The metabolic syndrome in schizophrenia: is inflammation a contributing cause?

Dopamine D2 Receptor Signaling in the Nucleus Accumbens Comprises a Metabolic-Cognitive Brain Interface Regulating Metabolic Components of Glucose Reinforcement

Appetitive drive is influenced by coordinated interactions between brain circuits that regulate reinforcement and homeostatic signals that control metabolism. Glucose modulates striatal dopamine (DA) and regulates appetitive drive and reinforcement learning. Striatal DA D2 receptors (D2Rs) also regulate reinforcement learning and are implicated in glucose-related metabolic disorders. Nevertheless, interactions between striatal D2R and peripheral glucose have not been previously described. Here we show that manipulations involving striatal D2R signaling coincide with perseverative and impulsive-like responding for sucrose, a disaccharide consisting of fructose and glucose. Fructose conveys orosensory (ie, taste) reinforcement but does not convey metabolic (ie, nutrient-derived) reinforcement. Glucose however conveys orosensory reinforcement but unlike fructose, it is a major metabolic energy source, underlies sustained reinforcement, and activates striatal circuitry. We found that mice with deletion of dopamine- and cAMP-regulated neuronal phosphoprotein (DARPP-32) exclusively in D2R-expressing cells exhibited preferential D2R changes in the nucleus accumbens (NAc), a striatal region that critically regulates sucrose reinforcement. These changes coincided with perseverative and impulsive-like responding for sucrose pellets and sustained reinforcement learning of glucose-paired flavors. These mice were also characterized by significant glucose intolerance (ie, impaired glucose utilization). Systemic glucose administration significantly attenuated sucrose operant responding and D2R activation or blockade in the NAc bidirectionally modulated blood glucose levels and glucose tolerance. Collectively, these results implicate NAc D2R in regulating both peripheral glucose levels and glucose-dependent reinforcement learning behaviors and highlight the notion that glucose metabolic impairments arising from disrupted NAc D2R signaling are involved in compulsive and perseverative feeding behaviors.

Evaluating Diabetes Care for Patients With Serious Mental Illness Using the Chronic Care Model: A Pilot Study

People with serious mental illness (SMI) have a higher incidence of type 2 diabetes mellitus (T2DM) and shorter life span due to medical health problems. The chronic care model (CCM) has been used to improve care of patients with T2DM. One clinical organization that provided primary care to patients with SMI had excellent diabetes outcomes but did not have information on how they achieved those outcomes. Thus, we conducted a pilot study chart review for 30 patients with T2DM and SMI to determine how well the clinic’s system aligned with the overall CCM components and which components correlated with diabetes control. We also evaluated use of the CCM using the Assessment of Chronic Illness Care provider survey. Results showed that the clinic had an overall basic implementation level of the CCM, which allows opportunity for improvement. Two elements of the CCM were correlated with hemoglobin A_1C and both were in an unexpected direction: self-management support in the variable of percentage of visits that included patient-specific goal-setting (rs = .52; P = .004) and delivery system design in the variable of number of nurse practitioner visits per study period (r_s = .43; P = .02). These findings suggest that the clinic may have made more concentrated efforts to manage diabetes for patients who were not in good diabetes control. Providers noted the influence of SMI and social service organization support on these patients’ clinical outcomes. The findings will be reexamined after a fuller implementation of the CCM to further improve management in this population.

Comparison between long-acting injectable aripiprazole versus paliperidone palmitate in the treatment of schizophrenia: systematic review and indirect treatment comparison

We investigated the relative efficacy and tolerability of aripiprazole once monthly (AOM) versus paliperidone palmitate (PP) for treating schizophrenia. Extensive databases searches on short-term, placebo-controlled, randomized studies of AOM and PP were performed. Indirect treatment comparisons were performed between the two long-acting injectable antipsychotics (LAIAs). The primary efficacy endpoint was the mean change in the Positive and Negative Syndrome Scale total score from baseline between each LAIA and placebo. The effect sizes were mean differences and odds ratio (ORs) with 95% confidence intervals (CIs) for the primary efficacy endpoint and safety/tolerability between two LAIAs, respectively. Mean difference in the primary efficacy endpoint was significantly different, favouring AOM over PP (OR: -6.4; 95% CI: -11.402 to -1.358); sensitivity analyses and noninferiority test (AOM vs. PP) confirmed the primary results. The overall early dropout rate was not significantly different between AOM and PP (OR: 1.223; 95% CI: 0.737-2.03). However, there was a significant difference in the early dropout rate in terms of lack of efficacy favouring AOM over PP (OR: 0.394; 95% CI: 0.185-0.841). Within the context of the inherent limitations of the current analysis, our results may suggest that there may be relative advantages for AOM over PP in the short-term treatment of schizophrenia.

Antioxidant and anti-inflammatory nutrient status, supplementation, and mechanisms in patients with schizophrenia

Over 50 million people around the world suffer from schizophrenia, a severe mental illness characterized by misinterpretation of reality. Although the exact causes of schizophrenia are still unknown, studies have indicated that inflammation and oxidative stress may play an important role in the etiology of the disease. Pro-inflammatory cytokines are crucial for normal central nervous development and proper functioning of neural networks and neurotransmitters. Patients with schizophrenia tend to have abnormal immune activation resulting in elevated pro-inflammatory cytokine levels, ultimately leading to functional brain impairments. Patients with schizophrenia have also been found to suffer from oxidative stress, a result of an imbalance between the production of free radicals and the ability to detoxify their harmful effects. Furthermore, inflammation and oxidative stress are implicated to be related to the severity of psychotic symptoms. Several nutrients are known to have anti-inflammatory and antioxidant functions through various mechanisms in our body. The present review evaluates studies and literature that address the status and supplementation of omega-3 polyunsaturated fatty acids, vitamin D, B vitamins (B6, folate, B12), vitamin E, and carotenoids in different stages of schizophrenia. The possible anti-inflammatory and antioxidant mechanisms of action of each nutrient are discussed.

Impaired monocyte activation in schizophrenia: ultrastructural abnormalities and increased IL-1β production

Monocyte activation is consistently reported in patients with schizophrenia (SZ). We aimed to study the ultrastructure of monocytes and monocyte production of IL-1β in drug-free patients with SZ and controls. Monocytes from young (18-30 y.o.) healthy and SZ men in relapse were studied. Electron microscopy and morphometry were applied to estimate areas of monocytes, volume density (Vv), areas, and number of organelles. The production IL-1β by monocytes was estimated by the ELISA method. Group differences were examined using ANCOVA. Pearson's correlation coefficients were used to examine the effects of possible confounding variables. Correlation analyses were applied to detect the relationships between the parameters of monocytes measured and between the parameters measured and the IL-1β production. Area of nucleolus, Vv and area of mitochondria and lysosomes, and the number of lysosomes were significantly increased in patients as compared to controls. Area of mitochondria was correlated significantly with Vv and area of lysosomes, and the number of lysosomes was significantly correlated with area of monocyte and Vv of vacuoles only in the control group. The production of IL-1β by monocytes was higher in patients than in controls (p = 0.01) and was correlated with Vv of lysosomes (r = 0.68, p = 0.04) and area of lysosomes (r = 0.78, p = 0.013). The data provide new evidence for over activation of monocytes in SZ and disturbed metabolic relationships between lysosomes, mitochondria, and vacuoles.

