Increased levels of adipokines in bipolar disorder

Plasma IGFBP-3 and IGFBP-5 levels are decreased during acute manic episodes in bipolar disorder patients

Introduction: Bipolar disorder (BD) is a recurrent and disabling psychiatric disorder related to low-grade peripheral inflammation and altered levels of the members of the insulin-like growth factor (IGF) family. The aim of this study was to evaluate the plasma levels of IGF-2, insulin-like growth factor-binding protein 1 (IGFBP-1), IGFBP-3, IGFBP-5, IGFBP-7, and inflammatory markers such as tumor necrosis factor α (TNF-α), monocyte chemoattractant protein 1 (MCP-1), and macrophage inflammatory protein 1β (MIP-1β). Methods: We used the Young Mania Rating Scale (YMRS) to determine the severity of the symptomatology, while proteins were measured by enzyme-linked immunosorbent assay (ELISA). We included 20 patients with BD who suffered a manic episode and 20 controls. Some BD patients (n = 10) were evaluated after a period (17 ± 8 days) of pharmacological treatment. Results: No statistical difference was found in IGF-2, IGFBP-1, IGFBP-7, TNF-α, and MIP-1β levels. However, IGFBP-3 and IGFBP-5 levels were found to be statistically decreased in BD patients. Conversely, the MCP-1 level was significantly increased in BD patients, but their levels were normalized after treatment. Intriguingly, only IGFBP-1 levels were significantly decreased after treatment. No significant correlation was found between the YMRS and any of the proteins studied either before or after treatment or between IGF proteins and inflammatory markers. Discussion: To some extent, IGFBP-3 and IGFBP-5 might be further explored as potential indicators of treatment responsiveness or diagnosis biomarkers in BD.

Adiponectin blood levels and autism spectrum disorders: a systematic review

OBJECTIVE

To review the relationship between adiponectin levels and autism spectrum disorders (ASDs) in children.

BACKGROUND

ASDs are associated with pervasive social interaction and communication abnormalities. Researchers have studied various pathophysiological mechanisms underlying ASDs to identify predictors for an early diagnosis to optimize treatment outcomes. Immune dysfunction, perhaps mediated by a decrease in anti-inflammatory adipokine, adiponectin, along with changes in other adipokines, may play a central role in increasing the risk for ASDs. However, other factors, such as low maternal vitamin D levels, atherosclerosis, diabetes, obesity, cardio-metabolic diseases, preterm delivery, and oxytocin gene polymorphism may also contribute to increased risk for ASDs.

METHODS

Searches on the database; PubMed, Google Scholar, and Cochrane using keywords; adiponectin, adipokines, ASD, autism, autistic disorder, included English-language studies published till September 2022. Data were extracted on mean differences between adiponectin levels in children with and without ASDs.

RESULTS

The search yielded six studies providing data on adiponectin levels in young patients with ASDs. As can be seen from Table 1, four of the six studies were positive for an inverse correlation between ASD and adiponectin levels. In addition, two of the four positive and one negative studies found low adiponectin levels associated with and the severity of autistic symptoms. However, results from one reviewed study were insignificant.

CONCLUSION

Most studies reviewed yielded lower adiponectin levels in children with ASDs as well as the severity of autistic symptoms.

The immunomodulatory effect of lithium as a mechanism of action in bipolar disorder

Bipolar disorder (BD) is a chronic mental disorder characterized by recurrent episodes of mania and depression alternating with periods of euthymia. Although environmental and genetic factors have been described, their pathogenesis is not fully understood. Much evidence suggests a role for inflammatory mediators and immune dysregulation in the development of BD. The first-line treatment in BD are mood-stabilizing agents, one of which is lithium (Li) salts. The Li mechanism of action is not fully understood, but it has been proposed that its robust immunomodulatory properties might be one of the mechanisms responsible for its effectiveness. In this article, the authors present the current knowledge about immune system changes accompanying BD, as well as the immunomodulatory effect of lithium. The results of studies describing connections between immune system changes and lithium effectiveness are often incoherent. Further research is needed to understand the connection between immune system modulation and the therapeutic action of lithium in BD.

Ketamine study: Protocol for naturalistic prospective multicenter study on subcutaneous ketamine infusion in depressed patients with active suicidal ideation

Background

Psychiatric disorders are associated with more than 90% of reported suicide attempts worldwide, but few treatments have demonstrated a direct effect in reducing suicide risk. Ketamine, originally an anesthetic, has been shown anti-suicide effects in clinical trials designed to treat depression. However, changes at the biochemical level were assessed only in protocols of ketamine with very limited sample sizes, particularly when the subcutaneous route was considered. In addition, the inflammatory changes associated with ketamine effects and their correlation with response to treatment, dose-effect, and suicide risk warrant further investigation. Therefore, we aimed to assess whether ketamine results in better control of suicidal ideation and/or behavior in patients with depressive episodes and whether ketamine affects psychopathology and inflammatory biomarkers.

Materials and methods

We report here the design of a naturalistic prospective multicenter study protocol of ketamine in depressive episodes carried out at Hospital de Clínicas de Porto Alegre (HCPA) and Hospital Moinhos de Vento (HMV). The study was planned to recruit adult patients with Major depressive disorder (MDD) or Bipolar disorder (BD) types 1 or 2, who are currently in a depressive episode and show symptoms of suicidal ideation and/or behavior according to the Columbia-Suicide Severity Rating Scale (C-SSRS) and have been prescribed ketamine by their assistant psychiatrist. Patients receive ketamine subcutaneously (SC) twice a week for 1 month, but the frequency can be changed or the dose decreased according to the assistant physician’s decision. After the last ketamine session, patients are followed-up via telephone once a month for up to 6 months. The data will be analyzed using repeated measures statistics to evaluate the reduction in suicide risk as a primary outcome, as per C-SSRS.

Discussion

We discuss the need for studies with longer follow-ups designed to measure a direct impact on suicide risk and that additional information about the safety and tolerability of ketamine in particular subset of patients such as those with depression and ideation suicide. In line, the mechanism behind the immunomodulatory effects of ketamine is still poorly understood.

Trial registration

https://clinicaltrials.gov/, identifier NCT05249309.

Appetite-regulating hormones in bipolar disorder: A systematic review and meta-analysis

Impaired hormonal regulation of appetite may contribute to higher cardiovascular risk in bipolar disorder (BD). We performed a systematic review and meta-analysis of studies investigating peripheral blood levels of appetite-regulating hormones in BD and controls. A total of 32 studies were included. Leptin and insulin levels were significantly elevated in patients with BD during euthymia, but not in other mood states. Greater differences in the number of male participants between patients with BD and healthy controls were associated with higher effect size estimates for the levels of insulin. There were significant positive correlations of effect size estimates for the levels of adiponectin with the percentage of individuals with type I BD and duration of BD. Our findings point to the mechanisms underlying high rates of cardiometabolic comorbidities in BD. Moreover, they suggest that investigating hormonal regulation of appetite might help to understand differences in the neurobiology of BD types.

Changes in adipokine concentrations in antidepressant-resistant bipolar depression after ketamine infusion and electroconvulsive therapy

OBJECTIVES

This study attempts to assess the concentration of two opposite-acting adipokines (anti-inflammatory adiponectin and pro-inflammatory resistin) in antidepressant-resistant patients undergoing ketamine infusion (KI) and electroconvulsive therapy (ECT).

METHODS

The study group comprised 52 patients hospitalised due to episodes of depression in the course of bipolar disorders. The Hamilton depression scale was used to assess the intensity of the depression symptoms before starting therapy and one day after its completion. The serum concentration of adipokines was determined before and after the therapeutic intervention using an ELISA method.

RESULTS

Baseline adipokine levels differed between patients receiving KI and ECT therapy. Regardless of the procedure used, these levels changed after treatment, with the nature of these changes being different. In the case of KI, the adiponectin levels increased, and resistin levels decreased. In contrast, after ECT, the concentrations of both adipokines decreased. Changes in adipokine concentrations correlated with improvement in mental status, as assessed by the Hamilton Rating Scale, type of bipolar disorder, and gender.

CONCLUSIONS

Adipokines remain interesting candidate biomarkers in assessing the state and course of the disease depending on the therapeutic procedure applied. However, the relatively small study group and limited original research available for discussion justify further investigation.

Hunger Hormones in Disruptive Mood Dysregulation Disorder in Adolescents: An Exploratory Study

Background:

Hunger hormones, including ghrelin and leptin, are associated with appetitive behaviors in various psychiatric disorders. Biochemical and hormonal status in disruptive mood dysregulation disorder (DMDD) in adolescents is largely unexplored.

Objectives:

The study aimed to assess levels of leptin and ghrelin and find their association with lipid profiles in adolescents with DMDD.

Methods:

Twenty adolescents with a DSM 5 diagnosis of DMDD with age and gender-matched 19 healthy controls were recruited, followed by clinical assessment. They were assessed for leptin, ghrelin, and lipid profiles, respectively.

