Total and differential white blood cell counts, high-sensitivity C-reactive protein, and the metabolic syndrome in non-affective psychoses

The Modulated Role of Toxoplasma gondii on Eosinophils in Psychiatric Disorders after Cannabis Cessation

The aim of our study was to evaluate the impact of T. gondii status on eosinophils count (EOS), the eosinophil-to-lymphocyte ratio (ELR), and the eosinophil-to-neutrophil-to-lymphocytes ratio (ENLR) before and after cannabis cessation in patients with psychiatric disorders. One hundred and eighty-eight patients were included in the study. T. gondii, EOS, ELR, ENLR, and urinary cannabis were measured at baseline and after 4 weeks of cannabis cessation. Highest levels and increase of PNE (p = 0.02), ENLR levels (p = 0.031) and highest level of ELR (p = 0.03) were found in patients after cannabis cessation only in patients positive for T. gondii serology (Toxo+ group). At four weeks, significant interactions between cannabis and T. gondii status for EOS (p = 0.038), and for ENLR (p = 0.043) levels were found, as well as for the evolution between baseline and 4 weeks for ENLR level (p = 0.049). After cannabis cessation, we found a positive correlation between negative symptoms and EOS levels at 4 weeks in the Toxo+ group. This study shows that the increase of inflammation after cannabis cessation might be modulated by T. gondii seropositivity status in patients after cannabis cessation.

Effects of a six-month yoga intervention on the immune-inflammatory pathway in antipsychotic-stabilized schizophrenia patients: A randomized controlled trial

BACKGROUND

Schizophrenia is a complex neuropsychiatric disorder for which several etiopathological theories have been proposed, one of the prominent ones being immune dysfunction. Recent studies on yoga as an add-on therapy have shown improvement in negative symptoms, cognition, and quality of life in schizophrenia patients. However, the biological mechanism/s of action of yoga in schizophrenia are not clear. The current study was aimed at exploring the effects of long-term (6 months) add-on yoga therapy on the immune inflammatory pathway in schizophrenia patients.

METHODS

Sixty schizophrenia patients were randomized to add-on yoga therapy (YT=30) and treatment-as-usual (TAU=30) groups of which 21 patients in YT and 20 in TAU group completed the study. Blood samples and clinical assessments were obtained at baseline and at the end of 6 months. The plasma levels of nine cytokines (IL-2, IL-4, IL-5, IL-10, IL-12(p70), IL-13, GM-CSF, IFN-γ, and TNF-α) were quantified using multiplex suspension array. The clinical assessments included SAPS, SANS, BPRS, PSS, CGI, SOFS and WHOQUOL-BREF.

RESULTS

Patients in the yoga group showed significant reductions in plasma TNF-α (Z = 2.99, p = 0.003) and IL-5 levels (Z = 2.20, p = 0.03) and greater clinical improvements in SAPS, SANS, PSS, and SOFS scores as compared to TAU group. Further, plasma TNF-α levels exhibited a positive correlation with negative symptoms (r_s =0.45, p = 0.02) and socio-occupational functioning (r_s =0.61, p = 0.002) in the YT group.

CONCLUSIONS

The findings of the study suggest that improvements in schizophrenia psychopathology with yoga interventions are associated with immuno-modulatory effects.

The chain mediating role of C-reactive protein and triglyceride-glucose index between lung function and cognitive function in a systemic low-grade inflammation state

OBJECTIVES

This study examined whether serum C-reactive protein (CRP) level and triglyceride-glucose index (TyG) explained the association between lung function and subsequent cognitive function in middle-aged and older adults with a systemic low-grade inflammation state.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

The sample consisted of 1, 742 participants recruited from the English Longitudinal Study of Ageing (ELSA).

METHODS

Lung function and covariates were measured at baseline (wave 4, 2008/09). Serum CRP level and TyG were examined at a four-year follow-up (wave 6, 2012/13). Cognitive function was assessed at eight years post baseline (wave 8, 2016/17) in the main interview. The mediation was initially assessed using multivariate linear regression models. Indirect effects were assessed using the structural equation modeling and the bootstrap method.

RESULTS

We observed that serum CRP level and TyG significantly mediated the relationships between lung function (forced expiratory volume in 1s (FEV1) and forced vital capacity (FVC)) and cognitive function (immediate recall and delay recall). Moreover, serum CRP level mediated the association between lung function (FEV1 and FVC) and TyG. Our finding also suggested that FEV1 (1.19% mediated) and FVC (1.72% mediated) might influence cognitive function partly through the chain mediating role of both serum CRP level and TyG.

CONCLUSIONS AND IMPLICATIONS

The present study revealed that serum CRP level and TyG play a chain mediating role in the relationship between lung function at baseline and subsequent cognitive impairment in a nationally representative cohort of middle-aged and older adults with a systemic low-grade inflammation state.

Could CRP be a differential biomarker of illness stages in schizophrenia? A systematic review and meta-analysis

BACKGROUND

Patients with schizophrenia display peripheral inflammation but the impact of illness phase is not clear. Our meta-analysis investigated the difference in CRP levels between patients with schizophrenia and controls according to their illness phase.

METHODS

After a systematic search, all studies measuring CRP in patients with schizophrenia and controls were included. Standardized mean differences were calculated between patients and controls according to illness phase. The influence of sociodemographic and clinical variables on our results was investigated using a meta-regression analysis.

RESULTS

Fifty studies were included in this meta-analysis. Patients with schizophrenia had higher CRP levels than controls in the acute (p < 0.00001) and stable (p < 0.00001) stage of their disease. Patients with acute exacerbation of schizophrenia had higher CRP levels than stable patients (p = 0.02) but this difference did not persist when considering antipsychotic-medicated patients in both phases. Meta-regressions found that the increase of CRP in acutely ill patients as compared to controls was influenced by age (p < 0.01), BMI (p = 0.01) and first episode (p = 0.02), whereas the increase in CRP levels of stable patients as compared to controls was moderated by BMI (p = 0.004).

CONCLUSIONS

In conclusion, this meta-analysis provides strong evidence that patients with schizophrenia have higher CRP levels than controls, but also show an increase in inflammatory response in the acute stage of the disease as compared to the stable stage. CRP could thus be considered as a state marker and a trait marker of the disease.

Immuno-metabolic profile of patients with psychotic disorders and metabolic syndrome. Results from the FACE-SZ cohort

Background

Metabolic syndrome (MetS) is a highly prevalent and harmful medical disorder often comorbid with psychosis where it can contribute to cardiovascular complications. As immune dysfunction is a key shared component of both MetS and schizophrenia (SZ), this study investigated the relationship between immune alterations and MetS in patients with SZ, whilst controlling the impact of confounding clinical characteristics including psychiatric symptoms and comorbidities, history of childhood maltreatment and psychotropic treatments.

