Immunity, inflammation, and bipolar disorder: diagnostic and therapeutic implications

Causal role of immune cells in major depressive disorder and bipolar disorder: Mendelian randomization (MR) study

BACKGROUND

Major depressive disorder (MDD) and bipolar disorder (BD) are prevalent psychiatric conditions linked to inflammatory processes. However, it is unclear whether associations of immune cells with these disorders are likely to be causal.

METHODS

We used two-sample Mendelian randomization (MR) approach to investigate the relationship between 731 immune cells and the risk of MDD and BD. Rigorous sensitivity analyses are conducted to assess the reliability, heterogeneity, and horizontal pleiotropy of the findings.

RESULTS

Genetically-predicted CD27 on IgD+ CD38- unswitched memory B cell (inverse variance weighting (IVW): odds ratio (OR) [95 %]: 1.017 [1.007 to 1.027], p = 0.001), CD27 on IgD+ CD24+ B cell (IVW: OR [95 %]: 1.021 [1.011 to 1.031], p = 4.821E-05) and other 12 immune cells were associated with increased risk of MDD in MR, while HLA DR++ monocyte %leukocyte (IVW: OR [95 %]: 0.973 [0.948 to 0.998], p = 0.038), CD4 on Central Memory CD4+ T cell (IVW: OR [95 %]: 0.979 [0.963 to 0.995], p = 0.011) and other 13 immune cells were associated with decreased risk of MDD in MR. Additionally, CD33+ HLA DR+ Absolute Count (IVW: OR [95 %]: 1.022[1.007 to 1.036], p = 0.007), CD28+ CD45RA- CD8+ T cell %T cell (IVW: OR [95 %]: 1.024 [1.008 to 1.041], p = 0.004) and other 18 immune cells were associated with increased risk of BD in MR, while CD62L on CD62L+ myeloid Dendritic Cell (IVW: OR [95 %]: 0.926 [0.871 to 0.985], p = 0.014), IgD- CD27- B cell %lymphocyte (IVW: OR [95 %]: 0.918 [0.880 to 0.956], p = 4.654E-05) and other 13 immune cells were associated with decreased risk of BD in MR.

CONCLUSIONS

This MR study provides robust evidence supporting a causal relationship between immune cells and the susceptibility to MDD and BD, offering valuable insights for future clinical investigations. Experimental studies are also required to further examine causality, mechanisms, and treatment potential for these immune cells for MDD and BD.

Genetic causal association between varicella-zoster virus infection and psychiatric disorders: A 2-sample Mendelian randomization study

BACKGROUND

Psychiatric disorders, such as schizophrenia (SCZ), major depressive (MDD), and bipolar disorder (BD) have a profound impact on millions of individuals worldwide. The critical step toward developing effective preventive and treatment strategies lies in comprehending the causal mechanisms behind these diseases and identifying modifiable risk factors associated with them.

METHODS

In this study, we conducted a 2-sample Mendelian randomization analysis to explore the potential links between chickenpox(varicella-zoster virus infection) and three major psychiatric disorders(SCZ, MDD, BD).

RESULTS

In our MR study, among the three major psychiatric disorders, chickenpox was shown to be causally related to BD, indicating that infection with chickenpox may increase the risk of developing BD (IVW: OR = 1.064, 95% CI =1.025-1.104, P=0.001; RAPS: OR=1.066, 95% CI=1.024-1.110, P=0.002), while there was no causal relationship between SCZ and MDD. Similar estimated causal effects were observed consistently across the various MR models. The robustness of the identified causal relationship between chickenpox and BD holds true regardless of the statistical methods employed, as confirmed by extensive sensitivity analyses that address violations in model assumptions. The MR-Egger regression test failed to reveal any signs of directional pleiotropy (intercept = -0.042, standard error (SE) = 0.029, p = 0.236). Similarly, the MR-PRESSO analysis revealed no evidence of directional pleiotropy or outliers among the chickenpox-related instrumental variables (global test p = 0.653). Furthermore, a leave-one-out sensitivity analysis yielded consistent results, further underscoring the credibility and stability of the causal relationship.

CONCLUSIONS

Our findings provide compelling evidence of a causal effect of chickenpox on the risk of BD. To gain a more comprehensive understanding of this association and its underlying mechanisms, additional research is needed. Such investigations are pivotal in identifying effective interventions for promoting BD prevention.

Curcumin as a Multifunctional Spice Ingredient against Mental Disorders in Humans: Current Clinical Studies and Bioavailability Concerns

BACKGROUND

Mental disorders in terms of depression, anxiety, and stress are one of the major causes of burden globally. Over the last two decades, the use of plant-based substances in the treatment of mental disorders in combination or not with medication has increasingly attracted the interest of the scientific research community. However, even if there is a plethora of naturally occurring bioactive compounds, most of them have low bioavailability, rendering them unable to insert into the bloodstream to exert their biological activities.

METHODS

This is a comprehensive narrative review that critically summarizes and scrutinizes the new approaches to the treatment of mental disorders using curcumin, also highlighting its bioavailability properties. The most accurate were searched using effective and relevant keywords.

RESULTS

This narrative review reveals substantial evidence that curcumin can exert significant effects on several mental disorders. However, despite the low cost, the extensive and confirmed potency of curcumin and its involvement in signaling pathways and the scientifically confirmed data regarding its molecular mechanisms of action against mental disorders, this naturally occurring compound presents low oral bioavailability. Pharmaceutical technology has provided solutions to increase the bioavailability of curcumin. Combination with piperine, galactomannosides, liposomal formulation or nanoformulation overcomes the bioavailability and solubility disadvantages.

CONCLUSIONS

Although curcumin demonstrates anti-anxiety, anti-depressive and anti-stress properties, studies on humans are limited and heterogeneous. Further research is highly recommended to determine the most functional formula, dose, duration, and possible side effects of curcumin on mental disorders in humans. Based on the current knowledge, the curcumin nanoformulation and Theracurmin, a form of colloidal submicroscopic particles, seem to be the most effective bioavailable formulations, which may be examined in future clinical human studies.

The emerging neuroimmune hypothesis of bipolar disorder: An updated overview of neuroimmune and microglial findings

Bipolar disorder (BD) is a severe and multifactorial disease, with onset usually in young adulthood, which follows a progressive course throughout life. Replicated epidemiological studies have suggested inflammatory mechanisms and neuroimmune risk factors as primary contributors to the onset and development of BD. While not all patients display overt markers of inflammation, significant evidence suggests that aberrant immune signaling contributes to all stages of the disease and seems to be mood phase dependent, likely explaining the heterogeneity of findings observed in this population. As the brain's immune cells, microglia orchestrate the brain's immune response and play a critical role in maintaining the brain's health across the lifespan. Microglia are also highly sensitive to environmental changes and respond to physiological and pathological events by adapting their functions, structure, and molecular expression. Recently, it has been highlighted that instead of a single population of cells, microglia comprise a heterogeneous community with specialized states adjusted according to the local molecular cues and intercellular interactions. Early evidence has highlighted the contribution of microglia to BD neuropathology, notably for severe outcomes, such as suicidality. However, the roles and diversity of microglial states in this disease are still largely undermined. This review brings an updated overview of current literature on the contribution of neuroimmune risk factors for the onset and progression of BD, the most prominent neuroimmune abnormalities (including biomarker, neuroimaging, ex vivo studies) and the most recent findings of microglial involvement in BD neuropathology. Combining these different shreds of evidence, we aim to propose a unifying hypothesis for BD pathophysiology centered on neuroimmune abnormalities and microglia. Also, we highlight the urgent need to apply novel multi-system biology approaches to characterize the diversity of microglial states and functions involved in this enigmatic disorder, which can open bright perspectives for novel biomarkers and therapeutic discoveries.