Results:

Adolescents with DMDD were comparable in age, education, family income, domicile status, psychiatric illness in the family, and body mass index (BMI) with matched controls. There was no difference in mean lipid profile and ghrelin in both groups. However, the DMDD group had statistically significant higher mean level of leptin as compared to the control group (t=1.84, p < 0.05). As measured by the Modified Overt Aggression Scale in DMDD, aggression showed a significant positive correlation with measures of lipid profile.

Conclusion:

Adolescents with DMDD have elevated serum leptin levels. Further research is needed to confirm this finding.

Comparison of Peripheral Biomarkers and Reduction of Stress Response in Patients With Major Depressive Disorders vs. Panic Disorder

Alteration in stress response seems to affect the development of psychiatric disorders. In this study, we aimed to investigate whether baseline peripheral biomarkers could predict the reduction of stress response among patients with major depressive disorder (MDD) and panic disorder (PD). Patients with MDD (n = 41) and PD (n = 52) and healthy controls (HC, n = 59) were selected and regularly followed up with five visits for 12 weeks. The severity of stress at every visit was assessed using the Stress Response Inventory (SRI), and peripheral biomarkers were measured by blood tests at baseline and 2, 4, 8, and 12 weeks. Interleukin (IL)-6, IL-10, tumor necrosis factor (TNF)-α, interferon (IFN)-γ, C-reactive protein (CRP), adiponectin, and leptin levels were analyzed using enzyme-linked immunosorbent assays. Reduction of stress response was defined as the difference in SRI score between baseline and 12 weeks divided by the baseline score. SRI scores were significantly (p < 0.0001) higher in patients with MDD and PD than in HC at every visit after adjusting for variables. In multivariable linear regression, adiponectin levels at baseline were significantly associated with reduction of stress response in patients with PD. When adiponectin increased 1 mg/l, stress response decreased 0.781 points (β = -0.781, S.E. = 0.220, p = 0.001). Among the subscales of SRI, somatization had a moderate negative correlation with adiponectin levels (r = -0.469). There was no significant association between baseline peripheral biomarkers and reduction of stress response in patients with MDD. Our study showed an inverse association between baseline adiponectin levels and stress response changes in patients with PD, but not in patients with MDD. Thus, differentiated approaches for assessing and treating stress responses of patients with PD and MDD might be helpful. Larger and longitudinal studies are necessary to establish the role and mechanism of action of adiponectin in regulating stress responses in PD.

Peripheral levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and interleukin-1β across the mood spectrum in bipolar disorder: A meta-analysis of mean differences and variability

IMPORTANCE

It is unclear whether differences exist in the magnitude and variability of pro-inflammatory mediators in the different phases of bipolar disorder (BD) and among subjects with BD, as compared to healthy controls.

OBJECTIVE

To run a comparative meta-analysis of C-Reactive Protein (CRP), IL-1, IL-6, TNF-α in BD vs healthy controls, measuring mean and variability effects on all subjects. Sensitivity analyses include disease activity.

DATA SOURCES

Systematic review of observational studies in PubMed and PsycInfo up to February 2nd, 2020.

STUDY SELECTION

Case-control studies reporting inflammatory mediators' levels in BD and controls.

DATA EXTRACTION AND SYNTHESIS

Summary distribution measures of circulating CRP, IL-1β, IL-6, TNF-α in participants with BD and control groups were extracted. Random-effects multivariate meta-analyses were conducted based on individual study/mediator effect sizes (Hedge's g).

MAIN OUTCOMES AND MEASURES

Co-primary outcomes were inflammatory mediators' levels (Hedge's g) and variability (coefficient of variance ratio (CVR)) differences between participants with BD across the mood spectrum and controls.

RESULTS

Out of the initial 729 papers, 72 were assessed and then excluded after full-text review, and ultimately 53 studies were included in the systematic review, while 49 were included in the meta-analysis. The mean age was 36.96 (SD: 9.29) years, and the mean female percentage was 56.31 (SD: 16.61). CRP (g = 0.70, 95% CI 0.31-1.09, k = 37, BD = 2,215 vs HC = 3,750), IL-6 (g = 0.81, 95% CI 0.46-1.16, k = 45, BD = 1,956 vs HC = 4,106), TNF-α (g = 0.49, 95% CI 0.19-0.78, k = 49, BD = 2,231 vs HC = 3,017) were elevated in subjects with BD vs HC, but not IL-1β (g = -0.28, 95% CI -0.68-0.12, k = 4, BD = 87 vs HC = 66). When considering euthymic, depressive, and manic episodes separately, CRP and TNF-α were elevated in both depressive and manic episodes, but not in euthymia, while IL-6 remained elevated regardless of the disease state. No difference in CVR emerged for CRP, IL-1β, and TNF-α, while a lower CVR was observed for IL-6. When considering disease phases, CVR was higher in BD than in HCs for CRP during depressive episodes, lower for IL-6 during euthymia, and higher during manic episodes for CRP, IL-6, and TNF-α. Sensitivity analyses after excluding outliers identified with funnel plot visual inspection, low-quality studies, and considering only studies matched per body mass index confirmed the main results. Meta-regression showed that age (IL-6, TNF-α), gender (CRP), duration of illness (CRP) moderated elevated individual inflammatory levels.

CONCLUSIONS AND RELEVANCE

Peripheral pro-inflammatory marker elevations were confirmed in BD. CRP and TNF-α could represent state markers, as they were only elevated during mood episodes, while IL-6 appeared to be a trait marker for BD. Increased variability of specific inflammatory mediators in specific disease active states suggests that a subset of subjects with BD may exhibit elevated inflammation as part of a manic or depressive episode.

Inflammation Biomarkers in Psychiatry

Introduction:

There has long been a need for diagnostic, theragnostic, and prognostic biomarkers for psychiatric disorders. Biomarkers help in reducing ambiguity and arbitrariness and increase objectivity. In this context, many candidates for hormonal, immunological, serological, and neuroimaging markers have been proposed, but none of these marker candidates alone nor a biomarker panel has been approved for any disease. The fact that almost all psychiatric disorders are heterogeneous makes this process challenging. However, strong biomarker candidates have been identified, especially in light of the large number of clinical and preclinical studies conducted within the last five years.

Objective:

The aim of this article was to compile and discuss the current information on immune biomarkers in major psychiatric disorders, such as schizophrenia, depression, bipolar disorder, and anxiety disorders.

Methods:

In this study, respected scientific databases were searched using key terms related to the subject, and the related literature was examined in detail.

Results:

There are many relationships between psychiatric disorders and immune system parameters. Evidence also suggests that neuroinflammation is involved in the etiopathogenesis of psychiatric disorders. Markers, such as proinflammatory cytokines, tumor necrosis factor alpha, and C-reactive protein have been associated with psychiatric disorders in numerous studies.

Conclusions:

The neuroinflammation hypothesis has an important place in the etiopathogenesis of psychiatric disorders. Uncertainty remains as to whether neuroinflammation is a cause or consequence of psychiatric disorders. Some researchers have indicated that intestinal microbiota composition disorders and dysbiosis are sources of neuroinflammation. Immune marker studies are of great importance in terms of eliminating this uncertainty and overcoming diagnostic and treatment difficulties in the clinic. In this review, biomarker studies on psychiatric disorders were examined from the viewpoint of the immune system and discussed in light of the current studies.

Association of serum adiponectin levels and body mass index with worsening depressive symptoms in elderly individuals: a 10-year longitudinal study

Objectives: Data regarding the association between adiponectin levels and body mass index (BMI) and long-term changes in depressive symptoms are limited and inconsistent. Thus, we investigated whether circulating adiponectin levels and BMI were independently and combinedly correlated to longitudinal changes in depressive symptoms.Methods: This prospective cohort study evaluated 269 elderly Japanese individuals aged ≥70 years who participated in the Tsurugaya Project conducted between 2002 and 2012. A short form of the Geriatric Depression Scale (GDS) was used to assess depressive status. Serum adiponectin levels were measured using an enzyme-linked immunosorbent assay or a latex particle-enhanced turbidimetric immunoassay. BMI was calculated as body weight (kg)/height (m²).Results: Multiple linear regression analysis revealed that baseline serum adiponectin levels were positively associated with changes in GDS scores (β = 0.14, P = 0.035). However, no association was observed after adjusting for BMI (β = 0.09, P = 0.185). Low BMI was associated with increased GDS scores at the 10-year follow-up (β = -0.14, P = 0.033). Participants with a combination of high adiponectin levels and low BMI had a 3.3-fold higher risk of worsening depressive symptoms than those with low adiponectin levels and high BMI (odds ratio: 3.35, 95% confidence interval: 1.60-7.00; P = 0.001).Conclusions: This longitudinal study indicated that high serum adiponectin levels and low BMI were both associated with worsening depressive symptoms among older Japanese individuals. Furthermore, the combination of high adiponectin levels and low BMI was associated with worsening depressive symptoms.

