Peripheral markers of oxidative stress and antioxidative defense in euthymia of bipolar disorder--Gender and obesity effects

The Association Between the Composite Dietary Antioxidant Index and Frailty Symptoms: Mediating Effects of Oxidative Stress

Background

There is growing evidence that an antioxidant diet is a protective factor against frailty. However, few studies have examined the effect of comprehensive dietary antioxidants on frailty symptoms. The aim of this study was to examine the relationships between the composite dietary antioxidant index (CDAI) and frailty and the underlying mechanisms involved.

Methods

Based on the National Health and Nutrition Survey (NHANES) 2003-2018, this study included 11,277 older persons aged ≥60 years. In this study, frailty was defined as having a total score >0.21 on the 49-item frailty index. Six dietary antioxidants were selected for use in calculating the CDAI. A weighted multiple logistic regression model with subgroup analysis and restricted cubic splines (RCSs) were used to examine the association between the CDAI and frailty. To examine the role of oxidative stress, mediation analyses were also conducted.

Results

The association between the CDAI score and frailty risk was significant according to the multivariate model. Compared with participants in tertile 1, participants in both tertile 2 and tertile 3 had lower odds of developing frailty symptoms (OR=0.86; 95% CI=0.75-0.97; P=0.02; and OR=0.81; 95% CI=0.70-0.93; P=0.003). According to the subgroup analyses, the differences in interactions were not statistically significant. There was also a potential nonlinear relationship between the CDAI score and frailty risk. The serum albumin concentration and uric acid concentration had significant mediating effects on the association between the CDAI score and frailty index, with 19.25% (P=0.002) and 21.26% (P < 0.001) of the total, respectively.

Conclusion

Frailty is negatively associated with the CDAI score, which may be partially mediated by oxidative stress.

Sex differences in bipolar disorder: The dorsolateral prefrontal cortex as an etiopathogenic region

Bipolar disorder (BD) is worldwide a prevalent mental illness and a leading risk factor for suicide. Over the past three decades, it has been discovered that sex differences exist throughout the entire panorama of BD, but the etiologic regions and mechanisms that generate such differences remain poorly characterized. Available evidence indicates that the dorsolateral prefrontal cortex (DLPFC), a critical region that controls higher-order cognitive processing and mood, exhibits biological disparities between male and female patients with psychiatric disorders, which are highly correlated with the co-occurrence of psychotic symptoms. This review addresses the sex differences in BD concerning epidemiology, cognitive impairments, clinical manifestations, neuroimaging, and laboratory abnormalities. It also provides strong evidence linking DLPFC to the etiopathogenesis of these sex differences. We emphasize the importance of identifying gene signatures using human brain transcriptomics, which can depict sexually different variations, explain sex-biased symptomatic features, and provide novel targets for sex-specific therapeutics.

Comparison of oxidative stress parameters, thiol-disulfide homeostasis, and pro-inflammatory cytokines levels in patients with bipolar disorder and their first-degree relatives

BACKGROUND

In this study, we aimed to compare the oxidative stress parameters, thiol-disulfide homeostasis, and plasma pro-inflammatory cytokines levels of patients with bipolar disorder (BD), BD patients' first-degree relatives (FDRs), and the healthy controls (HCs).

METHODS

Thirty-five patients with BD, 35 FDRs of BD, and 35 healthy controls (HCs) were included. The individuals' ages varied from 28 to 58, and the groups were well-matched in terms of age and gender. The total thiol (TT), native thiol (NT), disulfide (DIS), total oxidant status (TOS), total antioxidant status (TAS), IL-1β, IL-6, and TNF-α concentrations were measured from serum samples. The oxidative stress index (OSI) was calculated using mathematical formulas.

RESULTS

TOS was significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons). OSI, DIS, oxidized thiol, and the ratio of thiol oxidation-reduction levels were significantly higher in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). TAS, TT, NT, and reduced thiol levels were significantly lower in both patients with BD and FDRs than HCs (p < 0.01 for all pairwise comparisons). IL-1β, IL-6, and TNF-α were significantly higher in both patients and FDRs than HCs (p < 0.01 for all pairwise comparisons).

LIMITATIONS

Small sample size.

CONCLUSIONS

Early diagnosis is important for treating of bipolar disorder. TT, NT, DIS, TOS, TAS, OSI, IL1-β, IL-6, and TNF-α can be used as potential biomarkers in the early diagnosis and intervention of BD. Furthermore, oxidative/antioxidative markers and plasma pro-inflammatory cytokine parameters may guide the determination of the disease's activity and response to treatment.

Predictive value of oxidative stress biomarkers in drug-free patients with bipolar disorder

OBJECTIVE

Oxidative stress is one of the primary etiological mechanisms of bipolar disorder (BD).

METHODS

The present study was conducted over a period of 24 months on Tunisian on 34 drug‑free male patients with BD (mean age: 34.5 years) and 101 age and gender matched controls (mean age: 34.20 years) were enrolled in the study.

RESULTS

Plasma reduced glutathione (GSH) and total thiols levels were significantly decreased in patients compared to controls (respectively p < .001; p = .009). In addition, malondialdehyde (MDA), advanced oxidation protein products (AOPP), protein carbonyls (PC) and homocysteine (Hcys) concentrations and glutathione peroxidase (GSH-Px) activity were significantly increased in patients compared to controls (p = .002; p < .001; p = .001; p < .001 and p = .016, respectively). The binary logistic regression analysis revealed that MDA, AOPP and Hcys could be considered as independent risk factors for BD. When using CombiROC analysis, a remarkable increase in the area under the curve (AUC) with higher sensitivity (Se) and specificity (Sp) for MDA, AOPP, PC, GSH-Px and Hcys combined markers was observed.

CONCLUSIONS

Overall, the identification of the predictive value of these five selected biomarkers related to oxidative stress in drug free patients should lead to a better identification of the etiological mechanism of BD.

Oxidative stress parameters and antioxidants in adults with unipolar or bipolar depression versus healthy controls: Systematic review and meta-analysis

BACKGROUND

To study differences in oxidative stress markers and antioxidants among patients with bipolar depression (BPD) and unipolar depression (UPD).

METHODS

Data sources. Electronic MEDLINE/PubMed/Cochrane Library/Scopus/TripDatabase database search until 30/06/2021.

STUDY SELECTION

Included were articles comparing antioxidant or oxidative stress markers between adults with BPD or UPD and healthy controls (HCs).

DATA EXTRACTION

Two authors extracted data independently. Random effects meta-analysis, calculating standardized mean differences for results from ≥3 studies.

RESULTS

Oxidative stress markers reported in 40 studies -1 published repeatedly- (UPD, studies = 30 n = 3072; their HCs, n = 2856; BPD, studies = 11 n = 393; their HCs, n = 540; with 1 study reporting on both UPD and BPD) included thiobarbituric acid reactive substances (TBARS), antioxidant uric acid and antioxidant-enhancing enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione-peroxidase (GPX). Compared with HCs, UPD and BPD were associated with significantly higher levels of TBARS, without differences between UPD and BPD (P = 0.11). Compared with HCs, UPD and BPD did not differ regarding the activity of the CAT (P = 0.28), SOD (P = 0.87) and GPX (P = 0.25) enzymes. However, uric acid levels were significantly higher vs HCs in BPD than in UPD among adult patients (P = 0.004). Results were heterogenous, which, for some parameters, decreased after stratification by the blood source (serum, plasma red blood cells, whole blood).

LIMITATIONS

The main limitations are the small number of studies/participants in the BPD subgroup, and heterogeneity of the results.

SUMMATIONS

Both BPD and UPD may be associated with an impaired oxidative stress balance, with significantly higher uric acid levels vs. HCs in UPD than in BPD.