A molecular pathway analysis stresses the role of inflammation and oxidative stress towards cognition in schizophrenia

Cognitive processes have a genetic component and are impaired in Schizophrenia (SKZ). The exact nature of such impairment escapes definition. The aim of the present contribution was the identification of the molecular pathways enriched with mutations (SNPs) associated with cognitive performance during antipsychotic treatment. 765 individuals from the CATIE study, males = 559, mean age 40.93 ± 11.03 were included. Working memory and the verbal memory were the evaluated outcomes. A mixed regression model for repeated measures served in R for clinical and molecular pathway analysis. The analysis of quality was conducted under the following criteria: minor allele frequency >0.01, genotype call rate >95%, missing data frequency <5%, Hardy-Weimberg equilibrium threshold >0.0001. The inflation factor was controlled by lambda values. Input for the pathway analysis was SNPs at a p level <0.05 of association genome-wide. Gender, age, education and the duration of the disease were the clinical and socio-demographic variables associated with the cognitive performance. 4268977 SNPs were available after imputation and quality analysis. Pathways related to inflammation and oxidation were the most strongly associated with verbal memory and working memory at a conservative adjusted p value < 0.01. We report that inflammation and in particular the pathway associated with arachidonic acid was enriched in mutations associated with poorer performance at the verbal memory and working memory tasks in SKZ patients.

Depot risperidone-induced adverse metabolic alterations in female rats

Atypical antipsychotics are associated with adverse metabolic effects including weight gain, increased adiposity, dyslipidaemia, alterations in glucose metabolism and insulin resistance. Increasing evidence suggests that metabolic dysregulation precedes weight gain development. The aim of this study was to evaluate alterations in adipokines, hormones and basic serum biochemical parameters induced by chronic treatment with depot risperidone at two doses (20 and 40 mg/kg) in female Sprague-Dawley rats. Dose-dependent metabolic alterations induced by risperidone after 6 weeks of treatment were revealed. Concomitant to weight gain and increased liver weight, an adverse lipid profile with an elevated triglyceride level was observed in the high exposure group, administered a 40 mg/kg dose repeatedly, while the low dose exposure group, administered a 20 mg/kg dose, developed weight gain without alterations in the lipid profile and adipokine levels. An initial peak in leptin serum level after the higher dose was observed in the absence of weight gain. This finding may indicate that the metabolic alterations observed in this study are not consequent to body weight gain. Taken together, these data may support the primary effects of atypical antipsychotics on peripheral tissues.

Immune involvement in the pathogenesis of schizophrenia: a meta-analysis on postmortem brain studies

Although the precise pathogenesis of schizophrenia is unknown, genetic, biomarker and imaging studies suggest involvement of the immune system. In this study, we performed a systematic review and meta-analysis of studies investigating factors related to the immune system in postmortem brains of schizophrenia patients and healthy controls. Forty-one studies were included, reporting on 783 patients and 762 controls. We divided these studies into those investigating histological alterations of cellular composition and those assessing molecular parameters; meta-analyses were performed on both categories. Our pooled estimate on cellular level showed a significant increase in the density of microglia (P=0.0028) in the brains of schizophrenia patients compared with controls, albeit with substantial heterogeneity between studies. Meta-regression on brain regions demonstrated this increase was most consistently observed in the temporal cortex. Densities of macroglia (astrocytes and oligodendrocytes) did not differ significantly between schizophrenia patients and healthy controls. The results of postmortem histology are paralleled on the molecular level, where we observed an overall increase in expression of proinflammatory genes on transcript and protein level (P=0.0052) in patients, while anti-inflammatory gene expression levels were not different between schizophrenia and controls. The results of this meta-analysis strengthen the hypothesis that components of the immune system are involved in the pathogenesis of schizophrenia.

Effects of the modified electric convulsive treatment (MECT) on cell factors of schizophrenia

The expression of cell factors of schizophrenia and the effect of the modified electric convulsive treatment (MECT) were studied. In total, 156 patients with schizophrenia were selected, and divided into the drug group (70 cases) and the drug combined with MECT group (combined group) (86 cases) according to the treatment methods. In addition, 70 cases of healthy volunteers (control group) were selected according to the closest matching method based on 1:1 of age and gender. The drug treatment, consisted of anti-psychotic drugs, such as risperidone 2-8, quetiapine 300-750, ziprasidone 80-160 or aripiprazole 10-30 mg/day, and for the control group, we used the electric spasm therapeutic instrument, Thymatron^®IV Systems up to 6 times, 3 times a week. The levels of interleukin (IL)-10, IL-4, IL-6 and IL-1 were detected before and after treatment by ELISA. The positive and negative symptom scale (PANSS) was used to evaluate the efficiency. Before the treatment, IL-1 and IL-6 levels of drug and combined groups were significantly higher than those of the control group (P<0.05), while IL-4 and IL-10 had no difference with the control group. There was no significant difference of each factor between the drug and combined groups. After treatment, IL-1, IL-6 and IL-10 of the drug group did not change compared to the levels before treatment, but IL-4 increased significantly; IL-1 and IL-10 of the combined group did not change, while IL-4 and IL-6 increased significantly; IL-1, IL-4 and IL-6 of the drug and combined groups were significantly (P<0.05) higher than those in the control group, but not IL-10. IL-1, IL-4 and IL-6 levels of the combined group were significantly higher (P<0.05) than those of the drug group. After treatment, the PANSS scores of the two groups decreased and the combined group decreased more significantly (P<0.05). The reduction rate of the combined group was significantly higher (P<0.05) than that of the drug group. The total efficiency of the combined group was significantly higher than that of the drug group, and after comparing these levels, there was statistical significance (P<0.05). IL-1, IL-4, IL-6 and IL-10 levels of the drug and combined groups before treatment were not associated with PANSS scores and the variation of IL-1, IL-4, IL-6 and IL-10 of the drug and combined groups had no correlation with the reduction rate of the PANSS. The results showed that, cell factors of schizophrenia had an abnormal expression, and medication and MECT can affect the expression level. In addition, MECT can improve the effect in the treatment of schizophrenia, but had no obvious correlation with the change of cell factors.

Antigliadin Antibodies (AGA IgG) Are Related to Neurochemistry in Schizophrenia

Inflammation may play a role in schizophrenia; however, subgroups with immune regulation dysfunction may serve as distinct illness phenotypes with potential different treatment and prevention strategies. Emerging data show that about 30% of people with schizophrenia have elevated antigliadin antibodies of the IgG type, representing a possible subgroup of schizophrenia patients with immune involvement. Also, recent data have shown a high correlation of IgG-mediated antibodies between the periphery and cerebral spinal fluid in schizophrenia but not healthy controls, particularly AGA IgG suggesting that these antibodies may be crossing the blood-brain barrier with resulting neuroinflammation. Proton magnetic resonance spectroscopy (MRS) is a non-invasive technique that allows the quantification of certain neurochemicals in vivo that may proxy inflammation in the brain such as myoinositol and choline-containing compounds (glycerophosphorylcholine and phosphorylcholine). The objective of this exploratory study was to examine the relationship between serum AGA IgG levels and MRS neurochemical levels. We hypothesized that higher AGA IgG levels would be associated with higher levels of myoinositol and choline-containing compounds (glycerophosphorylcholine plus phosphorylcholine; GPC + PC) in the anterior cingulate cortex. Thirty-three participants with a DSM-IV diagnosis of schizophrenia or schizoaffective disorder had blood drawn and underwent neuroimaging using MRS within 9 months. We found that 10/33 (30%) had positive AGA IgG (≥20 U) similar to previous findings. While there were no significant differences in myoinositol and GPC + PC levels between patients with and without AGA IgG positivity, there were significant relationships between both myoinositol (r = 0.475, p = 0.007) and GPC + PC (r = 0.36, p = 0.045) with AGA IgG levels. This study shows a possible connection of AGA IgG antibodies to putative brain inflammation as measured by MRS in schizophrenia.