Method

A total of 310 patients meeting DSM-IV criteria for SZ or schizoaffective disorders (SZA), with or without MetS, were systematically assessed and included in the FondaMental Advanced Centers of Expertise for Schizophrenia (FACE-SZ) cohort. Detailed clinical characteristics of patients, including psychotic symptomatology, psychiatric comorbidities and history of childhood maltreatment were recorded and the serum levels of 18 cytokines were measured. A penalized regression method was performed to analyze associations between inflammation and MetS, whilst controlling for confounding factors.

Results

Of the total sample, 25% of patients had MetS. Eight cytokines were above the lower limit of detection (LLOD) in more than 90% of the samples and retained in downstream analysis. Using a conservative Variable Inclusion Probability (VIP) of 75%, we found that elevated levels of interleukin (IL)-6, IL-7, IL-12/23 p40 and IL-16 and lower levels of tumor necrosis factor (TNF)-α were associated with MetS. As for clinical variables, age, sex, body mass index (BMI), diagnosis of SZ (not SZA), age at the first episode of psychosis (FEP), alcohol abuse, current tobacco smoking, and treatment with antidepressants and anxiolytics were all associated with MetS.

Conclusion

We have identified five cytokines associated with MetS in SZ suggesting that patients with psychotic disorders and MetS are characterized by a specific “immuno-metabolic” profile. This may help to design tailored treatments for this subgroup of patients with both psychotic disorders and MetS, taking one more step towards precision medicine in psychiatry.

Gait Alterations in the Prediction of Metabolic Syndrome in Patients With Schizophrenia: A Pilot Study With PODOSmart ® Insoles

BACKGROUND

Second-generation antipsychotics (APs) are associated with metabolic syndrome (MetS), characterized by abnormal pro-inflammatory cytokine production and oxidative stress due to the reduced antioxidant systems, and neurological effects, including mobility impairment. This pilot study investigated relationships between inflammatory-metabolic biomarkers, MetS and gait alterations in patients with psychosis treated with APs.

METHODS

Patients with psychosis treated with APs, 20 with MetS (MPS group) and 20 without MetS (PS group) were studied, usinganthropometric data, blood measurements and gait analysis performed with the PODOSmart ® gait analysis device.

RESULTS AND DISCUSSION

The MPS group had significantly higher mean body mass index (BMI) and arterial blood pressure (BP) than the PS group. PODOSmart ® gait analysis recorded significant differences between groups in pronation-supination at Heel Off (HO), gaitline HO and gaitline Toe Off (TO). Multifactorial elastic net regression models demonstrated significant association with MetS of inflammatory markers, specific AP2 treatment, gender, age; BMI; BP and smoking (accuracy λ = 0.08), and in relation to gait parameters (accuracy λ = 0.750), the three pronation- supination variables, i.e., at HO, flat foot in (AP2 related) and TO, and propulsion speed. The gait parameters were at the edges of the model, thus indicating a more significant role of these parameters compared to the other clinical variables. Early diagnosis of MetS in patients with schizophrenia via identification of gait alterations can be a screening measure for serious cardiovascular complications related to psychosis and APs, to enable timely dietary intervention that can control the pro-inflammatory state and reduce oxidative stress.

Clinical, Biochemical and Genetic Variables Associated With Metabolic Syndrome in Patients With Schizophrenia Spectrum Disorders Using Second-Generation Antipsychotics: A Systematic Review

Background: Individuals with severe mental illness experience increased morbidity and mortality compared to the general population. Adverse effects of antipsychotics, including weight gain, may contribute to the development of metabolic syndrome (MetS), which is associated with increased risks of all-cause and cardiovascular disease mortality. We aim to provide a comprehensive overview of clinical, biochemical and genetic factors associated with MetS among patients with schizophrenia spectrum disorders using second-generation antipsychotics (SGA). Methods: A literature search was performed in Pubmed and Embase to identify all cohort studies, cross-sectional studies and clinical trials investigating associations with MetS in patients with schizophrenia spectrum disorders using SGAs. We extracted and enumerated clinical, biochemical and genetic factors reported to be associated with MetS. We defined factors associated with MetS as factors being reported as associated with MetS in two or more studies. Results: 58 studies were included in this review (n = 12,123). In total, 62 factors were found to be associated with increased risk of MetS. Thirty one out of 58 studies investigated factors that were reported as associated with MetS in two or more studies. With regard to clinical factors, we found gender, higher age, concomitant use of mood stabilizers, higher baseline and current BMI, earlier SGA exposure, higher dose, longer duration of treatment, psychosis and tobacco smoking to be significantly associated with MetS. Furthermore, the biochemical factors hypo-adiponectinemia, elevated levels of C-reactive protein (CRP) and higher white blood cell (WBC) count were identified as factors associated with MetS. Among pharmacogenetic factors, the rs1414334 C-allele of the HTR2C-gene was associated with MetS in patients using SGA. Conclusion: In this systematic review investigating clinical, biochemical and genetic factors associated with MetS in patients using SGAs we found that higher age, higher baseline BMI, higher current BMI and male as well as female gender were positively associated with MetS across all antipsychotics. This study may set the stage for the application of clinical, biochemical and genetic factors to predict the risk of developing MetS in patients using SGAs. Future research is needed to determine which patients using SGAs are at risk to develop MetS in clinical practice.

C-Reactive Protein/Albumin and Neutrophil/Albumin Ratios as Novel Inflammatory Markers in Patients with Schizophrenia

OBJECTIVE

Peripheral biomarker studies in schizophrenia are insufficient to correspond to whether inflammatory markers are trait- or state-related. The main objective of this study was to compare novel biomarkers C-reactive protein/albumin ratio (CAR), neutrophil/albumin ratio (NAR), and complete blood count-derived inflammatory markers; neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), red-cell distribution width (RDW), and mean platelet volume (MPV) between patients with acutely exacerbated and remitted schizophrenia and healthy controls.

METHODS

Anonymous data of a total of 618 patients with schizophrenia (179 in remission, 439 with acute exacerbation) and 445 psychiatrically and medically healthy subjects admitted to outpatient units were included. One-way ANOVA with Tukey's HSD post-hoc test, Pearson's correlation test, receiver operating characteristic analysis, and binomial logistic regression analysis were performed.

RESULTS

CAR, NAR, NLR, PLR, MLR, RDW, MPV values were found higher in patients with schizophrenia than in healthy subjects. Except for NAR (p=0.007), none of the markers differed between acute exacerbation and remission. As a cut-off value of CAR, 0.388 differentiated patients with schizophrenia from controls (sensitivity 81%, specificity 81%). CAR, NAR, and MPV significantly predicted the diagnosis of schizophrenia.