Synovial Fluid-Derived Extracellular Vesicles of Patients with Arthritides Contribute to Hippocampal Synaptic Dysfunctions and Increase with Mood Disorders Severity in Humans

Arthritides are a highly heterogeneous group of disorders that include two major clinical entities, localized joint disorders such as osteoarthritis (OA) and systemic autoimmune-driven diseases such as rheumatoid arthritis (RA). Arthritides are characterized by chronic debilitating musculoskeletal conditions and systemic chronic inflammation. Poor mental health is also one of the most common comorbidities of arthritides. Depressive symptoms which are most prevalent, negatively impact patient global assessment diminishing the probability of achieving the target of clinical remission. Here, we investigated new insights into mechanisms that link different joint disorders to poor mental health, and to this issue, we explored the action of the synovial fluid-derived extracellular vesicles (EVs) on neuronal function. Our data show that the exposure of neurons to different concentrations of EVs derived from both RA and OA synovial fluids (RA-EVs and OA-EVs) leads to increased excitatory synaptic transmission but acts on specific modifications on excitatory or inhibitory synapses, as evidenced by electrophysiological and confocal experiments carried out in hippocampal cultures. The treatment of neurons with EVs membrane is also responsible for generating similar effects to those found with intact EVs suggesting that changes in neuronal ability arise upon EVs membrane molecules′ interactions with neurons. In humans with arthritides, we found that nearly half of patients (37.5%) showed clinically significant psychiatric symptoms (CGIs score ≥ 3), and at least mild anxiety (HAM-A ≥ 7) or depression (MADRS and HAM-D ≥ 7); interestingly, these individuals revealed an increased concentration of synovial EVs. In conclusion, our data showing opposite changes at the excitatory and inhibitory levels in neurons treated with OA- and RA-EVs, lay the scientific basis for personalized medicine in OA and RA patients, and identify EVs as new potential actionable biomarkers in patients with OA/RA with poor mental health.

The Relationship between F2-Isoprostanes Plasma Levels and Depression Symptoms in Healthy Older Adults

The increasing proportion of older citizens in our society reflects a need to better understand age-related biological underpinnings of mood, as depression in older age may be under-diagnosed. Pre-clinical and human studies evidence a relationship between oxidative stress (OS) biomarkers in depression symptoms, and an influence of biological factors such as Body Mass Index (BMI), but focus has been clinical or younger samples, and less is known about patterns in healthy older adults. We investigated these associations with data derived from the Australian Research Council Longevity Study (ARCLI; ANZCTR12611000487910), in 568 healthy adults aged 60–75 years using F₂-Isoprostanes plasma levels, and controlling for demographic factors, in assessing mood via the Beck Depression Inventory-II, Chalder Fatigue Scale, and General Health Questionnaire 12. Elevated F₂-Isoprostanes contributed to depressed mood on the BDI-II and reduced general health on the GHQ-12. BMI was positively associated with Chalder Fatigue scores, yet better ratings on the GHQ-12. Females had significantly higher F₂-Isoprostanes than males. The results suggest that in otherwise healthy older adults, mood and mental health are reduced with increases in oxidative stress markers, exhibiting similar patterns observed in clinical groups. Sex as a factor should be considered when assessing OS levels in systemic pathologies. BMI as a modifiable risk factor for maintenance of mental health, and OS modification through nutrient supplementation, are discussed. The findings contribute to understanding oxidative stress marker patterns in healthy older adults and their potential role in mood symptoms and mental health.

Shared postulations between bipolar disorder and polycystic ovary syndrome pathologies

INTRODUCTION

Women with bipolar disorder (BD) present a high prevalence of polycystic ovary syndrome (PCOS) and other reproductive disorders even before diagnosis or treatment of the disease. Postulations on the potential molecular mechanisms of comorbid PCOS in women with BD remain limited to influence of medications and need further extension.

OBJECTIVES

This review focuses on evidence suggesting that common metabolic and immune disorders may play an important role in the development of BD and PCOS.

RESULTS

The literature covered in this review suggests that metabolic and immune disorders, including the dysfunction of the hypothalamic-pituitary-adrenal axis, chronic inflammatory state, gut microbial alterations, adipokine alterations and circadian rhythm disturbance, are observed in patients with BD and PCOS. Such disorders may be responsible for the increased prevalence of PCOS in the BD population and indicate a susceptibility gene overlap between the two diseases. Current evidence supports postulations of common metabolic and immune disorders as endophenotype in BD as well as in PCOS.

CONCLUSIONS

Metabolic and immune disorders may be responsible for the comorbid PCOS in the BD population. The identification of hallmark metabolic and immune features common to these two diseases will contribute to the clarification of the effect of BD on the reproductive endocrine function and development of symptomatic treatments targeting the biomarkers of the two diseases.

Nutrition, Overweight, and Cognition in Euthymic Bipolar Individuals Compared to Healthy Controls

Bipolar disorder (BD) is associated with impairments in cognitive functions, in which metabolic factors, e.g., overweight, seem to play a significant role. The aim of this study was to investigate the association between nutritional factors and cognitive performance in euthymic individuals with BD. A study cohort of 56 euthymic individuals with BD was compared to a sample of 53 mentally healthy controls. To assess cognitive function, the following tests were applied: California Verbal Learning Test, Trail Making Test A/B, d2 Test of Attention-Revised, and Stroop’s Color-Word Interference Test. Furthermore, a 4-day food record was processed to evaluate dietary intake of macronutrients, specific micronutrients, and food diversity. Body mass index and waist to height ratio were calculated to assess overweight and central obesity. Results showed no nutritional differences between individuals with BD and controls. Individuals with BD performed worse in the d2 test than controls. Hierarchical regression analyses yielded no association between cognitive and nutritional parameters. However, waist to height ratio was negatively correlated with almost all cognitive tests. Central obesity seems to affect cognitive functioning in BD, while the lack of finding differences in nutritional data might be due to problems when collecting data and the small sample size. Consequently, further studies focusing on objectively measuring food intake with adequate sample size are needed.

Malondialdehyde as a candidate biomarker for bipolar disorder: A meta-analysis

Malondialdehyde (MDA) represents one of the final products of lipid peroxidation that is thought to be enhanced and accelerated in patients affected by bipolar disorder (BD). Purpose of the present article is to critically summarize the available data about MDA as a candidate biomarker for BD. First, we carried out a systematic review of the literature selecting those papers that evaluated MDA levels in BD. Then, we performed two separate meta-analyses: one of the studies that compared healthy controls (HC) with unmedicated BD and one with the studies that assessed MDA levels before and after treatment in BD, showing that bipolar patients experience more oxidative stress than healthy subjects and that treatment is effective in reducing MDA levels. In the first set of studies, we also explored through a meta-regression whether age, gender and experiencing an episode specifically influenced the difference between BD and HC in MDA levels. Bipolar patients compared to healthy subjects had higher MDA levels (SMD: 0.94, 95% CI: 0.23-1.64). Age (p < 0.01), gender (p < 0.01) and the presence of a current mood episode (p < 0.01) significantly influenced MDA plasma/serum levels. Specifically, studies that included more female, older subjects and more BD in euthymia were more likely to have higher MDA levels. Finally, patients after treatment had lower levels of MDA compared to baseline (SMD: -0.52, 95% CI: -0.85 -0.19). More studies are needed to draw definitive conclusions.