Altered cytokine profile, pain sensitivity, and stress responsivity in mice with co-disruption of the developmental genes Neuregulin-1×DISC1

The complex genetic origins of many human disorders suggest that epistatic (gene×gene) interactions may contribute to a significant proportion of their heritability estimates and phenotypic heterogeneity. Simultaneous disruption of the developmental genes and schizophrenia risk factors Neuregulin-1 (NRG1) and Disrupted-in-schizophrenia 1 (DISC1) in mice has been shown to produce disease-relevant and domain-specific phenotypic profiles different from that observed following disruption of either gene alone. In the current study, anxiety and stress responsivity phenotypes in male and female mutant mice with simultaneous disruption of DISC1 and NRG1 were examined. NRG1×DISC1 mutant mice were generated and adult mice from each genotype were assessed for pain sensitivity (hot plate and tail flick tests), anxiety (light-dark box), and stress-induced hypothermia. Serum samples were assayed to measure circulating levels of pro-inflammatory cytokines. Mice with the NRG1 mutation, irrespective of DISC1 mutation, spent significantly more time in the light chamber, displayed increased core body temperature following acute stress, and decreased pain sensitivity. Basal serum levels of cytokines IL8, IL1β and IL10 were decreased in NRG1 mutants. Mutation of DISC1, in the absence of epistatic interaction with NRG1, was associated with increased serum levels of IL1β. Epistatic effects were evident for IL6, IL12 and TNFα. NRG1 mutation alters stress and pain responsivity, anxiety, and is associated with changes in basal cytokine levels. Epistasis resulting from synergistic NRG1 and DISC1 gene mutations altered pro-inflammatory cytokine levels relative to the effects of each of these genes individually, highlighting the importance of epistatic mechanisms in immune-related pathology.

Adverse Events in Childhood as a Risk Factor for Elevated BMI among People with Schizophrenia and Bipolar Disorder

Diseases of obesity have become a major cause of morbidity and mortality among people with schizophrenia and bipolar disorder. Childhood adversity has been associated with adult obesity in the general public, but has not been examined among people with mental illness. This study used a secondary analysis to examine childhood adversity and body mass index in people with schizophrenia and bipolar disorder. Among females, a history of physical abuse from parents or paternal emotional neglect was associated with an increased risk for obesity (OR = 3.34 and 2.44, respectively).

Physiological characteristics of patients with schizophrenia prematurely dying from circulatory diseases

INTRODUCTION

Patients with schizophrenia before reaching geriatric age are at high risk of circulatory mortality. However, investigations are lacking on the characteristics of physiological measurement among these at-risk patients.

METHODS

In this study, we followed acutely inpatients with schizophrenia disorder for cause of death through record linkage to the Death Certification System in Taiwan. Cases of patients who died because of circulatory morbidity (ICD-9 401-443) before turning 65 years old were used. Each schizophrenia case was then matched with two mentally healthy controls for the age and sex, and date of laboratory examination. Clinical data of all subjects were obtained by reviewing medical records.

RESULTS

Totally, 81 patients with schizophrenia who died from circulatory diseases at mean ages of 48.0 ± 10.7 years were investigated. The mean age at the final acute psychiatric hospitalization was 43.0 ± 10.9 years. Multivariate analysis showed that elevated fasting serum glucose levels (95% confidence interval [CI] for odds ratio (OR) = 1.00-1.03), blood leukocyte counts (95% CI for odds ratio (OR) = 1.07-1.55), and heart rates on electrocardiogram (95% CI for OR = 1.04-1.10) in the final psychiatric hospitalization collectively provided the predictive validity for premature circulatory death.

CONCLUSION

Systemic inflammatory activation and autonomic nervous system dysfunction along with dysregulation of glucose metabolism rather than lipids could be the physiological characteristics of schizophrenia patients at risk of premature circulatory mortality.

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 of depression and psychotropic medication on cardiac-related outcomes in a nationwide community-dwelling elderly population in Taiwan

The objective of this study was to examine the association of depression, psychotropic medications, and mental illness with cardiovascular disease in a nationwide community-dwelling elderly population in Taiwan. A total of 5664 participants who enrolled in the Healthy Aging Longitudinal Study in Taiwan (HALST) were included in the study. Multiple logistic regression was applied to investigate the association of depression, psychotropic medication use, and mental illness, separately, with cardiovascular disease. The results suggested that cardiovascular disease was significantly associated with various definitions of depression, including: the Center for Epidemiologic Studies-Depression scale (CES-D) ≥ 16, self-reported, and physician-diagnosed for depression (adjusted odds ratio [AOR] = 1.51; 95% confidence interval (CI): 1.14-2.00 for CES-D; AOR = 3.29; 95% CI: 1.99-5.42 for self-reported; and AOR = 2.45; 95% CI: 1.51-3.97 for physician-diagnosed). Additionally, significant associations of cardiovascular disease with the use of antipsychotics (AOR = 2.04; 95% CI: 1.25-3.34), benzodiazepines (BZDs) (AOR = 1.84; 95% CI: 1.52-2.21), and Z-drugs (AOR = 1.41; 95% CI: 1.03-1.93), respectively, were also observed, but not the use of antidepressants. In addition, a significant association of cardiovascular disease with mental illness was found in this study (AOR = 2.33; 95% CI: 1.68-3.24). In line with previous reports, these findings provided supportive evidence that depression and/or mental illness were significantly associated with cardiovascular disease in a community-dwelling elderly population in Taiwan. Moreover, significant associations of cardiovascular disease with the use of antipsychotics, BZDs, and Z-drugs, individually, were found. Further investigation would be of importance to clarify the causal relationship of depression and/or psychotropic medications with cardiovascular disease, especially among elderly populations.

Is it time for immunopsychiatry in psychotic disorders?

INTRODUCTION

Immune dysregulation is suggested to play an important aetiological role in schizophrenia (SZ) and bipolar disorder (BD) potentially driving neurodevelopmental pathways. Immune dysfunction may precede the onset of psychiatric disorders and parallel the development of multiaxial comorbidity, including suicidal behaviour and metabolic and autoimmune disorders. Depicting the source of the chronic low-grade inflammatory component in SZ and BD is thus a research priority. Strong environmental insults early in life, such as infections, acting on a background of genetic vulnerability, may induce potent and enduring inflammatory responses setting a state of liability to second-hit environmental encounters, namely childhood trauma, drug abuse or additional infectious exposures. The immunogenetic background of susceptibility, suggested to be not only lying within the HLA locus but also implicating inherited deficits of the innate immune system, may amplify the harmful biological effects of infections/psychosocial stress leading to the manifestation of a broad range of psychiatric symptoms.