CONCLUSION

CAR and NAR are reliable biomarkers of inflammation and a combination of inflammatory markers including CAR and NAR could be used to reflect the increased inflammatory status in schizophrenia, regardless of relapse or remission.

Meta-analysis of total and differential white blood cell counts in schizophrenia

OBJECTIVE

Schizophrenia is associated with alterations in blood inflammatory markers, including cytokines. Total white blood cell (WBC) count is a marker of low-grade inflammation. We conducted a meta-analysis of total and differential WBC counts in patients with schizophrenia.

METHOD

Articles were identified through a systematic search of PsycINFO, Pub Med, Web of Science, and the associated references. Data were analyzed using a random effects approach.

RESULTS

Twenty-four studies met the inclusion criteria. Blood total WBC, monocytes, and neutrophils were significantly higher in schizophrenia vs. controls with small-to-medium effect sizes (standardized mean difference [SMD] = 0.39-0.53, P < 0.01 for each). In first-episode psychosis compared with controls, neutrophils and monocytes were significantly increased with similar effect sizes (SMD = 0.40-0.41, P ≤ 0.01 for each), and there was a trend for higher total WBC (SMD = 0.46, P = 0.05).

CONCLUSIONS

Consistent with studies of other inflammatory markers, we found evidence for increased total and differential WBC counts in schizophrenia. Our results complement other studies of WBC counts in schizophrenia. These findings are relevant to the pathophysiology and potentially the treatment of schizophrenia.

Total and differential white blood cell counts, inflammatory markers, adipokines, and incident metabolic syndrome in phase 1 of the clinical antipsychotic trials of intervention effectiveness study

OBJECTIVE

The metabolic syndrome is highly prevalent in patients with schizophrenia. We previously found that blood C-reactive protein (CRP), interleukin-6 (IL-6), and leptin levels were predictors of current metabolic syndrome in schizophrenia. In the present study, we investigated whether baseline levels of total and differential white blood cell (WBC) counts, inflammatory markers, and adipokines predicted incident metabolic syndrome in schizophrenia.

METHOD

For subjects from the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia trial who did not have metabolic syndrome at baseline (n = 726), WBC counts, inflammatory markers, and adipokines were investigated as predictors of incident metabolic syndrome over 12 months of antipsychotic treatment. Cox proportional hazards regression models, controlling for multiple potential confounding factors, were used to investigate these associations.

RESULTS

39% of subjects (n = 280) had incident metabolic syndrome over 12 months. After controlling for potential confounders, baseline blood IL-6 (HR = 1.12, 95% CI 1.01-1.24, p = 0.031) and leptin (HR = 1.12, 95% CI 1.01-1.24, p = 0.038) were significant predictors of incident metabolic syndrome, and there was a trend-level association with CRP (HR = 1.09, 95% CI 1.00-1.19, p = 0.059).

CONCLUSIONS

Our findings provide additional evidence that measurement of inflammatory markers and adipokines are germane to the clinical care of patients with schizophrenia. Specifically, these markers may identify-prior to treatment-patients with schizophrenia at heightened risk for incident adverse cardiometabolic effects of antipsychotics. Given the tremendous burden of cardiovascular disease morbidity and mortality in schizophrenia, vigilant screening for and treatment of metabolic risk factors in this patient population are warranted.

C-Reactive Protein: Higher During Acute Psychotic Episodes and Related to Cortical Thickness in Schizophrenia and Healthy Controls

There is increasing evidence for the role of inflammation in schizophrenia, yet the stability of increased peripheral inflammation in acute psychosis and the degree to which peripheral inflammation relates to cortical thickness, a measure of the degree of neuropathology, are unknown. In independent samples, we assessed the peripheral inflammation marker C-reactive protein (CRP) to determine the extent to which: (1) CRP was elevated and stable across admissions for acute psychosis, (2) cognition, daily function and symptom severity are characteristic of chronically ill patients with schizophrenia displaying elevated CRP, and (3) CRP levels predict cortical thickness. Study 1 assessed peripheral CRP (primary outcome) and other blood measures in 174/280 people with acute psychosis while Study 2 assessed peripheral CRP, cognition and cortical thickness (primary outcomes), symptoms, and daily function in 85/97 chronically ill patients with schizophrenia and 71/87 healthy controls. In acute psychosis, CRP and neutrophil-to-lymphocyte ratio were significantly elevated relative to a normal cutoff (with 59.8% of patients having elevated CRP) which remained elevated across admissions. CRP was significantly elevated in 43% of chronically ill patients with schizophrenia compared to 20% in controls. Elevated CRP patients displayed significantly worse working memory and CRP was inversely correlated with cortical thickness in frontal, insula, and temporal brain regions. This work supports the role of inflammation in psychotic illnesses and suggests that use of peripheral markers (e.g., CRP) in conjunction with diagnosis could be used to identify patients with more cortical neuropathology and cognitive deficits.

Relation of inflammatory markers with symptoms of psychotic disorders: a large cohort study

AIMS

Immunological mechanisms may play a role in symptomatology of patients with a psychotic disorder. Besides metabolic problems and medication use, inflammatory processes that may occur due to the disorder may cause increased inflammatory markers and concurrent psychiatric symptoms. The aim of this study is to investigate whether levels of C-reactive protein (CRP) and white blood cell count (WBC) are related to positive and negative symptoms of psychotic disorders, and whether age, gender, duration of illness, smoking behavior, haloperidol equivalents, mediation use, body mass, and metabolic syndrome affect this relation.

METHODS

CRP and WBC values of 2123 patients with a psychotic disorder were related to positive and negative symptoms measured with a psychiatric interview. CRP was analyzed by survival analysis accounting for detection limit and WBC by linear mixed model analysis. In case of a significant association, the confounding factors were added to the model.

RESULTS

Both WBC and CRP were related to both positive and negative symptoms, even after correction for age, gender, smoking, use of medication and metabolic problems. Of the covariates, gender, metabolic problems, smoking and statins also showed a strong association with inflammatory markers.

CONCLUSIONS

This study in a large patient-group confirmed that inflammatory markers are related to psychotic disorders, particularly negative symptoms. Future studies could use more precise measures of inflammatory markers and measure symptomatic state at specific moments in illness progression.

A probe in the connection between inflammation, cognition and suicide

BACKGROUND

Increased inflammation is linked to suicide risk. However, it is unclear whether increased inflammation drives suicidal crises or is a trait associated with lifetime suicidal behavior. Limited data exist on the sources of increased inflammation observed in suicidal patients and on its downstream effects.