Therapeutic Interventions to Mitigate Mitochondrial Dysfunction and Oxidative Stress–Induced Damage in Patients with Bipolar Disorder

Bipolar disorder (BD) is characterized by mood changes, including recurrent manic, hypomanic, and depressive episodes, which may involve mixed symptoms. Despite the progress in neurobiological research, the pathophysiology of BD has not been extensively described to date. Progress in the understanding of the neurobiology driving BD could help facilitate the discovery of therapeutic targets and biomarkers for its early detection. Oxidative stress (OS), which damages biomolecules and causes mitochondrial and dopamine system dysfunctions, is a persistent finding in patients with BD. Inflammation and immune dysfunction might also play a role in BD pathophysiology. Specific nutrient supplements (nutraceuticals) may target neurobiological pathways suggested to be perturbed in BD, such as inflammation, mitochondrial dysfunction, and OS. Consequently, nutraceuticals may be used in the adjunctive treatment of BD. This paper summarizes the possible roles of OS, mitochondrial dysfunction, and immune system dysregulation in the onset of BD. It then discusses OS-mitigating strategies that may serve as therapeutic interventions for BD. It also analyzes the relationship between diet and BD as well as the use of nutritional interventions in the treatment of BD. In addition, it addresses the use of lithium therapy; novel antipsychotic agents, including clozapine, olanzapine, risperidone, cariprazine, and quetiapine; and anti-inflammatory agents to treat BD. Furthermore, it reviews the efficacy of the most used therapies for BD, such as cognitive–behavioral therapy, bright light therapy, imagery-focused cognitive therapy, and electroconvulsive therapy. A better understanding of the roles of OS, mitochondrial dysfunction, and inflammation in the pathogenesis of bipolar disorder, along with a stronger elucidation of the therapeutic functions of antioxidants, antipsychotics, anti-inflammatory agents, lithium therapy, and light therapies, may lead to improved strategies for the treatment and prevention of bipolar disorder.

Analysis of Seasonal Clinical Characteristics in Patients With Bipolar or Unipolar Depression

This study was to investigate the characteristics of seasonal symptoms and non-enzymatic oxidative stress in the first hospitalized patients with bipolar and unipolar depression, aiming to differentiate bipolar depression from unipolar depression and reduce their misdiagnosis. A total of 450 patients with bipolar depression and 855 patients with depression were included in the present study. According to the season when the patients were admitted to the hospital due to the acute onset of depression, they were further divided into spring, summer, autumn and winter groups. According to the characteristics of symptoms of bipolar disorder in the DSM-5, the characteristic symptoms of bipolar disorder were collected from the medical record information, and clinical biochemical indicators that can reflect the oxidative stress were also recorded. The seasonal risk factors in patients with bipolar or unipolar depression were analyzed. The relationship of age and gender with the bipolar or unipolar depression which attacked in winter was explored. There were significant differences between groups in the melancholic features, atypical features and conjugated bilirubin in spring. In summer, there were significant differences between groups in the melancholic features, uric acid and conjugated bilirubin. In autumn, there were marked differences between groups in melancholic features, anxiety and pain, atypical features, uric acid, total bilirubin, conjugated bilirubin and albumin. In winter, the conjugated bilirubin and prealbumin were significantly different between two groups. The melancholic features and uric acid that in summer as well as melancholic features, uric acid and total bilirubin in autumn were the seasonal independent risk factors for the unipolar depression as compared to bipolar depression. In winter, significant difference was noted in the age between two groups. In conclusion, compared with patients with unipolar depression, patients with bipolar depression have seasonal characteristics. Clinical symptoms and indicators of oxidative stress may become factors for the differentiation of seasonal unipolar depression from bipolar depression. Young subjects aged 15-35 years are more likely to develop bipolar depression in winter.

Oxidative stress parameters and antioxidants in patients with bipolar disorder: Results from a meta-analysis comparing patients, including stratification by polarity and euthymic status, with healthy controls

OBJECTIVE

To investigate oxidative stress markers and antioxidants in bipolar disorder (BD).

METHODS

Electronic MEDLINE/PubMed/Cochrane-Library/Scopus/TripDatabase search until 06/30/2019 for studies comparing antioxidant or oxidative stress markers between BD and healthy controls (HCs). Standardized mean differences (SMD) and 95% confidence intervals (CIs) were calculated for ≥3 studies.

RESULTS

Forty-four studies (n = 3,767: BD = 1,979; HCs = 1,788) reported on oxidative stress markers malondialdehyde (MDA), thiobarbituric acid reactive substances (TBARS), and total nitrites; antioxidants glutathione (GSH), uric acid, and zinc; or antioxidantenhancing enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), and GSH-transferase (GST). Compared with HCs, BD was associated with higher GST (P = .01), CAT (P = .02), nitrites (P < .0001), TBARS (P < .0001), MDA (P = .01), uric acid (P < .0001), and lower GSH (P = .006), without differences in SOD, GPX, and zinc. Compared to HCs, levels were higher in BD-mania for TBARS (P < .0001) and uric acid (P < .0001); in BD-depression for TBARS (P = .02); and BD-euthymia for uric acid (P = .03). Uric acid levels were higher in BD-mania vs BD-depression (P = .002), but not vs BD euthymia. TBARS did not differ between BD-mania and BD-depression. Medication-free BD-mania patients had higher SOD (P = .02) and lower GPX (P < .0001) than HCs. After treatment, BD did not differ from HCs regarding SOD and GPX.

CONCLUSIONS

Beyond a single biomarker of oxidative stress, the combination of several parameters appears to be more informative for BD in general and taking into account illness polarity. BD is associated with an imbalance in oxidative stress with some phase-specificity for uric acid and TBARS and possible treatment benefits for SOD and GPX. Future studies should take into account confounding factors that can modify oxidative stress status and simultaneously measure oxidative stress markers and antioxidants including different blood sources.

The Relationship Between Food Craving, Appetite-Related Hormones and Clinical Parameters in Bipolar Disorder

Obesity and weight gain in bipolar disorder (BD) have multifactorial underlying causes such as medication side effects, atypical depressive symptomatology, genetic variants, and disturbances in the neuro-endocrinal system. Therefore, we aim to explore the associations between food craving (FC), clinical parameters, psychotropic medication, and appetite-related hormones. In this cross-sectional investigation, 139 individuals with BD and 93 healthy controls (HC) completed the food craving inventory (FCI). In addition, blood samples (including leptin and acylated ghrelin) were analyzed and sociodemographic and anthropometric data were collected. Individuals with BD reported higher frequencies of total FC as well as craving for fat and fast food than HC. Additionally, we found a significant negative correlation between FC and ghrelin levels in BD. Smokers with BD reported significantly more craving for high fat foods than non-smokers. Age was significantly associated with FC independent of group. Individuals with BD taking olanzapine and quetiapine reported higher frequencies of craving for sweet food, while patients currently taking lithium reported less total FC compared to those without lithium therapy. Likewise, patients currently taking valproate reported less total FC and less craving for sweets than those not taking valproate. FC appears to be of clinical relevance in individuals with BD. Contrary to previous data, this does not seem to be a female phenomenon only and might encompass more than the specific craving for carbohydrates. Although due to the cross sectional design, causality cannot be determined, the association between depressive symptomatology and fast food craving warrants further research.

Construction of a nitro-oxidative stress-driven, mechanistic model of mood disorders: A nomothetic network approach

Major depression is accompanied by increased IgM-mediated autoimmune responses to oxidative specific epitopes (OSEs) and nitric oxide (NO)-adducts. These responses were not examined in bipolar disorder type 1 (BP1) and BP2. IgM responses to malondialdehyde (MDA), phosphatidinylinositol, oleic acid, azelaic acid, and NO-adducts were determined in 35 healthy controls, and 47 major depressed (MDD), 29 BP1, and 25 BP2 patients. We also measured serum peroxides, IgG to oxidized LDL (oxLDL), and IgM/IgA directed to lipopolysaccharides (LPS). IgM responses to OSEs and NO-adducts (OSENO) were significantly higher in MDD and BP1 as compared with controls, and IgM to OSEs higher in MDD than in BP2. Partial Least Squares (PLS) analysis showed that 57.7% of the variance in the clinical phenome of mood disorders was explained by number of episodes, a latent vector extracted from IgM to OSENO, IgG to oxLDL, and peroxides. There were significant specific indirect effects of IgA/IgM to LPS on the clinical phenome, which were mediated by peroxides, IgM OSENO, and IgG oxLDL. Using PLS we have constructed a data-driven nomothetic network which ensembled causome (increased plasma LPS load), adverse outcome pathways (namely neuro-affective toxicity), and clinical phenome features of mood disorders in a data-driven model. Based on those feature sets, cluster analysis discovered a new diagnostic class characterized by increased plasma LPS load, peroxides, autoimmune responses to OSENO, and increased phenome scores. Using the new nomothetic network approach, we constructed a mechanistically transdiagnostic diagnostic class indicating neuro-affective toxicity in 74.3% of the mood disorder patients.

