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

Intricate mechanism of anxiety disorder, recognizing the potential role of gut microbiota and therapeutic interventions

Anxiety is a widespread psychological disorder affecting both humans and animals. It is a typical stress reaction; however, its longer persistence can cause severe health disorders affecting the day-to-day life activities of individuals. An intriguing facet of the anxiety-related disorder can be addressed better by investigating the role of neurotransmitters in regulating emotions, provoking anxiety, analyzing the cross-talks between neurotransmitters, and, most importantly, identifying the biomarkers of the anxiety. Recent years have witnessed the potential role of the gut microbiota in human health and disorders, including anxiety. Animal models are commonly used to study anxiety disorder as they offer a simpler and more controlled environment than humans. Ultimately, developing new strategies for diagnosing and treating anxiety is of paramount interest to medical scientists. Altogether, this review article shall highlight the intricate mechanisms of anxiety while emphasizing the emerging role of gut microbiota in regulating metabolic pathways through various interaction networks in the host. In addition, the review will foster information about the therapeutic interventions of the anxiety and related disorder.

Effects of fish oil supplementation on bone turnover markers in depression: a pilot study

Background and objective

There is a close correlation between bone loss, depression, and antidepressants. N-3 PUFA supplementation has been considered an effective add-on therapeutic approach in ameliorating bone loss and relieving depression. However, the adjunctive effect of n-3 PUFA on bone metabolism in participants with depression is still unknown. This is a pilot study to investigate the dynamics of bone metabolism in depression and evaluate the efficacy of fish oil on bone loss in depression.

Methods

In this study, we focused on the change of bone turnover markers in depression, the effect of n-3 PUFA supplementation on bone turnover markers, and its association with clinical characteristics. A case-control study and a secondary analysis of a previously published randomized clinical trial (NCT03295708) that evaluates the efficacy of n-3 PUFA supplementation in venlafaxine-treated depressed participants have been included.

Results

The levels of PINP (z = -2.233, p = 0.026) in depressed participants were significantly increased compared with healthy controls at baseline. The secondary analysis has shown significant differences exited on CTX (χ 2 = 4.848, p = 0.028) and OSTEOC (χ 2 = 6.178, p = 0.013) between n-3 PUFA and placebo group. The levels of CTX and OSTEOC (p < 0.05) significantly decreased in the placebo group, which indicates that venlafaxine treatment reduces both bone formation and resorption markers. While the levels of OSTEOC and PINP were increased in the n-3 PUFA group (p < 0.05). Moreover, the change in bone turnover markers showed consistency with clinical symptomatic outcomes.

Conclusion

Participants with first-diagnosed, drug-naïve depression show active bone formation. Venlafaxine decreases bone remodeling, while n-3 PUFA increases bone formation, bringing light to preventing and treating bone loss in depression.

Clinical trial registration

ClinicalTrials.gov, NCT03295708.

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.

The Efficacy of Omega-3 Fatty Acids as the Monotherapy for Depression: A Randomized, Double-Blind, Placebo-Controlled Pilot Study

OBJECTIVE

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) have demonstrated protective effects in major depressive disorder (MDD) patients receiving antidepressant treatment. However, there have been a few double-blind randomized controlled trials focused on n-3 PUFAs as monotherapy in MDD, and the outcomes have been mixed. This study aimed to assess the clinical effects of n-3 PUFAs monotherapy in patients with MDD.

METHODS

A total of 60 patients with MDD participated in this 12-week double-blind randomized controlled trial. They were randomized to either the n-3 PUFAs group (n = 30; 3.2 g of eicosapentaenoic acid, EPA and docosahexaenoic acid, DHA per day) or the placebo group (n = 30; 3.2 g of soybean oil per day). The severity of depression was evaluated using the Hamilton Rating Scale for Depression (HRSD).

RESULTS

The n-3 PUFAs group had a significantly lower HRSD score compared with the placebo group at week 4 (p = 0.004), week 6 (p = 0.006), week 8 (p = 0.004), and week 12 (p = 0.01). The n-3 PUFAs group showed slightly higher rates for both remission (26.7% vs. 10%, p = 0.095) and response (23.3% vs. 6.7%, p = 0.145) compared with the placebo group at week 12, but these differences did not reach statistical significance.

CONCLUSIONS

These findings suggested that monotherapy of n-3 PUFAs could improve depression and potentially serve as an alternative option for MDD patients.