AIMS

To examine factors associated with inflammation and with suicidal ideation severity in acutely suicidal depressed patients.

METHODS

Fifty-two adult depressed patients of both sexes hospitalized for severe suicidal ideation were characterized for suicidality, depression, anxiety, medical comorbidity, psychological and physical pain, impulsivity, verbal fluency, C-reactive protein (CRP) and interleukin (IL) 6. Two generalized linear models were performed with either CRP or suicidal ideation severity as dependent variables.

RESULTS

CRP levels were positively associated with age, body mass index (BMI), IL6, current physical pain and number of lifetime suicide attempts. Suicidal ideation severity was not significantly correlated with either CRP or IL6. Suicidal ideation severity was positively associated with female sex, presence of an anxiety disorder, current physical pain, number of lifetime suicide attempts and with delay discounting for medium and large losses.

CONCLUSIONS

Increased inflammation is not associated with acute suicidal risk, but seems to represent a trait associated with lifetime suicidal behavior.

Total and differential white blood cell counts and hemodynamic parameters in first-episode psychosis

There is evidence for blood inflammatory abnormalities in patients with first-episode psychosis (FEP). The monocyte- and neutrophil-to-lymphocyte ratios (MLR; NLR) are markers of inflammation and endothelial dysfunction, and predictors of cardiovascular disease, the leading cause of death in schizophrenia. We investigated relationships between white blood cell (WBC) counts and hemodynamic parameters associated with cardiovascular disease risk in 25 subjects age 18-50 hospitalized for FEP and 44 controls. Subjects had a blood draw, vital signs, and medical history. Patients with FEP had significantly higher NLR, MLR, pulse pressure, and rate pressure product (RPP) than controls (p < 0.05 for each), after controlling for potential confounders. In linear regression analyses, higher monocytes were a significant predictor of higher pulse pressure (p = 0.033) and higher MLR predicted RPP at the trend level (p = 0.051) in FEP, after controlling for potential confounders. To our knowledge, ours is the first report of increased RPP, a measure of myocardial workload, in FEP. We also replicated findings of increased NLR, MLR and pulse pressure in FEP. Our findings underscore that measurement of routine vital signs and blood total and differential WBC counts are germane to the clinical care of patients with psychosis as markers of cardiovascular disease risk.

C-Reactive Protein as a Peripheral Biomarker in Schizophrenia. An Updated Systematic Review

Objectives: The objective of this systematic review was to synthetize the published data on the relationships between elevated blood C-reactive protein (CRP) levels and schizophrenia (SZ) onset risk, illness characteristics and treatments, cognition and physical health. Method: The systematic bibliographic searches have been carried out according to the Cochrane methodology. Medline, web of science, Google Scholar with each database being searched from inception to November 2017. Results: 53 studies were included in the present review. While meta-analyses including case-control studies suggest a clear association between CRP and SZ, one other study has suggested that CRP-associated genes were associated with a lower risk of SZ onset. Increased CRP has been significantly associated with positive symptoms in acute phase psychosis, while studies including community-dwelling stabilized subjects did not find such an association. Abnormal CRP has been associated with a wide range of cognitive impairment in SZ stabilized individuals. Body Mass index has been extensively associated with increased CRP in SZ subjects; and increased CRP has been identified as a risk factor for metabolic syndrome and cardiovascular risk in SZ subjects. Increased CRP has also been associated with high nicotine dependence in SZ smokers and one study has suggested that increased CRP was associated with sedentary behavior. Conclusion: In the light of the above-mentioned studies, increased hs-CRP may be reasonably suggested as a marker for SZ onset risk, as well as a risk factor for increased positive symptoms, cognitive impairment, hypovitaminosis D, microbiota disturbances, cardiovascular and metabolic syndrome risk in SZ subjects, and increased nicotine dependence in SZ smokers. In case of increased CRP levels, anti-inflammatory strategies (add-on anti-inflammatory drugs including aspirin and omega 3 fatty acids, vitamin D supplementation, physical activity, probiotics) should be also further evaluated. Limits: Most of the studies were cross-sectional and cohort studies are needed to determine the temporal relationship between increased CRP and the psychiatric outcomes.

Unrecognized Prevalence of Macrocytosis among the Patients with First Episode of Psychosis and Depression

BACKGROUND

Mood disorders and psychosis has been reported among the patients with macrocytosis; however, its prevalence among the first episode of psychosis and depression is unknown. The purpose of the study was to establish the prevalence of macrocytosis among the patients with the first episode of depression and psychosis.

MATERIALS AND METHODS

In this cross-sectional study, three groups comprising patients with first episode of depression (n = 100), patients with the first episode of psychosis (n = 100), and healthy controls (n = 100) were included. Blood samples were collected from each participant and analyzed using the automated coulter counter. The hematological variables (e.g., macrocytosis, anemia) in the three groups were compared using the Chi-square and analysis of variance tests.

RESULTS

The prevalence of macrocytosis among patients with depression and psychosis was 2.6 (8%) and 3.3 times (11%) higher, respectively than that among the healthy controls (3%). In addition, the hemoglobin concentration, mean corpuscular volume and mean platelet volume in patients with first episodes of psychosis and depression significantly differed from those in healthy controls P < 0.001.

CONCLUSION

This study showed that the prevalence of macrocytosis among the first episode of depression and psychosis was higher than healthy controls. Macrocytosis may have etiological and prognostic significance among these patients. Prospective studies are needed to explore the clinical significance of macrocytosis among the patients with depression and psychosis in the clinical practice.

The Gut Microbiota and the Emergence of Autoimmunity: Relevance to Major Psychiatric Disorders

BACKGROUND

Autoimmune phenotypes are prevalent in major psychiatric disorders. Disequilibria of cellular processes occurring in the gastrointestinal (GI) tract likely contribute to immune dysfunction in psychiatric disorders. As the venue of a complex community of resident microbes, the gut in a homeostatic state equates with a functional digestive system, cellular barrier stability and properly regulated recognition of self and non-self antigens. When gut processes become disrupted as a result of environmental or genetic factors, autoimmunity may ensue.

METHODS

Here, we review the issues pertinent to autoimmunity and the microbiome in psychiatric disorders and show that many of the reported immune risk factors for the development of these brain disorders are in fact related and consistent with dysfunctions occurring in the gut. We review the few human microbiome studies that have been done in people with psychiatric disorders and supplement this information with mechanistic data gleaned from experimental rodent studies.

RESULTS

These investigations demonstrate changes in behavior and brain biochemistry directly attributable to alterations in the gut microbiome. We present a model by which autoantigens are produced by extrinsicallyderived food and microbial factors bound to intrinsic components of the gut including receptors present in the enteric nervous system.