OBJECTIVES

The present review aims to discuss the following: (i) biological arguments in favour of a chronic low-grade inflammation in SZ and BD and its potential origin in the interaction between the immunogenetic background and environmental infectious insults, and (ii) the consequences of this inflammatory dysfunction by focusing on N-methyl-D-aspartate (NMDA) receptor antibodies and activation of the family of human endogenous retroviruses (HERVs).

CONCLUSIONS

Specific therapeutic approaches targeting immune pathways may lead the way to novel personalized medical interventions, improvement of quality of life and average life expectancy of psychiatric patients, if not even prevent mood episodes and psychotic symptoms.

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.

Lifestyle and Behavioral Interventions to Reduce the Risk of Metabolic Syndrome in Community-Dwelling Adults With Serious Mental Illness: Implications for Nursing Practice

Adults with mental illness are at increased risk of being diagnosed with metabolic syndrome and consequently cardiovascular disease, diabetes, and stroke. The current article explores community-based interventions to decrease the risk of metabolic syndrome by changing health behaviors among adults with serious mental illness (SMI). Ovid Medline, PsycINFO, and CINAHL were searched for nonpharmacological studies of behavioral or lifestyle interventions addressing risk of metabolic syndrome among adults with SMI. Thirteen studies, seven with statistically significant results, were included in the review. Despite the well-known risks of metabolic syndrome, the majority of available studies had small samples with insufficient power. There was little consistency in methods or outcome measures. Studies that were client-directed and involved peer and staff support appeared most useful in changing health behaviors and improving quality of life. Further research is needed to guide nursing practice in implementing effective methods to reduce the risk of metabolic syndrome in community-dwelling adults with SMI.

Complications and mortality in patients with schizophrenia and diabetes: population-based cohort study

BACKGROUND

The long-term outcome of patients with both diabetes and schizophrenia remains unclear.

AIMS

To explore whether having schizophrenia increases the risk of advanced complications and mortality in people with diabetes.

METHOD

This is a population-based matched cohort study using Taiwan's National Health Insurance Research Database. A total of 11 247 participants with diabetes and schizophrenia and 11 247 participants with diabetes but not schizophrenia were enrolled. We used Cox proportional hazard models to determine the effect of schizophrenia on macrovascular and microvascular complications, and all-cause mortality.

RESULTS

The adjusted hazard ratios were 1.49 (95% CI 1.32-1.68) for macrovascular complications, 1.05 (95% CI 0.91-1.21) for microvascular complications and 3.68 (95% CI 3.21-4.22) for all-cause mortality in patients with diabetes and schizophrenia compared with those patients with diabetes but not schizophrenia.

CONCLUSIONS

Patients with both diabetes and schizophrenia had an increased risk of macrovascular complications and all-cause mortality but did not have statistically significant elevated risk of microvascular complications.

Promoting physical health for people with schizophrenia by reducing disparities in medical and dental care

OBJECTIVE

Acquiring a diagnosis of schizophrenia reduces life expectancy for many reasons including poverty, difficulties in communication, side-effects of medication and access to care. This mortality gap is driven by natural deaths; cardiovascular disease is a major cause, but outcomes for people with severe mental illness are worse for many physical health conditions, including cancer, fractures and complications of surgery. We set out to examine the literature on disparities in medical and dental care experienced by people with schizophrenia and suggest possible approaches to improving health.

METHOD

This narrative review used a targeted literature search to identify the literature on physical health disparities in schizophrenia.

RESULTS

There is evidence of inequitable access to and/or uptake of physical and dental health care by those with schizophrenia.

CONCLUSION

The goal was to reduce the mortality gap through equity of access to all levels of health care, including acute care, long-term condition management, preventative medicine and health promotion. We suggest solutions to promote health, wellbeing and longevity in this population, prioritising identification of and intervention for risk factors for premature morbidity and mortality. Shared approaches are vital, while joint education of clinicians will help break down the artificial mind-body divide.

Plasma adiponectin levels in schizophrenia and role of second-generation antipsychotics: a meta-analysis

BACKGROUND

People with schizophrenia are more likely than general population to suffer from metabolic abnormalities, with second-generation antipsychotics (SGAs) increasing the risk. Low plasma adiponectin levels may lead to metabolic dysregulations but evidence in people with schizophrenia, especially for the role of SGAs, is still inconclusive.

OBJECTIVE

To compare plasma adiponectin levels between people with schizophrenia and healthy controls, and to estimate the relative effect of schizophrenia and SGAs on adiponectin.

METHODS

We performed a systematic review and meta-analysis of observational studies published up to 13 June 2014 in main electronic databases. Pooled standardized mean differences (SMDs) between index and control groups were generated. Appropriate subanalyses and additional subgroup analyses were carried out.

RESULTS

Data from 2735 individuals, 1013 with and 1722 without schizophrenia, respectively, were analysed. Schizophrenia was not associated with lower adiponectin levels (SMD of -0.28, 95%CI: -0.59, 0.04; p=0.09). However, individuals with schizophrenia taking SGAs had plasma levels significantly lower than controls (p=0.002), which was not the case of drug free/drug naïve subjects (p=0.52). As regards single antipsychotic drugs clozapine (p<0.001) and olanzapine (p=0.04)--but not risperidone (p=0.88)--were associated with adiponectin levels lower than controls.

CONCLUSIONS

People with schizophrenia per se may not have levels of adiponectin lower than controls, though treatment with SGAs is associated with this metabolic abnormality. This bears clinical significance because of hypoadiponectinemia involvement in cardiovascular diseases, even if mechanisms whereby SGAs affect adiponectin remain unexplained. Longitudinal studies evaluating long-term effects of SGAs on adiponectin are needed.

The epidemiology of diabetes in psychotic disorders

Diabetes is highly prevalent in people with psychotic disorders, including schizophrenia and schizoaffective disorders. Exact prevalence is difficult to estimate, since diabetes is often underdiagnosed in people with psychosis. Results of several studies show that the prevalence of diabetes exceeds that in the general population, with documented prevalence in those with psychosis ranging from 1·26% to 50% across studies (median 13%). The association between diabetes and psychosis is complex and multifactorial. Many of the traditional risk factors for disease have increased prevalence in patients with psychotic disorders. In addition to these traditional risk factors, people with psychosis have unique risks that might have additive or even synergistic effects. These risks include the use of antipsychotic medication, the effects of adverse social determinants of health, and genetic loading. Despite evidence that rates of diabetes are increased in individuals with psychosis, many of these patients are not diagnosed or treated, resulting in increased diabetes-associated morbidity and mortality. Specific patient factors, provider issues, and systems-level factors contribute to the treatment gap. Interventions at both the clinical and public health levels are needed to successfully address this problem.

Plasma omentin levels in drug-free patients with schizophrenia

AIMS

We aimed to investigate plasma omentin concentrations in non-obese, drug-free patients with schizophrenia in comparison with healthy volunteers.

METHOD

Thirty-two patients with schizophrenia and 33 control subjects were recruited. Plasma omentin levels were determined by enzyme-linked immunosorbent assay.

