healthy dietary pattern have fewer depressive symptoms and lower risk of developing depressive symptoms.

Nutrition interventions in populations with mental health conditions: a scoping review

Nutrition is a modifiable factor for intervention in mental disorders. This scoping review characterized nutrition intervention research in mental disorders. A 3-category framework characterized nutrition interventions: Guide (e.g., counselling), Provide (e.g., food provisions), and Add (e.g., supplementation). Nutrition interventions were classified as single-component (e.g., Guide) or complex (e.g., Guide-Provide). Sixty-nine trials met inclusion criteria, 96% were randomized controlled trials. Most commonly diagnosed mental disorders were depressive disorder (i.e., persistent) or major depressive disorder (n = 39), schizophrenia (n = 17), and other psychotic disorders (n = 13). Few trials included patients with anxiety disorders (n = 2) or bipolar disorders (n = 3). Several trials (n = 15, 22%) assessed and implemented nutrition interventions to improve dietary patterns, of which 11 (73%) reported statistically significant and clinically important positive effects of nutrition interventions on mental disorders. The majority of the trials (n = 61, 90%) investigated supplementation, most commonly adding essential fatty acids, vitamins, or minerals. The majority (n = 48, 70%) reported either statistically significant or clinically important effect and 31 (51%) reported both. Though most interventions led to statistically significant improvements, trials were heterogeneous for targeted mental disorders, nutrition interventions, and outcomes assessed. Given considerable heterogeneity, further research from robust and clinically relevant trials is required to support high-quality health care with effective nutrition interventions. Novelty Future research on whole-diet interventions powered to detect changes in mental health outcomes as primary objectives is needed. Dietitians may be an opportunity to improve feasibility and efficacy of nutrition interventions for mental disorder patients. Dietitians may be of value to educate mental health practitioners on the importance of nutrition.

Effects of Fish Oil Monotherapy on Depression and Prefrontal Neurochemistry in Adolescents at High Risk for Bipolar I Disorder: A 12-Week Placebo-Controlled Proton Magnetic Resonance Spectroscopy Trial

Objectives: To evaluate the clinical and neurochemical effects of 12-week fish oil, a source of omega-3 polyunsaturated fatty acids (n-3 PUFAs), in depressed adolescents with a family history of bipolar I disorder. Methods: Adolescents with a current Diagnostic and Statistical Manual of Mental Disorders, 4th edition, Text Revision diagnosis of Major Depressive Disorder or Depressive Disorder not otherwise specified, a Childhood Depression Rating Scale-Revised (CDRS-R) Version raw score of ≥40, and at least one biological parent with bipolar I disorder were randomized to double-blind treatment with fish oil (2100 mg/day) or placebo for 12 weeks. The primary outcome measure was change in CDRS-R total score, and secondary outcomes measures were change in manic symptoms (Young Mania Rating Scale), global symptom and functioning measures (Clinical Global Impression-Severity [CGI-S] /CGI Improvement [CGI-I], Children's Global Assessment Scale, and Child Behavior Checklist), safety and laboratory measures, and anterior cingulate cortex (ACC) and bilateral ventrolateral prefrontal cortex neurometabolite concentrations using proton magnetic resonance spectroscopy at 4 T. Results: Fifty-six patients were randomized, and 42 completed the 12-week trial (placebo: n = 21; fish oil, n = 21). Subjects randomized to fish oil, but not placebo, exhibited a significant baseline to endpoint increase in erythrocyte n-3 PUFAs. Reductions in CDRS-R scores did not differ between treatment groups (p = 0.15), and similar remission (p = 0.58) and response (p = 0.77) rates were observed. Fish oil produced a significantly greater decrease in CGI-S (p = 0.0042) and CGI-I (p = 0.036) scores compared with placebo. Baseline to endpoint change in ACC creatine (p = 0.004) and ACC choline (Cho) (p = 0.024) differed significantly between groups. Baseline ACC Cho levels were inversely correlated with baseline and baseline to endpoint change in CDRS-R scores, and baseline to endpoint change in ACC Cho correlated with baseline-endpoint change in CDRS-R scores and n-3 PUFA. There were no group differences in safety and tolerability ratings or laboratory measures. Conclusions: Fish oil monotherapy was not superior to placebo for reducing depressive symptoms in high-risk youth as assessed by the CDRS-R, but was safe and well tolerated and superior to placebo on clinician ratings of global symptom improvement. Associations among ACC Cho levels, depression symptom severity, and n-3 PUFA warrant additional investigation.