Inflammation and emotion regulation: a narrative review of evidence and mechanisms in emotion dysregulation disorders

Emotion dysregulation (ED) describes a difficulty with the modulation of which emotions are felt, as well as when and how these emotions are experienced or expressed. It is a focal overarching symptom in many severe and prevalent neuropsychiatric diseases, including bipolar disorders (BD), attention deficit/hyperactivity disorder (ADHD), and borderline personality disorder (BPD). In all these disorders, ED can manifest through symptoms of depression, anxiety, or affective lability. Considering the many symptomatic similarities between BD, ADHD, and BPD, a transdiagnostic approach is a promising lens of investigation. Mounting evidence supports the role of peripheral inflammatory markers and stress in the multifactorial aetiology and physiopathology of BD, ADHD, and BPD. Of note, neural circuits that regulate emotions appear particularly vulnerable to inflammatory insults and peripheral inflammation, which can impact the neuroimmune milieu of the central nervous system. Thus far, few studies have examined the link between ED and inflammation in BD, ADHD, and BPD. To our knowledge, no specific work has provided a critical comparison of the results from these disorders. To fill this gap in the literature, we review the known associations and mechanisms linking ED and inflammation in general, and clinically, in BD, ADHD, and BD. Our narrative review begins with an examination of the routes linking ED and inflammation, followed by a discussion of disorder-specific results accounting for methodological limitations and relevant confounding factors. Finally, we critically discuss both correspondences and discrepancies in the results and comment on potential vulnerability markers and promising therapeutic interventions.

Neutrophil/high-density lipoprotein cholesterol (HDL), monocyte/HDL and platelet/HDL ratios are increased in acute mania as markers of inflammation, even after controlling for confounding factors

OBJECTIVE

Recent studies show that inflammation is related to the pathogenesis of acute mania of bipolar disorder. Neutrophil/high-density lipoprotein (HDL) ratio (NHR), lymphocyte/HDL ratio (LHR), monocyte/HDL ratio (MHR) and platelet/HDL ratio (PHR) have recently been investigated as novel markers of inflammation. In addition, the atherogenic index of plasma (AIP) and atherogenic coefficient (AC) are the leading atherogenic indices. The study aimed to investigate these inflammation and atherogenic index markers in acute mania of bipolar disorder. Another aim was to determine whether there is a relationship between these markers and disease severity and psychotic symptoms.

METHODS

A total of 109 BD-M and 101 (HC) were enrolled in the study. The differences in NHR, LHR, MHR, PHR, AIP and AC and their association with illness severity and psychotic symptoms were analyzed after adjusting for age, sex, total cholesterol level, body-mass index and smoking status. Then, a receiver operating characteristic (ROC) curve and linear discriminant analysis (LDA) were used to analyze these parameters' diagnostic potential. Moreover, the Young Mania Rating Scale (YMRS) and Clinical Global Impression Scale for use in bipolar illness-Severity subscale (CGI-BP-S) were used to assess the severity of clinical symptoms.

RESULTS

We found higher levels of NHR, MHR, PHR and AIP, but not LHR and AC, after adjusting confounding factors in patients with BD-M compared to HCs. In logistic regression analysis, higher levels of MHR and NHR were associated with BD-M. MHR, NHR and PHR were predictors for differentiating the BD-M group from the HC group. However, the severity of the illness or the psychotic feature of the manic episode did not significantly affect the parameters. In the ROC curve analysis of BD-M, the indicators with an area under the curve (AUC) higher than 0.6 were the MHR, NHR, PHR and LHR.

CONCLUSIONS

These results provide information about the role of inflammation in the pathophysiology of BD-M. Even after controlling for confounding factors, MHR, NHR, PHR and AIP are potential biomarkers for BD-M. Moreover, the increase in AIP may explain the co-morbidity between BD and cardiovascular diseases. However, the severity of the illness or the psychotic feature of the manic episode did not significantly affect the levels of inflammation ratios used in our study. Due to the low cost and widespread use of lipid metabolism and related inflammation rates, it may be beneficial to know the MHR, NHR, PHR and AIP levels in BD-M patients.

Inflammation Markers in Patients with Bipolar Disorder Who Have Committed Offenses and Their Relationship with Criminal Behavior

Background and Objectives: This study aimed to examine the function of various inflammation parameters and their interactions in the pathology of Bipolar disorder (BD) and to assess whether they could be biomarkers in the relationship between criminal behavior and BD. Materials and Methods: Overall, 1029 participants, including 343 patients with BD who have committed offenses, 343 nonoffending patients with BD, and 343 healthy controls, were included in this retrospective study. Neutrophil, lymphocyte, monocyte, and platelet counts; high-density lipoprotein (HDL-c) levels; systemic immune-inflammatory index (SII), systemic inflammatory response index (SIRI), neutrophil to high-density lipoprotein ratio (NHR), lymphocyte to high-density lipoprotein ratio (LHR), monocyte to high-density lipoprotein ratio (MHR), platelet to high-density lipoprotein ratio (PHR) were measured. Results: Significant differences were observed between the groups in terms of SII, SIRI, NHR, LHR, MHR, PHR, neutrophil, and monocyte values (p < 0.001). The lymphocyte counts were significantly higher in the patients with BD who committed offenses (p = 0.04). The platelet counts were significantly lower in the patients with BD who committed offenses compared to nonoffending patients with BD (p = 0.015). The HDL-c levels were significantly lower in the patients with BD who have committed offenses than those of nonoffending patients with BD (p < 0.001). Bipolar disorder, not receiving active psychiatric treatment, having a diagnosis of bipolar manic episodes, and having low platelet and HDL values constitute a risk of involvement in crime. Conclusions: The present study emphasizes the role of systemic inflammation in the pathophysiology of patients with BD with and without criminal offenses and the relationship between inflammation and criminal behavior.

Does celecoxib with sodium valproate have an augmentation effect on acute mania in bipolar disorder? A double-blind controlled clinical trial in Iran

Inflammatory processes in the brain play a role in acute mania etiopathogenesis. There is little evidence indicating the efficacy of celecoxib adjuvant therapy in treatmenting of manic episodes of bipolar disorder. Therefore, this clinical trial aimed to assess the celecoxib effect on treating acute mania. In a double-blind, placebo-controlled trial, 58 patients meeting the criteria for acute mania were enrolled. After considering eligibility, 45 patients were included in the study and randomly divided into two groups. The first group (23 patients) received sodium valproate 400 mg/day along with celecoxib 400 mg/day, and the second group (22 patients) received sodium valproate 400 mg/day and a placebo. The subjects were evaluated by the Young Mania Rating Scale (YMRS) at the beginning of the study and 9, 18, and 28 days following the initiation of the medication. Evaluation of baseline factors indicated a significant difference in age ( P  = 0.01) and psychiatric history ( P  = 0.02) between the two groups. However, other factors were similar between groups ( P  ≥ 0.05). Comparing the YMRS score between celecoxib and placebo groups revealed no significant difference on days 0, 9, 18, and 28. However, the YMRS score at the end of the study decreased by 16.05 ± 7.65 in the intervention group ( P  < 0.001) and 12.50 ± 5.98 in controls ( P  < 0.001) compared to the baseline, the trend of change was not significant between the two groups during the time of the study ( F  = 0.38; P  = 0.84). Although celecoxib adjuvant therapy indicated no considerable side effects, a longer treatment duration may be needed to detect its beneficial effects for treating acute mania in bipolar patients. Trial registration: Iran clinical trial register: IRCT20200306046708N1.

Structural and functional MRI correlates of inflammation in bipolar disorder: A systematic review

BACKGROUND

Bipolar disorder (BD) is a common affective disorder characterized by recurrent oscillations between mood states and associated with inflammatory diseases and chronic inflammation. However, data on MRI abnormalities in BD and their relationship with inflammation are heterogeneous and no review has recapitulated them.

METHODS

In this pre-registered (PROSPERO: CRD42022308461) systematic review we searched Web of Science Core Collection and PubMed for articles correlating functional or structural MRI measures with immune-related markers in BD.

RESULTS

We included 23 studies (6 on functional, 16 on structural MRI findings, 1 on both, including 1'233 BD patients). Overall, the quality of the studies included was fair, with a low risk of bias.

LIMITATIONS

Heterogeneity in the methods and results of the studies and small sample sizes limit the generalizability of the conclusions.

CONCLUSIONS

A qualitative synthesis suggests that the links between immune traits and functional or structural MRI alterations point toward brain areas involved in affective and somatomotor processing, with a trend toward a negative correlation between peripheral inflammatory markers and brain regions volume. We discuss how disentangling the complex relationship between the immune system and MRI alterations in BD may unveil mechanisms underlying symptoms pathophysiology, potentially with quickly translatable diagnostic, prognostic, and therapeutic implications.

Suicide in bipolar disorder patients is associated with hippocampal microglia activation and reduction of lymphocytes-activation gene 3 (LAG3) microglial checkpoint expression

BACKGROUND

Bipolar disorder (BD) is associated with marked functional impairments along with increased rate of suicide. Although there is ample evidence for the involvement of inflammatory processes and microglia activation in the pathophysiology of BD, the mechanisms that regulate these cells in BD patients, and particularly the role of microglia checkpoints, is still unclear.

