Treatment with risperidone for 4 weeks increased plasma 3-methoxy-4-hydroxypnenylglycol (MHPG) levels, but did not alter plasma brain-derived neurotrophic factor (BDNF) levels in schizophrenic patients

Rationale and neurobiological effects of treatment with antipsychotics in patients with chronic schizophrenia considering dopamine supersensitivity

The long-term treatment of patients with schizophrenia often involves the management of relapses for most patients and the development of treatment resistance in some patients. To stabilize the clinical course and allow as many patients as possible to recover, clinicians need to recognize dopamine supersensitivity, which can be provoked by administration of high dosages of antipsychotics, and deal with it properly. However, no treatment guidelines have addressed this issue. The present review summarized the characteristics of long-acting injectable antipsychotics, dopamine partial agonists, and clozapine in relation to dopamine supersensitivity from the viewpoints of receptor profiles and pharmacokinetics. The potential merits and limitations of these medicines are discussed, as well as the risks of treating patients with established dopamine supersensitivity with these classes of drugs. Finally, the review discussed the biological influence of antipsychotic treatment on the human brain based on findings regarding the relationship between the hippocampus and antipsychotics.

Plasma levels of 3-methoxy-4-hydroxyphenylglycol levels, number of hospitalization and cognitive function predicts the cognitive effect of atypical antipsychotic monotherapy in patients with acute schizophrenia

Although the effects of atypical antipsychotics with regard to improving neurocognitive function are not sufficiently high. The present study applied an atypical antipsychotic monotherapy for patients with acute schizophrenia to (1) examine the percentage of patients who respond well to this treatment, (2) explore the factors that predict response (e.g. the improvement of neurocognition), and (3) identify the factors associated with improved neurocognitive function. We studied 40 patients with acute schizophrenia who had received atypical antipsychotic monotherapy for 24 weeks. The following parameters were evaluated at baseline and 24 weeks after the start of treatment: psychotic symptoms, neurocognitive function, and blood biological markers including homovanillic acid, 3-methoxy-4-hydroxyphenylglycol, and brain-derived neurotrophic factor. Marked improvements in neurocognitive function were noted in 7.5%-25% of patients. The factors that significantly predicted neurocognitive function improvement were the frequency of hospitalization (verbal memory and verbal fluency), 3-methoxy-4-hydroxyphenylglycol (verbal fluency and executive function), and verbal memory (working memory). Approximately 20% of the patients showed good response to treatment with antipsychotics. Frequency of hospitalization, 3-methoxy-4-hydroxyphenylglycol level, and other parameters predicted responsiveness to these drug therapies. Thus, it might be useful to apply these factors to predict responses to treatment.

The neurobiological hypothesis of neurotrophins in the pathophysiology of schizophrenia: A meta-analysis

BACKGROUND

Schizophrenia is associated with patterns of aberrant neurobiological circuitry. The disease complexity is mirrored by multiple biological interactions known to contribute to the disease pathology. One potential contributor is the family of neurotrophins which are proteins involved in multiple functional processes in the nervous system, with crucial roles in neurodevelopment, synaptogenesis and neuroplasticity. With these roles in mind, abnormal neurotrophin profiles have been hypothesized to contribute to the pathology of schizophrenia.

METHODS

We performed a systematic review and a meta-analysis to scrutinize the neurobiological hypothesis of neurotrophins in schizophrenia, examining the correlation between peripheral levels of brain-derived neurotrophic factor (BDNF), nerve growth factor (NGF), neurotrophin-3 (NT-3) and neurotrophin 4/5 (NT-4/5) associated with schizophrenia.

RESULTS

Fifty-two studies were reviewed and twenty-two studies were included in this meta-analysis. Using a random effects model, we confirmed that decreased levels of neurotrophins (BDNF, NGF and NT-4/5) were associated with schizophrenia (Hedges's g = -0.846; SE = 0.058; 95% confidence interval: -0.960 to -0.733; Z-value = -14.632; p-value = 0.000). Subgroup analysis indicated that neurotrophin levels are significantly decreased in both medicated and drug-näive patients. Meta-regression of continuous variables such as mean age, duration of illness and PANSS total score did not show significant effects (p > 0.05) in relation to neurotrophins levels.

DISCUSSION

We confirm that decreased peripheral neurotrophin levels are significantly associated with schizophrenia, thereby confirming the neurobiological hypothesis of neurotrophins in schizophrenia. Low levels of neurotrophins in peripheral blood of patients with schizophrenia may explain, in part, the pathophysiology of schizophrenia.

BDNF as a marker of response to cognitive remediation in patients with schizophrenia: A randomized and controlled trial

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is considered to be a putative biomarker for cognitive recovery in schizophrenia. However, current evidence is still scarce for pharmacological treatments, and the use of BDNF as a biomarker has only been tested once with cognitive remediation treatment (CRT).

METHODS

A randomized and controlled trial (NCT02341131) with 70 schizophrenia outpatients and 15 healthy volunteers was conducted. The participants with schizophrenia were randomly assigned to either CRT or the control group. All the participants were assessed in terms of cognition, quality of life, and their serum BDNF levels at both baseline and after the intervention. Additionally, comparisons of the effects of the different genotypes of the Val66Met polymorphism at the BDNF gene on the outcome variables were also performed.

RESULTS

The patients in the CRT group presented with improvements in both cognition and quality of life. However, no significant changes were detected in the serum levels of BDNF. Interestingly, we found a significant positive interaction effect between the serum BDNF levels and the different BDNF genotypes. The Val/Val group showed significantly higher serum levels after the CRT treatment. However, the interaction among the serum BDNF levels, the BDNF genotypes and the treatment condition was not statistically significant.

CONCLUSIONS

The replication of the previous finding of increased serum BDNF levels after cognitive remediation in clinically stable individuals with schizophrenia was not achieved. However, our data indicated that genetic variability may be mediating serum BDNF activity in the context of CRT.

Genetic Association of the Norepinephrine Transporter Gene G1287A Polymorphism with Risk of Schizophrenia: A Case-Control Study and Meta-Analysis

BACKGROUND

The G1287A polymorphism (rs5569) in exon 9 of the norepinephrine transporter (NET) gene has been associated with schizophrenia in several populations. However, the results are conflicting. Moreover, few studies have investigated the relationship between the G1287A polymorphism and schizophrenia among the Chinese Han population.

METHODS

A case-control study was designed to explore whether the G1287A genetic variant is related to schizophrenia in the Chinese Han population. The results from this study were then included in the performance of a meta-analysis to further analyze the association of the G1287A polymorphism with schizophrenia.

RESULTS

No significant differences in the genotype and allele distributions of G1287A were found between Chinese Han patients with schizophrenia and control participants. Similarly, in gender-specific analyses, no significant differences were found for G1287A genotype and allele distributions in either the male or the female case-control comparisons. Finally, the results of this meta-analysis also showed that the NET gene G1287A polymorphism was not associated with schizophrenia in the total population under allelic, recessive, dominant, or homozygous genetic models.

CONCLUSION

Our case-control study and meta-analysis suggest that the NET gene G1287A polymorphism may not be involved in the etiology of schizophrenia in the Chinese Han population.

Predicting relapse in schizophrenia: Is BDNF a plausible biological marker?

