Suicide attempt and n-3 fatty acid levels in red blood cells: a case control study in China

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

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

Effect of age and dietary habits on Red Blood Cell membrane fatty acids in a Southern Europe population (Basque Country)

The levels of blood eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are very variable and, in general, low in most of the world population. In this study, the effects of age, sex, COVID-19, and dietary habits on the lipid profile of the erythrocyte membranes were assessed in a sub-cohort of healthy population (N = 203) from a large cohort of individuals from the Basque Country, Spain, (AKRIBEA). Sex did not have an effect on RBC lipid profile. COVID-19 infected participants showed higher levels of DGLA. Oldest participants showed higher oleic acid, EPA and DHA levels. Arachidonic acid in RBC correlated positively with the intake of sunflower oil, butter, eggs, processed and red meat, whereas DHA and EPA correlated positively with oily and lean fish. Basque Country population showed lipid profiles similar to other high fish consuming countries, such as Italy and Japan. Baseline levels of the whole lipidomic profile of the RBC including SFA, MUFA and PUFA should be examined to obtain a better description of the health and nutritional status.

Plasma Phospholipid Polyunsaturated Fatty Acid Associations with Neurocognition

Neurocognitive deficits are implicated in major depressive disorder (MDD) and suicidal behavior, and cognitive function may be affected by blood levels of polyunsaturated fatty acids (PUFAs). Neuroprotective functions have been described for omega-3 (n-3) PUFAs, while omega-6 (n-6) PUFAs exhibit broadly opposing activities. Both classes of PUFAs are linked to MDD and suicidal behavior. However, few studies have investigated the relationships between PUFAs and neurocognitive function with respect to MDD or suicidal behavior. Among participants with MDD (n = 45) and healthy volunteers (HV, n = 30) we assessed performance on tasks of attentional capacity and executive function and its relationship to plasma phospholipid PUFA levels, expressed as a percentage of total plasma phospholipids, for eicosapentaenoic acid (EPA%), docosahexaenoic acid (DHA%), and arachidonic acid (AA%). Regression models tested the correlations between PUFA levels and task performance in three groups: MDD with a history of suicide attempt (SA, n = 20), MDD with no attempts (NA, n = 25), and HV. Interaction testing indicated a significant positive correlation of EPA% with continuous performance test scores in the NA group (F = 4.883, df = 2,72, p = 0.01), a measure of sustained attention. The AA% correlated negatively with performance on two executive function tasks, object alternation (beta = -3.97, z-score = -2.67, p = 0.008) and the Wisconsin card sort (beta = 0.80, t-score = -2.16, df = 69, p = 0.035), after adjustment for group and age, with no group effects. Our findings suggest a role for PUFA imbalance in attentional functioning and executive performance; however, no MDD-specific effect was observed.

The impact of lipid polyunsaturation on the physical and mechanical properties of lipid membranes

The lipid composition of cellular membranes and the balance between the different lipid components can be impacted by aging, certain pathologies, specific diets and other factors. This is the case in a subgroup of individuals with psychiatric disorders, such as schizophrenia, where cell membranes of patients have been shown to be deprived in polyunsaturated fatty acids (PUFAs), not only in brain areas where the target receptors are expressed but also in peripheral tissues. This PUFA deprivation thus represents a biomarker of such disorders that might impact not only the interaction of antipsychotic medications with these membranes but also the activation and signaling of the targeted receptors embedded in the lipid membrane. Therefore, it is crucial to understand how PUFAs levels alterations modulate the different physical properties of membranes. In this paper, several biophysical approaches were combined (Laurdan fluorescence spectroscopy, atomic force microscopy, differential scanning calorimetry, molecular modeling) to characterize membrane properties such as fluidity, elasticity and thickness in PUFA-enriched cell membranes and lipid model systems reflecting the PUFA imbalance observed in some diseases. The impact of both the number of unsaturations and their position along the chain on the above properties was investigated. Briefly, data revealed that PUFA presence in membranes increases membrane fluidity, elasticity and flexibility and decreases its thickness and order parameter. Both the level of unsaturation and their position affect these membrane properties.

Potential Suicide Prophylactic Activity by the Fish Oil Metabolite, 4-Hydroxyhexenal

Low levels of n-3 poly-unsaturated fatty acids (n-3 PUFAs) and high levels of n-6 PUFAs in the blood circulation are associated with an increased risk for suicide. Clinical studies indicate that docosahexaenoic acid (DHA, a n-3 PUFA found in fish-oil) displays protective effects against suicide. It has recently been proposed that the activation of the transcription factor NRF2 might be the pharmacological activity that is common to current anti-suicidal medications. Oxidation products from fish oil, including those from DHA, are electrophiles that reversibly bind to a protein ‘KEAP1’, which acts as the molecular inhibitor of NRF2 and so indirectly promotes NRF2-transcriptional activity. In the majority of publications, the NRF2-stimulant effect of DHA is ascribed to the metabolite 4-hydroxyhexenal (4HHE). It is suggested to investigate whether 4HHE will display a therapeutically useful anti-suicidal efficacy.

A Revision on the Effectiveness of Omega-3 Polyunsaturated Fatty Acids as Monotherapy in the Treatment of Major Depressive Disorder

BACKGROUND

Insufficient effectiveness and a difficult tolerability profile of antidepressant drugs for the treatment of major depressive disorder (MDD) have been reported, and polyunsaturated fatty acids (PUFAs) have been posited as reliable therapeutic alternatives. The present study investigated the efficacy of omega-3 PUFAs as monotherapy for MDD.

METHODS

Two well-trained reviewers independently looked at the most significant randomized clinical trials (RCTs) from the PubMed database regarding PUFAs' employment in MDD compared to placebo; "major depressive disorder" and "omega-3 fatty acids," or "omega-6 fatty acids," or "polyunsaturated fatty acids (PUFA)," or "n - 3 polyunsaturated fatty acids," or "eicosapentaenoic acid (EPA)," or "docosahexaenoic acid (DHA)" were used as the medical subject keywords.

RESULTS

Of the initial 96 potential RCTs based on titles and abstracts, 82 studies did not meet the inclusion criteria and were excluded. Six studies were excluded from the remaining 14 after full text revision. Eight RCTs met all the inclusion/exclusion criteria without reporting clear evidence of PUFAs' effectiveness in the treatment of MDD.

CONCLUSION

At present, there is no opportunity to recommend the use of omega-3 PUFAs monotherapy for the treatment of MDD, although their supplementation may be useful in some specific populations.