Malondialdehyde and bipolar disorder: A short comprehensive review of available literature

BACKGROUND

The pathogenetic mechanisms of Bipolar Disorder (BD) have not been totally clarified. Oxidative stress seems to be involved in the etiology of BD, and malondialdehyde (MDA) represents a candidate biomarker for monitoring this aspect in different medical conditions including mood disorders. This article has the objective to critically summarize the available data about the association between MDA and BD.

METHODS

A research in Pubmed, PsycINFO and Isi Web of Knowledge was fulfilled to identify studies in which MDA levels were measured in BD patients for the purpose of securing a comprehensive review concerning the issue.

RESULTS

We detected 20 articles that satisfied the inclusion criteria: most of them observed higher MDA levels (or Thiobarbituric acid-reactive substances-TBARS) in BD patients compared to healthy controls (HC), although there are some contrasting results, depending in particular on the phase of illness or the inclusion criteria or the methodological differences.

LIMITATIONS

We included studies, exclusively in English, that used different laboratory methods to measure MDA.

CONCLUSIONS

The analysed articles suggest that MDA or TBARS are increased in BD patients with respect to HC, thus supporting the hypothesis that MDA may be a promising and potential biomarker to monitor the course of BD, although further studies are needed to confirm this hypothesis.

Adiponectin is decreased in bipolar depression

Objectives: Bipolar disorder (BD) is often accompanied by medical comorbidities, which affect illness course and prognosis. Adipokines may not only be involved in the aetiopathogenetic mechanisms of these comorbidities; there might be an association between adipokines and the neuropsychiatric core features of BD such as mood disturbances and cognitive deficits.Methods: In this investigation, fasting blood samples from 120 individuals with BD (75 euthymic and 45 with mild depressive symptoms) and 68 control subjects were taken and adiponectin and leptin concentrations were analysed.Results: We found that, in female participants, adiponectin levels differed significantly between patients and controls indicating lower levels in individuals with BD, even after controlling for BMI (F(1,92) = 4.65, P = 0.034, partial η² = 0.05). After stratification by mood status we found a significant difference in adiponectin between controls, euthymic and depressive patients (F(2, 180) = 4.90, P = 0.008, partial η² = 0.05).Conclusions: This investigation confirms previous findings of an association between low adiponectin levels and depressive state in individuals with BD. Beyond its immediate effect on central nervous system function, adiponectin might interfere with pathophysiological mechanisms of BD and its somatic comorbidities via involvement in metabolic and inflammatory processes.

Weight Gain During Treatment of Bipolar Disorder (BD)-Facts and Therapeutic Options

Bipolar disorder (BPD) is a mood disorder, which is characterized by alternating affective states, namely (hypo)mania, depression, and euthymia. Evidence is growing that BPD has indeed a biologic substrate characterized by chronic inflammation, oxidative stress, and disturbed energy metabolism. Apart from this, there is obviously a hereditary component of this disease with multi-genetic factors. Most probably a susceptibility threshold favors the outbreak of clinical disease after a cascade of stress events that remain to be elucidated in more detail. Evidence is also growing that weak points in brain energy metabolism contribute to outbreak and severity of BPD. Conventional psychopharmacologic therapy must be reassessed under the aspects of weight cycling and development of central obesity as a deterioration factor for a worse clinical course leading to early cardiovascular events in BPD subgroups.

Peripheral Oxidative Stress Markers in Patients with Bipolar Disorder during Euthymia and in Siblings

AIMS

Oxidative stress is increased during the acute phases of bipolar disorder (BD). Our aim here was to analyze oxidative stress biomarkers in patients with BD during euthymia and their siblings.

METHOD

A cross-sectional study was performed in euthymic patients with BD-I (n=48), unaffected siblings (n=23) and genetically unrelated healthy controls (n=21). Protein carbonyl content (PCC), total antioxidant capacity (TRAP), lipid peroxidation (TBARS) and uric acid were measured as biomarkers of oxidative stress in blood.

RESULTS

The antioxidant capacity (TRAP) was lower (p<0.001) in patients with BD compared to their siblings and controls, whereas no differences were observed in PCC, TBARS or uric acid. In patients, the concentrations of TRAP and TBARS were positively associated with the dose of valproic acid (p<0.05 and p<0.001, respectively). The concentrations of these biomarkers were not significantly associated with any of socio-demographic and clinical variables.

CONCLUSION

A selective reduction in antioxidant capacity is present in BD during euthymia state, whereas other markers of oxidative stress are unaltered during euthymia. Siblings did not show any alterations in oxidative stress biomarkers. Oxidative stress might represent a state-dependent marker in BD. The association between treatment with valproic acid and oxidative stress markers in euthymia deserves further studies.

The relationship between "Eyes Reading" ability and verbal memory in bipolar disorder

In psychiatric disorders, neurocognitive impairments are prevalent and have been associated with poor outcome. Deficits in Theory of Mind (ToM, "mentalising") have also been observed in bipolar disorder (BD); however, the literature shows inconsistent data. The aim of this study was to explore ToM performance in a well-characterized sample of euthymic individuals with BD and its relationship with neurocognitive function. One hundred sixteen euthymic patients with BD between 18 and 74 years (mean age = 42.4, SD = 13.8) and 79 healthy controls (mean age = 39.8, SD = 16.5) were investigated with an extensive neurocognitive test battery (Trail Making Test A/B, d2 Test of Attention, Stroop Color-Word Test, California Verbal Learning Test, Multiple Choice Vocabulary Test). Additionally, all participants were given the Reading the Mind in the Eyes Test (RMET) to measure affective ToM, the ability to make assumptions about other people´s feelings. Overall, "Eyes Reading" performance was not impaired in individuals with BD compared with controls. However, a significant relationship between RMET and verbal memory in BD was shown, particularly in males. Data showed worse RMET performance in patients with memory deficits compared to patients without memory deficits and controls. Due to cross-sectional data, no conclusions can be made with respect to cause and effect.

A step ahead: Exploring the gut microbiota in inpatients with bipolar disorder during a depressive episode

OBJECTIVES

There is evidence that the gut microbiota plays a major role in the pathogenesis of diseases of the central nervous system through the gut-brain axis. The aim of the present study was to analyze gut microbiota composition in bipolar disorder (BD) and its relation to inflammation, serum lipids, oxidative stress, tryptophan (TRP)/kynurenine (KYN) levels, anthropometric measurements and parameters of metabolic syndrome. Further, microbial community differences of individuals with BD compared with healthy controls (HC) were explored.

METHODS

In this cross-sectional study, we performed 16S rRNA gene sequencing of stool samples from 32 BD individuals and 10 HC. Laboratory parameters included inflammatory markers, serum lipids, KYN, oxidative stress and anthropometric measures. Microbial community analysis and correlation to clinical parameters was performed with QIIME, differential abundance analysis of taxa encompassed linear discriminant analysis effect size (LEfSe).