Understanding the biological processes that underlie why patients relapse is an issue of fundamental importance to the detection and prevention of relapse in schizophrenia. Brain Derived Neurotrophic Factor (BDNF), a facilitator of brain plasticity, is reduced in patients with schizophrenia. In the present study, we examined whether decreases in plasma BDNF levels could be used as a biological predictor of relapse in schizophrenia. A total of 221 patients were prospectively evaluated for relapse over 30months in the Preventing Relapse in Schizophrenia: Oral Antipsychotics Compared to Injectables: eValuating Efficacy (PROACTIVE) study. Serial blood samples were collected at a maximum of 23 time points during the 30-month trial and BDNF levels were measured in plasma samples by ELISA. Receiver Operating Characteristic (ROC) curve analysis indicated that BDNF was not a significant predictor of relapse, hospitalization or exacerbation. Regardless of treatment group (oral second generation antipsychotic vs. long-acting injectable risperidone microspheres), baseline BDNF value did not differ significantly between those who experienced any of the adverse outcomes and those who did not. While contrary to the study hypothesis, these robust results offer little support for the use of plasma BDNF alone as a biomarker to predict relapse in schizophrenia.

Interplay of Brain-Derived Neurotrophic Factor and Cytokines in Schizophrenia

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family and plays an important role in neuroplasticity, differentiation and survival of neurons, as well as their function. Neuroinflammation has been explored in the pathophysiology of many mental disorders, such as schizophrenia. Cytokines representing different types of immune responses have an impact on neurogenesis and BDNF expression. Cross-regulation of BDNF and cytokines is accomplished through several signalling pathways. Also, typical and atypical antipsychotic drugs variously modulate the expression of BDNF and serum levels of cytokines, which can possibly be used in evaluation of therapy effectiveness. Comorbidity of metabolic syndrome and atopic diseases has been considered in the context of BDNF and cytokines interplay in schizophrenia.

Brain-derived neurotrophic factor serum and plasma levels in the treatment of acute schizophrenia with olanzapine or risperidone: 6-week prospective study

Antipsychotics have been the mainstay of the treatment of schizophrenia, and their potential role in neuroprotection could be related to brain-derived neurotrophic factor (BDNF). So far different effects on both serum and plasma levels of BDNF were reported related to the various antipsychotic treatments. Aim of this study was to investigate the influence of olanzapine or risperidone on both plasma and serum levels of BDNF in patients with acute schizophrenia. For 50 participants with acute episode of schizophrenia both plasma and serum BDNF, along with the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression scale, were assessed pretreatment and post treatment - after 6 weeks of either risperidone or olanzapine. Results show that a weak correlation between pretreatment plasma and serum levels of BNDF was found no longer significant after 6 weeks of treatment. Antipsychotics, olanzapine and risperidone showed no significant effect on post treatment plasma and serum levels of BDNF. Pretreatment plasma level of BDNF and PANSS positive subscale were positively correlated. Post treatment serum level of BDNF and Clinical Global Impression were negatively correlated. In conclusion, plasma and serum BDNF levels could be different markers to some extent with regard to clinical symptoms, response to therapy and outcome. The interrelation between serum and plasma BDNF should be established in further studies.

Serum brain-derived neurotrophic factors in Taiwanese patients with drug-naïve first-episode schizophrenia: Effects of antipsychotics

OBJECTIVES

Brain-derived neurotrophic factors (BDNF) are known to be related to the psychopathology of schizophrenia. However, studies focussing on drug-naïve first-episode schizophrenia are still rare.

METHODS

Over a 5-year period, we investigated the serum BDNF levels in patients with first-episode drug-naïve schizophrenia and compared them to age- and sex-matched healthy controls. We also explored the association between antipsychotic doses, positive and negative syndrome scale (PANSS) scores, and serum BDNF levels before and after a 4-week antipsychotic treatment.

RESULTS

The baseline serum BDNF levels of 34 patients were significantly lower than those of the controls (df = 66, P = .001). Although the PANSS scores of 20 followed-up patients improved significantly after antipsychotic treatment, the elevation of the serum BDNF levels was not statistically significant (P = .386). In addition, Pearson's correlation test showed significant correlations between pre-treatment negative scale scores and percentage changes in BDNF (P = .002).

CONCLUSIONS

The peripheral BDNF levels in Taiwanese patients with drug-naïve first-episode schizophrenia, compared with healthy controls, did not elevate after antipsychotic treatment, and pre-treatment negative symptoms played a pivotal role in trajectories of serum BDNF levels. Large samples will be needed in future studies to verify these results.

Longitudinal assessment of brain-derived neurotrophic factor in Sardinian psychotic patients (LABSP): a protocol for a prospective observational study

INTRODUCTION

Brain-derived neurotrophic factor (BDNF) plays a crucial role in neurodevelopment, synaptic plasticity and neuronal function and survival. Serum and plasma BDNF levels are moderately, but consistently, decreased in patients with schizophrenia (SCZ) compared with healthy controls. There is a lack of knowledge, however, on the temporal manifestation of this decline. Clinical, illness course and treatment factors might influence the variation of BDNF serum levels in patients with psychosis. In this context, we propose a longitudinal study of a cohort of SCZ and schizophrenic and schizoaffective disorder (SAD) Sardinian patients with the aim of disentangling the relationship between peripheral BDNF serum levels and changes of psychopathology, cognition and drug treatments.

METHODS AND ANALYSIS

Longitudinal assessment of BDNF in Sardinian psychotic patients (LABSP) is a 24-month observational prospective cohort study. Patients with SAD will be recruited at the Psychiatry Research Unit of the Department of Medical Science and Public Health, University of Cagliari and University of Cagliari Health Agency, Cagliari, Italy. We will collect BDNF serum levels as well as sociodemographic, psychopathological and neurocognitive measures. Structured, semistructured and self-rating assessment tools, such as the Positive and Negative Syndrome Scale for psychopathological measures and the Brief Assessment of Cognition in Schizophrenia for cognitive function, will be used.

ETHICS AND DISSEMINATION

This study protocol was approved by the University of Cagliari Health Agency Ethics Committee (NP2016/5491). The study will be conducted in accordance with the principles of good clinical practice, in the Declaration of Helsinki in compliance with the regulations. Participation will be voluntary and written informed consent will be obtained for each participant upon entry into the study. We plan to disseminate the results of our study through conference presentations and publication in international peer-reviewed journals. Access to raw data will be available in anonymised form upon request to the corresponding author.

Biomarkers in schizophrenia: A focus on blood based diagnostics and theranostics

Identifying biomarkers that can be used as diagnostics or predictors of treatment response (theranostics) in people with schizophrenia (Sz) will be an important step towards being able to provide personalized treatment. Findings from the studies in brain tissue have not yet been translated into biomarkers that are practical in clinical use because brain biopsies are not acceptable and neuroimaging techniques are expensive and the results are inconclusive. Thus, in recent years, there has been search for blood-based biomarkers for Sz as a valid alternative. Although there are some encouraging preliminary data to support the notion of peripheral biomarkers for Sz, it must be acknowledged that Sz is a complex and heterogeneous disorder which needs to be further dissected into subtype using biological based and clinical markers. The scope of this review is to critically examine published blood-based biomarker of Sz, focusing on possible uses for diagnosis, treatment response, or their relationship with schizophrenia-associated phenotype. We sorted the studies into six categories which include: (1) brain-derived neurotrophic factor; (2) inflammation and immune function; (3) neurochemistry; (4) oxidative stress response and metabolism; (5) epigenetics and microRNA; and (6) transcriptome and proteome studies. This review also summarized the molecules which have been conclusively reported as potential blood-based biomarkers for Sz in different blood cell types. Finally, we further discusses the pitfall of current blood-based studies and suggest that a prediction model-based, Sz specific, blood oriented study design as well as standardize blood collection conditions would be useful for Sz biomarker development.