Resolvin D1 protects against cadmium chloride-induced memory loss and hippocampal damage in rats: A comparison with docosahexaenoic acid

BACKGROUND

Intoxication with cadmium (Cd) ions leads to hippocampal damage and cognitive impairment. However, omega-3 polyunsaturated fatty acids (n-3 PUFAs) exert neuroprotective effects in different animal models of neurodegeneration.

PURPOSE

This study compared the neuroprotective effect of the n-3 PUFA, docosahexaenoic acid (DHA), and its downstream metabolite, resolvin D1 (RVD1), on hippocampal damage and memory deficits in cadmium chloride (CdCl₂)-treated rats.

RESEARCH DESIGN

Control or CdCl₂ (0.5 mg/kg)-treated rats were subdivided into three groups (n = 18/each) and treated for 6 weeks as follows: (1) fed control diet, (2) fed DHA-rich diets (0.7 g/100 g), or (3) treated with RVD1 (0.2 μg/kg, i.p).

RESULTS

Treatment with a DHA-rich diet or RVD1 significantly increased the levels of docosahexaenoic acid and RVD1, respectively, in the hippocampal of CdCl₂-treated rats without affecting the reduction in the expression of the 15-lipooxygenase-1 (ALOX15). These effects were associated with improvements in rats' memory function and hippocampal structure, as well as a redction in the hippocampal levels of reactive oxygen species (ROS), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), nuclear localization of the nuclear factor-kappa beta p65 (NF-κB p65), and expression of cleaved caspase-3. Concomitantly, hippocampi of both groups of rats showed significantly higher levels of Bcl-2, superoxide dismutase (SOD), and glutathione (GSH), as well as enhanced nuclear levels of the nuclear factor erythroid 2-related factor 2 (Nrf-2). The effects of RVD1 on all these markers in the CdCl₂-induced rats were more profound than those of DHA. Also, the increase in the nuclear protein levels of Nrf-2 and the decrease in the levels of Bax and nuclear protein levels of NF-κB p65 were only seen in the hippocampal of CdCl₂ + RVD1-treated rats.

CONCLUSION

RVD1 is more powerful than DHA in preventing CdCl₂-induced memory loss and hippocampal damage in rats.

Disentangling the Molecular Mechanisms of the Antidepressant Activity of Omega-3 Polyunsaturated Fatty Acid: A Comprehensive Review of the Literature

Major depressive disorders (MDDs) are often associated with a deficiency in long-chain omega-3 polyunsaturated fatty acids (ω-3 PUFAs), as well as signs of low-grade inflammation. Epidemiological and dietary studies suggest that a high intake of fish, the major source of ω-3 PUFAs, is associated with lower rates of MDDs. Meta-analyses of randomized placebo-controlled ω-3 PUFAs intervention-trials suggest that primarily eicosapentaenoic acid (EPA), but not docosahexaenoic acid (DHA), is responsible for the proposed antidepressant effect. In this review, we dissect the current biological knowledge on EPA and DHA and their bioactive lipid metabolites to search for a pharmacological explanation of this, to date, unexplained clinical observation. Through enzymatic conversion by cyclooxygenase (COX), lipoxygenase (ALOX), and cytochrome P-450 monooxygenase (CYP), EPA and DHA are metabolized to major anti-inflammatory and pro-resolving lipid mediators. In addition, both ω-3 PUFAs are precursors for endocannabinoids, with known effects on immunomodulation, neuroinflammation, food intake and mood. Finally, both ω-3 PUFAs are crucial for the structure and organization of membranes and lipid rafts. While most biological effects are shared by these two ω-3 PUFAs, some distinct features could be identified: (1) The preferential CYP monooxygenase pathway for EPA and EPA derived eicosanoids; (2) The high CB2 receptor affinities of EPA-derived EPEA and its epoxy-metabolite 17,18-EEQ-EA, while the DHA-derived endocannabinoids lack such receptor affinities; (3) The competition of EPA but not DHA with arachidonic acid (AA) for particular glycerophospholipids. EPA and AA are preferentially incorporated into phosphatidylinositols, while DHA is mainly incorporated into phosphatidyl-ethanolamine, -serine and -choline. We propose that these distinct features may explain the superior antidepressant activity of EPA rich ω-3 PUFAs and that these are potential novel targets for future antidepressant drugs.

Blood omega-3 fatty acids and death from COVID-19: A pilot study

Very-long chain omega-3 fatty acids (EPA and DHA) have anti-inflammatory properties that may help reduce morbidity and mortality from COVID-19 infection. We conducted a pilot study in 100 patients to test the hypothesis that RBC EPA+DHA levels (the Omega-3 Index, O3I) would be inversely associated with risk for death by analyzing the O3I in banked blood samples drawn at hospital admission. Fourteen patients died, one of 25 in quartile 4 (Q4) (O3I ≥5.7%) and 13 of 75 in Q1-3. After adjusting for age and sex, the odds ratio for death in patients with an O3I in Q4 vs Q1-3 was 0.25, p = 0.07. Although not meeting the classical criteria for statistical significance, this strong trend suggests that a relationship may indeed exist, but more well-powered studies are clearly needed.

Relationships between inflammatory markers and suicide risk status in major depression

Pro-inflammatory status has been implicated in depression and suicidal behaviors. Polyunsaturated fatty acids (PUFAs) and cytokines, two types of inflammatory biomarkers, have been associated with suicide, independent of depression severity. How these biomarkers relate to each other is less clear. We measured plasma phospholipid levels of arachidonic acid (AA%), docosahexaenoic acid (DHA%), and eicosapentaenoic acid (EPA%) as a percentage of total phospholipids, as well as serum interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α), in 80 patients with major depressive disorder (MDD) and 24 healthy controls (HC). Individual PUFA and cytokine species were compared using ANOVA across four suicide risk-stratified groups: 1) highest-risk, recent (within 5 years) suicide attempters (n = 20); 2) high-risk, severe current suicidal ideators (having intent or plan) with no recent attempt history (n = 22); 3) low-risk, current non-ideators who were also lifetime non-attempters (n = 38); and 4) HC (n = 24). None of the participants were enrolled following an acute suicide attempt. Of biomarkers studied, only DHA% (p = 0.012) and IL-1β (p = 0.002) differed between groups. In post-hoc testing, DHA% was lower in attempters than ideators (p = 0.018) or MDD non-ideators (trend level, p = 0.073). IL-1β was lowest in attempters, differentiating them from ideators (p = 0.009) and HC (p = 0.004). Recent suicide attempt, one of the most powerful predictors of suicide risk, was also most closely tied to inflammatory indices in this study. Low DHA% as an indicator of suicide risk is consistent with previous reports; however, lower IL-1β was unexpected and may relate to acuity/chronicity of inflammation. There is a need for prospective studies of immune status with respect to suicidal behaviors.