CONCLUSION

This new focus on examining activities outside of the CNS for relevance to the etiology and pathophysiology of psychiatric disorders may require new modalities or a re-evaluation of pharmaceutical targets found in peripheral systems.

Associated illness severity in schizophrenia and diabetes mellitus: A systematic review

OBJECTIVE

We aimed to elucidate whether schizophrenia and type II diabetes mellitus may present with associated illness severity, in light of accumulating evidence to suggest both conditions have important shared inflammatory components with many shared inflammatory genetic factors.

METHODS

We conducted a systematic review employing PRISMA criteria, searching EMBASE, Ovid MEDLINE, PsychInfo, Web of Science and Google Scholar to February 1st, 2017, for clinical studies assessing schizophrenia severity alongside dysglycaemia. A narrative synthesis was employed to discuss and compare findings between studies.

RESULTS

Eleven observational studies were included in the analysis. Ten presented evidence in support of an association between schizophrenia severity and dysglycaemia. This association appeared particularly strong regarding negative symptomatology and impaired cognitive function, between which there may be some overlap. Studies examining positive symptomatology returned mixed results.

CONCLUSION

Whilst study design varied amongst the included studies, the results suggest that further work examining the effect of hyperglycaemia on schizophrenia severity may be relevant, particularly longitudinal studies assessing negative symptomatology and cognitive function. To the authors' knowledge, this is the first systematic review conducted to address this question.

Towards an Immunophenotype of Schizophrenia: Progress, Potential Mechanisms, and Future Directions

The evidence to date, coupled with advances in immunology and genetics has afforded the field an unparalleled opportunity to investigate the hypothesis that a subset of patients with schizophrenia may manifest an immunophenotype, toward new potential diagnostics and therapeutics to reduce risk, alleviate symptoms, and improve quality of life in both at-risk populations and patients with established schizophrenia. In this paper, we will first summarize the findings on immune dysfunction in schizophrenia, including (1) genetic, prenatal, and premorbid immune risk factors and (2) immune markers across the clinical course of the disorder, including cytokines; C-reactive protein; immune cells; antibodies, autoantibodies and comorbid autoimmune disorders; complement; oxidative stress; imaging of neuroinflammation; infections; and clinical trials of anti-inflammatory agents and immunotherapy. We will then discuss a potential mechanistic framework toward increased understanding of a potential schizophrenia immunophenotype. We will then critically appraise the existing literature, and discuss suggestions for the future research agenda in this area that are needed to rigorously evaluate this hypothesis.

Serum high-sensitivity C-reactive protein: A delicate sentinel elevated in drug-free acutely agitated patients with schizophrenia

Increased levels of high-sensitivity C reactive protein (hsCRP) have been reported in schizophrenia, but to date, no study is designed to examine serum hsCRP in acutely agitated patients with schizophrenia, an extreme state that requires immediate diagnosis and medical treatment. Serum hsCRP levels were assessed in 32 clinically acutely agitated patients and 42 healthy control subjects matched for demographic properties. Further, serum hsCRP levels in acutely agitated patients were compared with control subjects and with the levels after the patients were treated with anti-psychiatric medications. Meanwhile, the influence of clinical subtypes, family history, and gender, as well as the levels of white blood cell (WBC) counts were also considered. In results, serum hsCRP levels were significantly higher in acutely agitated patients with schizophrenia than in healthy subjects. The elevation of serum hsCRP in patients was not affected by gender, family history (P>0.05), and clinical classification of schizophrenia (P>0.05). However, the elevation of hsCRP was suppressed by the medical treatment for schizophrenia with acute agitation (P<0.05). In addition, WBC counts, another inflammation-related indicator, were also increased significantly in acutely agitated patients compared with healthy subjects, consistent with the elevation of serum hsCRP. In conclusion, hsCRP is an important indicator of immune alterations in the pathogenesis of schizophrenia and has potential to be developed into a sensitive marker for the acute agitation in schizophrenia.

Autoimmune diseases, gastrointestinal disorders and the microbiome in schizophrenia: more than a gut feeling

Autoimmunity, gastrointestinal (GI) disorders and schizophrenia have been associated with one another for a long time. This paper reviews these connections and provides a context by which multiple risk factors for schizophrenia may be related. Epidemiological studies strongly link schizophrenia with autoimmune disorders including enteropathic celiac disease. Exposure to wheat gluten and bovine milk casein also contribute to non-celiac food sensitivities in susceptible individuals. Co-morbid GI inflammation accompanies humoral immunity to food antigens, occurs early during the course of schizophrenia and appears to be independent from antipsychotic-generated motility effects. This inflammation impacts endothelial barrier permeability and can precipitate translocation of gut bacteria into systemic circulation. Infection by the neurotropic gut pathogen, Toxoplasma gondii, will elicit an inflammatory GI environment. Such processes trigger innate immunity, including activation of complement C1q, which also functions at synapses in the brain. The emerging field of microbiome research lies at the center of these interactions with evidence that the abundance and diversity of resident gut microbiota contribute to digestion, inflammation, gut permeability and behavior. Dietary modifications of core bacterial compositions may explain inefficient gluten digestion and how immigrant status in certain situations is a risk factor for schizophrenia. Gut microbiome research in schizophrenia is in its infancy, but data in related fields suggest disease-associated altered phylogenetic compositions. In summary, this review surveys associative and experimental data linking autoimmunity, GI activity and schizophrenia, and proposes that understanding of disrupted biological pathways outside of the brain can lend valuable information regarding pathogeneses of complex, polygenic brain disorders.

Association between C-reactive protein and suicidal behavior in an adult inpatient population

OBJECTIVES

To examine the relationship of inflammation and suicidal behavior in hospitalized adult psychiatric patients.

METHOD

We retrospectively examined serum high sensitivity C-reactive protein (hsCRP) levels in inpatients at a tertiary-level university hospital (N = 184). The inpatients comprised three cohorts: 1) patients admitted following a suicide attempt, 2) patients with suicidal ideation, and 3) inpatient psychiatric controls. Additionally, we gathered demographic data, clinical data, smoking status, white blood cell count, and fasting lipid panel.

RESULTS

As CRP level increased, the probability of patients belonging to the suicide attempt group increased as compared to both the probabilities of being in inpatient psychiatric control and or suicide ideation groups [OR = 2.09, CI = (1.29, 3.38) and OR = 1.75, CI = (1.15, 2.66) respectively]. We also observed a significant effect of depression in that depressed patients were more likely to have a suicide attempt when compared to patients with no depression or with mania [OR = 10.38, CI = (1.97, 54.70)].

CONCLUSIONS

There seems to be an inflammation gradient, measured by CRP levels, from recent suicide attempters, suicidal ideators and psychiatric controls. We replicated the association between a pro-inflammatory state and suicidal behavior in a sample of "real world" severely ill psychiatric inpatients.