Serum levels of brain-derived neurotrophic factor (BDNF), proBDNF and plasma 3-methoxy-4-hydroxyphenylglycol levels in chronic schizophrenia

BACKGROUND

We investigated the serum levels of brain-derived neurotrophic factor (BDNF), proBDNF and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in patients with chronic schizophrenia.

METHODS

Sixty-eight patients who met the DSM-IV-TR criteria and had a chronic schizophrenia (CS) duration of ≥ 5 years were enrolled. Their serum brain-derived BDNF and proBDNF levels were measured by enzyme-linked immunosorbent assays, and their plasma MHPG levels were analyzed by high-performance liquid chromatography with electrochemical detection.

RESULTS

The plasma MHPG levels were significantly lower in the CS group (3.9  ±  1.8 ng/ml) compared to those in the group of 32 age- and sex-matched healthy controls (5.1  ±  2.4 ng/ml). The serum BDNF levels were significantly lower in the CS group (8.9  ±  4.8 ng/ml) compared to the control group (12.2.1  ±  6.8 ng/ml). No correlation was observed between plasma MHPG and BDNF in the CS group.

CONCLUSION

These results suggest that hypo-activity of noradrenergic neurons and decreased BDNF secretion exist in chronic schizophrenic patients.

Interaction of BDNF with cytokines in chronic schizophrenia

Brain-derived neurotrophic factor (BDNF) interacts with cytokines. Although both BDNF and cytokines occur at abnormal levels in schizophrenia patients, their interactions have not yet been examined. We therefore compared serum BDNF, TNF-α, interleukin (IL)-2, IL-6, and IL-8 levels in 92 chronically medicated schizophrenia patients and 60 healthy controls. We correlated these serum levels within these subject groups with each other and with clinical symptoms assessed according to the Positive and Negative Syndrome Scale (PANSS). Compared to the control group, the schizophrenia patients had significantly lower BDNF and TNF-α levels, and higher IL-2, IL-6, and IL-8 levels. The patients also showed a significant positive correlation between BDNF and both IL-2 and IL-8 levels, and low BDNF and TNF-α levels together were associated with poor performance on the PANSS cognitive factor. Thus, an interaction between cytokines and neurotrophic factors may be implicated in the pathophysiology of chronic schizophrenia. In particular, the cytokine TNF-α may interact with BNDF causing cognitive impairment.

Diagnostic Accuracy of Brain-derived Neurotrophic Factor and Nitric Oxide in Patients with Schizophrenia: A pilot study

Background

Brain-derived neurotrophic factor (BDNF) and nitric oxide (NO) play multiple roles in the developing and adult CNS. Since BDNF and NO metabolisms are dysregulated in schizophrenia, we measured these markers simultaneously in the blood of schizophrenics and assessed their diagnostic accuracy.

Methods

Thirty-eight patients with schizophrenia classified according to demographic characteristics, symptomatologyand therapy and 39 age- and gender-matched healthy controls were enrolled. BDNF was determined by the ELISA technique while the concentration of nitrite/nitrate (NO2−/NO3−) was measured by the colorimetric method.

Results

Serum BDNF levels were significantly lower (20.38±3.73 ng/mL, P = 1.339E-05), whilst plasma NO2−/NO3− concentrations were significantly higher (84.3 (72–121) μmol/L, P=4.357E-08) in patients with schizophrenia than in healthy controls (25.65±4.32 ng/mL; 60.9 (50–76) μmol/L, respectively). The lowest value of BDNF (18.14±3.26 ng/mL) and the highest NO2−/NO3− concentration (115.3 (80–138) μmol/L) were found in patients treated with second-generation antipsychotics (SGA). The patients diseased before the age of 24 and the patients suffering for up to one year had significantly lower serum BDNF levels than those diseased after the age of 24 and the patients who were ill longer than one year. Both BDNF and NO2−/NO3− showed good diagnostic accuracy, but BDNF had better ROC curve characteristics, especially in patients with negative symptomatology.

Conclusions

BDNF and nitrite/nitrate showed inverse changes in schizophrenic patients. The most pronounced changes were found in patients treated with second-generation antipsychotics. Although BDNF is not specific of schizophrenia, it may be a clinically useful biomarker for the diagnosis of patients expressing predominantly negative symptoms.

Peripheral brain-derived neurotrophic factor in schizophrenia and the role of antipsychotics: meta-analysis and implications

It has been postulated that schizophrenia (SZ) is related to a lower expression of brain-derived neurotrophic factor (BDNF). In the past few years, an increasing number of divergent clinical studies assessing BDNF in serum and plasma have been published. It is now possible to verify the relationship between BDNF levels and severity of symptoms in SZ as well as the effects of antipsychotic drugs on BDNF using meta-analysis. The aims of this study were to verify if peripheral BDNF is decreased in SZ, whether its levels are correlated with positive and negative symptomatology and if BDNF levels change after antipsychotic treatment. This report consists of two distinct meta-analyses of peripheral BDNF in SZ including a total of 41 studies and more than 7000 participants: (1) peripheral BDNF levels in serum and plasma were moderately reduced in SZ compared with controls. Notably, this decrease was accentuated with the disease duration. However, the extent of peripheral BDNF level decrease did not correlate with the severity of positive and negative symptoms. (2) In plasma, but not serum, peripheral BDNF levels are consistently increased after antipsychotic treatment irrespective of the patient's response to medication. In conclusion, there is compelling evidence that there are decreased levels of peripheral BDNF in SZ, in parallel to previously described reduced cerebral BDNF expression. It remains unclear whether these systemic changes are causally related to the development of SZ or if they are merely a pathologic epiphenomenon.

Use of translational pharmacodynamic biomarkers in early-phase clinical studies for schizophrenia

Schizophrenia is a severe mental disorder characterized by cognitive deficits, and positive and negative symptoms. The development of effective pharmacological compounds for the treatment of schizophrenia has proven challenging and costly, with many compounds failing during clinical trials. Many failures occur due to disease heterogeneity and lack of predictive preclinical models and biomarkers that readily translate to humans during early characterization of novel antipsychotic compounds. Traditional early-phase trials consist of single- or multiple-dose designs aimed at determining the safety and tolerability of an investigational compound in healthy volunteers. However, by incorporating a translational approach employing methodologies derived from preclinical studies, such as EEG measures and imaging, into the traditional Phase I program, critical information regarding a compound's dose-response effects on pharmacodynamic biomarkers can be acquired. Furthermore, combined with the use of patients with stable schizophrenia in early-phase clinical trials, significant 'de-risking' and more confident 'go/no-go' decisions are possible.

A longitudinal study of alterations of hippocampal volumes and serum BDNF levels in association to atypical antipsychotics in a sample of first-episode patients with schizophrenia

Background

Schizophrenia is associated with structural and functional abnormalities of the hippocampus, which have been suggested to play an important role in the formation and emergence of schizophrenia syndrome. Patients with schizophrenia exhibit significant bilateral hippocampal volume reduction and progressive hippocampal volume decrease in first-episode patients with schizophrenia has been shown in many neuroimaging studies. Dysfunction of the neurotrophic system has been implicated in the pathophysiology of schizophrenia. The initiation of antipsychotic medication alters the levels of serum Brain Derived Neurotrophic Factor (BDNF) levels. However it is unclear whether treatment with antipsychotics is associated with alterations of hippocampal volume and BDNF levels.