Polyunsaturated fatty acids as predictors of future suicide attempt

Polyunsaturated fatty acids (PUFAs) and cholesterol are lipids implicated in suicide risk. We prospectively studied plasma glycerophospholipid PUFAs and cholesterol as putative predictors of suicide attempts. In a multicenter cohort study, we enrolled 123 patients admitted to the emergency department (ED) for suicidal ideation or suicide attempt. Clinical assessments were performed, with follow-up telephone evaluations 6, 12, 18, and 24 months later. Blood samples were obtained in the ED and assayed for PUFAs. Using survival analysis, suicide events were not predicted by eicosapentaenoic acid (EPA, HR: -0.83, 95%CI: 0.39-1.76, p = 0.621) or docosahexaenoic acid (DHA, HR: -0.60, 95%CI: 0.19-1.86, p = 0.371). However, higher arachidonic acid (AA) was a trend for a protective factor (HR=0.30, 95%CI: 0.08-1.08, p = 0.065) in the entire trans-diagnostic sample. This protective effect was significant in all participants with a prior suicide attempt history (n = 85; HR=0.16, 95%CI: 0.04-0.67, p = 0.012), and in the subgroup of attempters with major depressive disorder (MDD; n = 55, HR=0.15, 95%CI:0.03-0.76, p = 0.002). Total LDL- and HDL-cholesterol did not predict subsequent suicide events. AA, but not DHA or EPA, positively correlated with baseline depression severity in MDD patients (r = 0.3, p = 0.006). Contrary to our hypothesis that low n-3 PUFA levels would create risk, we found that while higher AA was associated with greater depression severity at baseline, low AA unexpectedly predicted subsequent suicide attempts, the more so in higher-risk patients. Although surprising, this result agrees with a minority of reports concerning n-6 PUFAs and may represent complex interactions with sample characteristics.

The Importance of Marine Omega-3s for Brain Development and the Prevention and Treatment of Behavior, Mood, and Other Brain Disorders

Most of the global population is deficient in long-chain marine omega-3s. In particular, docosahexaenoic acid (DHA), a long-chain omega-3 fatty acid, is important for brain and eye development. Additionally, DHA plays a significant role in mental health throughout early childhood and even into adulthood. In the brain, DHA is important for cellular membrane fluidity, function and neurotransmitter release. Evidence indicates that a low intake of marine omega-3s increases the risk for numerous mental health issues, including Attention Deficit Hyperactivity Disorder (ADHD), autism, bipolar disorder, depression and suicidal ideation. Studies giving supplemental marine omega-3s have shown promise for improving numerous mental health conditions. This paper will review the evidence surrounding marine omega-3s and mental health conditions.

Lipids and Suicide Risk

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

Brain serotonin transporter binding, plasma arachidonic acid and depression severity: A positron emission tomography study of major depression

BACKGROUND

Serotonin transporter (5-HTT) binding and polyunsaturated fatty acids (PUFAs) are implicated in major depressive disorder (MDD). Links between the two systems in animal models have not been investigated in humans.

METHODS

Using positron emission tomography (PET) and [¹¹C]DASB, we studied relationships between 5-HTT binding potential and plasma levels of PUFAs docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and arachidonic acid (AA) in medication-free MDD patients (n = 21). PUFAs were quantified using transesterification and gas chromatography. Binding potential BP_P, and alternative outcome measures BP_F and BP_ND, were determined for [¹¹C]DASB in six a priori brain regions of interest (ROIs) using likelihood estimation in graphical analysis (LEGA) to calculate radioligand total distribution volume (V_T), and a validated hybrid deconvolution approach (HYDECA) that estimates radioligand non-displaceable distribution volume (V_ND) without a reference region. Linear mixed models used PUFA levels as predictors and binding potential measures as outcomes across the specified ROIs; age and sex as fixed effects; and subject as random effect to account for across-region binding correlations. As nonlinear relationships were observed, a quadratic term was added to final models.

RESULTS

AA predicted both 5-HTT BP_P and depression severity nonlinearly, described by an inverted U-shaped curve. 5-HTT binding potential mediated the relationship between AA and depression severity.

LIMITATIONS

Given the small sample and multiple comparisons, results require replication.

CONCLUSIONS

Our findings suggest that AA status may impact depression pathophysiology through effects on serotonin transport. Future studies should examine whether these relationships explain therapeutic effects of PUFAs in the treatment of MDD.

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.

Neuroprotective effect of omega-3 fatty acids on spinal cord injury induced rats

INTRODUCTION

In this study, the effects of omega-3 fatty acids were examined in a rat model of spinal cord injury.

METHODS

The rats were classified into sham, control, spinal cord injury plus 50 mg/kg Omega-3 fatty acids and spinal cord injury plus 100 mg/kg Omega-3 fatty acids. The levels of oxidative, apoptotic, and inflammatory markers were examined in each of these groups.

RESULTS

Altered lipid peroxidation, reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (Gpx), and catalase were normalized. Omega-3 fatty acid supplementation decreased tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) levels by >50%. TNF-α and IL-6 mRNA expression were reduced. Caspase-3, p53, bax, and pro-NGF mRNA expression levels were increased by 1.3-, 1.4-, 1.2-, and 0.9-fold, respectively, whereas bcl-2 mRNA expression was decreased by 0.77-fold in control rats. Omega-3 fatty acid supplementation decreased p53, caspase-3, bax, and pro-NGF mRNA expression by >40%, while the level of bcl-2 mRNA expression was increased by 286.9%. Omega-3 fatty acid supplementation decreased caspase-3 and p53 protein expression by >30%.

CONCLUSION

Taken together, our results suggested that omega-3 fatty acid supplementation reduced oxidative stress, apoptosis, and the levels of inflammatory markers in ischemia-reperfusion-induced rats.

The synergistic therapeutic efficacy of vancomycin and omega-3 fatty acids alleviates Staphylococcus aureus-induced osteomyelitis in rats

Our study evaluated the synergistic impact of vancomycin and omega-3 fatty acids against osteomyelitis in a Staphylococcus aureus-induced rat model of osteomyelitis. The animals were grouped as follows: sham (group I), osteomyelitis (group II, control), vancomycin (20 mg/kg body weight, group III), omega-3 fatty acids (20 mg/kg body weight, group IV) and vancomycin (20 mg/kg body weight) + omega-3 fatty acids (20 mg/kg body weight) (group V). Lipid peroxidation, superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, reduced glutathione (GSH), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) were measured. The determination of bacterial growth and histopathological analyses were carried out. The lipid peroxidation, GSH, SOD, catalase and Gpx levels recovered to near-normal levels following combined treatment with vancomycin and omega-3 fatty acids. The TNF-α and IL-6 levels were reduced to near-normal levels. Combined supplementation with vancomycin and omega-3 fatty acids significantly reduced bacterial growth in bone and the implanted wire. Furthermore, the bone infection levels and histopathological score were reduced. In summary, combined treatment with vancomycin and omega-3 fatty acids was effective against bacterial growth and bone infection compared to monotherapy with vancomycin or omega-3 fatty acids.