RESULTS

Plasma levels of omentin (ng/ml) were found to be markedly lower in patients with schizophrenia (median = 7.7, 25th percentile = 6.3, 75th percentile = 604.9) than in controls (median = 486, 25th percentile = 326, 75th percentile = 794.2, p < 0.01). No significant difference was found between drug-free (n = 23) and drug-naive (n = 9) patients with respect to plasma omentin levels. Omentin concentrations correlated negatively with severity of illness, suggesting that patients with more severe pathology had lower fasting levels of omentin (n = 32; r = -0.387; p = 0.029).

CONCLUSION

The present results suggest that plasma omentin levels are decreased in physically healthy, non-obese, antipsychotic-free patients with schizophrenia when compared with physically and mentally healthy individuals. To our knowledge, this is the first study that demonstrated the association between omentin and schizophrenia.

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.

Neuroprogression in schizophrenia: Pathways underpinning clinical staging and therapeutic corollaries

OBJECTIVE

Whilst dopaminergic dysfunction remains a necessary component involved in the pathogenesis of schizophrenia, our current pharmacological armoury of dopamine antagonists does little to control the negative symptoms of schizophrenia. This suggests other pathological processes must be implicated. This paper aims to elaborate on such theories.

METHODS

Data for this review were sourced from the electronic database PUBMED, and was not limited by language or date of publication.

RESULTS

It has been suggested that multiple 'hits' may be required to unveil the clinical syndrome in susceptible individuals. Such hits potentially first occur in utero, leading to neuronal disruption, epigenetic changes and the establishment of an abnormal inflammatory response. The development of schizophrenia may therefore potentially be viewed as a neuroprogressive response to these early stressors, driven on by changes in tryptophan catabolite (TRYCAT) metabolism, reactive oxygen species handling and N-methyl d-aspartate (NMDA) circuitry. Given the potential for such progression over time, it is prudent to explore the new treatment strategies which may be implemented before such changes become established.

CONCLUSIONS

Outside of the dopaminergic model, the potential pathogenesis of schizophrenia has yet to be fully elucidated, but common themes include neuropil shrinkage, the development of abnormal neuronal circuitry, and a chronic inflammatory state which further disrupts neuronal function. Whilst some early non-dopaminergic treatments show promise, none have yet to be fully studied in appropriately structured randomized controlled trials and they remain little more than potential attractive targets.

Endothelial nitric oxide synthetase genetic variants, metabolic syndrome and endothelial function in schizophrenia

OBJECTIVE

The increasing rates of metabolic syndrome and cardiovascular disease in schizophrenia led to investigation into their causes, including atypical antipsychotics and pharmacogenetic variants. This study focused on the peripheral vasculature as a cardiovascular phenotype and the influence of atypical antipsychotics, the aberrant metabolism of nitric oxide caused by endothelial nitric oxide synthetase (eNOS) genetic variants and metabolic syndrome in a cross-sectional sample of schizophrenia subjects.

METHODS

Associations between eNOS genetic variants and endothelial function was assessed in a cohort of schizophrenia patients taking antipsychotic drugs, whom were undergoing a clinical assessment for endothelial function via the method of peripheral artery tonometry (RH-PAT), as well as metabolic syndrome criteria screening. Analyses were conducted on the entire cohort, then again after stratifying by metabolic syndrome, to investigate the effect of the eNOS variants and metabolic syndrome on endothelial functionality.

RESULTS

We included 203 subjects with a mean age of 46 years. The cohort was 36% female, 36% had metabolic syndrome and 85% were currently using atypical antipsychotics. We found associations between the eNOS T⁻⁷⁸⁶C and worse endothelial functioning (lower RH-PAT values) only in schizophrenia patients without metabolic syndrome.

CONCLUSIONS

Our results suggested that when schizophrenia patients progress to meet metabolic syndrome criteria, the genetic protection of the eNOS T⁻⁷⁸⁶C variant on endothelial function is no longer seen: Other factors of this pro-inflammatory state may be overriding this effect. The results of this study need replication and the factors driving endothelial dysfunction in patients with metabolic syndrome warrant further investigation.

Immune system and glucose metabolism interaction in schizophrenia: a chicken-egg dilemma

Impaired glucose metabolism and the development of metabolic syndrome contribute to a reduction in the average life expectancy of individuals with schizophrenia. It is unclear whether this association simply reflects an unhealthy lifestyle or whether weight gain and impaired glucose tolerance in patients with schizophrenia are directly attributable to the side effects of atypical antipsychotic medications or disease-inherent derangements. In addition, numerous previous studies have highlighted alterations in the immune system of patients with schizophrenia. Increased concentrations of interleukin (IL)-1, IL-6, and transforming growth factor-beta (TGF-β) appear to be state markers, whereas IL-12, interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), and soluble IL-2 receptor (sIL-2R) appear to be trait markers of schizophrenia. Moreover, the mononuclear phagocyte system (MPS) and microglial activation are involved in the early course of the disease. This review illustrates a "chicken-egg dilemma", as it is currently unclear whether impaired cerebral glucose utilization leads to secondary disturbances in peripheral glucose metabolism, an increased risk of cardiovascular complications, and accompanying pro-inflammatory changes in patients with schizophrenia or whether immune mechanisms may be involved in the initial pathogenesis of schizophrenia, which leads to disturbances in glucose metabolism such as metabolic syndrome. Alternatively, shared underlying factors may be responsible for the co-occurrence of immune system and glucose metabolism disturbances in schizophrenia.

Is there an association between peripheral immune markers and structural/functional neuroimaging findings?

OBJECTIVES

There is mounting evidence that inflammatory processes play a key role in emotional as well as cognitive dysfunctions. In this context, research employing magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MR spectroscopy) suggests a possible link between structural/functional anomalies in the brain and an increase of circulating inflammation markers. The present paper reviews this research, with particular focus on major depressive disorder (MDD), cognitive impairment in older adults, Alzheimer's disease (AD) and schizophrenia.

RESULTS

In MDD, cognitive impairment and AD, inflammatory processes have been found to be associated with both structural and functional anomalies, perhaps under the influence of environmental stress. Not enough research can suggest similar considerations in schizophrenia, although studies in mice and non-human primates support the belief that inflammatory responses generated during pregnancy can affect brain development and contribute to the etiology of schizophrenia.

CONCLUSIONS

The present review suggests a link between inflammatory processes and MRI detected anomalies in the brain of individuals with MDD, older adults with cognitive impairment as well as of individuals with AD and schizophrenia.

Changes in pro-inflammatory cytokines and body weight during 6-month risperidone treatment in drug naïve, first-episode schizophrenia

OBJECTIVE

The present study aimed to examine the changes in pro-inflammatory cytokines and body weight during 6-month risperidone treatment in drug naïve, first-episode schizophrenia.

METHODS

Sixty-two drug naïve, first-episode schizophrenia (SZ group) and 60 healthy individuals (control group) were enrolled in the study. Serum interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α) levels, and body weight were measured at baseline for both groups, and repeated for the SZ group at five different time points during 6-month risperidone treatment.