Methods

In the present longitudinal study we investigated the association between serum BDNF levels and hippocampal volumes in a sample of fourteen first-episode drug-naïve patients with schizophrenia (FEP). MRI scans, BDNF and clinical measurements were performed twice: at baseline before the initiation of antipsychotic treatment and 8 months later, while the patients were receiving monotherapy with second generation antipsychotics (SGAs).

Results

We found that left hippocampal volume was decreased (corrected left HV [t = 2.977, df = 13, p = .011] at follow-up; We also found that the higher the BDNF levels change the higher were the differences of corrected left hippocampus after 8 months of treatment with atypical antipsychotics (Pearson r = 0.597, p = 0.024).

Conclusions

The association of BDNF with hippocampal volume alterations in schizophrenia merits further investigation and replication in larger longitudinal studies.

Vascular endothelial growth factor and brain-derived neurotrophic factor in quetiapine treated first-episode psychosis

Objective. It has been suggested that atypical antipsychotics confer their effects via brain-derived neurotrophic factor (BDNF). We investigated the effect of quetiapine on serum levels of BDNF and vascular endothelial growth factor (VEGF) in drug-naive first-episode psychosis subjects. Methods. Fifteen patients drawn from a larger study received quetiapine treatment for twelve weeks. Baseline levels of serum BDNF and VEGF were compared to age- and sex-matched healthy controls and to levels following treatment. Linear regression analyses were performed to determine the relationship of BDNF and VEGF levels with outcome measures at baseline and week 12. Results. The mean serum BDNF level was significantly higher at week 12 compared to baseline and correlated with reductions in Brief Psychiatric Rating Scale (BPRS) and general psychopathology scores. Changes in serum VEGF levels also correlated significantly with a reduction in BPRS scores, a significant improvement in PANNS positive symptoms scores, and displayed a positive relationship with changes in BDNF levels. Conclusions. Our findings suggest that BDNF and VEGF are potential biomarkers for gauging improvement of psychotic symptoms. This suggests a novel neurotrophic-based mechanism of the drug effects of quetiapine on psychosis. This is the first report of VEGF perturbation in psychosis.

Switching to antipsychotic monotherapy can improve attention and processing speed, and social activity in chronic schizophrenia patients

OBJECTIVE

This study sought to examine whether switching polypharmacy therapy to monotherapy would improve the cognitive function and social function of patients with schizophrenia.

METHODS

Thirty-nine patients with schizophrenia who were receiving therapy with two antipsychotics were randomly divided into a switch to monotherapy group (switching group) and a polypharmacy continued group (continuing group). For the patients allocated to the switching group, the dose level of one of the two antipsychotic drugs was gradually reduced to zero. Psychotic symptoms, cognitive function and social function scale scores were assessed immediately before and 24 weeks after switching, and the time courses of these scores were compared between the two groups.

RESULTS

Compared with the continuing group, the switching group demonstrated significantly greater improvement in attention after switching (p = 0.02). Furthermore, the improvement in daily living (p = 0.038) and work skills (p = 0.04) was significantly greater in the switching group. In an analysis of the correlation among sub-items with respect to the degrees of improvement, a significant correlation was noted between improvement in executive function and improvement in daily living (r = -0.64, p = 0.005) and between improvement in work skills and improvement in attention (r = -0.51, p = 0.038).

CONCLUSION

In patients with schizophrenia receiving polypharmacy, switching to monotherapy resulted in improvements in attention. Furthermore, improvements in executive function led to improvements in daily living, and improvements in attention led to improvements in work skills. Thus, switching to monotherapy is a useful option.

Pharmacogenetics of clinical response to risperidone

Despite risperidone's proven safety and efficacy, existing pharmacogenetic knowledge could be applied to improve its clinical use. The present work aims to summarize the information about genetic polymorphisms affecting risperidone adverse reactions and efficacy during routine clinical practice. The most relevant genes involved in the metabolism of the drug (i.e., CYP2D6, CYP3A and ABCB1) appear to have the greatest potential to predict differences in plasma concentrations of the drug and its interactions, but also relate to side effects, such as neuroleptic syndrome, weight gain or polydipsia. Other genes that have been found in association at least twice with any adverse reactions including metabolic changes, extrapyramidal symptoms or prolactine increase are: 5HT2A; 5HT2C; 5HT6; DRD2; DRD3; and BDNF. Some of these genes (5HTR2A, DRD2 and DRD3), along with 5-HTTLPR and COMT, have also been reported to be related with negative clinical outcomes. However, there is not yet enough evidence to support their routine screening during clinical practice.

BDNF-TrkB signaling and neuroprotection in schizophrenia

Neurotrophins such as brain-derived neurotropic factor (BDNF), play critical role in neuronal survival, synaptic plasticity and cognitive functions. BDNF is known to mediate its action through various intracellular signaling pathways triggered by activation of tyrosine kinase receptor B (TrkB). Evidence from clinical as well pre-clinical studies indicate alterations in BDNF signaling in schizophrenia. Moreover, several antipsychotic drugs have time-dependent effects on BDNF levels in both schizophrenia subjects and animal models of schizophrenia. Given the emerging interest in neuroplasticity in schizophrenia understanding the neuroprotective and cell survival roles of BDNF signaling will enhance our knowledge of its diverse effects, which may lead to more effective treatments for schizophrenia. This article will present an overview of recent findings on the role of BDNF signaling in the pathophysiology and treatment of schizophrenia, with a special focus on its neuroprotective effects.

Trauma profile in Egyptian adolescents with first-episode schizophrenia: relation to psychopathology and plasma brain-derived neurotrophic factor

We aimed to investigate the relation of trauma profile to schizophrenia psychopathology in a sample of Egyptian drug-naïve adolescent patients with first-episode schizophrenia. In addition, a hypothesized mediating effect of brain-derived neurotrophic factor (BDNF) in this relation was formally tested. We assessed 74 eligible outpatients using the Positive and Negative Syndrome Scale (PANSS) for measuring psychopathology. Trauma histories were recorded with the help of the Cumulative Trauma Measure. Serum BDNF levels were estimated by enzyme-linked immunosorbent assay. Total cumulative trauma, personal identity trauma, and survival trauma were found to be the significant predictors for schizophrenia psychopathology. BDNF fully mediated the associations between total cumulative trauma and overall schizophrenia psychopathology. BDNF also mediated the associations between some types of trauma and both PANSS-positive and PANSS-negative symptom factors. We concluded that total cumulative trauma and certain trauma types are linked with schizophrenia psychopathology. BDNF appears to mediate these links.

Reliable biomarkers and predictors of schizophrenia and its treatment

Biomarkers are chemical and physiologic parameters that can provide reliable and predictive information about the course and treatment of a given illness. Biomarkers are being increasingly sought after in other medical conditions, and in some instances (eg, breast cancer therapy) are beginning to be incorporated into clinical decision making. There is a confluence of research investigating potential biomarkers for schizophrenia. This article reviews early progress and strategies for evaluating biomarkers, as well as how this approach can advance the treatment of schizophrenia toward personalized medicine.