N-3 PUFA supplementation alleviates anxiety symptoms by manipulating erythrocyte fatty acid levels in depression

PURPOSE

Major depressive disorder (MDD) is frequently accompanied by the symptoms of clinical anxiety. Since our previous research has found that n-3 PUFA supplementation alleviates anxiety in MDD, this study was aimed to further explore whether n-3 PUFA supplementation improves anxiety symptoms in depression by directly manipulating fatty acid levels.

METHODS

A secondary analysis of biomarker data (erythrocyte fatty acid composition) collected as part of the randomized clinical trial which investigated the adjunctive effect of n-3 PUFAs was conducted on 72 venlafaxine-treated outpatients with first-diagnosed, drug-naïve depression. All participants with longitudinal biomarker data were included in the association analysis to determine how n-3 PUFA supplementation influences fatty acid composition and alleviates anxiety symptoms in depression.

RESULTS

Decreases of the C20:3n6 were found in all participants at both follow-up time points (χ2 = 96.36, p = 0.000). The n-3 index (χ2 = 10.59, p = 0.001), EPA (χ2 = 24.31, p = 0.000), and C22:5n3/C20:5n3 ratio (χ2 = 10.71, p = 0.001) were increased, while C22:4n6 (χ2 = 7.703, p = 0.006) was decreased in n-3 PUFA group compared to the placebo group. The improvement in anxiety symptoms positively correlates with the extent of reduction of C16:0, C18:0, and total fatty acid levels as well as D5 desaturase activity (p < 0.05).

CONCLUSION

These data suggest that the anxiolytic effect exerted by n-3 PUFAs in first-diagnosed, drug-naïve depression is manipulated by erythrocyte fatty acid levels. Saturated fatty acid levels have an important role in predicting the severity of anxiety symptoms.

Depression, Anxiety, Emotional Eating, and Body Mass Index among Self-Reported Vegetarians and Non-Vegetarians: A Cross-Sectional Study in Peruvian Adults

Background: Vegetarianism is commonly associated with various health benefits. However, the association between this dietary regimen and aspects of mental health remains ambiguous. This study compared the symptoms of depression and anxiety, emotional eating (EmE), and body mass index (BMI) in Peruvian vegetarian and non-vegetarian adults. Methods: A cross-sectional study was conducted on 768 Peruvian adults, of whom 284 (37%) were vegetarians and 484 (63%) were non-vegetarians. The Depression Patient Health Questionnaire-2 (PHQ-2), Generalized Anxiety Disorder Scale-2 (GAD-2), and an EmE questionnaire were applied; additionally, the BMI was calculated. Simple and multiple linear regression and Poisson regression models with robust variance were used to evaluate the association between depression, anxiety, EmE, and BMI with dietary patterns. Results: The vegetarians (Adjusted Prevalence Ratio [PR] = 0.24, 95% CI 0.16-0.31; p < 0.001) reported more depressive symptoms than the non-vegetarians. This trend persisted for anxiety, with an adjusted PR of 0.17 (95% CI: 0.01-0.29; p = 0.012). However, the vegetarians (adjusted PR = -0.38, 95% CI: -0.61--0.14; p < 0.001) reported lower EmE scores compared to the non-vegetarians. Likewise, the vegetarians had a lower mean BMI than the non-vegetarians (B = -0.16, 95% CI: -0.21--0.08; p < 0.001). Conclusions: Vegetarian diets are associated with increased symptoms of depression and anxiety, as well as lower EmE and BMI scores. Further longitudinal studies are needed to elucidate these associations and determine causality and the underlying mechanisms involved.

Efficacy and acceptability of anti-inflammatory agents in major depressive disorder: a systematic review and meta-analysis

Background

Anti-inflammatory agents have emerged as a potential new therapy for major depressive disorder (MDD). In this meta-analysis, our aim was to evaluate the antidepressant effect of anti-inflammatory agents and compare their efficacy.

Methods

We conducted a comprehensive search across multiple databases, including PubMed, Embase, Web of Science, Cochrane Review, Cochrane Trial, and ClinicalTrials.gov, to identify eligible randomized clinical trials. The primary outcome measures of our meta-analysis were efficacy and acceptability, while the secondary outcome measures focused on remission rate and dropout rate due to adverse events. We used odds ratio (OR) and 95% confidence interval (95% CI) to present our results.