Role of Immune and Autoimmune Dysfunction in Schizophrenia

In this chapter, we review data in support of the concept that immune system dysregulation is the most plausible explanation that reconciles gene by environmental interactions in schizophrenia. Early investigations of this topic demonstrated aspects of aberrant activation of humoral immunity, including autoimmunity, associated with schizophrenia, whereas current research efforts have expanded this theme to include elements of innate immunity. Advances in our understanding of inflammation and molecules of both the adaptive and innate immune system and their functional roles in standard brain physiology provide an important context by which schizophrenia might arise as the result of the coupling of immune and neurodevelopmental dysregulation.

Total and differential white blood cell counts, inflammatory markers, adipokines, and the metabolic syndrome in phase 1 of the clinical antipsychotic trials of intervention effectiveness study

OBJECTIVE

The metabolic syndrome is highly prevalent in patients with schizophrenia, and is associated with a state of chronic, low-grade inflammation. We investigated relationships between total and differential white blood cell (WBC) counts, inflammatory markers, adipokines and the metabolic syndrome in patients with schizophrenia.

METHOD

For subjects with available data from the baseline/screening visit of the Clinical Antipsychotic Trials of Intervention Effectiveness (CATIE) schizophrenia trial, WBC counts, inflammatory markers, and adipokines were investigated as predictors of the metabolic syndrome (and its components), using linear and binary logistic regression models, controlling for potential confounding effects of age, sex, race, smoking, fasting status, alcohol, and illicit drug use.

RESULTS

After controlling for potential confounders, blood CRP, interleukin-6, and leptin were significant predictors of all five individual components of the metabolic syndrome (as both continuous and categorical outcome measures). Furthermore, total WBC (OR=2.31, 95% CI 1.58-3.41, p<0.01) and lymphocyte (OR=2.51, 95% CI 1.75-3.60, p<0.01) counts were the strongest predictors of current metabolic syndrome.

CONCLUSIONS

Our findings provide the strongest evidence to date that measurement of total and differential WBC counts are germane to the clinical care of patients with schizophrenia, and that inflammation and adipokines are associated with metabolic disturbance in these patients.

Inflammation and metabolic changes in first episode psychosis: preliminary results from a longitudinal study

Metabolic abnormalities are commonly observed in patients with psychosis, and may confer greater risk of developing cardiovascular disease later in life. Such abnormalities are associated with inflammation in the general population, and there is increasing evidence for elevated inflammation in patients with first episode psychosis (FEP). The aim of this preliminary study is to examine the effect of changes in inflammation, as measured by high-sensitivity C-reactive protein (hsCRP), on metabolic changes in a three-month longitudinal study in a FEP sample. Fifty-three FEP patients from in- and out-patient services in South London, England, were included in this longitudinal study. Social and clinical data were collected, and fasting blood samples and anthropometric measurements (weight, Body Mass Index (BMI), lipid profile and gluco-metabolic parameters) were obtained at baseline and at three-month follow-up. Correlation analyses showed that those with increases in hsCRP over the three-month period also had increases in triglyceride levels (r=0.49, p=0.02). No association was observed with other lipid profile, or gluco-metabolic parameters, across the whole sample. Increases in weight and BMI were also associated with increases in triglyceride levels (r=0.33, p=0.02; and r=0.31, p=0.03, respectively); however, a multiple linear regression analysis found that the effects of inflammation on triglycerides were independent from the effect of changes in weight, and from the baseline inflammatory state. Our preliminary findings suggest that those patients experiencing greater increases in inflammation early on in the course of their illness may be at greater risk of developing short-term metabolic abnormalities, in particular dyslipidaemia, independent of weight-gain. Future work should investigate the use of inflammatory markers to identify patients in greater need of physical health interventions.

Schizoaffective disorder and metabolic syndrome: A meta-analytic comparison with schizophrenia and other non-affective psychoses

People with psychotic disorders, including schizophrenia (SCZ), schizoaffective disorder (SD), or other non-affective psychoses (ONAP), have a higher risk of metabolic syndrome (MetS) than general population. However, previous meta-analyses failed to explore if people with SD are more likely to suffer from MetS than SCZ and ONAP. We carried out a systematic review and meta-analysis comparing rates of MetS in SD with those in SCZ or ONAP. We searched main electronic databases for relevant articles published up to January 2015, and for unpublished data, contacting corresponding authors, to minimize selective reporting bias. Odds ratios (ORs) based on random effects models, with 95% confidence intervals (CIs), and heterogeneity (I(2)), were estimated. We performed leave-one-out, quality-based, and subgroups analyses to check findings validity. Testing for publication bias, Egger's test estimates were reported. We included 7616 individuals (1632 with SD and 5984 with SCZ/ONAP) from 30 independent samples. SD, as compared with SCZ/ONAP, had a random-effect pooled OR (95%CI) for MetS of 1.41 (1.23-1.61; p < 0.001; I(2) = 5%). No risk of publication bias was found (p = 0.85). Leave-one-out, sensitivity, and subgroups analyses confirmed the association. To our knowledge, this is the first meta-analysis comparing MetS comorbidity between individuals with SD and those with SCZ or ONAP. SD subjects are more likely to suffer from MetS, with consistent findings across the studies included. However, the role of explanatory factors of this association, and the relative contribution of MetS subcomponents, deserve further research.

Elevated C-reactive protein is associated with sensory gating deficit in schizophrenia

Sensory and cognitive impairments and inflammatory processes are contributing factors to the pathogenesis of schizophrenia. A previous study found that an elevated CRP level (≥5mg/L) was associated with higher cognitive impairments in schizophrenia. We aimed to investigate the association between an elevated CRP level and sensory impairments defined by a sensory gating deficit (abnormal P50 suppression) in 55 outpatients. Fifteen patients (27.3%) had an elevated CRP level that was associated with higher rate of sensory gating deficit (60% vs. 12.5%, p<0.001). This is the first study suggesting a relationship between sensory gating deficit and inflammatory processes in schizophrenia.