Inflammation in patients with schizophrenia: the therapeutic benefits of risperidone plus add-on dextromethorphan

Increasing evidence suggests that inflammation contributes to the etiology and progression of schizophrenia. Molecules that initiate inflammation, such as virus- and toxin-induced cytokines, are implicated in neuronal degeneration and schizophrenia-like behavior. Using therapeutic agents with anti-inflammatory or neurotrophic effects may be beneficial for treating schizophrenia. One hundred healthy controls and 95 Han Chinese patients with schizophrenia were tested in this double-blind study. Their PANSS scores, plasma interleukin (IL)-1β, tumor necrosis factor-α (TNF-α) and brain-derived neurotrophic factor (BDNF) levels were measured before and after pharmacological treatment. Pretreatment, plasma levels of IL-1β and TNF-α were significantly higher in patients with schizophrenia than in controls, but plasma BDNF levels were significantly lower. Patients were treated with the atypical antipsychotic risperidone (Risp) only or with Risp+ dextromethorphan (DM). PANSS scores and plasma IL-1β levels significantly decreased, but plasma TNF-α and BDNF levels significantly increased after 11 weeks of Risp treatment. Patients in the Risp+ DM group showed a greater and earlier reduction of symptoms than did those in the Risp-only group. Moreover, Risp+ DM treatment attenuated Risp-induced plasma increases in TNF-α. Patients with schizophrenia had a high level of peripheral inflammation and a low level of peripheral BDNF. Long-term Risp treatment attenuated inflammation and potentiated the neurotrophic function but also produced a certain degree of toxicity. Risp+ DM was more beneficial and less toxic than Risp-only treatment.

CLINICAL TRIAL REGISTRATION

Protocol Record: HR-93-50;

TRIAL REGISTRATION NUMBER

NCT01189006; URL: http://www.clinicaltrials.gov.

Steroid psychosis in a polyarteritis nodosa patient successfully treated with risperidone: tracking serum brain-derived neurotrophic factor levels longitudinally

We previously reported a case in which steroid-induced psychosis was eliminated with risperidone treatment in a patient with polyarteritis nodosa (PN). In the present report, we longitudinally tracked the serum levels of brain-derived neurotrophic factor (BDNF). We found that corticosteroid lowered serum BDNF levels, and improvement of psychiatric symptoms was intact with the serum BDNF levels seen in the patients.

Aripiprazole altered plasma levels of brain-derived neurotrophic factor and catecholamine metabolites in first-episode untreated Japanese schizophrenia patients

OBJECTIVE

We investigated the effects of aripiprazole on plasma levels of brain-derived neurotrophic factor (BDNF) and catecholamine metabolites in first-episode untreated schizophrenia patients.

METHODS

The subjects were 50 Japanese first-episode untreated schizophrenia patients who met the Diagnostic and Statistical Manual of Mental Disorders Text Revision criteria and were treated with aripiprazole monotherapy. Twenty-nine were males, and 21 were females. The age ranged from 21 to 42 years (mean ± SD; 30.8 ± 5.3 years). Plasma BDNF and catecholamine metabolites were measured by ELISA and HPLC, respectively. Psychiatric symptoms were evaluated using by Positive and Negative Syndrome Scale.

RESULTS

Treatment with aripiprazole for 8 weeks significantly increased plasma BDNF levels. It also changed plasma levels of homovanillic acid and 3-methoxy-4-hydroxyphenylglycol. A negative correlation was also observed between duration of psychosis and plasma BDNF levels. No correlation was observed however between plasma BDNF levels and the dose of aripiprazole.

CONCLUSIONS

To the best of our knowledge, this is the first report showing that aripiprazole increases plasma BDNF levels in first-episode untreated schizophrenia patients. Furthermore, the BDNF Val66Met polymorphism was independent of the response to aripiprazole.

The role of BDNF in the pathophysiology and treatment of schizophrenia

Brain derived neurotrophic factor (BDNF) has been associated with the pathophysiology of schizophrenia (SCZ). However, it remains unclear whether alterations in BDNF observed in patients with SCZ are a core part of disease neurobiology or a consequence of treatment. In this manuscript we review existing knowledge relating the function of BDNF to synaptic transmission and neural plasticity and the relationship between BDNF and both pharmacological and non-pharmacological treatments for SCZ. With regards to synaptic transmission, exposure to BDNF or lack of this neurotrophin results in alteration to both excitatory and inhibitory synapses. Many authors have also evaluated the effects of both pharmacological and non-pharmacological treatments for SCZ in BDNF and despite some controversial results, it seems that medicated and non-medicated patients present with lower levels of BDNF when compared to controls. Further data suggests that typical antipsychotics may decrease BDNF expression whereas mixed results have been obtained with atypical antipsychotics. The authors found few studies reporting changes in BDNF after non-pharmacological treatments for SCZ, so the existing evidence in this area is limited. Although the study of BDNF provides some new insights into understanding of the pathophysiology and treatment of SCZ, additional work in this area is needed.

Effects of antipsychotics on the serum BDNF levels in schizophrenia

Brain-derived neurotrophic factor (BDNF) is active during a critical developmental period and likely influences the neuroplasticity of schizophrenia. This study longitudinally examined the effects of atypical antipsychotics on serum BDNF levels in schizophrenic patients. Specifically, this study measured serum BDNF levels in 53 patients with paranoid schizophrenia during a relapse and again 4 weeks following the administration of antipsychotic treatment (with risperidone in 32 cases, and clozapine in 21 cases). BDNF levels remained unchanged relative to study entry after 4 weeks of atypical antipsychotic treatment. However, serum BDNF was significantly increased in the subgroup receiving risperidone compared to that receiving clozapine, albeit only in the 15 male subjects and not in the 17 females. These results suggest that gender might significantly influence the antipsychotic treatment of schizophrenia from the perspective of BDNF. These findings may also indicate that the treatment with atypical antipsychotic agents differentially affects BDNF levels.

Brain-derived neurotrophic factor levels in schizophrenia: a systematic review with meta-analysis

Brain-derived neurotrophic factor (BDNF) regulates the survival and growth of neurons, and influences synaptic efficiency and plasticity. Several studies report reduced peripheral (blood) levels of BDNF in schizophrenia, but findings are inconsistent. We undertook the first systematic review with meta-analysis of studies examining blood BDNF levels in schizophrenia compared with healthy controls, and examined potential effects of age, gender and medication. Included are individual studies of BDNF blood (serum or plasma) levels in schizophrenia (including schizoaffective disorder, or first episode psychosis), compared with age-matched healthy controls, obtained by electronic Medline and Embase searches, and hand searching. The decision to include or exclude studies, data extraction and quality assessment were completed by two independent reviewers. The initial search revealed 378 records, of which 342 were excluded on reading the Abstract, because they did not examine BDNF blood levels in schizophrenia compared with healthy controls. Of 36 papers screened in full, 17 were eligible for inclusion, but one was subsequently removed as an outlier. The remaining 16 studies provided moderate quality evidence of reduced blood BDNF levels in schizophrenia (Hedges g=-0.458, 95% confidence interval=-0.770 to -0.146, P<0.004, random effects model). Subgroup analyses reveal reduced BDNF in both drug-naïve and medicated patients, and in males and females with schizophrenia. Meta-regressions showed an association between reduced BDNF in schizophrenia and increasing age, but no effects of medication dosage. Overall, blood levels of BDNF are reduced in medicated and drug-naïve patients with schizophrenia; this evidence is of moderate quality, that is, precise but with considerable, unexplained heterogeneity across study results.