RESULTS

At baseline, serum IL-1β, IL-6, and TNF-α levels in the SZ group (53.28 ± 12.62, 33.98 ± 14.13, 50.08 ± 12.86 pg/mL, respectively) were significantly higher than those in the control group (23.49 ± 15.27, 15.53 ± 7.16, 32.12 ± 15.23 pg/mL, respectively) (p's < 0.001). Within the SZ group, serum IL-1β levels decreased significantly at 2 weeks (48.02 ± 16.00 pg/mL, p < 0.01) and 1 month (44.70 ± 16.63 pg/mL, p < 0.001), but then gradually increased at 2 months (48.49 ± 18.87 pg/mL), 3 months (50.59 ± 18.48 pg/mL) and 6 months (53.64 ± 16.22 pg/mL) to the levels comparable to baseline; serum IL-6 levels changed significantly over the course of treatment (p = 0.001), but reached the levels comparable to baseline at 6 months (37.13 ± 13.23 pg/mL); serum levels of TNF-α increased significantly at 3 months (55.02 ± 16.69 pg/mL, p < 0.01) and 6 months (58.69 ± 13.57 pg/mL, p < 0.001); steady and significant weight gain was observed at each follow-up time point (p's < 0.001), from 56.71 ± 9.25 kg at baseline to 62.72 ± 9.53 kg at 6 months.

CONCLUSIONS

Risperidone treatment is associated with changes in serum pro-inflammatory cytokines levels and weight. There is an initial anti-inflammatory effect that reduces with treatment, potentially due to its weight gain side effect.

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.

Increased mortality in schizophrenia due to cardiovascular disease - a non-systematic review of epidemiology, possible causes, and interventions

BACKGROUND

Schizophrenia is among the major causes of disability worldwide and the mortality from cardiovascular disease (CVD) is significantly elevated. There is a growing concern that this health challenge is not fully understood and efficiently addressed.

METHODS

Non-systematic review using searches in PubMed on relevant topics as well as selection of references based on the authors' experience from clinical work and research in the field.

RESULTS

In most countries, the standardized mortality rate in schizophrenia is about 2.5, leading to a reduction in life expectancy between 15 and 20 years. A major contributor of the increased mortality is due to CVD, with CVD mortality ranging from 40 to 50% in most studies. Important causal factors are related to lifestyle, including poor diet, lack of physical activity, smoking, and substance abuse. Recent findings suggest that there are overlapping pathophysiology and genetics between schizophrenia and CVD-risk factors, further increasing the liability to CVD in schizophrenia. Many pharmacological agents used for treating psychotic disorders have side effects augmenting CVD risk. Although several CVD-risk factors can be effectively prevented and treated, the provision of somatic health services to people with schizophrenia seems inadequate. Further, there is a sparseness of studies investigating the effects of lifestyle interventions in schizophrenia, and there is little knowledge about effective programs targeting physical health in this population.

DISCUSSION

The risk for CVD and CVD-related deaths in people with schizophrenia is increased, but the underlying mechanisms are not fully known. Coordinated interventions in different health care settings could probably reduce the risk. There is an urgent need to develop and implement effective programs to increase life expectancy in schizophrenia, and we argue that mental health workers should be more involved in this important task.

Association of metabolic syndrome and inflammation with neurocognition in patients with schizophrenia

The aim of this study is to assess the relationships of metabolic syndrome (MetS) and inflammation with neurocognition in schizophrenia. In this cross-sectional study, we included patients with diagnosis of schizophrenia according to the DSM-IV-TR criteria. We collected socio-demographic information, clinical characteristics, anthropometric measurements, blood tests, and neurocognition measures. A multivariate analysis using multiple linear regressions was performed to determine variables that are potentially associated with neurocognition. The analyses were repeated using MetS as a dichotomised variable (< and ≥ 3 MetS criteria), a continuous variable (number of MetS criteria present), and for each component of MetS. One hundred and sixty-eight outpatients participated in our study. The prevalence of MetS was 27.4%. An association was found between the number of MetS criteria present and cognitive impairment. Among the different components of MetS, hypertriglycerides and abdominal obesity were the only factors associated with cognitive impairment. Other factors, such as smoking and alcohol dependence or abuse, also revealed a significant relationship, whereas inflammation was not associated with cognitive impairment. In conclusion, our findings suggest that MetS, alcohol use and non-smoking status are associated with cognitive impairment. These findings may support complementary therapeutic approaches in cognitive remediation that lessen the severity of cognitive impairment in schizophrenia.

A population-based cohort study to elucidate temporal relationship between schizophrenia and metabolic syndrome (KCIS no. PSY3)

BACKGROUND

The bidirectional relationships between metabolic syndrome (MetS) and schizophrenia (SCZ) play a crucial role in clinical treatment of both diseases but such bidirectional causal effects have not been comprehensively elucidated.

AIMS

To investigate the influence of MetS on incident SCZ and the opposite direction as well as their predictors for each direction with a population-based cohort sample.

METHOD

We enrolled 76,545 subjects who had participated in a community-based health screening program during 1999-2004. After excluding those with the existing MetS or SCZ at baseline, the two normal prospective cohorts corresponding to each independent variable of MetS or SCZ, respectively, were followed over time to ascertain incident outcome of SCZ and MetS. The crude and adjusted hazard ratios for the effect of the predictor on each incident outcome were estimated after controlling for the possible confounding factors.

RESULTS

The overall incidence rate (per 10(5)person-years) of SCZ was 61.15. The incidence rate in patients with MetS was lower than those without (44.24 versus 64.20), indicating the presence of MetS failed to find an increased risk of developing incident SCZ. However, participants with abnormal waist circumference (WC) were two times (95% CI: 1.37 to 2.93) more likely to yield incident SCZ compared to those with normal WC. In the opposite direction, the incidence of MetS was statistically higher in patients with SCZ than those without SCZ (11.25% vs 7.94%, respectively), suggesting SCZ conferred a higher risk for yielding incident MetS (adjusted hazard ratio=1.89, 95% CI: 1.36, 2.63).

CONCLUSIONS

After examining the bidirectional causal relationships between SCZ and MetS with the theoretically sound and large population-based prospective cohort study, central obesity, one of the individual components of MetS, was corroborated as an independent predictor for incident SCZ. Patients diagnosed with SCZ were at greater risk of having incident cases of MetS. Such significant temporal bidirectional relationships between SCZ and central obesity suggest a reciprocal interaction exits between SCZ and central obesity.

Obesity and psychiatric disorders: commonalities in dysregulated biological pathways and their implications for treatment

Rates of obesity are higher than normal across a range of psychiatric disorders, including major depressive disorder, bipolar disorder, schizophrenia and anxiety disorders. While the problem of obesity is generally acknowledged in mental health research and treatment, an understanding of their bi-directional relationship is still developing. In this review the association between obesity and psychiatric disorders is summarised, with a specific emphasis on similarities in their disturbed biological pathways; namely neurotransmitter imbalances, hypothalamus-pituitary-adrenal axis disturbances, dysregulated inflammatory pathways, increased oxidative and nitrosative stress, mitochondrial disturbances, and neuroprogression. The applicability and effectiveness of weight-loss interventions in psychiatric populations are reviewed along with their potential efficacy in ameliorating disturbed biological pathways, particularly those mediating inflammation and oxidative stress. It is proposed that weight loss may not only be an effective intervention to enhance physical health but may also improve mental health outcomes and slow the rate of neuroprogressive disturbances in psychiatric disorders. Areas of future research to help expand our understanding of the relationship between obesity and psychiatric disorders are also outlined.