Antidepressant efficacy and side effect burden: an updated guide for clinicians

Antidepressant treatment has been evolving and changing since the 1950s following the discovery of the classic antidepressant treatments including tricyclic antidepressants and monoamine oxidase inhibitors. The heterogeneity of the disorder became apparent in the beginning when individuals remained symptomatic despite medication compliance. This spurred further research in order to understand the neurobiology underlying the disorder. Subsequently, newer medications were designed to target specific neurotransmitters and areas of the brain involved in symptom development and maintenance. Our original review article looked at both classic and modern antidepressant medications used in the treatment of major depressive disorder. This manuscript is an update to the original review and serves to provide clinicians with information about novel antidepressant medications, augmentation strategies with atypical antipsychotics, over-the-counter medications, as well as nonpharmaceutical treatments that should be considered when treating each individual patient who remains symptomatic despite treatment efforts.

High-dose omega-3 polyunsaturated fatty acid supplementation might be more superior than low-dose for major depressive disorder in early therapy period: a network meta-analysis

BACKGROUND

The application of n-3 Polyunsaturated Fatty Acids (n-3 PUFAs) supplementation for major depressive disorder (MDD) has been widely discussed in recent years, but its efficacy and application are still controversial. This network meta-analysis was conducted to compare the efficacy of different dosages of n-3 PUFAs on MDD patients in the early period of treatment.

METHODS

Randomized controlled trials (RCTs) exploring the efficacy of n-3 PUFA supplementation for patients with MDD were retrieved from the databases of Pubmed, Embase and the Cochrane Library. RCTs comparing the efficacy of n-3 PUFA for adult (≥18 years) MDD patients without comorbidity were eligible for our study. The score of depressive symptoms in early therapy period of the treatment (≤9 weeks) was extracted. Standardized mean deviations (SMDs) of all the sores from the eligible RCTs were synthesized in a pairwise meta-analysis in frequentist framework and a random-effects network meta-analysis in Bayesian framework for the overall and subgroups (high- and low-dose) efficacy of n-3 PUFAs.

RESULTS

A total of 910 MDD patients in 10 trials with 3 adjuvant therapy strategies (high-dose n-3 PUFAs, low-dose n-3 PUFAs and placebo) were included. Results of pairwise meta-analysis showed that n-3 PUFAs were superior to placebo (SMD: 1.243 ± 0.596; 95% CI: 0.060 ~ 2.414). Results of the network meta-analysis showed that both the high (SMD: 0.908 ± 0.331; 95% CI: 0.262 ~ 1.581) and the low-dose (SMD: 0.601 ± 0.286; 95% CI: 0.034 ~ 1.18) n-3 PUFAs were superior to placebo, and the efficacy of high-dose n-3 PUFAs is superior to that of low-dose.

CONCLUSIONS

High-dose n-3 PUFAs supplementation might be more superior than low-dose in the early therapy period for MDD. More head-to-head clinical trials need to be carried out to provide more direct comparison and enhance the evidence of the efficacy of n-3PUFAs for MDD.

Fish-oil supplementation decreases Indoleamine-2,3-Dioxygenase expression and increases hippocampal serotonin levels in the LPS depression model

AIM

To test the hypothesis that the antidepressant-like effect of omega-3 polyunsaturated fatty acids is related to the Indoleamine-2,3-Dioxygenase (IDO) inhibition.

METHODS

Animals were supplemented for 50 days with 3.0 g/kg of Fish Oil (FO) or received water (Control group - C), via gavage. At the end of this period, both groups were injected with LPS 24 h before the modified forced swim test (MFST) and the open field. To assess the possible involvement of IDO in the FO effects, we performed two independent experiments, using two IDO inhibitors: the direct inhibitor 1-methyl-DL-tryptophan (1-MT) and the anti-inflammatory drug minocycline (MINO), administered 23 h, 5 h and 1 h before the tests. After the tests, the animals' hippocampi were removed for quantification of serotonin (5-HT) and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) by HPLC, and for IDO expression by western blot.