Naturally absorbed polyunsaturated fatty acids, lithium, and suicide-related behaviors: A case-controlled study

OBJECTIVE

Previous studies have investigated the effects of omega-3, omega-6 and lithium on suicide-related behaviors separately. This study was performed to comprehensively investigate the effects of naturally absorbed EPA, DHA, arachidonic acid and lithium in relation to suicide attempt and deliberate self-harm, with adjustment for each other.

METHODS

We analyzed plasma EPA, DHA, arachidonic acid levels and serum lithium levels of 197 patients including 33 patients with suicide attempts, 18 patients with deliberate self-harm, and 146 control patients.

RESULTS

Multivariate logistic regression analysis with adjustment for age, gender, EPA, DHA, arachidonic acid and log-transformed lithium levels revealed that the negative associations with EPA levels (adjusted OR 0.972, 95% CI 0.947-0.997, p = 0.031) and log-transformed lithium levels (adjusted OR 0.156, 95% CI 0.038-0.644, p = 0.01) and the positive association with DHA levels (adjusted OR 1.026, 95% CI 1.010-1.043, p = 0.002) were significant in patients with suicide attempts than in control patients. The analysis also demonstrated that the positive association with arachidonic acid levels (adjusted OR 1.015, 95% CI 1.005-1.025, p = 0.004) was significant in patients with deliberate self-harm than in control patients.

LIMITATIONS

The limitations are relatively small number of patients and the effects of demographics of individual patients could not be adjusted for the analyses.

CONCLUSIONS

The present findings suggest that, as naturally absorbed nutrients, higher EPA and lithium levels may be associated with less suicide attempt, and that higher arachidonic acid levels may be associated with more deliberate self-harm.

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

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

How lipids may affect risk for suicidal behavior

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

Plasma Phosphatidylethanolamine and Triacylglycerol Fatty Acid Concentrations are Altered in Major Depressive Disorder Patients with Seasonal Pattern

Disturbances in peripheral and brain lipid metabolism, including the omega-3 fatty acid docosahexaenoic acid (DHA), have been reported in major depressive disorder (MDD). However, these changes have yet to be confirmed in MDD with seasonal pattern (MDD-s), a subtype of recurrent MDD. The present exploratory study quantified plasma plasmalogen and diacyl-phospholipid species, and fatty acids within total phospholipids, cholesteryl esters, triacylglycerols and free fatty acids in non-medicated MDD-s participants (n = 9) during euthymia in summer or fall, and during depression in winter in order to screen for potential high sensitivity lipid biomarkers. Triacylglycerol alpha-linolenic acid concentration was significantly decreased, and myristoleic acid concentration was significantly increased, during winter depression compared to summer-fall euthymia. 1-stearyl-2-docosahexaenoyl-sn-glycero-3-phosphoethanolamine, a diacyl-phospholipid containing stearic acid and DHA, was significantly decreased in winter depression. Concentrations of cholesteryl ester oleic acid and several polyunsaturated fatty acids between summer/fall and winter increased in proportion to the increase in depressive symptoms. The observed changes in lipid metabolic pathways in winter-type MDD-s offer new promise for lipid biomarker development.

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

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

Polyunsaturated fatty acids and suicide risk in mood disorders: A systematic review

Deficiency of omega-3 polyunsaturated fatty acids (PUFAs) and an alteration between the ratio of omega-3 and omega-6 PUFAs may contribute to the pathogenesis of bipolar disorder and unipolar depression. Recent epidemiological studies have also demonstrated an association between the depletion of PUFAs and suicide. Our aim was to investigate the relationship between PUFAs and suicide; assess whether the depletion of PUFAs may be considered a risk factor for suicidal behavior; in addition to detailing the potential use of PUFAs in clinical practice. We performed a systematic review on PUFAs and suicide in mood disorders, searching MedLine, Excerpta Medica, PsycLit, PsycInfo, and Index Medicus for relevant epidemiological, post-mortem, and clinical studies from January 1997 to September 2016. A total of 20 articles from peer-reviewed journals were identified and selected for this review. The reviewed studies suggest that subjects with psychiatric conditions have a depletion of omega-3 PUFAs compared to control groups. This fatty acid depletion has also been found to contribute to suicidal thoughts and behavior in some cases. However, large epidemiological studies have generally not supported this finding, as the depletion of omega-3 PUFAs was not statistically different between controls and patients diagnosed with a mental illness and/or who engaged in suicidal behavior. Increasing PUFA intake may be relevant in the treatment of depression, however in respect to the prevention of suicide, the data is currently not supportive of this approach. Changes in levels of PUFAs may however be a risk factor to evaluate when assessing for suicide risk. Clinical studies should be conducted to prospectively assess whether prescriptive long-term use of PUFAs in PUFA-deficient people with depression, may have a preventative role in attenuating suicide.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The Role of Nutrients in Protecting Mitochondrial Function and Neurotransmitter Signaling: Implications for the Treatment of Depression, PTSD, and Suicidal Behaviors

Numerous studies have linked severe stress to the development of major depressive disorder (MDD) and suicidal behaviors. Furthermore, recent preclinical studies from our laboratory and others have demonstrated that in rodents, chronic stress and the stress hormone cortisol cause oxidative damage to mitochondrial function and membrane lipids in the brain. Mitochondria play a key role in synaptic neurotransmitter signaling by providing adenosine triphosphate (ATP), mediating lipid and protein synthesis, buffering intracellular calcium, and regulating apoptotic and resilience pathways. Membrane lipids are similarly essential to central nervous system (CNS) function because cholesterol, polyunsaturated fatty acids, and sphingolipids form a lipid raft region, a special lipid region on the membrane that mediates neurotransmitter signaling through G-protein-coupled receptors and ion channels. Low serum cholesterol levels, low antioxidant capacity, and abnormal early morning cortisol levels are biomarkers consistently associated with both depression and suicidal behaviors. In this review, we summarize the manner in which nutrients can protect against oxidative damage to mitochondria and lipids in the neuronal circuits associated with cognitive and affective behaviors. These nutrients include ω3 fatty acids, antioxidants (vitamin C and zinc), members of the vitamin B family (Vitamin B12 and folic acid), and magnesium. Accumulating data have shown that these nutrients can enhance neurocognitive function, and may have therapeutic benefits for depression and suicidal behaviors. A growing body of studies suggests the intriguing possibility that regular consumption of these nutrients may help prevent the onset of mood disorders and suicidal behaviors in vulnerable individuals, or significantly augment the therapeutic effect of available antidepressants. These findings have important implications for the health of both military and civilian populations.