METHODS

Immunohistochemical analyses of hippocampal sections from post-mortem brains of 15 BD patients and 12 control subjects were used to assess microglia density, by staining the microglia-specific receptor P2RY12, and microglia activation, by staining the activation marker MHC II. Given recent findings on the involvement of LAG3, which interacts with MHC II and serves as a negative microglia checkpoint, in depression and electroconvulsive therapy, we assessed the levels of LAG3 expression and their correlations with microglia density and activation.

RESULTS

There were no overall differences between BD patients and controls, but BD patients who committed suicide (N = 9) displayed a significant elevation in the overall microglia density and the density of MHC II-labeled microglia (but not other MHC II-labeled cells), compared with no suicide BD patients (N = 6) and controls. Furthermore, the percent of microglia expressing LAG3 was significantly reduced only in suicidal BD patients, with significant negative correlations between microglial LAG3 expression levels and the density of microglia, in general, and activated microglia, in particular.

CONCLUSION

Suicidal BD patients exhibit microglia activation, which is possibly mediated by reduced LAG3 checkpoint expression, suggesting that anti-microglial therapeutics, including LAG3 modulators, may be beneficial for this subgroup of patients.

Biomarkers and treatments for mood disorders encompassing the neurosteroid and endocannabinoid systems

Mood disorders, including major depressive disorder, postpartum depression, post-traumatic stress disorder and suicidality are highly prevalent, associated with a significant economic burden, and remain poorly diagnosed and poorly treated psychiatric conditions. In part, this may result from the lack of biomarkers that can guide precision medicine with individualized treatments for millions of individuals who suffer these debilitating conditions worldwide. While several biomarker candidates have been proposed for mood disorders, none has been implemented in clinical practice and the treatment still relies in the prescription of selective serotonin reuptake inhibitors that shows mixed efficacy and significant side effects. Both neurosteroid biosynthesis and the endocannabinoid system have recently provided evidence for pharmacological targets to improve mood symptoms and the neuroactive steroid allopregnanolone has recently been approved by the USA Food and Drug Administration for the treatment of post-partum depression. Clinical studies also show efficacy for the management of major depression and more studies are being conducted to study efficacy in post-traumatic stress disorder. Likewise, the endocannabinoid-like modulator, N-palmioyl ethanolamide (PEA) has shown efficacy in the treatment of major depression and bipolar disorder. While these new agents are coming forward in the field of neuropsychopharmacology as a new generation of fast-acting antidepressants, the hypothesis of whether their deficits underlying mood disorders could constitute valid predictive biomarkers to facilitate diagnosis and treatment of these conditions is under consideration.

Long-Term Lithium Therapy and Thyroid Disorders in Bipolar Disorder: A Historical Cohort Study

Lithium has been a cornerstone treatment for bipolar disorder (BD). Despite descriptions in the literature regarding associations between long-term lithium therapy (LTLT) and development of a thyroid disorder (overt/subclinical hypo/hyperthyroidism, thyroid nodule, and goiter) in BD, factors such as time to onset of thyroid abnormalities and impact on clinical outcomes in the course of illness have not been fully characterized. In this study we aimed to compare clinical characteristics of adult BD patients with and without thyroid disorders who were on LTLT. We aimed to identify the incidence of thyroid disorders in patients with BD on LTLT and response to lithium between patients with and without thyroid disorders in BD. The Cox proportional model was used to find the median time to the development of a thyroid disorder. Our results showed that up to 32% of patients with BD on LTLT developed a thyroid disorder, of which 79% developed hypothyroidism, which was corrected with thyroid hormone replacement. We did not find significant differences in lithium response between patients with or without thyroid disorders in BD. Findings from this study suggest that patients with BD and comorbid thyroid disorders when adequately treated have a response to lithium similar to patients with BD and no thyroid disorders.

Elevation of C-reactive protein in adolescent bipolar disorder vs. anxiety disorders

Bipolar disorder (BD) largely begins in adolescence, but diagnosis lags for years, causing significant morbidity and mortality, and demonstrating the need for better diagnostic tools. Suggesting an association between BD and immune activity, elevated levels of peripheral inflammatory markers, including C-reactive protein (CRP), have been found in adults with BD. As similar data are extremely limited in adolescents, this study examined CRP levels in adolescents with BD (n = 37) compared to those with anxiety disorders (ADs, n = 157) and healthy controls with no psychiatric diagnoses (HCs, n = 2760). CRP blood levels for patients aged 12-17 years were retrieved from a nationwide repository of deidentified clinical data. After excluding patients with inflammatory conditions, differences in CRP were examined using multivariate and weighted regressions (covariates: demographics and BMI). Mean CRP levels were significantly elevated in adolescents with BD relative to those with ADs and HCs. Mean CRP levels were lower in the ADs cohort versus HCs. Although CRP levels were significantly higher in males and younger patients, the significant between-cohort differences in CRP remained after controlling for multiple confounders. To our knowledge, our study is the first to compare CRP levels between adolescent BD, ADs, and HCs, comprising a novel and essential contribution. Our results suggest the presence of a unique immune process in adolescents with BD and indicate that CRP may represent a biomarker with a crucial role in the diagnostic assessment of adolescent BD.

Efficacy and safety of palmitoylethanolamide as an adjunctive treatment for acute mania: A randomized, double-blind, placebo-controlled trial

AIM

Palmitoylethanolamide is an endogenous fatty acid amide with neuroprotective and anti-inflammatory actions. We performed a randomized, double-blind, placebo-controlled clinical trial to investigate the efficacy and safety of palmitoylethanolamide combination therapy in acute mania.

METHODS

Patients in the acute phase of mania were assigned into two parallel groups given either lithium (blood level of 0.8-1.1 mEq/L) and risperidone 3 mg plus palmitoylethanolamide 600 mg or placebo twice per day for 6 weeks. All participants were assessed with the Young Mania Rating Scale (YMRS), Hamilton Depression Rating Scale (HDRS), and Extrapyramidal Symptom Rating Scale (ESRS) at baseline and at weeks 1, 2, 4, and 6.

RESULTS

A total of 63 patients (32 in palmitoylethanolamide and 31 in placebo groups) completed the trial. We found a significant effect for time×treatment interaction on the YMRS score (F = 5.22, d.f. = 2.34, P= 0.004) from baseline to study end point. Results from independent t test showed a significantly greater decrease in YMRS scores in the palmitoylethanolamide group, compared with the placebo group, from baseline to weeks 4 and 6 (P= 0.018 and P= 0.002, respectively). There was no significant difference between palmitoylethanolamide and placebo groups based on ESRS scores or ESRS changes in scores (P>0.05).

CONCLUSIONS

Our findings provide preliminary evidence that palmitoylethanolamide is an effective adjunctive medication that improves manic symptoms and overall clinical status in acute episodes of mania. However, larger sample sizes and more extended follow-up therapy are needed in future studies to confirm our findings.

Sex differences in the blood-brain barrier: Implications for mental health

Prevalence of mental disorders, including major depressive disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ) are increasing at alarming rates in our societies. Growing evidence points toward major sex differences in these conditions, and high rates of treatment resistance support the need to consider novel biological mechanisms outside of neuronal function to gain mechanistic insights that could lead to innovative therapies. Blood-brain barrier alterations have been reported in MDD, BD and SZ. Here, we provide an overview of sex-specific immune, endocrine, vascular and transcriptional-mediated changes that could affect neurovascular integrity and possibly contribute to the pathogenesis of mental disorders. We also identify pitfalls in current literature and highlight promising vascular biomarkers. Better understanding of how these adaptations can contribute to mental health status is essential not only in the context of MDD, BD and SZ but also cardiovascular diseases and stroke which are associated with higher prevalence of these conditions.

Obesity and overweight among children and adolescents with bipolar disorder from the general population: A review of the scientific literature and a meta-analysis

There is substantial evidence of the high prevalence of obesity (OB) and overweight (OW) and their association with increased medical and psychiatric burden among adults with bipolar disorder (BD). However, little is known regarding its prevalence among young people with BD, other than the risk from psychotropic medication, which has been the focus of research in this population. We present a systematic review and meta-analysis of the literature on prevalence and correlates of OB and OW children and adolescents with BD using a different perspective than impact of medication. Four studies met inclusion criteria. The prevalence of OB in children and adolescents with BD was 15% (95% CI 11-20%). We observed a higher prevalence of OB in comparison to the general population. Different studies found significant associations between OB, OW, and BD in young populations including non-Caucasian race, physical abuse, suicide attempts, self-injurious behaviours, psychotropic medication, and psychiatric hospitalizations.