Results

A total of 48 studies were included in our analysis. In terms of efficacy, anti-inflammatory agents demonstrated a significant antidepressant effect compared to placebo (OR = 2.04, 95% CI: 1.41-2.97, p = 0.0002). Subgroup analyses revealed that anti-inflammatory agents also exhibited significant antidepressant effects in the adjunctive therapy subgroup (OR = 2.17, 95% CI: 1.39-3.37, p = 0.0006) and in MDD patients without treatment-resistant depression subgroup (OR = 2.33, 95% CI: 1.53-3.54, p < 0.0001). Based on the surface under the cumulative ranking curve (SUCRA) value of network meta-analysis, nonsteroidal anti-inflammatory drugs (NSAIDs) (SUCRA value = 81.6) demonstrated the highest acceptability among the included anti-inflammatory agents.

Conclusion

In summary, our meta-analysis demonstrates that anti-inflammatory agents have significant antidepressant effects and are well-accepted. Furthermore, adjunctive therapy with anti-inflammatory agents proved effective in treating MDD. Among the evaluated anti-inflammatory agents, NSAIDs exhibited the highest acceptability, although its efficacy is comparable to placebo.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=422004), identifier CRD42023422004.

Sex differences in erythrocyte fatty acid composition of first-diagnosed, drug-naïve patients with major depressive disorders

Background: Since depression, sex hormones, and fatty acid status are interrelated, it is important to understand their relationships. In this study, we aimed to investigate sex differences in erythrocyte membrane fatty acid composition among first-diagnosed, drug-naïve patients with major depressive disorders. Methods: The study included 139 individuals with first-diagnosed, drug-naïve depression (male/female = 48/91) and 55 healthy controls (male/female = 24/31). The levels of erythrocyte membrane fatty acids were analyzed to compare the difference between males and females in both patients with depression and healthy controls, as well as to study their correlation with depressive symptoms. Results: In first-diagnosed, drug-naïve patients with major depressive disorders, sex disparities were observed in the levels of erythrocyte saturated fatty acids (SFAs) and n-6 PUFAs (such as C18:0, C20:4n6 and C22:4n6), where higher levels evident in females compared to in males. We found a noteworthy correlation between fatty acid levels and depressive symptoms, in which there is a significant association between female patients and depression but a weaker association between male patients and depression. Conclusion: Our findings demonstrate higher levels of n-6 PUFAs and SFAs in female patients with depression. The relationship between fatty acid composition and depressive symptoms was more prominent in females than males. These findings highlight the significance of considering sex as a crucial and interconnected factor in future investigations and potential adjunctive treatment for mood disorders by targeting fatty acid metabolism.

Nonpharmacologic and Pharmacologic Treatments of Adult Patients With Major Depressive Disorder: A Systematic Review and Network Meta-analysis for a Clinical Guideline by the American College of Physicians

BACKGROUND

Primary care patients and clinicians may prefer alternative options to second-generation antidepressants for major depressive disorder (MDD).

PURPOSE

To compare the benefits and harms of nonpharmacologic treatments with second-generation antidepressants as first-step interventions for acute MDD, and to compare second-step treatment strategies for patients who did not achieve remission after an initial attempt with antidepressants.

DATA SOURCES

English-language studies from several electronic databases from 1 January 1990 to 8 August 2022, trial registries, gray literature databases, and reference lists to identify unpublished research.

STUDY SELECTION

2 investigators independently selected randomized trials of at least 6 weeks' duration.

DATA EXTRACTION

Reviewers abstracted data about study design and conduct, participants, interventions, and outcomes. They dually rated the risk of bias of studies and the certainty of evidence for outcomes of interest.

DATA SYNTHESIS

65 randomized trials met the inclusion criteria; eligible data from nonrandomized studies were not found. Meta-analyses and network meta-analyses indicated similar benefits of most nonpharmacologic treatments and antidepressants as first-step treatments. Antidepressants had higher risks for discontinuation because of adverse events than most other treatments. For second-step therapies, different switching and augmentation strategies provided similar symptomatic relief. The certainty of evidence for most comparisons is low; findings should be interpreted cautiously.

LIMITATIONS

Many studies had methodological limitations or dosing inequalities; publication bias might have affected some comparisons. In some cases, conclusions could not be drawn because of insufficient evidence.

CONCLUSION

Although benefits seem to be similar among first- and second-step MDD treatments, the certainty of evidence is low for most comparisons. Clinicians and patients should focus on options with the most reliable evidence and take adverse event profiles and patient preferences into consideration.

PRIMARY FUNDING SOURCE

American College of Physicians. (PROSPERO: CRD42020204703).