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.

Lipidomics reveals early metabolic changes in subjects with schizophrenia: effects of atypical antipsychotics

There is a critical need for mapping early metabolic changes in schizophrenia to capture failures in regulation of biochemical pathways and networks. This information could provide valuable insights about disease mechanisms, trajectory of disease progression, and diagnostic biomarkers. We used a lipidomics platform to measure individual lipid species in 20 drug-naïve patients with a first episode of schizophrenia (FE group), 20 patients with chronic schizophrenia that had not adhered to prescribed medications (RE group), and 29 race-matched control subjects without schizophrenia. Lipid metabolic profiles were evaluated and compared between study groups and within groups before and after treatment with atypical antipsychotics, risperidone and aripiprazole. Finally, we mapped lipid profiles to n3 and n6 fatty acid synthesis pathways to elucidate which enzymes might be affected by disease and treatment. Compared to controls, the FE group showed significant down-regulation of several n3 polyunsaturated fatty acids (PUFAs), including 20:5n3, 22:5n3, and 22:6n3 within the phosphatidylcholine and phosphatidylethanolamine lipid classes. Differences between FE and controls were only observed in the n3 class PUFAs; no differences where noted in n6 class PUFAs. The RE group was not significantly different from controls, although some compositional differences within PUFAs were noted. Drug treatment was able to correct the aberrant PUFA levels noted in FE patients, but changes in re patients were not corrective. Treatment caused increases in both n3 and n6 class lipids. These results supported the hypothesis that phospholipid n3 fatty acid deficits are present early in the course of schizophrenia and tend not to persist throughout its course. These changes in lipid metabolism could indicate a metabolic vulnerability in patients with schizophrenia that occurs early in development of the disease.

Levels of S100B are raised in female patients with schizophrenia

BACKGROUND

The neurotrophic factor, S100B, is released primarily from astrocytes, with serum and CSF levels of S100B reported as altered in schizophrenia. However, many of these reports are contradictory. Here, serum levels of S100B in schizophrenia and influence of age, gender, medication and illness severity were examined.

METHODS

Serum S100B levels were measured in patients with schizophrenia treated with clozapine. Lifestyle, metabolic and illness severity parameters were correlated with S100B concentrations.

RESULTS

Data showed raised serum levels of S100B in schizophrenia female patients, but not male patients, compared to controls. Correlation analysis demonstrated a positive association between S100B serum concentrations and BMI.

CONCLUSIONS

This study supports previous findings that adipocytes may contribute to S100B serum concentrations in females, in addition to astrocytes. This study also supports the hypothesis that metabolic effects of medication, lifestyle choices and the illness itself, may be contributing factors to altered levels of S100B.

Treatment of obesity and diabetes using oxytocin or analogs in patients and mouse models

Obesity is important for the development of type-2 diabetes as a result of obesity-induced insulin resistance accompanied by impaired compensation of insulin secretion from pancreatic beta cells. Here, based on a randomized pilot clinical trial, we report that intranasal oxytocin administration over an 8-week period led to effective reduction of obesity and reversal of related prediabetic changes in patients. Using mouse models, we further systematically evaluated whether oxytocin and its analogs yield therapeutic effects against prediabetic or diabetic disorders regardless of obesity. Our results showed that oxytocin and two analogs including [Ser4, Ile8]-oxytocin or [Asu1,6]-oxytocin worked in mice to reverse insulin resistance and glucose intolerance prior to reduction of obesity. In parallel, using streptozotocin-induced diabetic mouse model, we found that treatment with oxytocin or its analogs reduced the magnitude of glucose intolerance through improving insulin secretion. The anti-diabetic effects of oxytocin and its analogs in these animal models can be produced similarly whether central or peripheral administration was used. In conclusion, oxytocin and its analogs have multi-level effects in improving weight control, insulin sensitivity and insulin secretion, and bear potentials for being developed as therapeutic peptides for obesity and diabetes.

Social isolation rearing induces mitochondrial, immunological, neurochemical and behavioural deficits in rats, and is reversed by clozapine or N-acetyl cysteine

Apart from altered dopamine (DA) function, schizophrenia displays mitochondrial and immune-inflammatory abnormalities, evidenced by oxidative stress, altered kynurenine metabolism and cytokine release. N-acetyl cysteine (NAC), an antioxidant and glutamate modulator, is effective in the adjunctive treatment of schizophrenia. Social isolation rearing (SIR) in rats is a valid neurodevelopmental animal model of schizophrenia. This study evaluated whether SIR-induced behavioural deficits may be explained by altered plasma pro- and anti-inflammatory cytokines, kynurenine metabolism, and cortico-striatal DA and mitochondrial function (via adenosine triphosphate (ATP) release), and if clozapine or NAC (alone and in combination) reverses these changes. SIR induced pronounced deficits in social interactive behaviours, object recognition memory, and prepulse inhibition (PPI), while simultaneously increasing striatal but reducing frontal cortical accumulation of ATP as well as DA. SIR increased pro- vs. anti-inflammatory cytokine balance and altered kynurenine metabolism with a decrease in neuroprotective ratio. Clozapine (5mg/kg/day×14days) as well as clozapine+NAC (5mg/kg/day and 150mg/kg/day×14days) reversed these changes, with NAC (150mg/kg/day) alone significantly but partially effective in some parameters. Clozapine+NAC was more effective than clozapine alone in reversing SIR-induced PPI, mitochondrial, immune and DA changes. In conclusion, SIR induces mitochondrial and immune-inflammatory changes that underlie cortico-striatal DA perturbations and subsequent behavioural deficits, and responds to treatment with clozapine or NAC, with an additive effect following combination treatment. The data provides insight into the mechanisms that might underlie the utility of NAC as an adjunctive treatment in schizophrenia.

The nature of relapse in schizophrenia

BACKGROUND

Multiple relapses characterise the course of illness in most patients with schizophrenia, yet the nature of these episodes has not been extensively researched and clinicians may not always be aware of important implications.

METHODS

We critically review selected literature regarding the nature and underlying neurobiology of relapse.

RESULTS

Relapse rates are very high when treatment is discontinued, even after a single psychotic episode; a longer treatment period prior to discontinuation does not reduce the risk of relapse; many patients relapse soon after treatment reduction and discontinuation; transition from remission to relapse may be abrupt and with few or no early warning signs; once illness recurrence occurs symptoms rapidly return to levels similar to the initial psychotic episode; while most patients respond promptly to re-introduction of antipsychotic treatment after relapse, the response time is variable and notably, treatment failure appears to emerge in about 1 in 6 patients. These observations are consistent with contemporary thinking on the dopamine hypothesis, including the aberrant salience hypothesis.

CONCLUSIONS

Given the difficulties in identifying those at risk of relapse, the ineffectiveness of rescue medications in preventing full-blown psychotic recurrence and the potentially serious consequences, adherence and other factors predisposing to relapse should be a major focus of attention in managing schizophrenia. The place of antipsychotic treatment discontinuation in clinical practice and in placebo-controlled clinical trials needs to be carefully reconsidered.

Effect of epigallocatechin gallate supplementation in schizophrenia and bipolar disorder: an 8-week, randomized, double-blind, placebo-controlled study

OBJECTIVES

Strategies that focus on the reduction of oxidative stress and inflammation may have therapeutic benefit for the treatment of schizophrenia. This clinical trial sought to determine, in a double-blind study, whether epigallocatechin gallate (EGCG), a green tea extract, is a useful adjunct to maintenance antipsychotic medication.