RESULTS

We found a negative correlation between microbial alpha-diversity and illness duration in BD (R = -0.408, P = 0.021). Furthermore, we identified bacterial clades associated with inflammatory status, serum lipids, TRP, depressive symptoms, oxidative stress, anthropometrics and metabolic syndrome in individuals with BD. LEfSe identified the phylum Actinobacteria (LDA= 4.82, P = 0.007) and the class Coriobacteria (LDA= 4.75, P = 0.010) as significantly more abundant in BD when compared with HC, and Ruminococcaceae (LDA= 4.59, P = 0.018) and Faecalibacterium (LDA= 4.09, P = 0.039) as more abundant in HC when compared with BD.

CONCLUSIONS

The present findings suggest that causes and/or consequences of BD may also lie outside the brain. Exploratory research of the gut microbiota in affective disorders like BD may identify previously unknown underlying causes, and offer new research and therapeutic approaches to mood disorders.

Sex Specific Changes in Tryptophan Breakdown Over a 6 Week Treatment Period

Introduction: Despite the knowledge of sex differences concerning neurobiological parameters as well as clinical course of illness in individuals with mood disorders, the literature concerning tryptophan (Trp) breakdown, specific for women and men, is sparse to date. The current study aimed to evaluate sex differences in Trp, kynurenine (Kyn) and Kyn/Trp concentrations in general, as well as differences in changes of those concentrations over the course of a 6-week rehabilitation program in individuals with life-time unipolar affective disorder. For this purpose changes in Trp and Kyn as well as the Kyn/Trp concentrations between the time of admission (t1) and discharge (t2) were analyzed in dependence of sex. Furthermore, correlations between Trp and Kyn levels and clinical parameters were performed separately for male and female participants. Material and Methods: Results: For the current analysis 426 individuals with lifetime affective disorder completing a 6-week rehabilitation program were included. In both sexes, psychiatric symptoms decreased significantly over time. There was a significant difference between women (n = 242) and men (n = 184) regarding the changes in Trp, Kyn, and Kyn/Trp over time even if controlled for relevant covariates [multivariate: F _{(3, 380)} = 2.663, η² = 0.021, p = 0.048]. Kyn as well as Kyn/Trp concentrations increased significantly in men over time (Kyn F = 4.809, η² = 0.012, p = 0.029; Kyn/Trp F = 7.923, η² = 0.020, p = 0.005). Results remained the same when controlled for psychiatric symptoms. Discussion: The main finding of the present study is the significant difference between women and men regarding the change in Trp, Kyn, and Kyn/Trp over a 6-week psychiatric treatment period, while the depression severity scores as well as general psychiatric symptoms decreased. Sex specific changes in Trp-Kyn pathways have only been explored to a very small extent to date in the literature but are of high clinical relevance in the context of personalized medicine.

Endoplasmic reticulum stress in bipolar disorder? - BiP and CHOP gene expression- and XBP1 splicing analysis in peripheral blood

BACKGROUND

Endoplasmic Reticulum stress activates the Unfolded Protein Response, which is partially impaired in Bipolar Disorder (BD) according to previous in-vitro studies. Thus, BiP and CHOP gene expression and XBP1 splicing were analyzed in peripheral blood of study participants with BD and controls.

METHODS

RNA was isolated from fasting blood of study participants with BD (n = 81) and controls (n = 54) and reverse transcribed into cDNA. BiP and CHOP gene expression was analyzed with quantitative RT-PCR. Atypical splicing of XBP1 mRNA was measured by semi-quantitative RT-PCR, gel-electrophoresis and densitometry. ANCOVAs with the covariates age, BMI, sex, lithium and anticonvulsants intake were used with SPSS. Bonferroni correction was used to correct for multiple testing (adjusted p = 0.0083).

RESULTS

BiP gene expression was significantly higher in BD than in controls (F(1/128) = 10.076, p = 0.002, Partial η² = 0.073). Total XBP1 (F(1/126) = 9.550, p = 0.002, Partial η² = 0.070) and unspliced XBP1 (F(1/128)= 8.803, p= 0.004, Patial η² = 0.065) were significantly decreased in BD. Spliced XBP1 (F(1/126) = 5.848, p = 0.017, Partial η² = 0.044) and the ratio spliced XBP1/ unspliced XBP1 did not differ between BD and controls (F(1/126) = 0.599, p = 0.441, Partial η² = 0.005). Gene expression did not differ between euthymia, depression and mania.

DISCUSSION

BiP gene expression was significantly higher in BD compared to controls. Total and unspliced XBP1 were significantly lower in BD than in the control group. Thus, both genes may be considered as putative trait markers. Nevertheless, XBP1 splicing itself did not differ between both groups.

In major affective disorders, early life trauma predict increased nitro-oxidative stress, lipid peroxidation and protein oxidation and recurrence of major affective disorders, suicidal behaviors and a lowered quality of life

Early life trauma (ELT) may increase the risk towards bipolar disorder (BD) and major depression (MDD), disorders associated with activated neuro-oxidative and neuro-nitrosative stress (O&NS) pathways. It has remained elusive whether ELTs are associated with O&NS and which ELTs are associated with distinct affective disorder phenotypes. This case-control study examined patients with BD (n = 68) and MDD (n = 37) and healthy controls (n = 66). The Child Trauma Questionnaire (CTQ) was used to assess specific ELT. We measured malondialdehyde (MDA), lipid hydroperoxides (LOOH), superoxide dismutase (SOD), catalase, advanced oxidation protein products (AOPP); NO metabolites (NOx), paraoxonase 1 activity, zinc, albumin, high density lipoprotein cholesterol and -SH groups and computed z-unit weighted composite scores. Physical neglect significantly predicts higher z-unit weighted composite scores of LOOH+SOD, LOOH+SOD+NOx, LOOH+SOD+NOx + MDA and LOOH+SOD+NOx + AOPP. Sexual abuse was associated with a significantly lower composite score of zinc+albumin+SH. Emotional abuse was associated with severity of depression and anxiety, number of depressive and manic episodes, alcohol and hypnotics use, lifetime suicidal behavior and lowered quality of life. Sexual abuse was associated with an increased risk towards BD, but not MDD. ELT, especially physical neglect, may drive increased (nitro-)oxidative stress coupled with lipid and protein oxidation, which - together with emotional abuse - may play a role in severity of illness, lowered quality of life and MDD. ELTs are also associated with the onset of BD, but this link did not appear to be related to activated O&NS pathways. These novel findings deserve confirmation in prospective studies.

Oxidatively-induced DNA damage and base excision repair in euthymic patients with bipolar disorder

Oxidatively-induced DNA damage has previously been associated with bipolar disorder. More recently, impairments in DNA repair mechanisms have also been reported. We aimed to investigate oxidatively-induced DNA lesions and expression of DNA glycosylases involved in base excision repair in euthymic patients with bipolar disorder compared to healthy individuals. DNA base lesions including both base and nucleoside modifications were measured using gas chromatography-tandem mass spectrometry and liquid chromatography-tandem mass spectrometry with isotope-dilution in DNA samples isolated from leukocytes of euthymic patients with bipolar disorder (n = 32) and healthy individuals (n = 51). The expression of DNA repair enzymes OGG1 and NEIL1 were measured using quantitative real-time polymerase chain reaction. The levels of malondialdehyde were measured using high performance liquid chromatography. Seven DNA base lesions in DNA of leukocytes of patients and healthy individuals were identified and quantified. Three of them had significantly elevated levels in bipolar patients when compared to healthy individuals. No elevation of lipid peroxidation marker malondialdehyde was observed. The level of OGG1 expression was significantly reduced in bipolar patients compared to healthy individuals, whereas the two groups exhibited similar levels of NEIL1 expression. Our results suggest that oxidatively-induced DNA damage occurs and base excision repair capacity may be decreased in bipolar patients when compared to healthy individuals. Measurement of oxidatively-induced DNA base lesions and the expression of DNA repair enzymes may be of great importance for large scale basic research and clinical studies of bipolar disorder.