Polyunsaturated fatty acids and recurrent mood disorders: Phenomenology, mechanisms, and clinical application

A body of evidence has implicated dietary deficiency in omega-3 polyunsaturated fatty acids (n-3 PUFA), including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and etiology of recurrent mood disorders including major depressive disorder (MDD) and bipolar disorder. Cross-national and cross-sectional evidence suggests that greater habitual intake of n-3 PUFA is associated with reduced risk for developing mood symptoms. Meta-analyses provide strong evidence that patients with mood disorders exhibit low blood n-3 PUFA levels which are associated with increased risk for the initial development of mood symptoms in response to inflammation. While the etiology of this n-3 PUFA deficit may be multifactorial, n-3 PUFA supplementation is sufficient to correct this deficit and may also have antidepressant effects. Rodent studies suggest that n-3 PUFA deficiency during perinatal development can recapitulate key neuropathological, neurochemical, and behavioral features associated with mood disorders. Clinical neuroimaging studies suggest that low n-3 PUFA biostatus is associated with abnormalities in cortical structure and function also observed in mood disorders. Collectively, these findings implicate dietary n-3 PUFA insufficiency, particularly during development, in the pathophysiology of mood dysregulation, and support implementation of routine screening for and treatment of n-3 PUFA deficiency in patients with mood disorders.

Fatty acid composition of the postmortem corpus callosum of patients with schizophrenia, bipolar disorder, or major depressive disorder

BACKGROUND

Studies investigating the relationship between n-3 polyunsaturated fatty acid (PUFA) levels and psychiatric disorders have thus far focused mainly on analyzing gray matter, rather than white matter, in the postmortem brain. In this study, we investigated whether PUFA levels showed abnormalities in the corpus callosum, the largest area of white matter, in the postmortem brain tissue of patients with schizophrenia, bipolar disorder, or major depressive disorder.

METHODS

Fatty acids in the phospholipids of the postmortem corpus callosum were evaluated by thin-layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15).

RESULTS

In contrast to some previous studies, no significant differences were found in the levels of PUFAs or other fatty acids in the corpus callosum between patients and controls. A subanalysis by sex gave the same results. No significant differences were found in any PUFAs between suicide completers and non-suicide cases regardless of psychiatric disorder diagnosis.

CONCLUSIONS

Patients with psychiatric disorders did not exhibit n-3 PUFAs deficits in the postmortem corpus callosum relative to the unaffected controls, and the corpus callosum might not be involved in abnormalities of PUFA metabolism. This area of research is still at an early stage and requires further investigation.

Lack of association of SNPs from the FADS1-FADS2 gene cluster with major depression or suicidal behavior

Fatty acid desaturase genes (FADS1-FADS2) encode desaturases participating in the biosynthesis of long-chain polyunsaturated fatty acids. As long-chain polyunsaturated fatty acids are implicated in major depressive disorder (MDD) and suicide risk, and as both are partly heritable, we studied the association of FADS1-FADS2 polymorphisms with MDD (635 cases, 480 controls) and suicide attempt status (291 attempters, 344 MDD nonattempters). Eighteen FADS-related single-nucleotide polymorphisms were genotyped from Caucasians enrolled in Madrid (n=791) or New York City (n=324) and entered as predictors into logistic regression analyses with diagnostic group or suicide attempt history as outcomes and location and sex as covariates. No associations were observed between any single-nucleotide polymorphisms and diagnosis or attempt status. As statistical power was adequate, we conclude that FADS1-FADS2 genetic variants may not be a common determinant of MDD.

Generalized Anxiety Disorder and Hypoglycemia Symptoms Improved with Diet Modification

Observational evidence suggests that a relationship may exist between high glycemic index diets and the development of anxiety and depression symptoms; however, as no interventional studies assessing this relationship in a psychiatric population have been completed, the possibility of a causal link is unclear. AB is a 15-year-old female who presented with concerns of generalized anxiety disorder and hypoglycemia symptoms. Her diet consisted primarily of refined carbohydrates. The addition of protein, fat, and fiber to her diet resulted in a substantial decrease in anxiety symptoms as well as a decrease in the frequency and severity of hypoglycemia symptoms. A brief return to her previous diet caused a return of her anxiety symptoms, followed by improvement when she restarted the prescribed diet. This case strengthens the hypothesis that dietary glycemic index may play a role in the pathogenesis or progression of mental illnesses such as generalized anxiety disorder and subsequently that dietary modification as a therapeutic intervention in the treatment of mental illness warrants further study.

Nutrition Review: Relationships of Nutrition With Depression and Anxiety

Although research on relationships of nutrition with depression and anxiety is very limited, both biological plausibility and existing empirical evidence lend strong support to causal links, especially between diet and depression. Clinical deficiencies of several vitamins and minerals result in depression. Nutrients that have received particular attention with relation to depression include omega-3 fatty acids, folate, cobalamin, and zinc. Antioxidant nutrients are other potentially beneficial dietary factors that should be investigated. Body weight issues may be related to depression and anxiety in very complex ways. Dietary strategies to prevent and treat depression are inexpensive and low risk and therefore warrant consideration in future research and clinical applications.

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

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

Global survey of the omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid in the blood stream of healthy adults

Studies reporting blood levels of the omega-3 polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), were systematically identified in order to create a global map identifying countries and regions with different blood levels. Included studies were those of healthy adults, published in 1980 or later. A total of 298 studies met all inclusion criteria. Studies reported fatty acids in various blood fractions including plasma total lipids (33%), plasma phospholipid (32%), erythrocytes (32%) and whole blood (3.0%). Fatty acid data from each blood fraction were converted to relative weight percentages (wt.%) and then assigned to one of four discrete ranges (high, moderate, low, very low) corresponding to wt.% EPA+DHA in erythrocyte equivalents. Regions with high EPA+DHA blood levels (>8%) included the Sea of Japan, Scandinavia, and areas with indigenous populations or populations not fully adapted to Westernized food habits. Very low blood levels (≤4%) were observed in North America, Central and South America, Europe, the Middle East, Southeast Asia, and Africa. The present review reveals considerable variability in blood levels of EPA+DHA and the very low to low range of blood EPA+DHA for most of the world may increase global risk for chronic disease.