Mechanisms of antidepressant action: an integrated dopaminergic perspective

The molecular mechanisms that cause and maintain the major depressive disorder (MDD) are currently unknown. Consistently, antidepressant treatments are characterized by insufficient success rates. This causes high social costs and severe personal sufferings. In the present review we analyze some of the paradigms that are used to explain MDD, particularly from the perspective of the dopaminergic (DA) system. DA has been more classically associated with psychosis and substance abuse disorders, even though a role of DA in MDD has been proposed as well and some antidepressants with DA profile exist. In the present work, we review some of the molecular mechanisms that underpin MDD from the perspective of the dopaminergic system, in the hope of unifying some of the major theories of MDD - the monoaminergic, inflammatory, epigenetics, neurotrophin and anti-apoptotic theories. Several shared components of these theories are highlighted, partially accounted by the functions of the DA system (see supplementary video).

Abnormal plasma monoamine metabolism in schizophrenia and its correlation with clinical responses to risperidone treatment

Abnormalities in plasma monoamine metabolism reflect partly the illness of schizophrenia and sometimes the symptoms. Such studies have been repeatedly reported but have rarely taken both metabolites and parent amines or inter-amine activity ratios into account. In this study, the monoamines, their metabolites, turnovers and between-metabolite ratios in plasma were measured longitudinally in 32 schizophrenic patients treated with risperidone for 6 weeks, to examine possible biochemical alterations in schizophrenia, and to examine the association between treatment responses and psychopathology assessed according to the Positive and Negative Syndrome Scale (PANSS). The results showed lower level of plasma 3,4-dihydroxyphenylacetic acid (DOPAC) in relapsed versus first-episode schizophrenic patients, higher norepinephrine (NE) turnover rate (TR) in undifferentiated in comparison to paranoid schizophrenic patients and relatively higher metabolic activity of dopamine (DA) to serotonin (5-HT) in first-episode versus relapsed schizophrenic patients. Risperidone treatment induced a decrement of plasma DA levels and increments of plasma DOPAC and DA TR in the total group of schizophrenic patients. The turnover rate of 5-HT was was reduced in undifferentiated and relapsed subgroups of schizophrenic patients. The linkages between 5-HT TR, DA/NE relative activity and clinical symptomatology were also identified. These findings are consistent with an involvement of these systems in the pathogenesis of schizophrenia as well as in the responses to treatment, and the usefulness of certain biochemical indices as markers for subgrouping.

Decreased serum brain-derived neurotrophic factor levels in schizophrenic patients with tardive dyskinesia

The pathogenesis of tardive dyskinesia (TD) may involve neurodegeneration and associated dysfunction of brain-derived neurotrophic factor (BDNF) for the survival and maintenance of function in neurons. We therefore compared serum BDNF levels in schizophrenic patients with (n=129) and without TD (n=235), and normal controls (n=323). Assessments included the abnormal involuntary movement scale (AIMS) and the positive and negative syndrome scale (PANSS). Our results were that patients with TD had lower serum BDNF levels than those without TD and normals. Lower serum BDNF levels were correlated with greater PANSS negative subscores, but not correlated with the AIMS scores. Serum BDNF levels did not differ between patients on typical and atypical antipsychotics and were not correlated with antipsychotic doses or years of exposure. We concluded that decreased BDNF levels might be associated with TD pathophysiology and more negative symptoms of schizophrenia.

No association between BDNF Val66Met polymorphism and emergence of psychiatric symptoms in systemic lupus erythematosus patients

BACKGROUND

Brain-derived neurotrophic factor (BDNF) plays an important role in the regulation of synaptic plasticity and neurotransmitter release across multiple neurotransmitter systems. Recent studies have suggested that BDNF plays a role in the pathogenesis of psychiatric symptoms in patients with systemic lupus erythematosus (SLE).

OBJECTIVES

We hypothesized that the polymorphism of BDNF Val66Met is associated with the emergence of psychiatric symptoms (PS) and serum BDNF levels in SLE patients. To examine the hypothesis, we compared the BDNF Val66Met polymorphism and serum BDNF levels in patients with SLE with or without PS.

METHODS

Psychiatric symptoms were assessed in 54 patients with SLE. PS were evaluated using the Brief Psychiatric Rating Scale. Genotyping was carried out using a 54-nuclease assay. Serum BDNF levels were measured by using enzyme-linked immunosorbent assay.

RESULTS

The presence of the Met allele was not significantly associated with the presence of PS or with serum BDNF levels in patients with SLE.

CONCLUSION

Our data do not support the common variant Val66Met of the BDNF gene as an etiologic factor in the various forms of PS and serum BDNF levels in SLE.

Reduced brain-derived neurotrophic factor serum concentrations in acute schizophrenic patients increase during antipsychotic treatment

INTRODUCTION

Brain-derived neurotrophic factor (BDNF) is not only involved in the development, differentiation, and survival of dopaminergic neurons; it also regulates fast neurotransmission and neuronal activity.

METHODS

In this study, 22 patients with acute schizophrenia and 22 age-matched healthy volunteers were recruited, and BDNF serum concentrations were measured in unmedicated patients and after 2 weeks and 4 weeks of medication.

RESULTS

Brain-derived neurotrophic factor serum levels of unmedicated schizophrenic patients (n = 22; 4.38 ± 2.1 ng/mL) were significantly decreased compared to the age-matched healthy volunteers (n = 44, df = 42, P = 0.029). In a mixed-model repeated-measures analysis of variance, a significant BDNF increase has been found during treatment (χ² = 2.91; df = 1; P < 0.0001). The percental change of BDNF (increase, 173% ± 110) correlated negatively with the percental change of PANSS score (decrease: 75% ± 22; n = 18; r = -0.554; P = 0.032).

CONCLUSIONS

Our study replicates studies showing that unmedicated patients with schizophrenia have decreased serum BDNF levels compared with healthy controls. Brain-derived neurotrophic factor increase during treatment seems to parallel positive and negative symptom improvement.

Relationships between stress, social adaptation, personality traits, brain-derived neurotrophic factor and 3-methoxy-4-hydroxyphenylglycol plasma concentrations in employees at a publishing company in Japan

There is growing evidence that blood levels of brain-derived neurotrophic factor (BDNF) and 3-methoxy-4-hydroxyphenylglycol (MHPG), a major metabolite of noradrenaline, are related to depression-associated personality traits as well as to depressive, suicidal and anxious states. Psychological job stress is well known to lead to symptoms of depression, anxiety and suicide. We have recently reported that psychological job stress among hospital employees altered blood levels of BDNF and MHPG (Mitoma et al., 2008). In the present study, we re-examined the effects of social adaptation and personality traits, as well as those of psychological job stress, on plasma levels of BDNF and MHPG in healthy employees (n=269, male/female=210/59, age=49 ± 10years) working in a publishing company in Japan. The values (mean ± SD) of scores on the Stress and Arousal Check Lists (s-SACL and a-SACL), Social Adaptation Self-evaluation Scale (SASS), plasma MHPG levels and plasma BDNF levels were 6.0 ± 3.4, 5.7 ± 2.3, 33.7 ± 6.8, 5.8 ± 4.3 and 4.6 ± 3.1ngml(-1), respectively. A positive correlation was found between plasma MHPG levels and scores on the s-SACL, but not the a-SACL. A positive correlation was also found between SASS scores and plasma MHPG levels and between SASS scores and plasma BDNF levels. A negative correlation was found between plasma BDNF levels and s-SACL scores. Furthermore, a positive correlation between NEO-Five factor Inventory (Openness) scores and plasma MHPG levels was observed, as well as between NEO-Five factor Inventory (Extroversion) scores and plasma BDNF levels. These results suggest that levels of plasma BDNF and plasma MHPG might be associated with psychological job stress and certain personality traits among employees in the publishing industry in Japan.