DNA redox modulations and global DNA methylation in bipolar disorder: Effects of sex, smoking and illness state

DNA redox modulations and methylation have been associated with bipolar disorder (BD) pathophysiology. We aimed to investigate DNA redox modulation and global DNA methylation and demethylation levels in patients with BD during euthymia, mania or depression in comparison to non-psychiatric controls. The roles of sex and smoking as susceptibility factors for DNA redox modulations and global DNA methylation and demethylation were also explored. Levels of 5-methylcytosine (5-mC), 5-hydroxymethylcytosine (5-hmC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were assessed in DNA samples of 75 patients with DSM-IV BD type I (37 euthymic, 18 manic, 20 depressive) in comparison to 60 non-psychiatric controls. Levels of 5-mC and 5-hmC were assessed using Dot Blot as a screening process, and verified using ELISA. Levels of 8-OHdG were assessed using ELISA. The levels of 8-OHdG significantly differed among non-psychiatric control, euthymia, mania and depression groups [F (3,110) = 2.771, p = 0.046], whereas there were no alterations in the levels of 5-hmC and 5-mC. Linear regression analyses revealed the significant effects of smoking (p = 0.031) and sex (p = 0.012) as well as state of illness on the levels of 8-OHdG (p = 0.025) in patients with BD. Our results suggest that levels of 8-OHdG may be affected by sex, illness states and smoking in BD.

Are there differences in lipid peroxidation and immune biomarkers between major depression and bipolar disorder: Effects of melancholia, atypical depression, severity of illness, episode number, suicidal ideation and prior suicide attempts

BACKGROUND

There is evidence that major depression (MDD) and bipolar disorder (BD) are accompanied by activated immune & oxidative (I&O) pathways.

METHODS

To compare I&O biomarkers between MDD and BD we assessed serum levels of thiobarbituric acid reactive substances (TBARS; a lipid peroxidation marker), soluble interleukin-2 receptor (sIL-2R), sIL-6R, IL-α, sIL-1R antagonist (sIL-1RA), tumor necrosis factor receptor 60kDa/80kDa (sTNFR60/R80) in 114 MDD and 133 BD patients, and 50 healthy controls. We computed z-unit weighted indices reflecting the 5 cytokine receptor levels (zCytR), cell-mediated immunity (zCMI) and I&O pathways (zCMI+TBARS).

RESULTS

There are no significant differences in biomarkers between MDD and BD. BD/MDD with atypical features is characterized by increased sIL-6R and TBARS, whereas melancholia is associated with higher TBARS and lower sTNFR60 levels. Severity of illness, as measured with the Hamilton Depression Rating Scale, is correlated with increased sIL-6R, sTNFR80, TBARS, zCytR and zCMI+TBARS. The number of episodes the year prior to blood sampling is positively associated with sTNFR80, TBARS, zCMI, zCMI+TBARS, while number of hospitalizations is positively associated with sIL-1RA. Prior suicidal attempts are associated with increased sIL-1RA, IL-1α, zCMI, TBARS and zCMI+TBARS, while TBARS is associated with current suicidal ideation.

CONCLUSIONS

There are no I&O biomarker differences between MDD and BD. Atypical depression is associated with increased IL-6 trans-signaling and lipid peroxidation. Severity of depression, number of episodes and suicidal attempts are associated with activated I&O pathways. Increased TBARS is the single best predictor of BD/MDD, atypical depression, melancholia and current suicidal ideation.

Frequency and correlates of tardive dyskinesia in Indian patients with type I bipolar disorder

BACKGROUND

Patients with Bipolar Disorder (BD) may have higher risk of Tardive Dyskinesia (TD). Theories for TD include inflammatory or oxidative stress and altered iron metabolism. The current frequency and clinical and biochemical correlates of TD in BD needs exploration.

OBJECTIVES

To assess: (1) the frequency of TD in BD; (2) clinical correlates of TD in BD; (3) oxidative stress markers, inflammatory markers and hepcidin in TD in BD.

MATERIALS & METHODS

In this cross-sectional study, 170 patients with BD were assessed for clinical characteristics using structured assessments. Inflammatory and oxidative markers like Interleukin-6 (IL-6), high sensitivity C-Reactive Protein (hsCRP), malondialdehyde (MDA), Total Antioxidant Status (TAS) and hepcidin were assessed by ELISA.

RESULTS

Frequency of TD was 10.6% (95%C.I.=6.4%-16.2%). Compared to patients without TD, patients with TD were older (F=0.340;p=0.000), had more episodes of illness (U=962.5;p=0.044) higher rates of medical comorbidity (_X2=6.924; p=0.009*), antipsychotic exposure (U=592.5;p=0.000), typical antipsychotic exposure (U=756.5;p=0.001) and cognitive deficits (F=1.129;p=0.001). The biomarkers levels did not differ between the groups. Hepcidin levels correlated with Abnormal involuntary Movements scale (AIMS) score (r=0.213;p=0.006). Patients treated with lithium were more likely to have TD, but also had greater exposure to antipsychotics than patients on valproate.

CONCLUSION

About one-tenth of patients with BD-I have TD. The presence of TD is associated several clinical characteristics such as age, exposure to typical antipsychotics and chronicity of illness. Hepcidin was associated with greater severity of dyskinetic movements and needs further exploration.

Accelerated epigenetic aging and mitochondrial DNA copy number in bipolar disorder

Bipolar disorder (BD) has been previously associated with accelerated aging; yet, the mechanisms underlying this association are largely unknown. The epigenetic clock has been increasingly recognized as a valuable aging marker, although its association with other biological clocks in BD patients and high-risk subjects, such as telomere length and mitochondrial DNA (mtDNA) copy number, has never been investigated. We included 22 patients with BD I, 16 siblings of BD patients, and 20 healthy controls in this analysis. DNA was isolated from peripheral blood and interrogated for genome-wide DNA methylation, mtDNA copy number, and telomere length. DNA methylation age (DNAm age) and accelerated aging were calculated using the Horvath age estimation algorithm in blood and in postmortem brain from BD patients and nonpsychiatric controls using publicly available data. Older BD patients presented significantly accelerated epigenetic aging compared to controls, whereas no difference was detected among the younger subjects. Patients showed higher levels of mtDNA copy number, while no difference was found between controls and siblings. mtDNA significantly correlated with epigenetic age acceleration among older subjects, as well and with global functioning in our sample. Telomere length did not show significant differences between groups, nor did it correlate with epigenetic aging or mtDNA copy number. These results suggest that BD may involve an accelerated epigenetic aging, which might represent a novel target for treating BD and subjects at risk. In particular, our results suggest a complex interplay between biological clocks to determine the accelerated aging and its consequences in BD.

The effects of aerobic exercise training on oxidant-antioxidant balance, neurotrophic factor levels, and blood-brain barrier function in obese and non-obese men

PURPOSE

The purpose of this study was to investigate the effects of obesity and aerobic exercise training on oxidant-antioxidant balance, neurotrophic factor levels, and blood-brain barrier (BBB) function.

METHODS

Ten non-obese healthy men (body mass index < 25 kg/m²) and 10 obese men (body mass index ≥ 25 kg/m²) were included in the study. Both groups performed treadmill exercise for 40 min 3 times weekly for 8 weeks at 70% heart rate reserve. Blood samples were collected to examine oxidant-antioxidant balance (reactive oxygen species (ROS) and superoxide dismutase (SOD) activity levels), neurotrophic factors (brain-derived neurotrophic factor (BDNF), nerve growth factor, and glial cell line-derived neurotrophic factor levels), and BBB function (S100β and neuron-specific enolase (NSE) levels) before and after exercise training.