Secondary Mania induced by TNF-α inhibitors: A systematic review

A growing number of studies support a bidirectional relationship between inflammation and bipolar disorders. Tumor necrosis factor-α (TNF-α) inhibitors have recently attracted interest as potential therapeutic compounds for treating depressive symptoms, but the risk for triggering mood switches in patients with or without bipolar disorders remains controversial. Thus, we conducted a systematic review to study the anti-TNF-α medication-induced manic or hypomanic episodes. PubMed, Scopus, Medline, and Embase databases were screened for a comprehensive literature search from inception until November 2020, using The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Out of the initial 75 references, the screening resulted in the inclusion of four case reports (each describing one patient) and a cohort study (in which 40 patients out of 7600-0.53% - experienced elated mood episodes after infliximab administration). Of these 44 patients, 97.7% experienced a manic episode and 2.3% hypomania. 93.2% of patients had no history of psychiatric disorder or psychotropic treatment. Only 6.8% had a history of psychiatric disorders with the affective spectrum (4.6% dysthymia and 2.3% bipolar disorder). The time of onset of manic or hypomanic symptoms varied across TNF-α inhibitors with an early onset for Infliximab and a later onset for Adalimumab and Etanercept. These findings suggest that medications targeting the TNF-α pathway may trigger a manic episode in patients with or without affective disorders. However, prospective studies are needed to evaluate the relative risk of such side effects and identify the population susceptible to secondary mania.

Lithium orotate: A superior option for lithium therapy?

Bipolar disorder (BD) poses a significant public health concern, with roughly one-quarter of sufferers attempting suicide. BD is characterized by manic and depressive mood cycles, the recurrence of which can be effectively curtailed through lithium therapy. Unfortunately, the most frequently employed lithium salt, lithium carbonate (Li₂ CO₃ ), is associated with a host of adverse health outcomes following chronic use: these unwanted effects range from relatively minor inconveniences (e.g., polydipsia and polyuria) to potentially major complications (e.g., hypothyroidism and/or renal impairment). As these undesirable effects can limit patient compliance, an alternative lithium compound with a lesser toxicity profile would dramatically improve treatment efficacy and outcomes. Lithium orotate (LiC₅ H₃ N₂ O₄ ; henceforth referred to as LiOr), a compound largely abandoned since the late 1970s, may represent such an alternative. LiOr is proposed to cross the blood-brain barrier and enter cells more readily than Li₂ CO₃ , which will theoretically allow for reduced dosage requirements and ameliorated toxicity concerns. This review addresses the controversial history of LiOr, complete with discussions of experimental and clinical efficacy, putative mechanisms of action, adverse effects, and its potential future in therapy.

Inflammation, anxiety, and stress in bipolar disorder and borderline personality disorder: A narrative review

Bipolar disorder (BD) and borderline personality disorder (BPD) are serious and prevalent psychiatric diseases that share common phenomenological characteristics: symptoms (such as anxiety, affective lability or emotion dysregulation), neuroimaging features, risk factors and comorbidities. While several studies have focused on the link between stress and peripheral inflammation in other affective disorders such as anxiety or depression, fewer have explored this relationship in BD and BPD. This review reports on evidence showing an interplay between immune dysregulation, anxiety and stress, and how an altered acute neuroendocrine stress response may exist in these disorders. Moreover, we highlight limitations and confounding factors of these existing studies and discuss multidirectional hypotheses that either suggest inflammation or stress and anxiety as the primum movens in BD and BPD pathophysiology, or inflammation as a consequence of the pathophysiology of these diseases. Untangling these associations and implementing a transdiagnostic approach will have diagnostic, therapeutic and prognostic implications for BD and BPD patients.

Concepts of Neuroinflammation and Their Relationship With Impaired Mitochondrial Functions in Bipolar Disorder

Bipolar disorder (BD) is a chronic psychiatric disease, characterized by frequent behavioral episodes of depression and mania, and neurologically by dysregulated neurotransmission, neuroplasticity, growth factor signaling, and metabolism, as well as oxidative stress, and neuronal apoptosis, contributing to chronic neuroinflammation. These abnormalities result from complex interactions between multiple susceptibility genes and environmental factors such as stress. The neurocellular abnormalities of BD can result in gross morphological changes, such as reduced prefrontal and hippocampal volume, and circuit reorganization resulting in cognitive and emotional deficits. The term "neuroprogression" is used to denote the progressive changes from early to late stages, as BD severity and loss of treatment response correlate with the number of past episodes. In addition to circuit and cellular abnormalities, BD is associated with dysfunctional mitochondria, leading to severe metabolic disruption in high energy-demanding neurons and glia. Indeed, mitochondrial dysfunction involving electron transport chain (ETC) disruption is considered the primary cause of chronic oxidative stress in BD. The ensuing damage to membrane lipids, proteins, and DNA further perpetuates oxidative stress and neuroinflammation, creating a perpetuating pathogenic cycle. A deeper understanding of BD pathophysiology and identification of associated biomarkers of neuroinflammation are needed to facilitate early diagnosis and treatment of this debilitating disorder.

Peripheral inflammation is associated with dysfunctional corticostriatal circuitry and executive dysfunction in bipolar disorder patients

Bipolar disorder (BD) has been linked to abnormal frontal and striatal function, and elevated inflammatory responses. However, the impact of peripheral inflammation on the corticostriatal functional connectivity (FC) remains obscure in BD. The current study aimed to explore the association between peripheral inflammation and corticostriatal connectivity in euthymic BD. We recruited 25 euthymic BD patients and 43 healthy controls (HCs) from the community. Resting state functional images were obtained using 3T magnetic resonance imaging (fMRI), and striatal seed-based whole-brain functional connectivity analyses were performed, with the fasting plasma high-sensitivity C-reactive protein (hs-CRP) level entered as a regressor of interest. The participants also completed the Wisconsin Card-Sorting Test (WCST) and the Continuous Performance Test (CPT). The euthymic BD group had a similar hs-CRP level to the HC group, but a significantly poorer cognitive performance. Compared with the HC group, a higher connectivity between the right dorsal caudal putamen (dcP) and the ventral lateral prefrontal cortex (vlPFC) in the BD group was significantly correlated with a higher hs-CRP level. Stronger dcP-vlPFC connectivity was correlated with a lower CPT unmasked d' in the BD group. BD patients might be particularly sensitive to the effects of inflammation on corticostriatal connectivity. The potentially greater sensitivity of BD patients to peripheral inflammation may differentially modulate the cognitive and reward related corticostriatal circuitry, which may contribute to the pathophysiology of cognitive-affective dysregulation in the euthymic state. Anti-inflammatory or other circuit-specific treatment is warranted for individualized treatment in BD.

Na+, K+-ATPase α Isoforms and Endogenous Cardiac Steroids in Prefrontal Cortex of Bipolar Patients and Controls

Bipolar disorder is a chronic multifactorial psychiatric illness that affects the mood, cognition, and functioning of about 1–2% of the world’s population. Its biological basis is unknown, and its treatment is unsatisfactory. The α1, α2, and α3 isoforms of the Na⁺, K⁺-ATPase, an essential membrane transporter, are vital for neuronal and glial function. The enzyme and its regulators, endogenous cardiac steroids like ouabain and marinobufagenin, are implicated in neuropsychiatric disorders, bipolar disorder in particular. Here, we address the hypothesis that the α isoforms of the Na⁺, K⁺-ATPase and its regulators are altered in the prefrontal cortex of bipolar disease patients. The α isoforms were determined by Western blot and ouabain and marinobufagenin by specific and sensitive immunoassays. We found that the α2 and α3 isoforms were significantly higher and marinobufagenin levels were significantly lower in the prefrontal cortex of the bipolar disease patients compared with those in the control. A positive correlation was found between the levels of the three α isoforms in all samples and between the α1 isoform and ouabain levels in the controls. These results are in accordance with the notion that the Na⁺, K⁺-ATPase-endogenous cardiac steroids system is involved in bipolar disease and suggest that it may be used as a target for drug development.