Leptin in bipolar disorder: A systematic review and meta-analysis

Background

Bipolar disorder (BD) is a psychiatric disorder associated with increased rates of obesity and inflammation. Leptin is an adipokine that is mainly produced by the white adipose tissue in response to insulin. It stimulates the immune system, increasing the production of pro-inflammatory cytokines. There is currently uncertainty regarding possible alterations in peripheral leptin levels across the mood states in BD.

Methods

This study comprises a between-group meta-analysis comparing serum and plasma leptin levels in people with BD in mania, depression or euthymia and healthy controls. We conducted a systematic search for all possibly eligible-English and non-English peer-reviewed articles. We calculated the effect size (ES) utilizing Hedges’ adjusted g using random effects.

Results

Eleven studies were included in the meta-analyses, providing data on 1118 participants. Serum and plasma leptin levels were not altered in subjects with BD when compared to healthy controls in mania (g = −0.99, 95% CI −2.43 to 0.43, P = 0.171), in depression (g = 0.17, 95% CI −0.45 to 0.79, P = 0.584), or in euthymia (g = 0.03, 95% CI −0.39 to 0.46, P = 0.882). However, we did observe a stronger association between leptin levels and both age and BMI in patients with BD in euthymia compared to healthy controls, such that the greater the age of the individuals, the greater the difference in leptin levels between BD and controls; and the higher the BMI, the greater the difference in leptin levels between BD and controls.

Conclusions

Our meta-analysis provides evidence that leptin levels are not altered in BD across the mood spectrum compared to healthy controls. The disproportionate increase of leptin levels with increase in BMI in BD speaks in favour of a potential inflammatory role of white adipose tissue in BD and a disproportionate increase of leptin levels with increase in age.

Neuroinflammation in Bipolar Depression

Bipolar disorder (BD) is a leading cause of worldwide disability among mood disorders. Pathological mechanisms are still vastly unclear, and current treatments with conventional medications are often unsatisfactory in maintaining symptoms control and an adequate quality of life. Consequently, current research is focusing on shedding new light on disease pathogenesis, to improve therapeutic effectiveness. Recent evidence has suggested a prominent role of inflammation in mood disorders. Elevated levels of peripheral proinflammatory mediators have been reported in BD, as well as in other mood disorders, and people with systemic autoimmune diseases have an increased risk of developing BD. These immunological alterations are stable, and current medications are unable to alter peripheral concentrations even when clinical improvement is evident. These findings have also been replicated in the central nervous system (CNS) milieu, whereas genetic studies have shown that these immune alterations are not due to the disorder itself, being detectable before the illness onset. Moreover, these inflammatory modifications seem to be affected by and linked to other biomarkers of the disorder, such as alterations of white matter (WM) microstructure, metabolism, kynurenine pathway, and circadian rhythmicity. Finally, these immune variations seem to be useful as predictors of therapeutic responsiveness to medications, and in discriminating between clinically different outcomes. The objective of this review is to summarize available evidence on the connection between inflammation and BD, focusing on peripheral inflammatory markers and recent findings on their connection with other typical features of BD, to outline a general overview of the disorder. Moreover, it is meant to analyze the issues with data gathering and interpretation, given the partially contradictory and inconsistent nature of results.

Peripheral adiponectin levels in anxiety, mood, trauma- and stressor-related disorders: A systematic review and meta-analysis

BACKGROUND

Anxiety, mood, trauma- and stressor-related disorders confer increased risk for metabolic disease. Adiponectin, a cytokine released by adipose tissue is associated with these disorders and obesity via inflammatory processes. Available data describing associations with mental disorders remain limited and conflicted.

METHODS

A systematic search was conducted for English, peer-reviewed articles from inception until February 2019 that assessed for serum or plasma adiponectin levels in adults with an anxiety, mood or trauma-related disorder. Diagnoses were determined by psychiatric interview, based on DSM-IV, DSM-5 or ICD-10 criteria. Analyses were performed using STATA 15 and Standardized mean difference (SMD) with 95% confidence interval was applied to pool the effect size of meta-analysis studies.

RESULTS

In total 65 eligible studies were included in the systematic review and 30 studies in this meta-analysis. 19,178 participants (11,262 females and 7916 males), comprising healthy adults and adults with anxiety, mood and trauma-related disorders, were included. Overall results indicated an inverse association between adiponectin levels and examined mental disorders. Specifically, patients with an anxiety disorder (SMD  = -1.18 µg/mL, 95% CI, -2.34; -0.01, p  = 0.047); trauma or stressor-related disorder (SMD  =  -0.34 µg/mL, 95% CI, -0.52; -0.17, p  = 0.0000) or bipolar disorder (SMD  =  -0.638 µg/mL, 95% CI, -1.16, -0.12, p  = 0.017) had significant lower adiponectin levels compared to healthy adults.

LIMITATIONS

Heterogeneity, potential publication bias, and lack of control for important potential confounders were significant limitations.

CONCLUSION

Peripheral adiponectin levels appear to be inversely associated with anxiety, mood, trauma- and stressor related disorders and may be a promising biomarker for diagnosis and disease monitoring.

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.

Changes in inflammation with treatment for bipolar II depression: Pilot trial data on differential effects of psychotherapy and medication

OBJECTIVES

Limited prospective data, mostly focused on bipolar I disorder, suggests that pro-inflammatory cytokines are elevated in abnormal mood states. We evaluated whether treatment normalizes peripheral markers of inflammation in bipolar II disorder.

METHODS

Using data from a randomized clinical trial of Interpersonal and Social Rhythm Therapy (IPSRT) + quetiapine vs. IPSRT + placebo for bipolar II depression, we examined whether these treatments for bipolar II depression impact inflammatory cytokines and whether observed changes in cytokines are associated with changes in depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD-17).

RESULTS

Cytokine values were available for 33 participants who completed baseline and 20-week followup visits. After excluding those with CRP values >=10 mg/L, there were 27 patients available for analysis (IPSRT+quetiapine N=10, IPSRT+placebo N=17). Baseline measure of inflammation did not appear to moderate treatment response, nor was change in HRSD-17 score correlated with changes in cytokines. Those who received IPSRT+quetiapine had significantly greater increases in IL-6 (p=0.02) and TNF-α (p=0.04), even after adjusting for changes in body mass index, than the IPSRT alone group. Descriptively, the quetiapine group showed increases in pro-inflammatory and decreases in anti-inflammatory cytokines and the psychotherapy group showed reduced pro-inflammatory cytokines.

CONCLUSIONS

Despite both groups showing depression improvement, this small study suggests a more pro-inflammatory cytokine profile over time with quetiapine plus psychotherapy compared to psychotherapy alone. Elevated risk of cardiovascular morbidity and mortality among those with bipolar II disorder underscores the importance of delivering treatments that do not exacerbate these risk factors.

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.

Adiponectin levels in patients with bipolar disorder: A systematic review and meta-analysis

Bipolar disorder (BD) is associated with high prevalence rates of obesity-related conditions and subclinical inflammation. Adiponectin is produced by adipose tissue and exerts anti-inflammatory activities. We aimed to perform a systematic review and meta-analysis of studies investigating adiponectin levels in BD patients and healthy controls. Electronic databases were searched from their inception until 15th Jan 2019. Random-effects models with the Hedges' g as the effect size (ES) estimate were used. We included 11 studies, representing 477 patients and 380 controls. Pooled data analysis revealed no significant differences in adiponectin levels between BD patients and controls (ES = 0.28, 95%CI: -0.34 - 0.90, p = 0.372). The levels of adiponectin were significantly higher during euthymia (ES = 1.09, 95%CI: 0.03-2.16, p = 0.044). The levels of adiponectin in depressed patients were lower, but this result did not reach statistical significance (ES = -0.90, 95%CI: -1.85 - 0.05, p = 0.063). Due to low number of studies, the subgroup analysis of manic patients was not performed; however, a severity of manic symptoms was not associated with the ES estimates. Longer illness duration and a higher percentage of BD type I (BD-I) patients were associated with higher ES estimates. A higher severity of depressive symptoms was associated with lower ES estimates. Heterogeneity was significant in all analyses. Results of the Egger's test were insignificant, showing no publication bias. Our results indicate that adiponectin might be a state marker of BD as it appears to be elevated in euthymia and decreased in depression. Illness progression and a diagnosis of BD-I might contribute to higher adiponectin levels.