Comparison of brain N-acetylaspartate levels and serum brain-derived neurotrophic factor (BDNF) levels between patients with first-episode schizophrenia psychosis and healthy controls

BACKGROUND

N-acetylaspartate (NAA) levels and serum brain-derived neurotrophic factor (BDNF) levels in patients with first-episode schizophrenia psychosis and age- and sex-matched healthy control subjects were investigated. In addition, plasma levels of homovanillic acid (HVA) and 3-methoxy-4-hydroxyphenylglycol (MHPG) were compared between the two groups.

METHOD

Eighteen patients (nine males, nine females; age range: 13-52 years) were enrolled in the study, and 18 volunteers (nine males, nine females; age range: 15-49 years) with no current or past psychiatric history were also studied by magnetic resonance spectroscopy (MRS) as sex- and age-matched controls.

RESULTS

Levels of NAA/Cr in the left basal ganglia (p=0.0065) and parieto-occipital lobe (p=0.00498), but not in the frontal lobe, were significantly lower in patients with first-episode schizophrenia psychosis than in control subjects. No difference was observed between the serum BDNF levels of patients with first-episode schizophrenia psychosis and control subjects. In regard to the plasma levels of catecholamine metabolites, plasma MHPG, but not HVA, was significantly lower in the patients with first-episode psychosis than in control subjects. In addition, a significantly positive correlation was observed between the levels of NAA/Cr of the left basal ganglia and plasma MHPG in all subjects.

CONCLUSION

These results suggest that brain NAA levels in the left basal ganglia and plasma MHPG levels were significantly reduced at the first episode of schizophrenia psychosis, indicating that neurodegeneration via noradrenergic neurons might be associated with the initial progression of the disease.

Brain-derived neurotrophic factor: findings in schizophrenia

PURPOSE OF REVIEW

To review the role of brain-derived neurotrophic factor (BDNF) in neuroplasticity related to schizophrenia and the recent findings that have been reported on the status of BDNF in patients with schizophrenia and its association with the clinical measures.

RECENT FINDINGS

Peripheral BDNF levels have been found altered in first-episode patients with psychosis and also in chronic schizophrenia patients. A few studies have reported changes in peripheral BDNF levels following antipsychotic treatment. The role of Val66Met polymorphism in BDNF has been shown to play an important role in structural and functional plasticity in schizophrenia.

SUMMARY

Although peripheral BDNF levels hold promise for providing new perspectives for the development of novel therapeutic strategies for the treatment of schizophrenia, additional studies including efforts to prove its potential as a biomarker are warranted.

Quetiapine and norquetiapine in plasma and cerebrospinal fluid of schizophrenic patients treated with quetiapine: correlations to clinical outcome and HVA, 5-HIAA, and MHPG in CSF

This study investigated concentrations of quetiapine and norquetiapine in plasma and cerebrospinal fluid (CSF) in 22 schizophrenic patients after 4-week treatment with quetiapine (600 mg/d), which was preceded by a 3-week washout period. Blood and CSF samples were obtained on days 1 and 28, and CSF levels of homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylglycol (MHPG) concentrations were measured at baseline and after 4 weeks of quetiapine, allowing calculations of differences in HVA (ΔHVA), 5-HIAA (Δ5-HIAA), and MHPG (ΔMHPG) concentrations. Patients were assessed clinically, using the Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression Scale at baseline and then at weekly intervals. Plasma levels of quetiapine and norquetiapine were 1110 ± 608 and 444 ± 226 ng/mL, and the corresponding CSF levels were 29 ± 18 and 5 ± 2 ng/mL, respectively. After the treatment, the levels of HVA, 5-HIAA, and MHPG were increased by 33%, 35%, and 33%, respectively (P < 0.001). A negative correlation was found between the decrease in PANSS positive subscale scores and CSF ΔHVA (r(rho) = -0.690, P < 0.01), and the decrease in PANSS negative subscale scores both with CSF Δ5-HIAA (r(rho) = -0.619, P = 0.02) and ΔMHPG (r(rho) = -0.484, P = 0.038). Because, unfortunately, schizophrenic patients experience relapses even with the best available treatments, monitoring of CSF drug and metabolite levels might prove to be useful in tailoring individually adjusted treatments.

Adding a low dose atypical antipsychotic drug to an antidepressant induced a rapid increase of plasma brain-derived neurotrophic factor levels in patients with treatment-resistant depression

Only two-thirds of depressive patients respond to antidepressant treatment. Recently, addition of an atypical antipsychotic drug to ongoing treatment with an antidepressant has been considered effective and well-tolerated. In the present study, we examined the effects of various atypical antipsychotic drugs as adjuvant to antidepressants, including selective serotonin reuptake inhibitors (SSRIs), serotonin noradrenaline reuptake inhibitors, tricyclic antidepressants and mood stabilizers, on plasma BDNF levels in refractory depressed patients. Forty-five patients who met the DSM-IV criteria for major depressive disorder (n=31) or bipolar disorder (10 with bipolar I, 4 with bipolar II) were enrolled in the study. Twenty-one were male and 24 were female, and their ages ranged from 28 to 71 (mean+/-SD=49+/-12) years. Plasma BDNF levels were measured using a sandwich ELISA. The plasma BDNF levels in responders (those showing a decline in HAM-D scores of 50% or more) were significantly increased 4weeks after the administration of each atypical antipsychotic drug, while the levels in non-responders were not changed. Furthermore, there was a significant correlation between the changes in HAM-D scores and the changes in plasma BDNF levels. These results suggest that adding an atypical antipsychotic drug to ongoing treatment with an antidepressant or mood stabilizer is useful and well-tolerated for refractory depressed patients, and the efficacy of atypical antipsychotics as an adjuvant might involve an increase of plasma BDNF levels.

Different patterns of longitudinal changes in plasma levels of catecholamine metabolites and brain-derived neurotrophic factor after administration of atypical antipsychotics in first episode untreated schizophrenic patients

In the present study, we longitudinally investigated the effects of risperidone, olanzapine, and aripiprazole on plasma levels of catecholamine metabolites and brain-derived neurotrophic factor (BDNF) in first-episode unmedicated schizophrenic patients. The subjects were 59 Japanese schizophrenic patients (35 males and 24 females; age range: 18-46 years; mean+/-SD: 25+/-16 years). The patients were treated with risperidone (n=32) in a dose range of 2-6 mg/day (mean+/-SD=3.4+/-1.9), olanzapine (n=18) in a dose range of 5-20 mg/day (mean+/-SD=12.1+/-5.8), or aripiprazole (n=9) in a dose range of 12-30 mg/day (mean+/-SD=22.8+/-10.1). All three drugs significantly decreased plasma homovanillic acid (HVA) levels within 8 weeks, although aripiprazole transiently raised this level before 8 weeks. All three drugs also significantly increased plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels within 8 weeks. On the other hand, none of them altered plasma BDNF levels. These results indicate that risperidone, olanzapine, and aripiprazole affect catecholaminergic systems in the brain, that the effects of aripiprazole on the dopaminergic systems seem to slightly different than those of risperidone and olanzapine, and that these atypical antipsychotic drugs might not alter BDNF levels, at least within 8 weeks of treatment.