Correlation between alterations of inflammatory markers and treatment with atypical antipsychotics in patients diagnosed with bipolar affective disorder

Introduction

Clinical evidences suggests that cerebral inflammatory processes are involved in the development of major affective disorders [1].

Obvious correlations exist between changes of inflammatory markers such as acute-phase protein C (PCR) and VES, in patients with bipolar spectrum diagnosis [2].

Objectives

Our aim is demonstrating the correlations between changes of PCR and VES and pharmacological treatment with atypical antipsychotics in patients with acute bipolar disorder, highlighting a trend.

Method

Twenty patients with bipolar disorder were assessed at the entrance (T0), after three weeks (T1) and after six weeks (T2) of hospitalization using specific rating scales and blood tests routines include PCR and VES.

Results

Is possible to appreciate a correlation between the affective phase of bipolar disorder and inflammatory markers with a proportional trend (Table 1).

Discussion and conclusion

The scores obtained seem to confirm the effect of antipsychotic in both sense of psychiatric symptomatology reduction and in anti-inflammatory action.

A confirmation of a correlation between the resolution of affective disorders and normalization of inflammatory markers confirm the intrinsic anti-inflammatory activity of such drug compounds [3].

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Efficacy of melatonin as an adjunct in the treatment of acute mania: a double-blind and placebo-controlled trial

This is a double-blind, placebo-controlled, parallel-grouped clinical trial, which was designed to investigate the potential effects of melatonin add-on treatment with lithium and risperidone on acute manic episodes in patients with bipolar disorder (BD). A total of 54 patients were included and randomly assigned into two groups of melatonin and placebo. The trial group received 3 mg/day risperidone, 900 mg/day lithium, and 6 mg/day melatonin. The placebo group received the same dose of risperidone and lithium plus placebo. The participants were evaluated at four sessions, consisting of baseline, weeks 1, 4, and 6. The manic symptoms and overall clinical improvement of the patients were assessed using the Young Mania Rating Scale (YMRS) and Clinical Global Impressions-Improvement (CGI-I), respectively. Two trial groups were matched based on all baseline characteristics. The patients in two trial groups had comparable serum lithium levels at weeks 1, 4, and 6. Our results from the general linear model repeated measures analysis showed a significant effect for time × treatment interaction on YMRS scores (P = 0.021 and F-value = 3.7). Furthermore, outcomes of the CGI-I rating scale demonstrated that patients in the melatonin group had better clinical improvements compared to the placebo group (P = 0.018). Our results provided preliminary evidence supporting melatonin as an effective adjunctive treatment leading to significant improvements in manic symptoms and overall clinical status in acute episodes of mania.

Inflammatory Response and Treatment-Resistant Mental Disorders: Should Immunotherapy Be Added to Pharmacotherapy?

Treatment resistance continues to challenge and frustrate mental health clinicians and provoke psychiatric researchers to seek additional explanatory theories for psychopathology. Because the inflammatory process activates symptoms of depression, anxiety, and psychosis, it is a reasonable route to follow for primary and/or indirect contribution to mental disorders. The current article reviews the research literature regarding the role the inflammatory process and immune system play in mental disorders as well as novel treatments under investigation for resistant depression, anxiety, substance use, and psychotic disorders. [Journal of Psychosocial Nursing and Mental Health Services, 58(1), 11-16.].

Dopamine activates NF-κB and primes the NLRP3 inflammasome in primary human macrophages

Induction of innate immune genes in the brain is thought to be a major factor in the development of addiction to substances of abuse. As the major component of the innate immune system in the brain, aberrant activation of myeloid cells such as macrophages and microglia due to substance use may mediate neuroinflammation and contribute to the development of addiction. All addictive drugs modulate the dopaminergic system and our previous studies have identified dopamine as a pro-inflammatory modulator of macrophage function. However, the mechanism that mediates this effect is currently unknown. Inflammatory activation of macrophages and induction of cytokine production is often mediated by the transcription factor NF-κB, and prior studies have shown that dopamine can modulate NF-κB activity in T-cells and other non-immune cell lines. Here we demonstrated that dopamine can activate NF-κB in primary human macrophages, resulting in the induction of its downstream targets including the NLRP3 inflammasome and the inflammatory cytokine IL-1β. These data also indicate that dopamine primes but does not activate the NLRP3 inflammasome in human macrophages. Activation of NF-κB was required for dopamine-mediated increases in IL-1β, as an inhibitor of NF-κB was able to abrogate the effects of dopamine on production of these cytokines. Connecting an increase in extracellular dopamine to NF-κB activation and inflammation suggests specific intracellular targets that could be used to ameliorate the inflammatory impact of dopamine in neuroinflammatory conditions associated with myeloid cell activation such as addiction.

•

Dopamine exposure primes, but does not activate the NLRP3 inflammasome.

•

Inflammasome priming can be mediated, at least partially, by a dopamine-induced increase in the activation and nuclear translocation of NF-κB in primary human macrophages.

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Dopamine additively increases the impact of cytomegalovirus on NF-κB activation in macrophages.

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Dopamine priming increases IL-1β release in response to inflammasome activation.

Adjunctive minocycline for major mental disorders: A systematic review

OBJECTIVES

This meta-analysis of randomized controlled trials (RCTs) examined the efficacy and safety of minocycline for three major mental disorders: schizophrenia, bipolar disorder and major depressive disorder (MDD).

METHODS

A systematic literature search of major electronic databases was conducted. Meta-analysis of clinical efficacy as defined by the respective studies, all-cause discontinuation, adverse drug reactions (ADRs) with standardized mean difference (SMD) and risk ratios (RRs) and their 95% confidence intervals (CI) was conducted using random-effects model. Quality assessment was performed with the Jadad scale and Cochrane risk of bias.

RESULTS

Sixteen RCTs (n=1357) on minocycline (50-300 mg/day) for schizophrenia (13 RCTs, n=1196), bipolar depression (1 RCT, n=49), and MDD (2 RCTs, n=112) were analyzed separately by diagnosis. Twelve RCTs mentioned randomized allocation specifically; the weighted Jadad scores were 4.0. Adjunctive minocycline outperformed placebo in improving total psychopathology [SMD: -0.45 (95%CI: -0.73, -0.16), p=0.002; I²=77%], positive [SMD: -0.15 (95%CI: -0.28, -0.02), p=0.02; I²=0%], negative [SMD: -0.62 (95%CI: -0.95, -0.28), p=0.0003; I²=85%] and general psychopathology scores [SMD: -0.28 (95%CI: -0.53, -0.03), p=0.03; I²=59%] in schizophrenia. Minocycline showed no significant effect on depressive and manic symptoms in both bipolar depression and MDD. Minocycline caused significantly less headache (p=0.02, number-needed-to-harm=14, 95%CI=5-14) than placebo in schizophrenia. All-cause discontinuation and other ADRs were similar between minocycline and placebo in each diagnostic category.

CONCLUSION

In this meta-analysis, adjunctive minocycline appeared to be efficacious and safe for schizophrenia. However, the efficacy of adjunctive minocycline for bipolar depression or MDD could not be demonstrated.

REVIEW REGISTRATION

PROSPERO: CRD42018102483.

Obsessive-Compulsive Disorder: Autoimmunity and Neuroinflammation

PURPOSE OF REVIEW

Here, we propose to review the immuno-inflammatory hypothesis in OCD given the concurrent incidence of autoimmune comorbidities, infectious stigma, and raised levels of inflammatory markers in a significant subset of patients. A better understanding of the immune dysfunction in OCD may allow stratifying the patients in order to design personalized pharmaco/psychotherapeutic strategies.

RECENT FINDINGS

A persistent low-grade inflammation involving both innate and adaptive immune system with coexisting autoimmune morbidities and stigma of infectious events has been prominently observed in OCD. Hence, specific treatments targeting inflammation/infection are a feasible alternative in OCD. This review highlights that OCD is associated with low-grade inflammation, neural antibodies, and neuro-inflammatory and auto-immune disorders. In some subset of OCD patients, autoimmunity is likely triggered by specific bacterial, viral, or parasitic agents with overlapping surface epitopes in CNS. Hence, subset-profiling in OCD is warranted to benefit from distinct immune-targeted treatment modalities.