Peripheral blood lymphocyte subpopulations in patients with bipolar disorder type II

We investigated the phenotype of peripheral blood lymphocytes of patients with bipolar disorder type II in different phases of the disease in order to check whether there are specific changes in the immune parameters. Lymphocytes subpopulations were analyzed ex vivo with flow cytometry in patients in euthymic, depression or hypomanic phase of the disease and compared with healthy controls. All BD patients were characterized by lower percentage of CD3⁺CD4⁺ and CD3⁺CD8⁺ cells compared with healthy people. But only patients in depression and remission had higher percentage of B cells (CD19⁺ cells) compared with healthy people. The percentage of CD4⁺CD25⁺ and CD8⁺CD25⁺ cells was decreased in patients in hypomanic phase compared with healthy control. Patients in remission were characterized by increased concentrations of IL-6 and IL-10 and decreased level of TNF in blood serum. Significant correlations between immunologic parameters and the results of Hamilton or Young scale have also been found. Our results demonstrate that there are significant differences in lymphocyte subpopulations which depend on the phase of the disease the patient is currently in.

The association between low-grade inflammation and the clinical features of bipolar disorder in Han Chinese population

Variety of evidence suggests that low-grade inflammation may be involved in the pathophysiology of bipolar disorder (BD). However, the conclusion regarding the relationship between inflammation and BD has been inconsistent. In this study, we aimed to survey the prevalence of low-grade inflammation in a large Han Chinese population with BD and assess its impact on the clinical features of BD. 430 eligible cases were drawn from patients who were admitted or had ever been admitted for BD to the inpatient service of the psychiatric department of the Third Hospital of Sun Yat-sen University. Subjects with current active physical diseases or white blood count (WBC) >19.0 × 10⁹/L (2 times the upper reference) were excluded. Serum C-reactive protein (CRP) levels and WBC were measured with fast blood sample. Low-grade inflammation was defined as CRP>3 mg/L or WBC > 9.5 × 10⁹/L(the upper reference). Clinical features of BD were collected through semi-structural interview conducted by trained interviewers with background of psychiatric education. If defined as CRP>3 mg/L, the prevalence of low-grade inflammation among BD was 10.1% (41/404), it was positively associated with BMI (p = 0.012), comorbidity of glycolipid metabolic diseases(p = 0.018). After adjusting for BMI, it was found to be positively related to recent suicide attempt (p = 0.03), initiation with (hypo)manic episode(p = 0.047), leaden paralysis (p = 0.037) and family history of mental disorders(p = 0.012), while the association between comorbidity of glycolipid metabolic diseases and low-grade inflammation disappeared (p = 0.330). If defined as WBC > 9.5 × 10⁹/L, the prevalence of low-grade inflammation was 8.1% (33/409), it was positively associated with psychotic features (p = 0.011) and adverse life events before the onset of illness(p < 0.001), but was not significantly influenced by BMI (p = 0.077). A much lower prevalence of low-grade inflammation in BD is found among Han Chinese population than among western population. Low-grade inflammation of different definition impacts differentially on the clinical features of BD.

Adipokine expression in systemic sclerosis lung and gastrointestinal organ involvement

OBJECTIVES

The immunomodulatory properties of adipokines have previously been reported in autoimmune disorders. Less is known about the role of adipokines in systemic sclerosis (SSc). Lung and gastrointestinal tract are frequently involved in SSc; therefore, these organs were analyzed for adipokine expression as well as pulmonary samples of patients suffering from idiopathic pulmonary fibrosis (IPF) as comparison.

METHODS

Gastric samples (antrum, corpus) of SSc were analyzed immunohistochemically for adiponectin, resistin and visfatin compared with non-SSc related gastritis. Inflammatory cells were quantified in gastric samples and correlated with adipokine expression. Lung samples of SSc, IPF and healthy controls were also analyzed. Protein levels of lung tissue lysates and bronchoalveolar lavages (BAL) in minor fibrotic stages were measured by ELISA.

RESULTS

Lung sections of donor parenchyma showed significantly stronger adiponectin signals as IPF and SSc (donor vs. IPF: p < 0.0001). In SSc and IPF, resistin and visfatin were increased within immune cell infiltrates, but overall no difference in expression for resistin or visfatin compared to controls was observed. In BAL and lung protein lysates of early stages of fibrosis, adiponectin and visfatin were not reduced in IPF and SSc compared to controls. In gastric samples collected by standard endoscopic gastric biopsy, adiponectin was also significantly reduced in SSc- compared to non-SSc gastritis (p = 0.049) while resistin and visfatin were comparable although deeper fibrotic layers were not included in the respective samples. Adiponectin-positive tissues showed higher amounts of CD4⁺ but not CD8⁺ T cells. Controls showed no correlation between CD4⁺ T cells and resistin, whereas SSc showed significantly more CD4⁺ T cells in resistin-negative tissues.

CONCLUSION

Adipokines are expressed in gastric and lung samples of patients with SSc and in lung samples affected by IPF. Prominently, adiponectin levels were reduced in fibrotic SSc gastritic tissue as well as in IPF and SSc lung tissue. Consequently, adiponectin expression seems to be associated with fibrotic progression in the context of SSc and IPF.

Circulating levels of adipokines are altered in patients with temporal lobe epilepsy

OBJECTIVE

A persistent low-grade inflammatory state has been described in patients with temporal lobe epilepsy (TLE) in the interictal period. Adipokines are cytokines produced by the adipose tissue that can influence inflammatory response. The purpose of this study was to evaluate the plasma levels of adipokines in patients with TLE in comparison with controls. In addition, we sought to investigate whether the levels of adipokines were associated with clinical parameters in TLE.

METHODS

Forty patients with TLE and 40 controls were enrolled in this study. All participants were subjected to clinical assessment that included the Mini International Neuropsychiatric Interview (MINI) and the Hamilton Depression Rating Scale (HAM-D). Peripheral blood was drawn, and plasma levels of adipokines (adiponectin, leptin, and resistin) were measured by enzyme-linked immunoassay (ELISA).

RESULTS

People with TLE presented higher leptin and lower adiponectin and resistin levels in comparison with controls. The levels of these adipokines correlated negatively with illness length but not with other clinical parameters. In a binary logistic regression model, higher leptin and lower adiponectin levels remained as significant predictors of TLE diagnosis.

CONCLUSIONS

These results corroborate the view that TLE is a multisystemic condition associated with low-grade inflammation.

Metabolic syndrome and vaspin in patients with bipolar disorder

Metabolic disorders and abnormal levels of circulating adipokines have been reported in patients with bipolar disorder (BD). The aim of this study was to investigate the differences in the correlations of vaspin plasma levels and metabolic parameters between two groups: patients with BD and mentally healthy persons. We measured plasma levels of vaspin, metabolic parameters, and metabolic syndrome (MS) in 101 patients with BD and 90 healthy control (HC) subjects. Patients with BD were evaluated with the Young Mania Rating Scale (YMRS) to assess manic symptoms and the Hamilton Depression Scale (HDS) to assess depressive symptoms. The Global Assessment of Functioning (GAF) was used to evaluate the general functions of the patients. Body mass index (BMI), weight, waist circumference (WC), fasting glucose, and triglyceride levels of the study group were statistically higher than those of the healthy controls (p = 0.001, p < 0.001, p < 0.001, p = 0.027, and p = 0.001 respectively). Plasma levels of vaspin were 0.978 ng/ml in patients with BD and 0.292 in the HC group (p < 0.001). Our study revealed associations between metabolic parameters/metabolic syndrome and vaspin plasma concentrations in patients with BD. Vaspin can play a specific role in the pathogenesis of metabolic disorders in these subjects and can be a specific indicator substance in BD.

Immune and metabolic alterations in first episode psychosis (FEP) patients

The molecular underpinnings associated to first episode psychosis (FEP) remains to be elucidated, but compelling evidence supported an association of FEP with blood alterations in biomarkers related to immune system, growth factors and metabolism regulators. Many of these studies have not been already confirmed in larger samples or have not considered the FEP diagnostic subgroups. In order to identify biochemical signatures of FEP, the serum levels of the growth factors BDNF and VEGF, the immune regulators IL-1RA, IL-6, IL-10 and IL-17, RANTES/CCL5, MIP-1b/CCL4, IL-8 and the metabolic regulators C-peptide, ghrelin, GIP, GLP-1, glucagon, insulin, leptin, PAI-1, resistin and visfatin were analysed in 260 subjects collected in the GET UP project. The results indicated an increase of MIP-1b/CCL4, VEGF, IL-6 and PAI-1, while IL-17, ghrelin, glucagon and GLP-1 were decreased in the whole sample of FEP patients (p < 0.01 for all markers except for PAI-1 p < 0.05). No differences were evidenced for these markers among the diagnostic groups that constitute the FEP sample, whereas IL-8 is increased only in patients with a diagnosis of affective psychosis. The principal component analysis (PCA) and variable importance analysis (VIA) indicated that MIP-1b/CCL4, ghrelin, glucagon, VEGF and GLP-1 were the variables mostly altered in FEP patients. On the contrary, none of the analysed markers nor a combination of them can discriminate between FEP diagnostic subgroups. These data evidence a profile of immune and metabolic alterations in FEP patients, providing new information on the molecular mechanism associated to the psychosis onset for the development of preventive strategies and innovative treatment targets.