RESULTS

LPS induced a depressive-like state in the animals, and this effect was blocked by 1-MT, MINO and FO. Regardless of IDO inhibition, FO supplemented animals displayed an antidepressant-like response by increasing swimming and decreasing immobility frequencies in the MFST when compared to the control group. The immune challenge induced an over-expression of IDO and reduced hippocampal 5-HT levels, both of which were reversed by MINO and FO.

CONCLUSION

FO induced a pronounced antidepressant-like effect and prevented LPS-induced depressive-like behavior, and this effect was related to decreased IDO expression and increased 5-HT levels in the hippocampus.

Fatty acids and recurrence of major depressive disorder: combined analysis of two Dutch clinical cohorts

OBJECTIVE

Omega-3 (n-3) and omega-6 (n-6) polyunsaturated fatty acid (PUFA) alterations in patients with major depressive disorder (MDD) have been shown to persist after remission. Whether these alterations are risk factors for MDD recurrence remains unknown. Here, we examined whether fatty acids predict time until MDD recurrence in remitted MDD patients.

METHODS

Data were used from remitted MDD patients of the Netherlands Study of Depression and Anxiety (n = 356) and the Depression Evaluation Longitudinal Therapy Assessment studies (n = 118). Associations of FAs with time until MDD recurrence up to 8-year follow-up were analyzed using Cox regression analyses. Study-specific estimates were pooled using mega- and meta-analysis techniques.

RESULTS

27.5% (NESDA) and 56.8% (DELTA) participants had an MDD recurrence. Pooled results showed that no FA was significantly associated with time until MDD recurrence (n-3 PUFAs: hazard ratio (HR) = 1.17, 95% confidence interval (CI) = 0.98-1.41, P = 0.082; n-6 PUFAs: HR = 1.08, 95% CI = 0.84-1.38, P = 0.55).

CONCLUSION

In remitted MDD patients, circulating PUFAs were not associated with prospective risk of MDD recurrence. Consequently, circulating PUFAs are unlikely to reflect a vulnerability marker for recurrence, so correcting n-3 PUFA 'deficits' through supplementation does not seem a promising option to prevent MDD recurrence.

A multi-national, multi-disciplinary Delphi consensus study on using omega-3 polyunsaturated fatty acids (n-3 PUFAs) for the treatment of major depressive disorder

INTRODUCTION

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) are recommended as an integrative treatment for major depressive disorder (MDD). In 2019, the International Society for Nutritional Psychiatry Research (ISNPR) developed the first practice guidelines for n-3 PUFA treatment of MDD. To strengthen these guidelines and enhance their clinical applicability, we synthesized the evidence and clinical experiences previously obtained through the Delphi methodology.

METHODS

Nineteen statements covering five major domains in MDD treatment were formulated through internal meetings. Fourteen international experts were invited to participate in the web-based Delphi process that validated the statements. Likert scales were used, and consensus level was set at 7.0/10.0, with the equivocal level set at 5.1-6.9. The items with scores < 5.0 were allocated into a second round Delphi survey with inverse questions.

RESULTS

All panelists completed the survey. Sixteen statements reached consensus, and the statement "n-3 PUFAs are one of the potential adjunctive treatments for adult MDD" reached the highest agreement. "N-3 PUFAs are one of the potential monotherapies for adult MDD" instead scored lowest. Regarding "special populations," many items, reached high consensus despite sub-optimal supportive evidence.

LIMITATION

The panelists had a specialized interest in n-3 PUFAs; focus was placed on clinical issues rather than on biological mechanisms.

CONCLUSIONS

The Delphi process helps bridge the gap between scientific evidence and clinical practice, supports certain uses of PUFA and identifies insufficiency in current evidence that merit future research.

Annual Research Review: Defining and treating pediatric treatment-resistant depression

BACKGROUND

Adolescent major depressive disorder (MDD) is a significant health problem, associated with substantial morbidity, cost, and mortality. Depression is a significant risk factor for suicide, which is now the second leading cause of death in young people. Up to twenty per cent of adolescents will experience MDD before adulthood, and while a substantial proportion will improve with standard-of-care treatments (psychotherapy and medication), roughly one third will not.