Future Directions for Understanding Adolescent Bipolar Spectrum Disorders: A Reward Hypersensitivity Perspective

The idea that bipolar spectrum disorders (BSDs) are characterized by enhanced sensitivity to rewarding stimuli is at the core of the reward hypersensitivity model, one of the most prominent and well-supported theories of BSDs. In this article, we present the reward hypersensitivity model of BSDs, review evidence supporting it, discuss its relevance to explaining why BSDs typically begin and consolidate during the period of adolescence, and consider three major unresolved issues for this model that provide important directions for future research. Finally, we present integrations of the reward hypersensitivity model with circadian rhythm and immune system models that should provide greater understanding of the mechanisms involved in BSDs, and then suggest additional directions for future research deriving from these integrated models.

Evaluation of Endothelial Dysfunction in Bipolar Affective Disorders: Serum Endocan and Urotensin-II Levels

Objective

This study investigated changes in urotensin-II (U-II) and endocan levels which can be used as an early biological marker of endothelial injury in the episode and remission phases of bipolar affective disorder (BAD).

Methods

We compared endocan and U-II levels, which has been shown to be closely associated with neurotransmitter systems in addition to continuity of endothelial structure and inflammatory response, in patients with BAD in remission for at least one year (n=42) and in patients still in manic or depressive episodes (n=16) with healthy controls (n=30).

Results

Both endocan and U-II levels were significantly higher in the bipolar patients than in the controls. Endocan and U-II levels were also significantly correlated with one another (p=0.000, r=0.833). Both endocan (p=0.000) and U-II levels (p=0.000) were significantly higher in the bipolar attack group compared to the subjects in remission, and in the remission group compared to the controls.

Conclusion

In this study we determined significantly higher endocan and U-II levels in BAD compared to the controls, while serum endocan and U-II levels of patients undergoing attacks were also significantly higher than those of the controls and also those of patients in remission.

Gut microbiota and bipolar disorder: a review of mechanisms and potential targets for adjunctive therapy

There is increasing evidence that connections formed between microbiome, the gut, and the brain play a role in health and well-being. Non-pharmaceutical targets for management of mood disorders, such as bipolar disorder, are relatively under-researched. At the same time, it is clear that there is an intimate connection between psychiatry and gastrointestinal health. Here, we have discussed various comorbid conditions associated with bipolar disorders such as inflammation, irritable bowel disease and antibiotic induced mania with importance to demonstrate possible involvement of the gut microbiota. Gut microbiota-targeted preclinical and clinical interventions have demonstrated enhancement in various psychological conditions. Further in this review, we explore links between bipolar disorder, inflammation and gut microbiome with a focus on dietary, pro- and pre-biotic interventions as potential adjuvant therapies for use in the management of mood disorders such as bipolar disorder.

In the Realm of Psychoneuroimmunology: The Role of Celecoxib as an Add-On Treatment for Bipolar Mania

Bipolar affective disorder (BPAD) is a chronic debilitating psychiatric illness seriously affecting the quality of patients' life. The available treatment is effective in about half of those suffering from the illness. The neurobiological basis of the disorder is not fully unraveled. With such lacunae, attempts have been made to decipher the underlying neuroimmunological process of the illness as is the case with other mental disorders. As a result, some inflammatory processes have been implicated in the etiology of BPAD, as described in this communication. Subsequently, the role of anti-inflammatory agents such as celecoxib was investigated by treating different phases of BPAD. Given the promising outcomes of several trials and reviews, celecoxib has gained momentum and has been recommended as an adjunctive treatment by some guidelines for treating resistant BPAD cases. This brief communication highlights some of the caveats in the randomized trials using celecoxib as an add-on treatment in bipolar mania specifically, which need to be addressed in future work.

Switch from previous major depression comorbid with CLIPPERS to mania-like episode following glucocorticosteroid therapy: a case report

Bipolar disorder is associated with high rates of general medical conditions, but few cases of overlap between bipolar disorder and chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) have been reported in the current literature. The following is a case of a 29-year-old patient with a previous major depressive episode comorbid with CLIPPERS. Following glucocorticosteroid therapy, the patient switched to mania-like presentation and was diagnosed with bipolar disorder due to another medical condition. So it is strongly suggested that high-dose corticosteroid pulse therapy could easily induce psychiatric disturbances for patients with previous psychiatric symptoms, and there may be potential links between bipolar disorder and CLIPPERS in the area of inflammation.

Na⁺, K⁺-ATPase Signaling and Bipolar Disorder

Bipolar disorder (BD) is a severe and common chronic mental illness characterized by recurrent mood swings between depression and mania. The biological basis of the disease is poorly understood and its treatment is unsatisfactory. Although in past decades the "monoamine hypothesis" has dominated our understanding of both the pathophysiology of depressive disorders and the action of pharmacological treatments, recent studies focus on the involvement of additional neurotransmitters/neuromodulators systems and cellular processes in BD. Here, evidence for the participation of Na⁺, K⁺-ATPase and its endogenous regulators, the endogenous cardiac steroids (ECS), in the etiology of BD is reviewed. Proof for the involvement of brain Na⁺, K⁺-ATPase and ECS in behavior is summarized and it is hypothesized that ECS-Na⁺, K⁺-ATPase-induced activation of intracellular signaling participates in the mechanisms underlying BD. We propose that the activation of ERK, AKT, and NFκB, resulting from ECS-Na⁺, K⁺-ATPase interaction, modifies neuronal activity and neurotransmission which, in turn, participate in the regulation of behavior and BD. These observations suggest Na⁺, K⁺-ATPase-mediated signaling is a potential target for drug development for the treatment of BD.

Offspring of parents with mood disorders: time for more transgenerational research, screening and preventive intervention for this high-risk population

PURPOSE OF REVIEW

Offspring of parents with mood disorders (major depressive and bipolar disorder) are at increased risk for developing mood disorders. In this review, an overview regarding the intergenerational transmission of mood disorders, screening, and preventive intervention is given for this vulnerable group.

RECENT FINDINGS

Offspring of parents with depression have a 40% chance of developing a depression, whereas offspring of parents with bipolar disorder have a 10% chance of developing a bipolar disorder by adulthood. Studies into the intergenerational transmission of mood disorders show that children of parents with mood disorders have increased biological dysregulation and neuropsychosocial impairments. Although there is a clear need for early identification of those at the highest risk, there are few systematic attempts in mental health care to screen children of parents with mood disorders. Lastly, preventive interventions seem to be effective in reducing depressive symptoms of children of parents with depression; however, those effects are small and short-lived.

SUMMARY

Offspring of parents with mood disorders constitute a vulnerable group at high risk of mood disorders. More research needs to be conducted regarding mechanisms of the intergenerational transmission. Moreover, screening and preventive interventions for these offspring should be systematically evaluated and implemented.

DNA Methylation and Psychiatric Disorders

DNA methylation has been an important area of research in the study of molecular mechanism to psychiatric disorders. Recent evidence has suggested that abnormalities in global methylation, methylation of genes, and pathways could play a role in the etiology of many forms of mental illness. In this article, we review the mechanisms of DNA methylation, including the genetic and environmental factors affecting methylation changes. We report and discuss major findings regarding DNA methylation in psychiatric patients, both within the context of global methylation studies and gene-specific methylation studies. Finally, we discuss issues surrounding data quality improvement, the limitations of current methylation analysis methods, and the possibility of using DNA methylation-based treatment for psychiatric disorders in the future.

Differences in the association between persistent pathogens and mood disorders among young- to middle-aged women and men in the U.S

BACKGROUND

A growing literature supports the role of immune system alterations in the etiology of mood regulation, yet there is little population-based evidence regarding the association between persistent pathogens, inflammation and mood disorders among younger women and men in the U.S.

METHODS

We used data from the National Health and Nutrition Examination Survey III on individuals 15-39 years of age assessed for major depression, dysthymia, and/or bipolar disorder I and tested for cytomegalovirus (N=6825), herpes simplex virus (HSV)-1 (N=5618) and/or Helicobacter pylori (H. pylori) (N=3167) seropositivity as well as C-reactive protein (CRP) level (N=6788). CMV immunoglobulin G (IgG) antibody level was also available for a subset of women (N=3358). We utilized logistic regression to estimate the odds ratio (OR) and 95% confidence interval (CI) for the association between pathogens, CRP levels and each mood disorder overall and among women and men, separately.

RESULTS

H. pylori seropositivity was associated with increased odds of dysthymia (OR 2.37, 95% confidence interval (CI): 1.07, 5.24) among women, but decreased odds among men (OR 0.51, 95% CI: 0.28, 0.92). CMV seropositivity was also associated with lower odds of depression (OR 0.54, 95% CI: 0.32, 0.91) among men, while elevated CMV IgG level was marginally associated with increased odds of mood disorders among women. Associations were not mediated by CRP level.