Role of Omega-3 Fatty Acids in the Etiology, Treatment, and Prevention of Depression: Current Status and Future Directions

Over the past three decades a body of translational evidence has implicated dietary deficiency in long-chain omega-3 (LCn-3) fatty acids, including eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and etiology of major depressive disorder (MDD). Cross-national and cross-sectional data suggest that greater habitual intake of preformed EPA+DHA is associated with reduced risk for developing depressive symptoms and syndromal MDD. Erythrocyte EPA and DHA composition is highly correlated with habitual fish or fish oil intake, and case-control studies have consistently observed lower erythrocyte EPA and/or DHA levels in patients with MDD. Low erythrocyte EPA+DHA composition may also be associated with increased risk for suicide and cardiovascular disease, two primary causes of excess premature mortality in MDD. While controversial, dietary EPA+DHA supplementation may have antidepressant properties and may augment the therapeutic efficacy of antidepressant medications. Neuroimaging and rodent neurodevelopmental studies further suggest that low LCn-3 fatty acid intake or biostatus can recapitulate central pathophysiological features associated with MDD. Prospective findings suggest that low LCn-3 fatty acid biostatus increases risk for depressive symptoms in part by augmenting pro-inflammatory responsivity. When taken collectively, these translational findings provide a strong empirical foundation in support of dietary LCn-3 fatty acid deficiency as a modifiable risk factor for MDD. This review provides an overview of this translational evidence and then discusses future directions including strategies to translate this evidence into routine clinical screening and treatment algorithms.

Hyphenated Analytical Methods in Determination of Biologically Active Compounds in Hen's Eggs

Hen's egg is a complete material needed for the development of the embryo; it is an important source of nutraceutical compounds, such as protein, fats, vitamins, trace metals, and minerals. Moreover, avian egg contains biologically active compounds that exhibit antibacterial and antimicrobial activities as well as antitumor, antiviral, antioxidant, immunomodulating, and therapeutic properties. Eggs are mostly very good sources of valuable, easily digestible proteins. This review focuses on the biologically active compounds from hen's egg and applications of these compounds in medicine and the pharmaceutical industry. Additionally, it gives an overview of the hyphenated separation techniques, including sample preparation, analysis, and identification, used in the proteomics and lipidomics analysis.

Omega-3 polyunsaturated fatty acid supplementation and white matter changes in major depression

White matter abnormalities are implicated in major depressive disorder (MDD). As omega-3 polyunsaturated fatty acids (PUFAs) are low in MDD and affect myelination, we hypothesized that PUFA supplementation may alleviate depression through improving white matter integrity. Acutely depressed MDD patients (n = 16) and healthy volunteers (HV, n = 12) had 25-direction diffusion tensor imaging before and after 6 weeks of fish oil supplementation. Plasma phospholipid omega-3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and omega-6 PUFA arachidonic acid (AA) levels were determined before and after supplementation using high-throughput extraction and gas chromatography and expressed as a percentage of total phospholipids (PUFA%). Fractional anisotropy (FA) was computed using a least-squares-fit diffusion tensor with non-linear optimization. Regression analyses were performed with changes in PUFA levels or Hamilton Depression Rating Scale scores as predictors, voxel-wise difference maps of FA as outcome, covariates age and sex, with family-wise correction for multiple comparisons. Increases in plasma phospholipid DHA% (but not EPA% or AA%) after fish oil predicted increases in FA in MDD but not HV, in a cluster including genu and body of the corpus callosum, and anterior corona radiata and cingulum (cluster-level p < 0.001, peak t-score = 8.10, p = 0.002). There was a trend for greater change in FA in MDD responders over nonresponders (t = -1.874, df = 13.56, p = 0.08). Decreased depression severity predicted increased FA in left corticospinal tract and superior longitudinal fasciculus (cluster-level p < 0.001, peak t-score = 5.04, p = 0.0001). Increased FA correlated with increased DHA% and decreased depression severity after fish oil supplementation suggests therapeutic effects of omega-3 PUFAs may be related to improvements in white matter integrity.

Design and methods for the Better Resiliency Among Veterans and non-Veterans with Omega-3's (BRAVO) study: A double blind, placebo-controlled trial of omega-3 fatty acid supplementation among adult individuals at risk of suicide

Suicide remains the 10th leading cause of death among adults in the United States (U.S.). Annually, approximately 30 per 100,000 U.S. military Veterans commit suicide, compared to 14 per 100,000 U.S. civilians. Symptoms associated with suicidality can be treatment resistant and proven-effective pharmaceuticals may have adverse side-effects. Thus, a critical need remains to identify effective approaches for building psychological resiliency in at-risk individuals. Omega-3 highly unsaturated fatty acids (n-3 HUFAs) are essential nutrients, which must be consumed in the diet. N-3 HUFAs have been demonstrated to reduce symptoms of depression, anxiety, and impulsivity - which are associated with suicide risk. Here we present the design and methods for the Better Resiliency Among Veterans and non-Veterans with Omega-3's (BRAVO) study, which is a double blind, randomized, controlled trial among individuals at risk of suicide of an n-3 HUFA versus placebo supplementation in the form of all natural fruit juice beverages. The BRAVO study seeks to determine if dietary supplementation with n-3 HUFAs reduces the risk for serious suicidal behaviors, suicidal thinking, negative emotions, and symptoms associated with suicide risk. Sub-analyses will evaluate efficacy in reducing depressive symptoms, alcohol, and nicotine use. A sub-study utilizes functional magnetic resonance imaging (fMRI) to evaluate the neuropsychological and neurophysiological effects of n-3 HUFAs. We also outline selection of appropriate proxy outcome measures for detecting response to treatment and collection of ancillary data, such as diet and substance use, that are critical for interpretation of results.

Fatty acid composition and fatty acid binding protein expression in the postmortem frontal cortex of patients with schizophrenia: A case-control study

BACKGROUND

Abnormal levels of n-3 polyunsaturated fatty acids (PUFAs), particularly docosahexaenoic acid (DHA), have been found in the postmortem frontal cortex, particularly the orbitofrontal cortex, of patients with schizophrenia. Altered mRNA expression of fatty acid binding protein (FABP) 5 and FABP7 has likewise been reported.

METHODS

This study investigated whether PUFAs in the frontal cortex [Brodmann area (BA) 8] and mRNA expression of FABP3, 5, and 7 were different between patients with schizophrenia (n=95) and unaffected controls (n=93).

RESULTS

In contrast to previous studies, no significant differences were found in DHA between the groups. Although arachidonic acid (AA) levels were significantly decreased in the schizophrenia group, no association was found between AA and schizophrenia on logistic regression analysis. Only FABP3 expression was significantly lower in the schizophrenia group than in the control group. Significant inverse associations were seen between only two saturated fatty acids, behenic acid and lignoceric acid, and FABP3 expression.