Total and differential white blood cell counts, high-sensitivity C-reactive protein, and cardiovascular risk in non-affective psychoses

Schizophrenia is associated with increased cardiovascular disease morbidity and mortality. Schizophrenia is also associated with immune and inflammatory abnormalities, including aberrant blood levels of lymphocytes, cytokines and high-sensitivity C-reactive protein (hsCRP). The purpose of this study is to investigate the relationship between total and differential white blood cell (WBC) counts, hsCRP, and indices of cardiovascular disease risk in patients with schizophrenia and related non-affective psychoses. 108 inpatients and outpatients age 18-70 with non-affective psychoses and 44 controls participated in this cross-sectional study. Subjects had a fasting blood draw between 8 and 9am for glucose, lipids, total and differential WBC counts, and hsCRP. Vital signs and medical history were obtained. Patients with non-affective psychosis had significantly higher hsCRP levels than controls (p=0.04). In linear regression analyses, lymphocyte and monocyte counts were a significant predictor of the total-to-HDL cholesterol ratio in subjects with non-affective psychosis (p⩽0.02 for each). In binary logistic regression analyses, total WBC count was a significant predictor of an elevated 10-year estimated risk of myocardial infarction and cardiovascular disease in subjects with non-affective psychosis (p⩽0.03 for each). Associations between total and differential WBC counts and cardiovascular disease risk indices were stronger in males than females with non-affective psychosis. Our findings provide further evidence that measurement of total and differential WBC counts may be germane to the clinical care of patients with schizophrenia and related disorders, and support an association between inflammation and cardiovascular disease risk in these patients.

IgG dynamics of dietary antigens point to cerebrospinal fluid barrier or flow dysfunction in first-episode schizophrenia

Schizophrenia is a complex brain disorder that may be accompanied by idiopathic inflammation. Classic central nervous system (CNS) inflammatory disorders such as viral encephalitis or multiple sclerosis can be characterized by incongruent serum and cerebrospinal fluid (CSF) IgG due in part to localized intrathecal synthesis of antibodies. The dietary antigens, wheat gluten and bovine milk casein, can induce a humoral immune response in susceptible individuals with schizophrenia, but the correlation between the food-derived serological and intrathecal IgG response is not known. Here, we measured IgG to wheat gluten and bovine milk casein in matched serum and CSF samples from 105 individuals with first-episode schizophrenia (n=75 antipsychotic-naïve), and 61 controls. We found striking correlations in the levels of IgG response to dietary proteins between serum and CSF of schizophrenia patients, but not controls (schizophrenia, R(2)=0.34-0.55, p⩽0.0001; controls R(2)=0.05-0.06, p>0.33). A gauge of blood-CSF barrier permeability and CSF flow rate, the CSF-to-serum albumin ratio, was significantly elevated in cases compared to controls (p⩽0.001-0.003). Indicators of intrathecal IgG production, the CSF IgG index and the specific Antibody Index, were not significantly altered in schizophrenia compared to controls. Thus, the selective diffusion of bovine milk casein and wheat gluten antibodies between serum and CSF in schizophrenia may be the function of a low-level anatomical barrier dysfunction or altered CSF flow rate, which may be transient in nature.

Schizophrenia and the gut-brain axis

Several risk factors for the development of schizophrenia can be linked through a common pathway in the intestinal tract. It is now increasingly recognized that bidirectional communication exists between the brain and the gut that uses neural, hormonal, and immunological routes. An increased incidence of gastrointestinal (GI) barrier dysfunction, food antigen sensitivity, inflammation, and the metabolic syndrome is seen in schizophrenia. These findings may be influenced by the composition of the gut microbiota. A significant subgroup of patients may benefit from the initiation of a gluten and casein-free diet. Antimicrobials and probiotics have therapeutic potential for reducing the metabolic dysfunction and immune dysregulation seen in patients with schizophrenia.

Cytokine and adipokine alterations in patients with schizophrenia treated with clozapine

Metabolic syndrome is associated with both schizophrenia and antipsychotic medication, especially clozapine, with alterations in inflammatory cytokines and adipokines. However, the data in this field is heterogeneous and the sample sizes of the patients are limited. In this study we assessed the serum levels of cytokines/adipokines IL-6, IL-1Ra, hs-CRP and adiponectin, and components of metabolic syndrome in 190 patients with treatment resistant schizophrenia treated with clozapine. Substantial metabolic comorbidity was found in this patient group; overweight/obesity, smoking, hypertriglyceridemia, low HDL-cholesterol, high HOMA-IR, low adiponectin levels, elevated hs-CRP levels and elevated IL-1Ra levels. Elevated IL-1Ra levels are associated with insulin resistance, obesity and hypertriglyceridemia. Low adiponectin levels were associated with hypertriglyceridemia, low HDL cholesterol and high glucose, and in male patients also with obesity and high IL-1Ra levels. After controlling for confounding factors age and smoking, levels of IL-1Ra and hs-CRP associated with obesity, and the levels of IL-6 associated with obesity in female patients. We conclude that there are partly gender dependent cytokine and adipokine alterations in patients with schizophrenia on clozapine treatment associated with metabolic comorbidity. The genetic background of these cytokine alterations needs to be further investigated.

Inflammation and the two-hit hypothesis of schizophrenia

The high societal and individual cost of schizophrenia necessitates finding better, more effective treatment, diagnosis, and prevention strategies. One of the obstacles in this endeavor is the diverse set of etiologies that comprises schizophrenia. A substantial body of evidence has grown over the last few decades to suggest that schizophrenia is a heterogeneous syndrome with overlapping symptoms and etiologies. At the same time, an increasing number of clinical, epidemiological, and experimental studies have shown links between schizophrenia and inflammatory conditions. In this review, we analyze the literature on inflammation and schizophrenia, with a particular focus on comorbidity, biomarkers, and environmental insults. We then identify several mechanisms by which inflammation could influence the development of schizophrenia via the two-hit hypothesis. Lastly, we note the relevance of these findings to clinical applications in the diagnosis, prevention, and treatment of schizophrenia.

A meta-analysis of cardio-metabolic abnormalities in drug naïve, first-episode and multi-episode patients with schizophrenia versus general population controls

A meta-analysis was conducted to explore the risk for cardio-metabolic abnormalities in drug naïve, first-episode and multi-episode patients with schizophrenia and age- and gender- or cohort-matched general population controls. Our literature search generated 203 relevant studies, of which 136 were included. The final dataset comprised 185,606 unique patients with schizophrenia, and 28 studies provided data for age- and gender-matched or cohort-matched general population controls (n=3,898,739). We found that multi-episode patients with schizophrenia were at increased risk for abdominal obesity (OR=4.43; CI=2.52-7.82; p<0.001), hypertension (OR=1.36; CI=1.21-1.53; p<0.001), low high-density lipoprotein cholesterol (OR=2.35; CI=1.78-3.10; p<0.001), hypertriglyceridemia (OR=2.73; CI=1.95-3.83; p<0.001), metabolic syndrome (OR=2.35; CI=1.68-3.29; p<0.001), and diabetes (OR=1.99; CI=1.55-2.54; p<0.001), compared to controls. Multi-episode patients with schizophrenia were also at increased risk, compared to first-episode (p<0.001) and drug-naïve (p<0.001) patients, for the above abnormalities, with the exception of hypertension and diabetes. Our data provide further evidence supporting WPA recommendations on screening, follow-up, health education and lifestyle changes in people with schizophrenia.