CONCLUSIONS

Our findings suggest that persistent pathogens such as CMV and H. pylori may differentially influence mood disorders among women and men, warranting further investigation into biological and/or sociocultural explanations for the contrasting associations observed.

Stem cells, pluripotency and glial cell markers in peripheral blood of bipolar patients on long-term lithium treatment

BACKGROUND

We investigated the effect of long-term lithium treatment on very-small embryonic-like stem cells (VSELs) and the mRNA expression of pluripotency and glial markers, in peripheral blood, in patients with bipolar disorder (BD).

METHODS

Fifteen BD patients (aged 53±7years) not treated with lithium, with duration of illness >10years, 15 BD patients (aged 55±6years) treated with lithium for 8-40years (mean 16years) and 15 control subjects (aged 50±5years) were included. The number of VSELs was measured by flow cytometric analysis. Assessment of the mRNA levels of pluripotency markers (Oct-4, Sox 2 and Nanog) and glial markers (glial fibrillary acidic protein - GFAP, Olig1 and Olig2) was performed, using the Real-time quantitative reverse transcription PCR.

RESULTS

In BD patients not taking lithium, the number of VSELs was significantly higher than in control subjects and correlated with the duration of illness. The expression of pluripotency markers was significantly higher than in the controls and correlated with the number of VSELs. The mRNA levels of the Olig1 and Olig 2 were higher than in the controls and those of the GFAP were higher than in patients receiving lithium. In lithium-treated BD patients the number of VSELs was similar to controls and correlated negatively with the duration of lithium treatment and serum lithium concentration. The mRNA levels of Oct-4, Sox-2, GFAP and Olig1 were not different from controls. The mRNA expression of Nanog was significantly higher and correlated with the number of VSELs. The mRNA expression of Olig 2 was higher than in the BD patients not taking lithium.

CONCLUSION

Long-term treatment with lithium may suppress the activation of regenerative processes by reducing the number of VSELs circulating in PB. These cells, in BD patients not treated with lithium, may provide a new potential biological marker of the illness and its clinical progress. The higher expression of peripheral mRNA markers in BD patients may involve ongoing inflammatory process, compensatory mechanisms and regenerative responses. Long-term lithium treatment may attenuate these mechanisms, especially in relation to the transcription factors Oct-4, Sox-2, GFAP and Olig1.

Assessment of Complement Cascade Components in Patients With Bipolar Disorder

Introduction: The immune system is undoubtedly involved in the pathogenesis of various psychiatric disorders, such as schizophrenia, bipolar disorder, or depression. Although its role is not fully understood, it appears that this area of research can help to understand the etiology of mental illness. One of the components of the human immune system is the complement system, which forms a part of the innate immune response. Physiologically, except for its essential protective role, it is a vital element in the regeneration processes, including neurogenesis. To date, few studies have tried to clarify the role of the complement cascade in mental disorders. Materials and Methods: We evaluated concentrations of C3a, C5a, and C5b-9 complement cascade components in the peripheral blood of 30 patients suffering from bipolar disorder (BD) for at least 10 years, in euthymia, who were not treated with lithium salts. In addition, we divided our study sample into BD type I (BD-I, 22 persons), and BD type II (BD-II, 8 patients). The control group consisted of 30 healthy volunteers matched for age, sex, BMI, and smoking habits. Results: Compared to healthy controls, BD patients had elevated concentrations of all the investigated components. Furthermore, in patients with BD-II, we observed higher concentrations of C5b-9 as compared to patients with BD-I. However, there was a significant effect of BD diagnosis only on the levels of C3a and C5a but not on the level of C5b-9 after adjustment for potential confounding factors. Conclusions: Increased concentrations of components C3a and C5a of the complement system in the investigated group as compared to healthy controls suggest involvement of the complement cascade in the pathogenesis of BD, and provides further evidence of immune system dysregulation in BD patients.

Thyroid autoimmunity in bipolar disorder: A systematic review

BACKGROUND

Accumulating evidence points to the pathophysiological relevance between immune dysfunction and mood disorders. High rates of thyroid dysfunction have been found in patients with bipolar disorder (BD), compared to the general population. A systematic review of the relationship between BD and thyroid autoimmunity was performed.

METHODS

Pubmed, EMBASE and PsycINFO databases were searched up till January 28th, 2017. This review has been conducted according to the PRISMA statements. Observational studies clearly reporting data among BD patients and the frequency of autoimmune thyroid pathologies were included.

RESULTS

11 original studies met inclusion criteria out of 340 titles first returned from the global search. There is evidence of increased prevalence of circulating thyroid autoantibodies in depressed and mixed BD patients, while there is no evidence showing a positive relationship between BD and specific autoimmune thyroid diseases. There is a controversy about the influence of lithium exposure on circulating thyroid autoantibodies, even if most of studies seem not to support this association. A study conducted on bipolar twins suggests that autoimmune thyroiditis is related to the genetic vulnerability to develop BD rather than to the disease process itself. Females are more likely to develop thyroid autoimmunity.

LIMITATIONS

The samples, study design and outcomes were heterogeneous.

CONCLUSION

Thyroid autoimmunity has been suggested to be an independent risk factor for bipolar disorder with no clear association with lithium exposure and it might serve as an endophenotype for BD.

Infectious and immunogenetic factors in bipolar disorder

OBJECTIVE

Despite the evidence supporting the association between infection and bipolar disorder (BD), the genetic vulnerability that mediates its effects has yet to be clarified. A genetic origin for the immune imbalance observed in BD, possibly involved in the mechanisms of pathogen escape, has, however, been suggested in recent studies.

METHOD

Here, we present a critical review based on a systematic literature search of articles published until December 2016 on the association between BD and infectious/immunogenetic factors.

RESULTS

We provide evidence suggesting that infectious insults could act as triggers of maladaptive immune responses in BD and that immunogenetic vulnerability may amplify the effects of such environmental risk factors, increasing susceptibility to subsequent environmental encounters. Quality of evidence was generally impaired by scarce attempt of replication, small sample sizes and lack of high-quality environmental measures.

CONCLUSION

Infection has emerged as a potential preventable cause of morbidity in BD, urging the need to better investigate components of the host-pathogen interaction in patients and at-risk subjects, and thus opening the way to novel therapeutic opportunities.

Antibiotics and mania: A systematic review

OBJECTIVES

Mania can occur secondary to a medical condition and can be elicited by various pharmacological treatments, both in patients with or without a history of affective disorder. Antibiotic-induced mania or antibiomania is suggested to be a rare phenomenon. We reviewed the literature in order to collect published reports of antibiomania and to summarize new insights about its mechanism and management.

METHODS

We performed a MEDLINE-search and used manual cross-referencing for reports of antibiotic-induced mania and included cases in which a (hypo)manic episode was diagnosed in close temporal relationship with the prescription of an antibiotic.

RESULTS

47 cases were published. Patients' ages ranged from 3 to 77 years (mean 40). Two-thirds of the cases were male. Twelve different anti-bacterial agents were implicated, with antitubercular agents, macrolides and quinolones being the most common causative groups.

CONCLUSIONS

Antibiotic treatment can be associated with (hypo)mania. The paucity of reported cases precludes statements regarding incidence or antibiotic-specific warnings. In the event of an antibiotic-induced mania, the suspicious drug should be discontinued and manic symptoms can be treated lege artis. The pathophysiological mechanism of antibiomania remains elusive.

Soluble Intracellular Adhesion Molecule-1 in Patients with Unipolar or Bipolar Affective Disorders: Results from a Pilot Trial

BACKGROUND

Immunological and vascular markers may play a role in the pathophysiology of mood disorders and mood changes.

AIM

To test whether the cell adhesion molecule soluble intracellular adhesion molecule-1 (sICAM-1) may serve as a biomarker for patients with unipolar or bipolar affective disorders when compared to a healthy control group, and whether sICAM-1 blood levels change during different mood states.

METHODS

sICAM-1 serum concentrations were compared between 20 healthy controls and 48 patients with affective disorders (unipolar, bipolar II and bipolar I disorder) during different mood states (euthymic mood state, depression or mania).