METHODS

Adults with schizophrenia, schizoaffective disorder or bipolar disorder who were maintained on antipsychotic and other psychotropic medications were randomized to supplemental EGCG or placebo. Study participants completed clinical assessments and blood draws to evaluate supplemental treatment effects on psychiatric symptoms and plasma inflammatory markers.

RESULTS

A total of 34 participants (17 EGCG, 17 placebo) were randomized and 25 participants (14 EGCG, 11 placebo) completed the study. Both treatment groups showed significant reductions in psychotic, depressive and anxiety symptoms from baseline to end of treatment. However, EGCG did not significantly affect psychiatric symptoms or inflammatory markers, as compared with placebo. Adverse effects were mild and comparable between groups.

CONCLUSION

There was no signal for a therapeutic effect of the green tea extract EGCG on psychiatric symptoms in this placebo-controlled pilot study.

Exploring the pathogenetic association between schizophrenia and type 2 diabetes mellitus diseases based on pathway analysis

BACKGROUND

Schizophrenia (SCZ) and type 2 diabetes mellitus (T2D) are both complex diseases. Accumulated studies indicate that schizophrenia patients are prone to present the type 2 diabetes symptoms, but the potential mechanisms behind their association remain unknown. Here we explored the pathogenetic association between SCZ and T2D based on pathway analysis and protein-protein interaction.

RESULTS

With sets of prioritized susceptibility genes for SCZ and T2D, we identified significant pathways (with adjusted p-value < 0.05) specific for SCZ or T2D and for both diseases based on pathway enrichment analysis. We also constructed a network to explore the crosstalk among those significant pathways. Our results revealed that some pathways are shared by both SCZ and T2D diseases through a number of susceptibility genes. With 382 unique susceptibility proteins for SCZ and T2D, we further built a protein-protein interaction network by extracting their nearest interacting neighbours. Among 2,104 retrieved proteins, 364 of them were found simultaneously interacted with susceptibility proteins of both SCZ and T2D, and proposed as new candidate risk factors for both diseases. Literature mining supported the potential association of partial new candidate proteins with both SCZ and T2D. Moreover, some proteins were hub proteins with high connectivity and interacted with multiple proteins involved in both diseases, implying their pleiotropic effects for the pathogenic association. Some of these hub proteins are the components of our identified enriched pathways, including calcium signaling, g-secretase mediated ErbB4 signaling, adipocytokine signaling, insulin signaling, AKT signaling and type II diabetes mellitus pathways. Through the integration of multiple lines of information, we proposed that those signaling pathways, which contain susceptibility genes for both diseases, could be the key pathways to bridge SCZ and T2D. AKT could be one of the important shared components and may play a pivotal role to link both of the pathogenetic processes.

CONCLUSIONS

Our study is the first network and pathway-based systematic analysis for SCZ and T2D, and provides the general pathway-based view of pathogenetic association between two diseases. Moreover, we identified a set of candidate genes potentially contributing to the linkage between these two diseases. This research offers new insights into the potential mechanisms underlying the co-occurrence of SCZ and T2D, and thus, could facilitate the inference of novel hypotheses for the co-morbidity of the two diseases. Some etiological factors that exert pleiotropic effects shared by the significant pathways of two diseases may have important implications for the diseases and could be therapeutic intervention targets.

Brain insulin dysregulation: implication for neurological and neuropsychiatric disorders

Arduous efforts have been made in the last three decades to elucidate the role of insulin in the brain. A growing number of evidences show that insulin is involved in several physiological function of the brain such as food intake and weight control, reproduction, learning and memory, neuromodulation and neuroprotection. In addition, it is now clear that insulin and insulin disturbances particularly diabetes mellitus may contribute or in some cases play the main role in development and progression of neurodegenerative and neuropsychiatric disorders. Focusing on the molecular mechanisms, this review summarizes the recent findings on the involvement of insulin dysfunction in neurological disorders like Alzheimer's disease, Parkinson's disease and Huntington's disease and also mental disorders like depression and psychosis sharing features of neuroinflammation and neurodegeneration.

Meningeal and choroid plexus cells--novel drug targets for CNS disorders

The meninges and choroid plexus perform many functions in the developing and adult human central nervous system (CNS) and are composed of a number of different cell types. In this article I focus on meningeal and choroid plexus cells as targets for the development of drugs to treat a range of traumatic, ischemic and chronic brain disorders. Meningeal cells are involved in cortical development (and their dysfunction may be involved in cortical dysplasia), fibrotic scar formation after traumatic brain injuries (TBI), brain inflammation following infections, and neurodegenerative disorders such as Multiple Sclerosis (MS) and Alzheimer's disease (AD) and other brain disorders. The choroid plexus regulates the composition of the cerebrospinal fluid (CSF) as well as brain entry of inflammatory cells under basal conditions and after injuries. The meninges and choroid plexus also link peripheral inflammation (occurring in the metabolic syndrome and after infections) to CNS inflammation which may contribute to the development and progression of a range of CNS neurological and psychiatric disorders. They respond to cytokines generated systemically and secrete cytokines and chemokines that have powerful effects on the brain. The meninges may also provide a stem cell niche in the adult brain which could be harnessed for brain repair. Targeting meningeal and choroid plexus cells with therapeutic agents may provide novel therapies for a range of human brain disorders.

Expression levels of neuroimmune biomarkers in hypothalamus of allergic mice after phthalate exposure

Previously, we demonstrated that maternal exposure to phthalates enhances atopic dermatitis in male mouse offspring. However, whether phthalate exposure affects neuroimmune biomarkers in allergic mice has not yet been studied. Di-(2-ethylhexyl) phthalate (DEHP) and di-isononyl phthalate (DINP) are environmental chemicals that are commonly used as plasticizers. This study was designed to investigate the expression levels of neuroimmune biomarkers in the hypothalamus of a murine model of allergic asthma after phthalate exposure throughout juvenility until adulthood. Six-week-old C3H/HeJ Jcl male mice were treated with DEHP or DINP (0, 0.02, 0.4 or 8 nmol per body per week) and ovalbumin (OVA; 1 µg per body per 2 weeks) for 7 weeks intratracheally. On the day after the completion of the phthalate and OVA treatment, the hypothalamus from each mouse was collected, and the mRNA expression levels of neuroimmune biomarkers were examined using a real-time RT-PCR analysis. The mRNA expression levels of the proinflammatory cytokines interleukin (IL)-1β and tumor necrosis factor (TNF)-α, the chemokine CCL3, the transcription factor nuclear factor (NF)-κB, the oxidative stress marker heme-oxygenase (HO)1, a nerve growth factor, and the microglia marker Iba1 were remarkably up-regulated in the hypothalami of mice treated with 8 nmol of DEHP in the presence of the allergen. However, no significant changes were observed, except for reductions in the TNF-α and CCL2 mRNA levels, in mice exposed to DINP combined with the allergen. This study is the first report to show that high-dose DEHP exposure throughout juvenility until adulthood may induce neuroinflammation by modulating neuroimmune biomarkers in the hypothalami of allergic mice.