RESULTS

The obese group showed significantly greater changes than the non-obese group in serum ROS (-0.46 ± 0.31 mmol/L vs. -0.10 ± 0.17 mmol/L, p = 0.005), serum S100β levels (-8.50 ± 5.92 ng/L vs. -0.78 ± 5.45 ng/L, p = 0.007), and serum NSE levels (-0.89 ± 0.54 µg/L vs. -0.01 ± 0.74 µg/L, p = 0.007) after training. At baseline, the obese group showed significantly higher serum ROS and S100β levels and significantly lower serum SOD activity and BDNF levels than the non-obese group (p < 0.05). The obese group showed significantly lower serum ROS, S100β, and NSE levels and significantly higher serum SOD activity and BDNF levels after training compared with baseline (p < 0.05).

CONCLUSION

These results suggest that obesity can reduce serum neurotrophic factor levels and can induce BBB dysfunction. On the other hand, aerobic exercise can improve an oxidant-antioxidant imbalance in obese subjects and limit BBB dysfunction.

Gender differences in the association between physical activity and cognitive function in individuals with bipolar disorder

INTRODUCTION

Bipolar disorder (BD) is accompanied by a high number of comorbidities and associated with an overall increased mortality. Especially obesity, systemic inflammatory processes and cognitive deficits are highly prevalent and increase with the course of illness. Physical activity (PA) is associated with beneficial effects on somatic comorbidities such as obesity or cardiovascular disease in individuals without psychiatric disorder. Furthermore, PA might increase neurocognitive performance and reduce systemic inflammation.

OBJECTIVE

The aim of the study was to investigate the association between PA and neurocognitive function in euthymic individuals suffering from BD.

METHODS AND PARTICIPANTS

120 individuals with BD, euthymic at test time, completed the self-reported International Physical Activity Questionnaire (IPAQ) assessing PA of the past seven days and were accordingly assigned to a specific activity category (low, moderate or vigorous). Furthermore, clinical parameters were gathered and cognitive tests analysing verbal-dependent intelligence, attention, executive functioning as well as memory were administered.

RESULTS

Female individuals in the vigorous PA group performed significantly higher in most of the cognitive domains compared to females with moderate or low PA. In males, we only found a significant difference in one test for attention between moderate/vigorous and the low activity group.

CONCLUSION

Differences between PA groups in cognitive performance in female individuals with BD were obvious in almost all cognitive domains. As cognitive deficits are strongly associated with a worse course of disease and outcome, PA might offer a concomitant therapy targeting not only somatic comorbidities such as obesity and cardiovascular disease, but also neurocognition.

The role of tryptophan metabolism and food craving in the relationship between obesity and bipolar disorder

BACKGROUND & AIMS

Individuals with bipolar disorder (BD) have a significantly increased risk of obesity-related conditions. The imbalance between food intake and energy expenditure is assumed to be a major risk factor for obesity in BD. This study analyzed food craving in relation to anthropometric, metabolic, and neurobiological parameters in a well-characterized cohort of euthymic individuals with BD.

METHODS

One-hundred-thirty-five patients completed the Food-Craving Inventory assessing four categories of food craving (fat, fast-food, sweets and carbohydrate craving). Additionally, clinical, metabolic and anthropometric parameters were assessed.

RESULTS

Higher levels of fat craving were observed in males, versus females, with BD. High levels of carbohydrate craving positively correlated with kynurenine and the kynurenine-to-tryptophan ratio. Higher serum nitrite and neopterin levels were related to fat craving. Parameters of fat metabolism (triglycerides, high-density lipoprotein) were associated with fat and fast-food craving. Anthropometric measures of obesity (e.g. body mass index, waist-to-hip-ratio) were not related to food craving.

CONCLUSIONS

Overweight/obese individuals with BD show an increased driving of tryptophan down the kynurenine pathways, as indicated by an increase in the serum kynurenine-to-tryptophan ratio. The driving of tryptophan down the kynurenine pathway is mediated by immune-inflammatory activity and stress. The correlation of increased kynurenine with food craving, especially carbohydrate craving, probably indicates a regulatory deficit in the maintenance of chronic inflammatory processes in obesity and BD. Food craving seems to be of clinical importance in the treatment of metabolic disturbances in BD, although not associated with anthropometric measures of obesity. Rather, food craving correlates with blood metabolic parameters and an increased activation of the kynurenine pathway, both of which are linked to higher affective symptomatology and the development of cardiovascular diseases.

Clinical staging and serum cytokines in bipolar patients during euthymia

AIMS

Changes in serum cytokines and altered neutrophin concentration have been associated with bipolar disorder (BD). Our aim here was to analyze peripheral blood biomarkers according to the clinical stages of BD.

METHOD

Euthymic BD-I patients were grouped according to their level of functioning in early-stage (n=25) and late-stage (n=23), and compared to healthy siblings (n=23) and genetically unrelated healthy controls (n=21). Neurotrophin (neurotrophin-3 and BDNF) concentration and biomarkers of inflammation, including cytokines (IL-6, IL-10 and TNF-α), leukocytes count and acute phase proteins, were measured.

RESULTS

IL-10 concentration was significantly increased in early-stage patients compared to late-stage patients, healthy siblings and controls whereas TNF-α concentration was significantly increased in late-stage patients compared to controls. Total leukocytes, neutrophil and monocyte count were significantly increased in late-stage patients compared to healthy siblings and controls. The concentration of IL-6, neurotrophin-3 and BDNF was unchanged in euthymia. Healthy siblings did not show significant changes in any biomarker.

CONCLUSIONS

The concentration of IL-10, TNF-α, neutrophil and monocytes subtype count in blood is altered in patients with BD during euthymic state. The link between peripheral inflammation and different stages in BD deserves further studies.

Tryptophan breakdown and cognition in bipolar disorder

INTRODUCTION

It has been demonstrated that bipolar disorder (BD) is often accompanied by cognitive deficits across all subdomains including verbal memory, attention and executive functioning. Cognitive deficits are observed both during episodes of mania or depression, as well as during the euthymic phase. It has been proposed that chronic immune-mediated inflammation in the central nervous system results in alterations in neural structures that subserve cognitive function. Kynurenine is an intermediate in the inflammatory cascade and can be peripherally measured to proxy inflammatory activity. Herein, we sought to determine whether serum levels of kynurenine and/or its metabolites were associated with cognitive function in BD.

METHODS

In this investigation 68 euthymic individuals with BD according to DSM-IV completed a cognitive test battery to asses premorbid intelligence (Multiple Choice Word Test; MWT-B), verbal memory (California Verbal Learning Test; CVLT), attention (d2 Test of Attention; d2 test, Trail Making Test-A; TMT-A, Stroop word reading/Stroop color naming) and executive functioning (TMT-B, Stroop interference). In addition, fasting blood samples were taken and serum levels of kynurenine and its metabolites 3-hydroxykynurenine and kynurenic acid were analyzed. Subsequently ratios were formed from individual parameters. Patient data were compared with those of a mentally healthy control group (n=93).

RESULTS

In male participants with BD only we found a significant negative correlation between the 3-hydroxykynurenine to kynurenic acid ratio and performance on the CVLT. Additionally, the kynurenine to 3-hydroxykynurenine ratio was associated with performance on a sub-score of the CVLT. Those associations were neither present in female individuals with BD nor in the control group.

DISCUSSION

Our findings suggest that a shift towards the hydroxykynurenine arm of the kynurenine pathway may be associated with poorer memory performance due to its effects on neuronal functioning and neurogenesis in the hippocampus. Our results implicate a mechanistic role of central inflammatory processes in cognitive functions in adults with bipolar disorder.