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

Bipolar disorder is now known to be associated not only with highly prevalent co-occurring psychiatric and substance use disorders but also with medical comorbidities, such as cardiovascular diseases, diabetes mellitus, obesity and thyroid dysfunction. Inflammatory disturbances repeatedly observed in bipolar disorder, can explain some of the comorbidity between bipolar disorder and medical disorder. This revised perspective of bipolar disorders should promote the development of therapeutic tools. Immuno-inflammatory dysfunction may well represent a significant component of the underlying pathophysiology of the disorder. We therefore propose to review the immuno-inflammatory hypothesis in bipolar disorder considering the co-occurence with autoimmune diseases, immunological and inflammatory markers, as well as immuno-genetic markers which could lead to personalized treatments.

Discordant patterns of bacterial translocation markers and implications for innate immune imbalances in schizophrenia

The origin of inflammation in psychiatric disorders is not well understood. The translocation of commensal microbiota across the gastrointestinal barrier can result in a persistent state of low-grade immune activation and/or inflammation. We measured serological surrogate markers of bacterial translocation (soluble CD14 (sCD14) and lipopolysaccharide binding protein (LBP)) in two psychiatric cohorts and compared these levels to C-reactive protein (CRP), body mass index (BMI), and food-related and autoimmune antibodies. The two cohorts were composed of the following: (1) n=141 schizophrenia, n=75 bipolar disorder, n=78 controls; (2) n=78 antipsychotic-naïve first-episode schizophrenia, n=38 medicated first-episode schizophrenia. sCD14 seropositivity conferred a 3.1-fold increased odds of association with schizophrenia (multivariate regressions, OR=3.09, p<0.0001) compared to controls. Case-control differences in sCD14 were not matched by LBP. Quantitative levels of LBP, but not sCD14, correlated with BMI in schizophrenia (R(2)=0.21, p<0.0001). sCD14 and LBP also exhibited some congruency in schizophrenia with both significantly correlated with CRP (R(2)=0.26-0.27, p<0.0001) and elevated in females compared to males (p<0.01). Antipsychotic treatment generally did not impact sCD14 or LBP levels except for significant correlations, especially sCD14, with gluten antibodies in antipsychotic-naïve schizophrenia (R(2)=0.27, p<0.0001). In bipolar disorder, sCD14 levels were significantly correlated with anti-tissue transglutaminase IgG (R(2)=0.37, p<0.001). In conclusion, these bacterial translocation markers produced discordant and complex patterns of activity, a finding that may reflect an imbalanced, activated innate immune state. Whereas both markers may upregulate following systemic exposure to Gram-negative bacteria, non-lipopolysaccharide-based monocyte activation, autoimmunity and metabolic dysfunction may also contribute to the observed marker profiles.

Differential correlations between plasma oxytocin and social cognitive capacity and bias in schizophrenia

Social cognitive impairment is related to poor social functioning in schizophrenia. This impairment includes both deficits in emotion perception and theory of mind (ToM), and cognitive biases including attributional bias and jumping to conclusions. Oxytocin (OXT) is a hormone that has been implicated in human social behavior, and that has also been associated with regulation of inflammation. In a cross-sectional study involving 60 patients with schizophrenia and 20 healthy controls, we examined associations between OXT and social cognitive capacity and bias. Secondary analyses examined associations between OXT and inflammation. We found significant correlations between OXT and social cognitive bias in the control group and in patients with delusions, but not in patients without delusions. Social cognitive capacity only correlated significantly with OXT in patients with delusions. A correlation between OXT and inflammation was observed only in patients without delusions. Findings suggest that OXT may be implicated in social cognition both in controls and in patients with delusions, but that this association may be blunted in patients without delusions. Inflammation appears to be related to OXT rather independently of social cognition. Future longitudinal and intervention studies with OXT are needed to clarify causality in the identified associations.

Malaise, melancholia and madness: the evolutionary legacy of an inflammatory bias

Evolutionary imperatives bred a vigorous and highly orchestrated behavioral and immune response to the microbial world that served to promote species survival and propagation. The resultant legacy is an inflammatory bias which goes largely unchecked in the modern world and is provoked not only by pathogens but also now by people. In this commentary, the authors' contributions to the special issue on Inflammation and Mental Health are described, beginning with the origins of the inflammatory bias, its roots in genetic predispositions to behavioral adaptations and ultimately maladaptations, and its consequences on the developing brain. In addition, the mechanisms by which the immune system engages behavior are described including a central role for the inflammasome which may serve to link psychological stress with inflammatory and behavioral responses. Neurotransmitter systems that mediate effects of the immune system on behavior are also described along with interactions of the inflammatory bias with depression and their convergent impact on the response to stress and medical illness. Finally, translational implications are discussed including data from a clinical trial using a cytokine antagonist in depressed patients, which suggests an interaction of the inflammatory bias with other evolutionary legacies including those related to food consumption and their modern consequences of obesity and the metabolic syndrome. Taken together, the articles offer a sampling of the rich literature that has evolved regarding the role of the immune system in behavioral disorders. The grounding of this relationship in our evolutionary past may serve to inform future research both theoretically and therapeutically.

Metabolic syndrome in schizophrenia

To review the data with respect to prevalence of metabolic syndrome (MetS) and its correlates in schizophrenia. For this review, electronic search engines PUBMED, Sciencedirect, and Google Scholar were used. Available data suggests that most of the studies have been of cross-sectional design. Prevalence rates of MetS have varied from 11% to 69% in medicated patients, and 4-26% in drug naive patients in cross-sectional evaluations. Longitudinal studies have shown the prevalence rates to range from 0% to 14% at the baseline in drug naive patients, which increase to as high as 52.4% by 3 months of antipsychotic medication treatment. The prevalence rates of MetS in patients with schizophrenia are much higher than that seen in general population or healthy controls. Though there is no causal association with any demographic or clinical variables, the risk increases with increase in age. Among antipsychotics, there seems to be an association between MetS and atypical antipsychotics like clozapine and olanzapine. Therefore, the psychiatrists should be more vigilant regarding the presence of MetS in these high risk groups. Research on biological correlates of MetS in schizophrenia is still in its primitive stage, however, these is some evidence to suggest an association of MetS with adiponectin levels, hematological indices, methylenetetrahydrofolate reductase (MTHFR) and Alpha-1A adrenergic receptor (ADRA1A) gene. These areas hold promise, and targeting these with appropriate interventions may help us to prevent the occurrence of MetS in patients with schizophrenia in future.