Adipocytokines and ghrelin level of bipolar patients from manic episode to euthymic episode

PURPOSE

Obesity and metabolic syndrome (MeS) are more frequently observed in bipolar patients than the general population. This may result from the differences of adipocytokines and ghrelin levels in bipolar disorder.

MATERIAL AND METHODS

We evaluated the leptin, adiponectin, resistin and ghrelin levels in bipolar patients (n = 30) in manic episode and in a control group (n = 30). After treatment, the same patients were evaluated again during the euthymic episode. We also measured the insulin, glucose, insulin resistance (HOMA), trygliceride (TG), total cholesterol (TCHOL), high density lipoprotein cholesterol (HDL) and low density lipoprotein cholesterol (LDL) in relation to the (MeS).

RESULTS

When controlling for age, BMI and glucose, leptin levels were higher in the bipolar disorder manic episode group (BD-ME) and bipolar euthymic episode group (BD-EE) than the control group; resistin levels were higher in the BD-ME compared to the control group and it had a positive correlation with Young Mania Rating Scale (YMRS). After treatment, ghrelin levels were higher in the BD-EE compared to the BD-ME group. There was no difference among the groups with respect to adiponectin.

CONCLUSIONS

The present results point that high leptin, resistin and ghrelin levels may be involved in the early pathophysiological process which can lead to later obesity and MeS in patients with bipolar disorder.

Circulating cathelicidin LL-37 level is increased in euthymic patients with bipolar disorder

More and more data seems to imply that immune mechanisms are involved in the pathomechanism of bipolar disorder (BD). However, the primary role of cathelicidin LL-37 is defense against pathogens, more and more data indicated that this peptide strongly modulates immune system functioning and contributes to immune pathology of chronic and inflammatory diseases. No data is available on the level of LL-37 in bipolar patients. The aim of the study was to examine the circulating levels of cathelicidin LL-37 in euthymic patients with BD. Forty patients with BD and fifty-nine healthy volunteers were enrolled into the study. Concentration of LL-37 in serum was assessed using immunoenzymatic test ELISA. The mean LL-37 concentration in bipolar patients and in healthy subjects were 4.60 ± 7.65 ng/mL and 1.92 ± 2.89 ng/mL, respectively, and the difference was statistically significant (p = 0.035). Within the BD group LL-37 level was significantly higher in women than in men (p = 0.045). The evaluation of serum LL-37 concentration during stable 8 week treatment indicated that at baseline (T1) mean level of LL-37 was 5.82 ± 10.59 ng/mL; and after treatment (T2) was 4.33 ± 5.87 ng/mL; the difference between T1 and T2 was not significant. Elevated serum levels of LL-37 in bipolar patients may suggest the role of this peptide in the pathomechanism of BD.

Plasma copeptin and metabolic dysfunction in individuals with bipolar disorder

AIM

This study aimed to compare plasma copeptin levels, the c-terminal of provasopressin, between individuals with bipolar disorder (BD) and healthy controls and to assess the relation between copeptin and metabolic parameters.

METHODS

We measured plasma levels of copeptin in individuals with BD (n = 55) and healthy controls (n = 21). Information related to psychiatric/medical history, as well as to metabolic comorbidities and laboratorial parameters was also captured. Insulin resistance and β-cell function in basal state were calculated from fasting plasma glucose and C-peptide using the HOMA2 calculator. Impaired glucose metabolism was defined as pre-diabetes or type 2 diabetes mellitus. Copeptin, adiponectin, and leptin plasma levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Plasma copeptin levels were lower in individuals with BD, relative to healthy controls (P < 0.001). There were significant interactions between BD and plasma copeptin on β-cell function (rate ratio [RR] = 1.048; P = 0.030) and on leptin levels (RR = 1.087; P = 0.012), indicating that there was a positive correlation between these markers in the BD group, but a negative one in healthy controls. Finally, in individuals with BD only, the association between β-cell function, body mass index (RR = 1.007; P < 0.001), and insulin resistance (RR = 1.001; P = 0.037) was moderated by copeptin levels.

CONCLUSION

Copeptin levels were lower in individuals with BD than in healthy controls. There were differential associations between copeptin and metabolic parameters within the BD and healthy control subgroups, suggesting an association between abnormal copeptin and metabolic dysregulation only in the BD population.

A systematic review of evidence for the role of inflammatory biomarkers in bipolar patients

Bipolar disorder (BD) is a neuropsychiatric disorder that is characterized by a phasic course of affective episodes interspersed with a euthymic state. Epidemiological, clinical, genetic, post-mortem and preclinical studies have shown that inflammatory reactions and immune modulation play a pivotal role in the pathophysiology of BD. It is conceptualized that biomarkers of inflammation and immune responses should be employed to monitor the disease process in bipolar patients. The objective of this systematic review is to analyse the inflammatory markers involved in human studies and to explore each individual marker for its potential clinical application and summarize evidence regarding their role in BD. A systematic review of human studies to measure inflammatory markers was conducted, and the studies were identified by searching PubMed/MEDLINE, PsycINFO, EMBASE, and Web of Science databases for peer-reviewed journals that were published until September 2015. In this review, we included peripheral markers, genetic, post-mortem and cell studies with inflammatory biomarker analysis in BD. One hundred and two (102) papers met the inclusion criteria. The pro-inflammatory cytokines were elevated and the anti-inflammatory cytokines were reduced in BD patients, particularly during manic and depressive phases when compared to the controls. These changes tend to disappear in euthymia, indicating that inflammation may be associated with acute phases of BD. Even though there are promising findings in this field, further clinical studies using more established detection techniques are needed to clearly show the benefit of using inflammatory markers in the diagnosis, follow-up and prognosis of patients with BD.

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.

Serum levels of adiponectin, CCL3/MIP-1α, and CCL5/RANTES discriminate migraine from tension-type headache patients

OBJECTIVES

Inflammatory molecules and neurotrophic factors are implicated in pain modulation; however, their role in primary headaches is not yet clear. The aim of this study was to compare the levels of serum biomarkers in migraine and tension-type headache.

METHODS

This was a cross-sectional study. We measured serum levels of adiponectin, chemokines, and neurotrophic factors in patients with migraine and tension-type headache. Depression and anxiety symptoms, headache impact and frequency, and allodynia were recorded.

RESULTS

We included sixty-eight patients with migraine and forty-eight with tension-type headache. Cutaneous allodynia (p = 0.035), CCL3/MIP-1α (p = 0.041), CCL5/RANTES (p = 0.013), and ADP (p = 0.017) were significantly higher in migraine than in tension-type headache. The differences occurred independently of anxiety and depressive symptoms, frequency and impact of headache, and the presence of pain.

CONCLUSIONS

This study showed higher CCL3/MIP-1α, CCL5/RANTES, and ADP levels in migraine in comparison with tension-type headache. Our findings suggest distinctive roles of these molecules in the pathophysiology of these primary headaches.

Medical comorbidity in bipolar disorder: The link with metabolic-inflammatory systems

BACKGROUND

Bipolar disorder (BD) is associated with chronic low-grade inflammation, several medical comorbidities and a decreased life expectancy. Metabolic-inflammatory changes have been postulated as one of the main links between BD and medical comorbidity, although there are few studies exploring possible mechanisms underlying this relationship. Therefore, the aims of the current narrative review were 1) synthesize the evidence for metabolic-inflammatory changes that may facilitate the link between medical comorbidity and BD and 2) discuss therapeutic and preventive implications of these pathways.

METHODS

The PubMed and Google Scholar databases were searched for relevant studies.

RESULTS

Identified studies suggested that there is an increased risk of medical comorbidities, such as autoimmune disorders, obesity, diabetes and cardiovascular disease in patients with BD. The association between BD and general medical comorbidities seems to be bidirectional and potentially mediated by immune dysfunction. Targeting the metabolic-inflammatory-mood pathway may potential yield improved outcomes in BD; however, further study is needed to determine which specific interventions may be beneficial.

LIMITATIONS

The majority of identified studies had cross-sectional designs, small sample sizes and limited measurements of inflammation.

CONCLUSIONS

Treatment and prevention of general medical comorbidities in mood disorders should include preferential prescribing of metabolically neutral agents and adjunctive lifestyle modifications including increased physical activity, improved diet and decreased substance abuse. In addition, the use of anti-inflammatory agents could be a relevant therapeutic target in future research.