METHODS

Here, we have reviewed the literature in order to discuss the concept of treatment-resistant depression (TRD) in adolescence, examine risk factors, diagnostic difficulties, and challenges in evaluating symptom improvement, and providing guidance on how to define adequate medication and psychotherapy treatment trials.

RESULTS

We propose a staging model for adolescent TRD and review the treatment literature. The evidence base for first- and second-line treatments primarily derives from four large pediatric clinical trials (TADS, TORDIA, ADAPT, and IMPACT). After two medications and a trial of evidence-based psychotherapy have failed to alleviate depressive symptoms, the evidence becomes quite thin for subsequent treatments. Here, we review the evidence for the effectiveness of medication switches, medication augmentation, psychotherapy augmentation, and interventional treatments (i.e., transcranial magnetic stimulation, electroconvulsive therapy, and ketamine) for adolescent TRD. Comparisons are drawn to the adult TRD literature, and areas for future pediatric depression research are highlighted.

CONCLUSIONS

As evidence is limited for treatments in this population, a careful consideration of the known risks and side effects of escalated treatments (e.g., mood stabilizers and atypical antipsychotics) is warranted and weighed against potential, but often untested, benefits.

Nutraceutical Augmentation Strategies for Depression: A Narrative Review

Context

Depression is one of the most commonly diagnosed psychiatric disorders, but antidepressant pharmacotherapy often fails to achieve remission, leading health care professionals and researchers to consider various augmentation strategies to improve clinical outcomes.

Objective

To assess the safety, tolerability, and efficacy of nutraceutical augmentation for depression.

Methods

Nutraceutical-focused systematic reviews and clinical practice guidelines identified the more commonly studied augmentation strategies for depression.

Results

S-adenosylmethionine, l-methylfolate, omega-3 fatty acids, and hydroxyvitamin D have sufficient scientific evidence to support their clinical consideration in the stepped care approach to the management of depression.

Conclusions

Clinical remission is the goal in the management of depression, and nutraceuticals may be part of an overall treatment approach to achieve that outcome.

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.

Depression as is Seen by Molecular Spectroscopy. Phospholipid- Protein Balance in Affective Disorders and Dementia

There is an expanding field of research investigating the instrumental methods to measure the development of affective disorders. The goal of the commentary is to turn the attention of medical practitioners at the molecular spectroscopy techniques (FTIR, Raman and UV-Vis) that can be applied for monitoring and quantification of the phospholipid-protein balance in human blood serum of depressed patients. Even facial overview of cited original research strongly suggests that disturbed phospholipid-protein balance could be one of the biomarkers of affective disorders. The blood serum monitoring of depressed patients would serve as a tool for more effective holistic therapy.

Calanus oil in the treatment of obesity-related low-grade inflammation, insulin resistance, and atherosclerosis

Calanus oil (COil) is a natural product extracted from marine zooplankton Calanus finmarchicus found in the North Atlantic Ocean. This oil is rich in wax esters of polyunsaturated fatty acids (PUFAs) and has been projected as the best alternative to fish oil because its production cannot keep pace with the demands from the growing markets. The COil is the only commercially available marine source of wax esters, whereas classic ω-3 PUFAs comes from triglycerides, ethyl esters, and phospholipids. It has, in recent decades, been seen that there is an unprecedented rise in the use of PUFA-rich oil in the aquaculture industry. A simultaneous rise in the demand of PUFAs is also observed in the health care industry, where PUFAs are suggested preventing various disorders related to lifestyles such as obesity, diabetes mellitus, chronic low-grade inflammation, atherosclerosis, and brain and cardiovascular disorders (CVDs). In this review, we will explore the metabolic aspects related to the use of COil as an antioxidant, anticholesterinemic, and anti-inflammatory dietary source and its impact on the prevention and therapy of obesity-related metabolic disorders.

Polyunsaturated Fatty Acids: What is Their Role in Treatment of Psychiatric Disorders?