CONCLUSIONS

We found no evidence that major PUFA levels in BA8 are involved in the etiology of schizophrenia. Although FABP3 expression was not correlated with any of the major PUFAs, it might play a novel role in the pathology of BA8 in a subset of patients with schizophrenia.

Detection and treatment of omega-3 fatty acid deficiency in psychiatric practice: Rationale and implementation

A body of translational evidence has implicated dietary deficiency in long-chain omega-3 (LCn-3) fatty acids, including eicosapenaenoic acid (EPA) and docosahexaenoic acid (DHA), in the pathophysiology and potentially etiology of different psychiatric disorders. Case–control studies have consistently observed low erythrocyte (red blood cell) EPA and/or DHA levels in patients with major depressive disorder, bipolar disorder, schizophrenia, and attention deficit hyperactivity disorder. Low erythrocyte EPA + DHA biostatus can be treated with fish oil-based formulations containing preformed EPA + DHA, and extant evidence suggests that fish oil supplementation is safe and well-tolerated and may have therapeutic benefits. These and other data provide a rationale for screening for and treating LCn-3 fatty acid deficiency in patients with psychiatric illness. To this end, we have implemented a pilot program that routinely measures blood fatty acid levels in psychiatric patients entering a residential inpatient clinic. To date over 130 blood samples, primarily from patients with treatment-refractory mood or anxiety disorders, have been collected and analyzed. Our initial results indicate that the majority (75 %) of patients exhibit whole blood EPA + DHA levels at ≤4 percent of total fatty acid composition, a rate that is significantly higher than general population norms (25 %). In a sub-set of cases, corrective treatment with fish oil-based products has resulted in improvements in psychiatric symptoms without notable side effects. In view of the urgent need for improvements in conventional treatment algorithms, these preliminary findings provide important support for expanding this approach in routine psychiatric practice.

The role of cytokines in the pathophysiology of suicidal behavior

OBJECTIVE

Immune dysregulation has been implicated in depression and other psychiatric disorders. What is less clear is how immune dysregulation can affect risk of suicidal behavior. We reviewed the scientific literature concerning cytokines related to suicidal ideation, suicidal behavior and suicide, and surveyed clinical and neurobiological factors associated with cytokine levels that may modulate effects of inflammation on suicide risk.

METHODS

We searched PubMed, Embase, Scopus and PsycINFO for relevant studies published from 1980 through February, 2015. Papers were included if they were written in English and focused on cytokine measurements in patients with suicidal behaviors.

RESULTS

The literature search yielded 22 studies concerning cytokines and suicidal ideation, suicide attempts or suicide completion. The most consistent finding was elevated interleukin (IL)-6, found in 8 out of 14 studies, in CSF, blood, and postmortem brain. In one study, IL-6 in CSF was also found to be higher in violent than nonviolent attempters and to correlate with future suicide completion. Low plasma IL-2 was observed in 2 studies of suicide attempters, while divergent results were seen for tumor necrosis factor (TNF)-α, interferon (IFN)-γ, transforming growth factor (TGF)-β, IL-4, and soluble Il-2 receptors.

CONCLUSIONS

Given the complexity suggested by the heterogenous cytokine findings, putative mediators and moderators of inflammation on suicidal behavior merit further study. Elevated IL-6 was the most robust cytokine finding, associated with suicidal ideation and both nonfatal suicide attempts and suicides. Future studies should evaluate the predictive value of high IL-6, consider how this may alter brain function to impact suicidal behavior, and explore the potential beneficial effects of reducing IL-6 on suicide risk.

Plasma linoleic acid partially mediates the association of bipolar disorder on self-reported mental health scales

We have shown that bipolar individuals have reduced quality diets, including lower intake of polyunsaturated fatty acids (PUFA). We have also reported reduced plasma levels of the n-6 PUFA, linoleic acid (LA), and the n-3 PUFA, eicosapentaenoic acid (EPA) in bipolar subjects. In the current analysis we hypothesized that LA and EPA plasma levels would mediate lower self-reported mental health and life functioning scores in bipolar subjects. In a cross-sectional study, we collected a 7-day diet record in bipolar (n = 56) and control subjects (n = 46) followed by a fasted blood draw. We used structured equation modeling path analysis to test for mediating effects of dietary intake and plasma levels of LA and EPA on self-reported mental health questionnaire scores, including the Life Functioning Questionnaire (LFQ), the Patient Health Questionnaire (PHQ9), and the Short Form Health Survey (SF12), extracting the mental health component summary score (SF12-MH). We adjusted for age, gender, psychiatric medication use, body mass index (BMI), and total caloric intake as covariates with bipolar disorder as the primary predictor. We found a significant path association from bipolar disorder to lower plasma LA levels (p = 0.03) and significant paths from plasma LA to PHQ9 (p = 0.05), LFQ (p = 0.01) and SF12-MH (p = 0.05) scores, such that lower plasma LA predicted worse outcomes. We found no significant paths from plasma EPA levels to any of the outcome measures. These findings suggest that plasma LA levels partially mediate the effect of bipolar disorder on self-reported measures of mental health and life functioning.

Fatty acid composition of the postmortem prefrontal cortex of patients with schizophrenia, bipolar disorder, and major depressive disorder

Postmortem brain studies have shown abnormal levels of n-3 polyunsaturated fatty acids (PUFAs), especially docosahexaenoic acid, in the frontal cortex (particularly the orbitofrontal cortex) of patients with depression, schizophrenia, or bipolar disorder. However, the results from regions in the frontal cortex other than the orbitofrontal cortex are inconsistent. In this study we investigated whether patients with schizophrenia, bipolar disorder, or major depressive disorder have abnormalities in PUFA levels in the prefrontal cortex [Brodmann area (BA) 8]. In postmortem studies, fatty acids in the phospholipids of the prefrontal cortex (BA8) were evaluated by thin layer chromatography and gas chromatography. Specimens were evaluated for patients with schizophrenia (n=15), bipolar disorder (n=15), or major depressive disorder (n=15) and compared with unaffected controls (n=15). In contrast to previous studies, we found no significant differences in the levels of PUFAs or other fatty acids in the prefrontal cortex (BA8) between patients and controls. Subanalysis by sex also showed no significant differences. No significant differences were found in any individual fatty acids between suicide and non-suicide cases. These psychiatric disorders might be characterized by very specific fatty acid compositions in certain areas of the brain, and BA8 might not be involved in abnormalities of PUFA metabolism.