Molecular Mechanisms of Bipolar Disorder: Progress Made and Future Challenges

Bipolar disorder (BD) is a chronic and progressive psychiatric illness characterized by mood oscillations, with episodes of mania and depression. The impact of BD on patients can be devastating, with up to 15% of patients committing suicide. This disorder is associated with psychiatric and medical comorbidities and patients with a high risk of drug abuse, metabolic and endocrine disorders and vascular disease. Current knowledge of the pathophysiology and molecular mechanisms causing BD is still modest. With no clear biological markers available, early diagnosis is a great challenge to clinicians without previous knowledge of the longitudinal progress of illness. Moreover, despite recommendations from evidence-based guidelines, polypharmacy is still common in clinical treatment of BD, reflecting the gap between research and clinical practice. A major challenge in BD is the development of effective drugs with low toxicity for the patients. In this review article, we focus on the progress made and future challenges we face in determining the pathophysiology and molecular pathways involved in BD, such as circadian and metabolic perturbations, mitochondrial and endoplasmic reticulum (ER) dysfunction, autophagy and glutamatergic neurotransmission; which may lead to the development of new drugs.

A meta-analysis of blood cytokine network alterations in psychiatric patients: comparisons between schizophrenia, bipolar disorder and depression

Schizophrenia, bipolar disorder and major depressive disorder (MDD) have all been associated with aberrant blood cytokine levels; however, neither the pattern of cytokine alterations nor the impact of clinical status have been compared across disorders. We performed a meta-analysis of blood cytokines in acutely and chronically ill patients with these major psychiatric disorders. Articles were identified by searching the PubMed, PsycInfo and Web of Science, and the reference lists of these studies. Sixty-eight studies met the inclusion criteria (40 schizophrenia, 10 bipolar disorder and 18 MDD) for acutely ill patients. Forty-six studies met the inclusion criteria (18 schizophrenia, 16 bipolar disorder and 12 MDD) for chronically ill patients. Levels of two cytokines (interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α)), one soluble cytokine receptor (sIL-2R), and one cytokine receptor antagonist (IL-1RA) were significantly increased in acutely ill patients with schizophrenia, bipolar mania and MDD compared with controls (P<0.01). Following treatment of the acute illness, IL-6 levels significantly decreased in both schizophrenia and MDD (P<0.01); sIL-2R levels increased in schizophrenia; and IL-1RA levels in bipolar mania decreased. In chronically ill patients, the levels of IL-6 were significantly increased in schizophrenia, euthymic (but not depressed) bipolar disorder and MDD compared with controls (P<0.01). The levels of IL-1β and sIL-2R were significantly increased in both chronic schizophrenia and euthymic bipolar disorder. Overall, there were similarities in the pattern of cytokine alterations in schizophrenia, bipolar disorder and MDD during acute and chronic phases of illness, raising the possibility of common underlying pathways for immune dysfunction. Effects of treatment on cytokines were more robust for schizophrenia and MDD, but were more frequently studied than for acute mania. These findings have important implications for our understanding of the pathophysiology and treatment of major psychiatric disorders.

Plasma adiponectin and depressive symptoms during pregnancy and the postpartum period: A prospective cohort study

BACKGROUND

Some authors have described an inverse association between adiponectin and depression, but this association has not yet been investigated during the perinatal period.

OBJECTIVE

To evaluate the association between the plasma adiponectin levels and symptoms of depression in women from early pregnancy to 30-45 days postpartum.

METHODS

A prospective cohort of 235 women was analyzed, with four waves of follow-up: 5-13th, 22-26th, and 30-36th gestational weeks and 30-45 days postpartum. Depressive symptoms were measured using the Edinburgh Postnatal Depression Scale (EPDS; cutoff ≥ 11). The plasma adiponectin concentrations were measured using an enzyme-linked immunosorbent assay. The statistical analyses included linear mixed effects regressions to model the association between these time-dependent variables.

RESULTS

The prevalence of depressive symptoms was 35.5%, 22.8%, 21.8%, and 16.9% and the median (µg/mL) adiponectin levels were 4.8, 4.7, 4.4, and 7.5 in the 1st, 2nd, and 3rd trimesters and the postpartum period, respectively. Women who remained non-depressed throughout the study tended to have higher values of adiponectin throughout pregnancy and the postpartum period compared to those who had depressive symptoms at least once, but this difference was not statistically significant (β=-0.14; p=0.071). There was no statistically significant association between the plasma adiponectin levels and the EPDS scores in the multiple model (β=-0.07; p=0.320).

LIMITATIONS

Losses to follow-up, different procedures for the blood draws at the prenatal and postpartum visits, and the presence of a nested clinical trial with omega-3 supplementation.

CONCLUSION

The plasma adiponectin levels were not associated with depressive symptoms during the perinatal period.

Association of peripheral inflammation with body mass index and depressive relapse in bipolar disorder

Bipolar I disorder (BD) is associated with increased inflammation, which is believed to be central to disease etiology and progression. However, BD patients also have high rates of obesity, itself an inflammatory condition, and the relative contributions of mood illness and obesity to inflammation are unknown. Moreover, the impact of inflammation on clinical illness course has not been well studied. The objectives of this analysis were therefore: (1) to determine if inflammation in BD is mood illness-related or secondary to elevated body mass index (BMI), and (2) to investigate the impact of inflammation on prospectively-ascertained relapse into depression and mania. We measured the serum levels of 7 inflammatory cytokines (TNF-α, γ-interferon, monocyte chemoattractant protein-1 [MCP-1], IL-1α, IL-2, IL-6, and IL-8) and 2 anti-inflammatory cytokines (IL-4 and IL-10) in 52 early-stage BD patients and 22 healthy subjects. In patients, a multivariate multiple regression model that controlled for psychotropic medications found that higher BMI, but not recent (past-6-month) mood episodes, predicted greater inflammatory cytokines (p=.05). Healthy subjects also had a BMI-related increase in inflammatory cytokines (p<.01), but it was counter-balanced by a compensatory increase in anti-inflammatory cytokines (p=.02), reducing their total inflammatory burden from higher BMI. In patients, linear regression showed that two inflammatory cytokines predicted depressive relapse in the 12 months after cytokine measurement: IL-1α (p<.01) and MCP-1 (p<.01). These results suggest that elevated BMI is a significant contributor to inflammation in BD, more so even than recent mood illness severity. They also point to inflammation as an important predictor of illness course, particularly depressive relapse.

Adipokines, metabolic dysfunction and illness course in bipolar disorder

Replicated evidence indicates that individuals with BD are differentially affected by metabolic comorbidities and that its occurrence is a critical mediator and/or moderator of BD outcomes. This study aimed to explore the role of adipokines on bipolar disorder (BD) course and its relationship with metabolic comorbidities (i.e. type 2 diabetes mellitus, obesity). We measured plasma levels of adiponectin and leptin, as well as anthropometric and metabolic parameters of 59 patients with BD and 28 healthy volunteers. Our results showed that, in female participants, adiponectin was lower in individuals with BD, relative to healthy controls (p = 0.017). In the BD population, adiponectin levels were correlated with fasting glucose (r = -0.291, p = 0.047), fasting insulin (r = -0.332, p = 0.023), C-peptide (r = 0.040, p = 0.040), homeostatic model assessment-insulin resistance (r = -0.411, p = 0.004), HDL (r = 0.508, p < 0.001), VLDL (r = -0.395, p = 0.005) and triglycerides (r = -0.310, p = 0.030). After adjustment for age, gender and BMI, individuals with BD and low adiponectin levels (i.e. < 7.5 μg/ml), had a higher number of mood episodes (p < 0.001), lower number of psychiatric hospitalizations (p = 0.007), higher depressive symptoms (p < 0.001) and lower levels of functioning (p = 0.020). In conclusion, adiponectin levels, either directly or as a proxy of metabolic dysfunction, is independently associated with an unfavorable course of illness in BD.

Glucose metabolism alterations in patients with bipolar disorder

Patients with bipolar disorder (BD) are more frequently affected by metabolic syndrome (MetS) than the general population, but the neurobiological correlates underlying such association are still not clarified and few studies in BD have evaluated the role of regulators of lipid and glucose metabolism. The present study was aimed to investigate putative alterations in markers linked to metabolic dysfunctions as C-peptide, Ghrelin, GIP, GLP-1, Glucagon, Insulin, Leptin, PAI-1 (total), Resistin and Visfatin in a sample of BD patients compared to controls. Furthermore, associations between changes of metabolic markers and relevant clinical features, such as severity of symptomatology, number and type of past mood episodes, drug treatments and presence/absence of metabolic alterations (MetS, diabetes and cardiovascular disease) were analyzed. A total of 57 patients with BD and 49 healthy controls were recruited. The main results showed lower serum levels of Glucagon, GLP-1, Ghrelin, and higher levels of GIP in BD patients as compared to controls (p = 0.018 for Ghrelin; p < 0.0001 for Glucagon; p < 0.0001 for GLP-1; p < 0.0001 for GIP). Further, Glucagon and GLP-1 levels were significantly associated with the number of past mood episodes. These findings support the hypothesis that alterations in Glucagon, GLP-1, GIP and Ghrelin might be involved in BD pathogenesis and might represent useful biomarkers for the development of preventive and personalized therapies in this disorder.