RESULTS

When compared to healthy controls, patients with affective disorders had significantly higher sICAM-1 levels during the euthymic state (p = 0.015). Differences became more pronounced during depression (p = 0.013). When unipolar and bipolar patients were analyzed separately, unipolar patients significantly differed from controls during the euthymic and depressive mood state, while bipolar II patients showed a trend towards higher sICAM-1 levels during depression. Patients with bipolar I disorders had significantly higher sICAM-1 levels during manic states when compared to controls (p = 0.007).

CONCLUSIONS

sICAM-1 elevation in unipolar and bipolar patients, independent of mood changes, might support the hypothesis of chronic immune activation and endothelial dysfunction in patients with affective disorders.

Biological hypotheses and biomarkers of bipolar disorder

The most common mood disorders are major depressive disorders and bipolar disorders (BD). The pathophysiology of BD is complex, multifactorial, and not fully understood. Creation of new hypotheses in the field gives impetus for studies and for finding new biomarkers for BD. Conversely, new biomarkers facilitate not only diagnosis of a disorder and monitoring of biological effects of treatment, but also formulation of new hypotheses about the causes and pathophysiology of the BD. BD is characterized by multiple associations between disturbed brain development, neuroplasticity, and chronobiology, caused by: genetic and environmental factors; defects in apoptotic, immune-inflammatory, neurotransmitter, neurotrophin, and calcium-signaling pathways; oxidative and nitrosative stress; cellular bioenergetics; and membrane or vesicular transport. Current biological hypotheses of BD are summarized, including related pathophysiological processes and key biomarkers, which have been associated with changes in genetics, systems of neurotransmitter and neurotrophic factors, neuroinflammation, autoimmunity, cytokines, stress axis activity, chronobiology, oxidative stress, and mitochondrial dysfunctions. Here we also discuss the therapeutic hypotheses and mechanisms of the switch between depressive and manic state.

The effect of long-term lithium treatment of bipolar disorder on stem cells circulating in peripheral blood

OBJECTIVES

To investigate the effect of long-term lithium treatment on very small embryonic-like stem cells (VSELs), haematopoietic stem cells (HSCs), mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) circulating in peripheral blood (PB), in bipolar disorder (BD).

METHODS

The study included 15 BD patients (aged 55 ± 6 years) treated with lithium for 8-40 years (mean 16 years), 15 BD patients (aged 53 ± 7 years) with duration of illness >10 years, who had never received lithium, and 15 healthy controls (aged 50 ± 5 years). The VSELs, HSCs, MSCs and EPCs were measured by flow cytometric analysis.

RESULTS

In BD subjects not taking lithium the number of CD34⁺VSELs was significantly higher, and MSCs and EPCs numerically higher, than in control subjects and the number of CD34⁺VSELs correlated with the duration of illness. In lithium-treated patients these values were similar to controls and the number of CD34⁺VSELs correlated negatively with the duration of lithium treatment and serum lithium concentration.

CONCLUSIONS

Long-term treatment with lithium may suppress the activation of regenerative processes by reducing the number of VSELs circulating in PB. These cells, in BD patients not treated with lithium, may provide a new potential biological marker of the illness and its clinical progress.

Is Toxoplasma gondii a Trigger of Bipolar Disorder?

Toxoplasma gondii, a ubiquitous intracellular parasite, has a strong tropism for the brain tissue, where it forms intracellular cysts within the neurons and glial cells, establishing a chronic infection. Although latent toxoplasmosis is generally assumed to be asymptomatic in immunocompetent individuals, it is now clear that it can induce behavioral manipulations in mice and infected humans. Moreover, a strong relation has emerged in recent years between toxoplasmosis and psychiatric disorders. The link between T. gondii and schizophrenia has been the most widely documented; however, a significant association with bipolar disorder (BD) and suicidal/aggressive behaviors has also been detected. T. gondii may play a role in the etiopathogenesis of psychiatric disorders affecting neurotransmitters, especially dopamine, that are implicated in the emergence of psychosis and behavioral Toxoplasma-induced abnormalities, and inducing brain inflammation by the direct stimulation of inflammatory cytokines in the central nervous system. Besides this, there is increasing evidence for a prominent role of immune dysregulation in psychosis and BD. The aim of this review is to describe recent evidence suggesting a link between Toxoplasma gondii and BD, focusing on the interaction between immune responses and this infectious agent in the etiopathogenesis of psychiatric symptoms.

Mitochondrial DNA sequence data reveals association of haplogroup U with psychosis in bipolar disorder

Converging genetic, postmortem gene-expression, cellular, and neuroimaging data implicate mitochondrial dysfunction in bipolar disorder. This study was conducted to investigate whether mitochondrial DNA (mtDNA) haplogroups and single nucleotide variants (SNVs) are associated with sub-phenotypes of bipolar disorder. MtDNA from 224 patients with Bipolar I disorder (BPI) was sequenced, and association of sequence variations with 3 sub-phenotypes (psychosis, rapid cycling, and adolescent illness onset) was evaluated. Gene-level tests were performed to evaluate overall burden of minor alleles for each phenotype. The haplogroup U was associated with a higher risk of psychosis. Secondary analyses of SNVs provided nominal evidence for association of psychosis with variants in the tRNA, ND4 and ND5 genes. The association of psychosis with ND4 (gene that encodes NADH dehydrogenase 4) was further supported by gene-level analysis. Preliminary analysis of mtDNA sequence data suggests a higher risk of psychosis with the U haplogroup and variation in the ND4 gene implicated in electron transport chain energy regulation. Further investigation of the functional consequences of this mtDNA variation is encouraged.

Bipolar disorder and diabetes mellitus: evidence for disease-modifying effects and treatment implications

BACKGROUND

Bipolar disorder refers to a group of chronic psychiatric disorders of mood and energy levels. While dramatic psychiatric symptoms dominate the acute phase of the diseases, the chronic course is often determined by an increasing burden of co-occurring medical conditions. High rates of diabetes mellitus in patients with bipolar disorder are particularly striking, yet unexplained. Treatment and lifestyle factors could play a significant role, and some studies also suggest shared pathophysiology and risk factors.

OBJECTIVE

In this systematic literature review, we explored data around the relationship between bipolar disorder and diabetes mellitus in recently published population-based cohort studies with special focus on the elderly.

METHODS

A systematic search in the PubMed database for the combined terms "bipolar disorder" AND "elderly" AND "diabetes" in papers published between January 2009 and December 2015 revealed 117 publications; 7 studies were large cohort studies, and therefore, were included in our review.

RESULTS

We found that age- and gender- adjusted risk for diabetes mellitus was increased in patients with bipolar disorder and vice versa (odds ratio range between 1.7 and 3.2).

DISCUSSION

Our results in large population-based cohort studies are consistent with the results of smaller studies and chart reviews. Even though it is likely that heterogeneous risk factors may play a role in diabetes mellitus and in bipolar disorder, growing evidence from cell culture experiments and animal studies suggests shared disease mechanisms. Furthermore, disease-modifying effects of bipolar disorder and diabetes mellitus on each other appear to be substantial, impacting both treatment response and outcomes.

CONCLUSIONS

The risk of diabetes mellitus in patients with bipolar disorder is increased. Our findings add to the growing literature on this topic. Increasing evidence for shared disease mechanisms suggests new disease models that could explain the results of our study. A better understanding of the complex relationship between bipolar disorder and diabetes mellitus could lead to novel therapeutic approaches and improved outcomes.

Levels of C-reactive protein (CRP) in elderly patients with unipolar depression - case control analysis

AIM

C-reactive protein (CRP) is the major acute-phase plasma protein. Studies show that patients with depression have elevated levels of CRP. The aim of the study was to determine differences in CRP serum level in elderly patients with unipolar depression (DEP) compared with non-depressed elderly patients (nonDEP) using case-control analysis.

METHODS

Serum level of CRP was measured in 404 (DEP: n = 202, nonDEP: n = 202) Caucasian inpatients aged ≥60 (350 women, 86.7%; mean age = 76.7 years).

RESULTS

Mean CRP level in the study groups was: DEP 2.67 ± 2.56 mg/dL, nonDEP 2.41 ± 2.19 mg/dL, the difference was not significant (p = 0.96). The overall rate of being above the high level of CRP (set at 3.0 mg/L) was 33.2% for DEP and 29.2% for nonDEP groups (p = 0.39). It was also found that, in the whole study group, CRP level was not correlated with age (p = 0.10).

CONCLUSIONS

Elderly patients with depression have no increased CRP levels. A high percentage (∼30%) of all subjects had a CRP level >3 mg/L, which is the cut-off point for increased cardiovascular risk.