Association of moderate and severe food insecurity with suicidal ideation in adults: national survey data from three Canadian provinces

PURPOSE

Although the important public health issues of food insecurity and suicide may be interconnected, they are rarely studied. Using data from a national survey, we examined whether household food insecurity was associated with suicidal ideation after adjusting for relevant covariates.

METHODS

We examined cross-sectional data from three Canadian provinces (n = 5,270) that were derived from the 2007 Canadian Community Health Survey and included adults (18+ years). Suicidal ideation was based on affirmative response to the question of whether or not the participant had seriously considered committing suicide in the previous 12 months. The Household Food Security Survey Module provided measures of moderate (indication of compromise in quality and/or quantity of food consumed) and severe (indication of reduced food intake and disrupted eating patterns) food insecurity status. Logistic regression determined associations between food insecurity and suicidal ideation with adjustment for demographics, body mass index, and presence of a mood disorder.

RESULTS

There were differences in the proportion experiencing suicide ideation according to moderate (14.7 vs 10.0 % without suicide ideation) and severe (16.4 vs 7.1 % without suicide ideation) food security (p < 0.001). With covariate adjustment, suicidal ideation was significantly associated with moderate (adjusted OR = 1.32, 95 % CI 1.06-1.64) and severe (adjusted OR = 1.77, 95 % CI 1.42-2.23) food insecurity.

CONCLUSIONS

The findings of a robust association between food insecurity and suicidal ideation suggest that interventions targeted at food security may reduce suicide-related morbidity and mortality. Longitudinal investigations that examine various dimensions of food insecurity will advance understanding of etiological pathways involved in food insecurity and suicide.

Exploring the Determinants of Suicidal Behavior: Conventional and Emergent Risk (DISCOVER): a feasibility study

BACKGROUND

Suicidal behavior is a growing public health concern resulting in morbidity and premature death. Although certain factors such as age, sex, and psychiatric disorders have been consistently reported to be associated with suicidal behavior, other factors including biological markers, diet, and physical activity may also influence suicidal behavior. The purpose of this pilot study was to evaluate the feasibility of conducting a full-scale study to identify the conventional and novel risk factors of suicidal behavior in individuals who made a recent suicide attempt.

METHODS

This pilot study was a case-control study of participants with recent (within 1 month of admission) suicide attempts admitted to hospital and compared to two control groups: 1) psychiatric inpatient participants without a history of suicide attempts and 2) community-based controls. We collected information on demographic variables, circumstances of suicide attempts (for cases), medical and psychiatric diagnoses, behavioral patterns, physical measurements, and social factors. Blood and urine samples were also collected for biological markers. Feasibility outcomes are as follows: 1) 50 % of all eligible cases will consent to participate, 2) 50 cases and 100 controls per year can be recruited, and 3) at least 80 % of the participants will provide blood samples for DNA and biological markers.

RESULTS

We recruited 179 participants in total; 51 cases, 57 psychiatric controls without suicide attempt, and 71 non-psychiatric controls in Hamilton, Ontario. Recruitment rate was 70 % (213/304), and we obtained urine and blood specimens from 90 % (191/213) of participants. Questionnaire completion rates were high, and data quality was very good with few data-related queries to resolve. We learned that cases tended to be hospitalized for long periods of time and the suicide attempt occurred more than a month ago in many of the cases; therefore, we expanded our inclusion criterion related to timing of suicide attempt to 3 months instead of 1 month.

CONCLUSIONS

The study procedures needed certain modifications including extending the time between suicide attempt and date of recruitment, and more detailed questionnaires related to diet were necessary while other questionnaires such as social support needed to be shortened. Overall, this study showed that it is feasible to conduct a larger-scale study.

DNA methylation perturbations in genes involved in polyunsaturated Fatty Acid biosynthesis associated with depression and suicide risk

Polyunsaturated fatty acid (PUFA) status has been associated with neuropsychiatric disorders, including depression and risk of suicide. Long-chain PUFAs (LC-PUFAs) are obtained in the diet or produced by sequential desaturation and elongation of shorter-chain precursor fatty acids linoleic acid (LA, 18:2n-6) and α-linolenic acid (ALA, 18:3n-3). We compared DNA methylation patterns in genes involved in LC-PUFA biosynthesis in major depressive disorder (MDD) with (n = 22) and without (n = 39) history of suicide attempt, and age- and sex-matched healthy volunteers (n = 59). Plasma levels of selected PUFAs along the LC-PUFA biosynthesis pathway were determined by transesterification and gas chromatography. CpG methylation levels for the main human LC-PUFA biosynthetic genes, fatty acid desaturases 1 (Fads1) and 2 (Fads2), and elongation of very long-chain fatty acids protein 5 (Elovl5), were assayed by bisulfite pyrosequencing. Associations between PUFA levels and diagnosis or suicide attempt status did not survive correction for multiple testing. However, MDD diagnosis and suicide attempts were significantly associated with DNA methylation in Elovl5 gene regulatory regions. Also the relative roles of PUFA levels and DNA methylation with respect to diagnostic and suicide attempt status were determined by least absolute shrinkage and selection operator logistic regression analyses. We found that PUFA associations with suicide attempt status were explained by effects of Elovl5 DNA methylation within the regulatory regions. The observed link between plasma PUFA levels, DNA methylation, and suicide risk may have implications for modulation of disease-associated epigenetic marks by nutritional intervention.

Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior

Serotonin regulates a wide variety of brain functions and behaviors. Here, we synthesize previous findings that serotonin regulates executive function, sensory gating, and social behavior and that attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share in common defects in these functions. It has remained unclear why supplementation with omega-3 fatty acids and vitamin D improve cognitive function and behavior in these brain disorders. Here, we propose mechanisms by which serotonin synthesis, release, and function in the brain are modulated by vitamin D and the 2 marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Brain serotonin is synthesized from tryptophan by tryptophan hydroxylase 2, which is transcriptionally activated by vitamin D hormone. Inadequate levels of vitamin D (∼70% of the population) and omega-3 fatty acids are common, suggesting that brain serotonin synthesis is not optimal. We propose mechanisms by which EPA increases serotonin release from presynaptic neurons by reducing E2 series prostaglandins and DHA influences serotonin receptor action by increasing cell membrane fluidity in postsynaptic neurons. We propose a model whereby insufficient levels of vitamin D, EPA, or DHA, in combination with genetic factors and at key periods during development, would lead to dysfunctional serotonin activation and function and may be one underlying mechanism that contributes to neuropsychiatric disorders and depression. This model suggests that optimizing vitamin D and marine omega-3 fatty acid intake may help prevent and modulate the severity of brain dysfunction.