The Potential Role of the NLRP3 Inflammasome as a Link between Mitochondrial Complex I Dysfunction and Inflammation in Bipolar Disorder

Mitochondrial dysfunction and activation of the inflammatory system are two of the most consistently reported findings in bipolar disorder (BD). More specifically, altered levels of inflammatory cytokines and decreased levels of mitochondrial complex I subunits have been found in the brain and periphery of patients with BD, which could lead to increased production of mitochondrial reactive oxygen species (ROS). Recent studies have shown that mitochondrial production of ROS and inflammation may be closely linked through a redox sensor known as nod-like receptor pyrin domain-containing 3 (NLRP3). Upon sensing mitochondrial release of ROS, NLRP3 assembles the NLRP3 inflammasome, which releases caspase 1 to begin the inflammatory cascade. In this review, we discuss the potential role of the NLRP3 inflammasome as a link between complex I dysfunction and inflammation in BD and its therapeutic implications.

Comparison of pro-inflammatory cytokines among patients with bipolar disorder and unipolar depression and normal controls

OBJECTIVE

Research evidence has shown that bipolar disorder (BD) and unipolar depression (UD) are both related to inflammatory dysregulation, but few studies have compared the levels of cytokines between these two disorders.

METHODS

Study subjects were age- and gender-matched outpatients with BD or UD and normal controls (NC). Severities of depression and mania symptoms were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Young Mania Rating Scale (YMRS). Pro-inflammatory cytokines, including soluble interleukin-6 receptor (sIL-6R), soluble interleukin-2 receptor (sIL-2R), C-reactive protein (CRP), soluble tumor necrosis factor receptor type 1 (sTNF-R1), soluble p-selectin receptor (sP-selectin), and monocyte chemotactic protein-1 (MCP-1), were assessed in all subjects by enzyme-linked immunosorbent assays.

RESULTS

In all, 130 patients with BD, 149 patients with UD, and 130 NC were enrolled in the study; 67.6% were female and the average age was mean ± standard deviation (SD) 43.5 ± 11.8 years. The BD group had a significantly higher smoking rate, more medical comorbidity, higher body mass index (BMI), and higher levels of sIL-2R, sIL-6R, CRP, sTNF-R1, and MCP-1 (all p < 0.01) than the UD and NC groups. When the remitted patients with BD (YMRS scores ≤ 12) were compared with the patients with UD, controlling for age, MADRS score, smoking, medical comorbidity, and BMI in the regression model, the results showed that the BD group had significantly higher levels of sIL-6R (p < 0.001), CRP (p = 0.045), sTNF-R1 (p = 0.036), and MCP-1 (p = 0.001) than the UD group.

CONCLUSIONS

Higher levels of sIL-6R, CRP, sTNF-R1, and MCP-1 were noted in BD than in UD. These results may suggest a more severe inflammatory dysregulation in BD. Further studies are required to investigate whether these cytokines could be biomarkers for affective disorders.

IL-23 and TGF-β1 levels as potential predictive biomarkers in treatment of bipolar I disorder with acute manic episode

BACKGROUND

Growing evidence suggests that immune dysfunction may be involved in the physiopathology of bipolar disorders, with typical first-line treatment using lithium and quetiapine serving to restore pro-inflammation status. This study aimed to explore the relationship between inflammatory cytokines-especially regulatory factors and the effect of combination treatment-with quetiapine and lithium in manic patients.

METHODS

41 patients of bipolar I disorder with manic episode were enrolled and received combination treatment with quetiapine and lithium. Blood sampling and assessments were performed at baseline and after 8-week treatment. YMRS was used to evaluate the severity of manic symptoms at the same time of detecting plasma levels. A control group comprised of 36 age and gender matched healthy volunteers were enrolled, and their blood samples were assessed at the time of enrollment.

RESULTS

TGF-β1 and IL-23 plasma levels in patients were significantly higher than healthy controls at baseline (P<0.05). When comparing remitted patients with non-remitted patients, initial plasma level TGF-β1 was higher (P=0.029) while IL-23 was lower (P=0.035). The plasma levels of TNF-α, TGF-β1, IL-23 and IL-17 significantly decreased after treatment among the patients who achieved response (P<0.05).

LIMITATIONS

The relatively small sample size in patients and control groups should be considered as a limitation of the study.

CONCLUSIONS

The high initial plasma level of TGF-β1 and low initial plasma level of IL-23 indicated better prognosis during combination treatment with quetiapine and lithium in manic patients. The trend of decreasing plasma levels of TNF-α, TGF-β1, IL-23 and IL-17 indicated therapeutic effect.

Bipolar disorder: role of immune-inflammatory cytokines, oxidative and nitrosative stress and tryptophan catabolites

Bipolar disorder (BD) is a complex disorder with a range of presentations. BD is defined by the presentation of symptoms of mania or depression, with classification dependent on patient/family reports and behavioural observations. Recent work has investigated the biological underpinnings of BD, highlighting the role played by increased immune-inflammatory activity, which is readily indicated by changes in pro-inflammatory cytokines or signalling, both centrally and systemically, e.g. increased interleukin-6 trans-signalling. Here, we review the recent data on immune-inflammatory pathways and cytokine changes in BD. Such changes are intimately linked to changes in oxidative and nitrosative stress (O&NS) and neuroregulatory tryptophan catabolites (TRYCATs), both centrally and peripherally. TRYCATs take tryptophan away from serotonin, N-acetylserotonin and melatonin synthesis, driving it down the TRYCAT pathway, predominantly as a result of the pro-inflammatory cytokine induction of indoleamine 2,3-dioxygenase. This has led to an emerging biological perspective on the aetiology, course and treatment of BD. Such data also better integrates the numerous comorbidities associated with BD, including addiction, cardiovascular disorders and increased reporting of pain. Immune-inflammatory, O&NS and TRYCAT pathways are also likely to be relevant biological underpinnings to the significant decrease in life expectancy in BD.

Changes in adipokine levels in autism spectrum disorders

BACKGROUND AND OBJECTIVE

The etiopathogenesis of autism spectrum disorders (ASD) is largely unknown, but it seems to involve dysfunction in several biological systems. Among many possible biological pathways, the immune system has emerged as potentially involved. Recent studies have shown association between cytokines (molecules that mediate immune cell interaction) and ASD. Adipokines are cytokines secreted mainly by adipose tissue and may have systemic effects. The main objective of this study was to compare the plasma levels of three adipokines between patients with ASD and healthy controls. Another aim was to correlate the levels of these adipokines and the severity of autistic symptoms as measured by the Social Responsiveness Scale (SRS).

METHODS

We collected plasma from 30 patients and 19 controls and measured the levels of adiponectin, leptin and resistin using a commercially available kit. We also used the SRS as a tool to assess the severity of autistic symptoms.

RESULTS

We found decreased levels of resistin, increased levels of leptin and unaltered levels of adiponectin in plasma from ASD subjects in comparison with controls. There was also a negative correlation between the levels of adiponectin and the severity of symptoms as assessed by the SRS.

CONCLUSION

There are significant changes in the plasma levels of adipokines from patients with ASDs. They suggest the occurrence of systemic changes in ASD and may be hallmarks of the disease.

Is there a "metabolic-mood syndrome"? A review of the relationship between obesity and mood disorders

Obesity and mood disorders are highly prevalent and co-morbid. Epidemiological studies have highlighted the public health relevance of this association, insofar as both conditions and its co-occurrence are associated with a staggering illness-associated burden. Accumulating evidence indicates that obesity and mood disorders are intrinsically linked and share a series of clinical, neurobiological, genetic and environmental factors. The relationship of these conditions has been described as convergent and bidirectional; and some authors have attempted to describe a specific subtype of mood disorders characterized by a higher incidence of obesity and metabolic problems. However, the nature of this association remains poorly understood. There are significant inconsistencies in the studies evaluating metabolic and mood disorders; and, as a result, several questions persist about the validity and the generalizability of the findings. An important limitation in this area of research is the noteworthy phenotypic and pathophysiological heterogeneity of metabolic and mood disorders. Although clinically useful, categorical classifications in both conditions have limited heuristic value and its use hinders a more comprehensive understanding of the association between metabolic and mood disorders. A recent trend in psychiatry is to move toward a domain specific approach, wherein psychopathology constructs are agnostic to DSM-defined diagnostic categories and, instead, there is an effort to categorize domains based on pathogenic substrates, as proposed by the National Institute of Mental Health (NIMH) Research Domain Criteria Project (RDoC). Moreover, the substrates subserving psychopathology seems to be unspecific and extend into other medical illnesses that share in common brain consequences, which includes metabolic disorders. Overall, accumulating evidence indicates that there is a consistent association of multiple abnormalities in neuropsychological constructs, as well as correspondent brain abnormalities, with broad-based metabolic dysfunction, suggesting, therefore, that the existence of a "metabolic-mood syndrome" is possible. Nonetheless, empirical evidence is necessary to support and develop this concept. Future research should focus on dimensional constructs and employ integrative, multidisciplinary and multimodal approaches.