In the central nervous system omega-3 fatty acids modulate cell signaling and affect dopaminergic and serotonergic pathways. On this basis, a new application for omega-3 fatty acids has been proposed, concerning the treatment of several psychiatric disorders. The present article is an update of a previous systematic review and is aimed to provide a complete report of data published in the period between 1980 and 2019 on efficacy and tolerability of omega-3 fatty acids in psychiatric disorders. In July 2019, an electronic search on PUBMED, Medline and PsychINFO of all RCTs, systematic reviews and meta-analyses on omega-3 fatty acids and psychiatric disorders without any filter or MESH restriction was performed. After eligibility processes, the final number of records included in this review was 126. One hundred and two of these studies were RCTs, while 24 were reviews and meta-analyses. The role of omega-3 fatty acids was studied in schizophrenia, major depression, bipolar disorder, anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, attention deficit hyperactivity disorder (ADHD), autism spectrum disorders, eating disorders, substance use disorder and borderline personality disorder. The main evidence of the efficacy of omega-3 fatty acids has been obtained in treating depressive symptoms in patients with major depression and, to a lesser degree, bipolar depression. Some efficacy was also found in early phases of schizophrenia in addition to antipsychotic treatment, but not in the chronic phases of psychosis. Small beneficial effects of omega-3 fatty acids were observed in ADHD and positive results were reported in a few trials on core symptoms of borderline personality disorder. For other psychiatric disorders results are inconsistent.

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.

Efficacy of omega-3 PUFAs in depression: A meta-analysis

We conducted this meta-analysis of double-blind randomized placebo-controlled trials to estimate the efficacy of omega-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), in the improvement of depression. We applied a systematic bibliographic search in PubMed and EMBASE for articles published prior to 20 December 2017. This meta-analysis was performed using RevMan 5.3 and R 3.4.3, and means and standard deviations were calculated in fixed- or random-effects models based on the results of the Q-test. A sensitivity analysis was also conducted to evaluate the stability of the results, and publication bias was evaluated by a funnel plot and Egger's linear regression analysis. Our search resulted in 180 articles; we analyzed 26 studies, which included 2160 participants. The meta-analysis showed an overall beneficial effect of omega-3 polyunsaturated fatty acids on depression symptoms (SMD = -0.28, P = 0.004). Compared with placebo, EPA-pure (=100% EPA) and EPA-major formulations (≥60% EPA) demonstrated clinical benefits with an EPA dosage ≤1 g/d (SMD = -0.50, P = 0.003, and SMD = -1.03, P = 0.03, respectively), whereas DHA-pure and DHA-major formulations did not exhibit such benefits.Current evidence supports the finding that omega-3 PUFAs with EPA ≥ 60% at a dosage of ≤1 g/d would have beneficial effects on depression. Further studies are warranted to examine supplementation with omega-3 PUFAs for specific subgroups of subjects with inflammation, severity of depression, and the dose response for both EPA and DHA supplementation.

Complementary therapies for clinical depression: an overview of systematic reviews

OBJECTIVES

As clinical practice guidelines vary widely in their search strategies and recommendations of complementary and alternative medicine (CAM) for depression, this overview aimed at systematically summarising the level 1 evidence on CAM for patients with a clinical diagnosis of depression.

METHODS

PubMed, PsycInfo and Central were searched for meta-analyses of randomised controlled clinical trials (RCTs) until 30 June 2018. Outcomes included depression severity, response, remission, relapse and adverse events. The quality of evidence was assessed according to Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) considering the methodological quality of the RCTs and meta-analyses, inconsistency, indirectness, imprecision of the evidence and the potential risk of publication bias.

RESULTS

The literature search revealed 26 meta-analyses conducted between 2002 and 2018 on 1-49 RCTs in major, minor and seasonal depression. In patients with mild to moderate major depression, moderate quality evidence suggested the efficacy of St. John's wort towards placebo and its comparative effectiveness towards standard antidepressants for the treatment for depression severity and response rates, while St. John's wort caused significant less adverse events. In patients with recurrent major depression, moderate quality evidence showed that mindfulness-based cognitive therapy was superior to standard antidepressant drug treatment for the prevention of depression relapse. Other CAM evidence was considered as having low or very low quality.

CONCLUSIONS

The effects of all but two CAM treatments found in studies on clinical depressed patients based on low to very low quality of evidence. The evidence has to be downgraded mostly due to avoidable methodological flaws of both the original RCTs and meta-analyses not following the Consolidated Standards of Reporting Trials and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Further research is needed.