Increased breakdown of kynurenine towards its neurotoxic branch in bipolar disorder

Introduction

Bipolar disorder (BD) is a chronic psychiatric disease which can take most different and unpredictable courses. It is accompanied by unspecific brainstructural changes and cognitive decline. The neurobiological underpinnings of these processes are still unclear. Emerging evidence suggests that tryptophan catabolites (TRYCATs), which involve all metabolites of tryptophan towards the kynurenine (KYN) branch, are involved in the etiology as well as in the course of BD. They are proposed to be mediators of immune-inflammation and neurodegeneration. In this study we measured the levels of KYN and its main catabolites consisting of the neurotoxic hydroxykynurenine (3-HK), the more neuroprotective kynurenic acid (KYNA) and anthranilic acid (AA) and evaluated the ratios between end-products and substrates as proxies for the specific enzymatic activity (3-HK/KYN, KYNA/KYN, AA/KYN) as well as 3-HK/KYNA as a proxy for neurotoxic vs. neuroprotective end-product relation in individuals with BD compared to healthy controls (HC).

Methods

We took peripheral TRYCAT blood levels of 143 euthymic to mild depressive BD patients and 101 HC. For statistical analyses MANCOVA’s controlled for age, sex, body mass index, cardiovascular disease and smoking were performed.

Results

The levels of KYNA (F = 5,579; p <.05) were reduced in BD compared to HC. The enzymatic activity of the kynurenine-3-monooxygenase (KMO) reflected by the 3-HK/KYN ratio was increased in BD individuals compared to HC (F = 5,394; p <.05). Additionally the ratio of 3-HK/KYNA was increased in individuals with BD compared to healthy controls (F = 11,357; p <.01).

Discussion

In conclusion our findings subserve the concept of KYN -pathway alterations in the pathophysiology of BD. We present evidence of increased breakdown towards the neurotoxic branch in KYN metabolism even in a euthymic to mild depressive state in BD. From literature we know that depression and mania are accompanied by inflammatory states which should be capable to produce an even greater imbalance due to activation of key enzymes in the neurotoxic direction of KYN -conversion. These processes could finally be involved in the development of unspecific brain structural changes and cognitive deficits which are prevalent in BD. Further research should focus on state dependent changes in TRYCATs and its relation to cognition, brain structure and staging parameters.

Abdominal obesity is associated with impaired cognitive function in euthymic bipolar individuals

OBJECTIVES

Overweight/obesity has been implicated to play a role in cognitive deficits in bipolar disorder (BD). This study aims to identify the relationship between body fat distribution and different domains of cognition in BD during euthymia.

METHODS

A sample of 100 euthymic individuals with BD was measured with a cognitive test battery (i.e., Trail Making Test-A-B/TM-A/B, d2 Test of Attention, Stroop test, California Verbal Learning Test/CVLT) and an anthropometric measures set (body mass index, waist circumference, hip circumference, waist-to-hip-ratio, waist-to-height-ratio, and lipometry). Patient data were compared with a healthy control group (n = 64).

RESULTS

Results show that overweight patients with BD exhibit lower performance in the TMT-A/B as well as in the free recall performance of the CVLT compared to normal-weight patients with BD and controls. In bipolar individuals, (abdominal) obesity was significantly associated with a poor cognitive performance. In bipolar females, associations with measures of verbal learning and memory were found; in bipolar males, associations with poor performance in the TMT-A/B and in the Stroop interference task were demonstrated. In controls, no associations were found.

CONCLUSIONS

There are several possible pathways moderating the association between obesity and cognition in BD. Anthropometric and lipometry data underline the substantial mediating impact of body fat distribution on cognition in BD.

Evaluation of Oxidative Stress in Bipolar Disorder in terms of Total Oxidant Status, Total Antioxidant Status, and Oxidative Stress Index

INTRODUCTION

Bipolar disorder is one of the most debilitating psychiatric disorders characterized by disruptive episodes of mania/hypomania and depression. Considering the complex role of biological and environmental factors in the etiology of affective disorders, recent studies have focused on oxidative stress, which may damage nerve cell components and take part in pathophysiology. The aim of the present study was to contribute to the data about oxidative stress in bipolar disorder by detecting the total antioxidant status (TAS), total oxidant status (TOS), and oxidative stress index (OSI) levels of manic episode (ME) and euthymic (EU) patients and by comparing these results with those of healthy controls (HCs).

METHODS

The study population consisted of 28 EU outpatients meeting the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for bipolar disorder I and 23 inpatients who were currently hospitalized in a psychiatry ward with the diagnosis of the bipolar disorder ME according to the DSM-5 criteria. Forty-three healthy subjects were included in the study as the control group (HC). Serum TAS, TOS, and OSI levels of all the participants were determined.

RESULTS

Statistical analysis of serum TAS, TOS, and OSI levels did not show any significant differences between the ME patients, EU patients, and HCs. Comparison between the bipolar disorder patients (ME+EU) and HC also did not reveal any statistically significant difference between these two groups in terms of serum TAS, TOS, and OSI levels.

CONCLUSION

To date, studies on oxidative stress in bipolar disorder have led to controversial results. In the present study, no statistically significant difference was detected between the oxidative parameters of bipolar disorder patients and HCs. In order to comprehensively evaluate oxidative stress in bipolar disorder, further studies are needed.

Obesity and Its Potential Effects on Antidepressant Treatment Outcomes in Patients with Depressive Disorders: A Literature Review

Accumulating evidence regarding clinical, neurobiological, genetic, and environmental factors suggests a bidirectional link between obesity and depressive disorders. Although a few studies have investigated the link between obesity/excess body weight and the response to antidepressants in depressive disorders, the effect of weight on treatment response remains poorly understood. In this review, we summarized recent data regarding the relationship between the response to antidepressants and obesity/excess body weight in clinical studies of patients with depressive disorders. Although several studies indicated an association between obesity/excess body weight and poor antidepressant responses, it is difficult to draw definitive conclusions due to the variability of subject composition and methodological differences among studies. Especially, differences in sex, age and menopausal status, depressive symptom subtypes, and antidepressants administered may have caused inconsistencies in the results among studies. The relationship between obesity/excess body weight and antidepressant responses should be investigated further in high-powered studies addressing the differential effects on subject characteristics and treatment. Moreover, future research should focus on the roles of mediating factors, such as inflammatory markers and neurocognitive performance, which may alter the antidepressant treatment outcome in patients with comorbid obesity and depressive disorder.

Cerebral White Matter Lesions and Affective Episodes Correlate in Male Individuals with Bipolar Disorder

Background

Cerebral white matter lesions (WML) have been found in normal aging, vascular disease and several neuropsychiatric conditions. Correlations of WML with clinical parameters in BD have been described, but not with the number of affective episodes, illness duration, age of onset and Body Mass Index in a well characterized group of euthymic bipolar adults. Herein, we aimed to evaluate the associations between bipolar course of illness parameters and WML measured with volumetric analysis.

Methods

In a cross-sectional study 100 euthymic individuals with BD as well as 54 healthy controls (HC) were enrolled to undergo brain magnetic resonance imaging using 3T including a FLAIR sequence for volumetric assessment of WML-load using FSL-software. Additionally, clinical characteristics and psychometric measures including Structured Clinical Interview according to DSM-IV, Hamilton-Depression, Young Mania Rating Scale and Beck’s Depression Inventory were evaluated.

Results

Individuals with BD had significantly more (F = 3.968, p < .05) WML (Mdn = 3710mm3; IQR = 2961mm3) than HC (Mdn = 2185mm3; IQR = 1665mm3). BD men (Mdn = 4095mm3; IQR = 3295mm3) and BD women (Mdn = 3032mm3; IQR = 2816mm3) did not significantly differ as to the WML-load or the number and type of risk factors for WML. However, in men only, the number of manic/hypomanic episodes (r = 0.72; p < .001) as well as depressive episodes (r = 0.51; p < .001) correlated positively with WML-load.

Conclusions

WML-load strongly correlated with the number of manic episodes in male BD patients, suggesting that men might be more vulnerable to mania in the context of cerebral white matter changes.