Adiponectin and depression: A meta-analysis

Adiponectin has been indicated to be linked with depression. In the present study, a meta-analysis was performed to evaluate the association between adiponectin levels and depression. Six studies with a total of 4,220 subjects were selected for inclusion in the analysis. The references were retrieved via PubMed, Cochrane Central Register of Controlled Trials and Embase, and the following Chinese databases: The China National Knowledge Infrastructure, China Biology Medicine disc, VIP Database for Chinese Technical Periodicals and Wan Fang Data. The analyses were performed using Review Manager 5.2 software. The standardized mean difference (SMD) with 95% confidence intervals (CIs) was assessed following pooling the collected data for analysis. A significant association was detected between adiponectin levels and depression in European populations. In the European group of patients with depression, improvements were observed in adiponectin levels (SMD, -5.00 µg/ml, 95% CI, -7.13 to -2.88). The current meta-analysis indicates that patients with patients had a lower adiponectin level when compared to healthy patients in European groups.

Cytokines in bipolar disorder: paving the way for neuroprogression

Bipolar disorder (BD) is a severe, chronic, and recurrent psychiatric illness. It has been associated with high prevalence of medical comorbidities and cognitive impairment. Its neurobiology is not completely understood, but recent evidence has shown a wide range of immune changes. Cytokines are proteins involved in the regulation and the orchestration of the immune response. We performed a review on the involvement of cytokines in BD. We also discuss the cytokines involvement in the neuroprogression of BD. It has been demonstrated that increased expression of cytokines in the central nervous system in postmortem studies is in line with the elevated circulating levels of proinflammatory cytokines in BD patients. The proinflammatory profile and the immune imbalance in BD might be regarded as potential targets to the development of new therapeutic strategies.

Comparison of inflammatory cytokine levels among type I/type II and manic/hypomanic/euthymic/depressive states of bipolar disorder

OBJECTIVE

Inflammatory cytokines have been suggested to be the trait or state markers of bipolar disorder, but with inconsistent results. This may be related to small sample sizes and poor control of some important confounding factors.

METHODS

Gender/age-matched outpatients with bipolar disorder and normal controls were enrolled. The clinical symptoms were rated using the Montgomery Åsberg Depression Rating Scale and Young Mania Rating Scale. Inflammatory cytokines, including soluble interleukin-6 receptor (sIL-6R), soluble interleukin-2 receptor (sIL-2R), C-reactive protein (CRP), soluble tumor necrosis factor receptor type 1 (sTNF-R1), soluble P-selectin receptor (sP-selectin), and monocyte chemotactic protein-1 (MCP-1), were assessed by enzyme-linked immunosorbent assays.

RESULTS

In total, 130 patients with bipolar disorder and 130 normal subjects were enrolled. Among the patients with bipolar disorder, 77 (59.2%) had bipolar I disorder, 53 (40.8%) had bipolar II disorder; 75 (57.7%) were in a euthymic state, 14 (10.8%) were in a manic/hypomanic state, and 41 (31.5%) were in a depressive state. The 130 bipolar patients had significantly higher levels of all cytokines than the normal controls (all p<0.0001). Using multivariate regression analysis with controlling of age, gender, BMI, smoking, duration of illness, and medication grouping, the patients with bipolar II disorder had significantly lower levels of sTNF-R1 than the patients with bipolar I disorder (p=0.038); the patients in a depressive state had significantly lower levels of sTNF-R1 than the patients in manic/hypomanic and euthymic states (p=0.009).

CONCLUSION

The study supported the association of bipolar disorder with inflammatory dysregulation, and sTNF-R1 may be a potential biomarker for staging bipolar disorder.

Links between sleep and body mass index in bipolar disorders: an exploratory study

STUDY OBJECTIVES

Obesity and excess bodyweight are highly prevalent in individuals with bipolar disorders (BD) and are associated with adverse consequences. Multiple factors may explain increased bodyweight in BD including side effects of psychotropic medications, and reduced physical activity. Research in the general population demonstrates that sleep disturbances may also contribute to metabolic burden. We present a cross-sectional study of the associations between body mass index (BMI) and sleep parameters in patients with BD as compared with healthy controls (HC).

METHODS

Twenty-six French outpatients with remitted BD and 29 HC with a similar BMI completed a 21-day study of sleep parameters using objective (actigraphy) and subjective (PSQI: Pittsburgh Sleep Quality Index) assessments.

RESULTS

In BD cases, but not in HC, higher BMI was significantly correlated with lower sleep efficiency (P=0.009) and with several other sleep parameters: shorter total sleep time (P=0.01), longer sleep onset latency (P=0.05), higher fragmentation index (P=0.008), higher inter-day variability (P=0.05) and higher PSQI total score (P=0.004).

CONCLUSIONS

The findings suggest a link between a high BMI and several sleep disturbances in BD, including lower sleep efficiency. Physiological mechanisms in BD cases may include an exaggeration of phenomena observed in non-clinical populations. However, larger scale studies are required to clarify the links between metabolic and sleep-wake cycle disturbances in BD.

PPAR-γ agonism as a modulator of mood: proof-of-concept for pioglitazone in bipolar depression

BACKGROUND

Insulin resistance and other cardio-metabolic risk factors predict increased risk of depression and decreased response to antidepressant and mood stabilizer treatments. This proof-of-concept study tested whether administration of an insulin-sensitizing peroxisome proliferator-activated receptor (PPAR)-γ agonist could reduce bipolar depression symptom severity. A secondary objective was to determine whether levels of highly sensitive C-reactive protein and interleukin (IL)-6 predicted treatment outcome.

METHODS

Patients (n = 34) with bipolar disorder (I, II, or not otherwise specified) and metabolic syndrome/insulin resistance who were currently depressed (Quick Inventory of Depressive Symptoms [QIDS] total score ≥11) despite an adequate trial of a mood stabilizer received open-label, adjunctive treatment with the PPAR-γ agonist pioglitazone (15-30 mg/day) for 8 weeks. The majority of participants (76 %, n = 26) were experiencing treatment-resistant bipolar depression, having already failed two mood stabilizers or the combination of a mood stabilizer and a conventional antidepressant.

RESULTS

Supporting an association between insulin sensitization and depression severity, pioglitazone treatment was associated with a decrease in the total Inventory of Depressive Symptomatology (IDS-C30) score from 38.7 ± 8.2 at baseline to 21.2 ± 9.2 at week 8 (p < 0.001). Self-reported depressive symptom severity and clinician-rated anxiety symptom severity significantly improved over 8 weeks as measured by the QIDS (p < 0.001) and Structured Interview Guide for the Hamilton Anxiety Scale (p < 0.001), respectively. Functional improvement also occurred as measured by the change in total score on the Sheehan Disability Scale (-17.9 ± 3.6; p < 0.001). Insulin sensitivity increased from baseline to week 8 as measured by the Insulin Sensitivity Index derived from an oral glucose tolerance test (0.98 ± 0.3; p < 0.001). Higher baseline levels of IL-6 were associated with greater decrease in depression severity (parameter estimate β = -3.89, standard error [SE] = 1.47, p = 0.015). A positive correlation was observed between improvement in IDS-C30 score and change in IL-6 (r = 0.44, p < 0.01).

CONCLUSIONS

Open-label administration of the PPAR-γ agonist pioglitazone was associated with improvement in depressive symptoms and reduced cardio-metabolic risk. Reduction in inflammation may represent a novel mechanism by which pioglitazone modulates mood. (ClinicalTrials.gov Identifier: NCT00835120).

Decreased serum levels of adiponectin in adult attention deficit hyperactivity disorder

The main aim of this study was to investigate serum levels of adiponectin in adult patients with attention deficit hyperactivity disorder (ADHD). The second objective was to examine the effects of rare missense mutations in T-cadherin, an adiponectin receptor encoded by the ADHD candidate gene CDH13, on serum adiponectin levels. Total and high molecular weight (HMW) adiponectin levels were measured by an enzyme-linked immunosorbent assay in 44 patients and 29 controls. We found decreased serum adiponectin levels in ADHD patients. In a logistic regression model, adjusting for confounding by age, body mass index, and gender, HMW adiponectin and its ratio to total adiponectin were significantly associated with ADHD. In partial correlations, HMW adiponectin and its ratio to total adiponectin were significantly inversely correlated with self-reported psychiatric symptomatology. A non significant trend for higher levels of total adiponectin was observed in patients carrying CDH13 missense mutations compared to patients with wild type CDH13. The association of CDH13 mutations with adiponectin levels should be investigated in larger studies. This study shows that ADHD patients have decreased serum adiponectin levels, which are inversely correlated to psychiatric symptoms, suggesting a possible involvement of adiponectin, in particular the HMW form, in the pathophysiology of ADHD.