Serum brain-derived neurotrophic factor levels as a novel biological marker for the activities of psychiatric symptoms in systemic lupus erythematosus

OBJECTIVES

Neuropsychiatric systemic lupus erythematosus (NPSLE) is a serious but potentially treatable disease. However, biological markers such as IgG index or IL-6 do not always reflect the severity of the psychotic symptoms of NPSLE. We hypothesized that serum BDNF levels may be a biological marker for reflecting the severity of the psychiatric symptoms of NPSLE.

METHODS

The participants enrolled in this study were 28 healthy volunteers and 54 Japanese SLE inpatients at the University Hospital of Occupational and Environmental Health, all of whom fulfilled the criteria for the classification of SLE. SLE patients were divided into the three groups: NPSLE with psychiatric symptoms including an acute confusional state, anxiety disorder, cognitive dysfunction, mood disorder, and psychosis (NP group); NPSLE without psychiatric symptoms (NN group); and SLE without neuropsychiatric symptoms (S group). The serum BDNF levels were measured by ELISA.

RESULTS

Serum BDNF levels were significantly increased in the NP group (mean +/- SE = 37.0 +/- 5.46 ng/ml) compared with those in the other three groups (NN group; mean +/- SE = 9.1 +/- 2.44 ng/ml, P < 0.0001, S group; mean +/- SE = 10.4 +/- 2.51 ng/ml, P < 0.0001, healthy control; mean +/- SE = 11.44 +/- 0.69, P < 0.0001). Subsequently, serum BDNF levels were decreased in parallel with the improvement of psychiatric symptoms in the NP group.

CONCLUSION

These results suggest that serum BDNF is a biological marker for the severity of psychiatric symptoms in NPSLE patients.

Reduced serum BDNF levels in patients with chronic schizophrenic disorder in relapse, who were treated with typical or atypical antipsychotics

Brain-derived neurotrophic factor signals and dopaminergic function in the brain are strongly associated, and research on BDNF in schizophrenia may enhance our insights on the pathophysiological mechanisms of this disease. In the present study we aimed to investigate the possible association between serum BDNF levels and schizophrenic relapses and the possible differential effects of treatment with typical and atypical antipsychotics on serum BDNF levels in the same group of patients. We measured serum BDNF levels in 47 patients with schizophrenia during a relapse and again 6 weeks after administration of antipsychotic treatment (14 on risperidone, 18 on haloperidol, 10 on olanzapine and five on amisulpride) and in 44 healthy volunteers. Patients with schizophrenia showed reduced serum BDNF levels in relation to healthy volunteers at study entry. No significant differences were revealed in BDNF serum levels after 6 weeks of antipsychotic treatment in the patients compared to their own levels at study entry. However, serum BDNF was significantly increased in the subgroup receiving olanzapine compared to the other antipsychotics. Our findings may indicate a differential effect of olanzapine on BDNF levels compared to haloperidol, risperidone, and amisulpride.

Blood levels of catecholamine metabolites and brain-derived neurotrophic factor in a case of Sydenham's chorea

We report a case of Sydenham's chorea with neuropsychiatric symptoms who was successfully treated with low-dose risperidone. We also longitudinally investigated serum BDNF levels and plasma levels of catecholamine metabolite in the patient. Serum BDNF levels were increased and plasma levels of HVA and MHPG were decreased according to the recovery from the active phase of the disease. These results suggest that dysfunctions of catecholaminergic neurons and neurotrophic factors might exist in Sydenham's chorea, and the decreasing catecholamine activities in response to risperidone might be associated with the improvement of the disease.

Associations between plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) and negative symptoms or cognitive impairments in early-stage schizophrenia

Schizophrenic patients demonstrate a variety of cognitive deficits, including attention, executive functions, and working memory, even in the early stage of disease. In the present study, we examined the association between blood levels of 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), or brain-derived neurotrophic factor (BDNF) and scores on the Wisconsin Card Sorting Test (WCST) in patients with early-stage schizophrenia. We also investigated the association between frontal GABA levels using 1H-magnetic resonance spectroscopy (MRS) at 3T and scores on the WCST in the same patients. Blood levels of BDNF and catecholamine metabolites and brain GABA levels using 1H-MRS were measured in 18 schizophrenic patients (nine males, nine females; age range 13-52 year). A significantly positive correlation was observed between plasma MHPG levels and %PEM (rho = -0.686, p = 0.0047). A trend toward negative correlation was found between frontal lobe GABA levels and the per cent of preservation error (%PEM) in the early stage of schizophrenia (rho = -0.420, p = 0.0836). These results suggest that noradrenergic neurons might be involved in neuropsychological functions in early-stage of schizophrenia.

Stress at work alters serum brain-derived neurotrophic factor (BDNF) levels and plasma 3-methoxy-4-hydroxyphenylglycol (MHPG) levels in healthy volunteers: BDNF and MHPG as possible biological markers of mental stress?

There is growing evidence that blood levels of brain-derived neurotrophic factor (BDNF) and catecholamine, and cytokines are related to not only to depressive, suicidal, and anxious states but also to depression-associated personality traits. Psychological job stress is well known to lead to symptoms of depression and anxiety. In the present study, we examined effects of psychological job stress on serum levels of BDNF and plasma levels of catecholamine metabolites, and cytokines in healthy volunteers (n=106, male/female=42/64, age=36+/-12 yr) working in a hospital setting. The values (mean+/-SD) of scores for stress items in the Stress and Arousal Check List (s-SACL), plasma MHPG levels, and, serum BDNF levels in all participants were 7.2+/-3.3, 5.2+/-3.4 ng/mL, and 23.3+/-14.7 ng/mL, respectively. A negative correlation was found between scores for s-SACL and serum BDNF levels (rho=-0.211, p=0.022). A positive correlation was also found between scores on the s-SACL and plasma levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) (rho=0.416, p=0.01), but not homovanillic acid (HVA). No relationship was found between s-SACL scores and plasma levels of interleukin-6 (IL-6) or tumor necrosis factor alpha (TNFalpha). These results suggest that serum BDNF levels and plasma MHPG levels might be biological markers reflective of psychological job stress in hospital employees.

Brain-derived neurotropic factor/TrkB signaling in the pathogenesis and novel pharmacotherapy of schizophrenia

The role of neurotropins, predominantly brain-derived neurotropic factor (BDNF), has been implicated in the pathophysiology as well as treatment outcome of schizophrenia. Both human and rodent studies indicate that the beneficial effects of antipsychotic drugs are mediated, at least in part, through BDNF and its receptor, TrkB. This review will discuss the available data on the levels of BDNF and TrkB in subjects with schizophrenia and in animals with and without conventional antipsychotics. The data concerning the impact of the antipsychotic drugs on BDNF/TrkB signaling will also be discussed. More importantly, this review will provide future perspective on BDNF/TrkB signaling as a novel molecular target to correct the pathogenesis and improve the long-term clinical outcome by treatments with conventional and adjunctive drugs.