Effects of antipsychotics on the serum BDNF levels in schizophrenia

Effects of antidepressant and antipsychotic medication on peripheral brain-derived neurotrophic factor concentration: Systematic review and meta-analysis

Brain-derived neurotrophic factor (BDNF) is an important regulatory protein in the pathophysiology of psychiatric disorders. Several studies have reported the relationship between peripheral BDNF concentrations and the use of psychoactive drugs. However, the results remain controversial. This study aimed to evaluate the effects of psychoactive drugs on BDNF concentrations and to explore the association between changes in BDNF concentrations and improvements in clinical scores. A systematic review and meta-analysis were conducted. Six electronic databases, including PubMed, Scopus, Medline, Web of Science, Google Scholar and Science Direct, were searched. Changes in BDNF concentrations were compared before and after psychoactive treatment, using the standardized mean difference (SMD) and 95 % confidence interval (95 % CI). Twenty-three studies were included. A significant increase in serum BDNF concentrations was observed after treatment with antipsychotics (SMD=0.43; 95 %CI: 0.26, 0.60) and antidepressants (SMD=0.49; 95 %CI: 0.23, 0.74). However, the plasma BDNF concentration was not affected by antidepressant and antipsychotic medication. Although an improvement in clinical scores was observed after treatment, no significant association was observed between changes in BDNF concentrations and the changes in the Positive and Negative Syndrome Scale (PANSS) and the Hamilton Depression Rating Scale (HAM-D) scores. In conclusion, antidepressants and antipsychotics increase serum BDNF concentrations.

Blood levels of brain-derived neurotrophic factor (BDNF) in people with multiple sclerosis (MS): A systematic review and meta-analysis

BACKGROUND

Multiple sclerosis is an autoimmune demyelinating disease marked by the involvement of multiple pathophysiological pathways, including BDNF. BDNF (brain-derived neurotrophic factor) is one of the main neurotrophic factors in the adult brain. The amount of BDNF in the blood can be utilized as a surrogate for the central expression of this marker. Given contradicting reports, we set out to answer the question, "How do blood levels of BDNF differ in people with multiple sclerosis (PwMS) compared to controls?"

METHODS

We performed a thorough search in MEDLINE, EMBASE, Web of Science, and the Cochrane Library databases, resulting in 13 eligible investigations. Eleven studies compared BDNF in serum of PwMS versus healthy controls (HC), and two studies provided BDNF levels in the plasma of PwMs. R version 4.0.4 was used for meta-analysis and visualizations. Mean difference (MD) was used for the measurement of effect size.

RESULTS

The final analysis included thirteen studies with 689 patients with MS and 583 controls. The preliminary results indicated that MS patients had statistically significant lower levels of BDNF than controls: SMD -5.1992 (95% CI [-8.4488; -1.9496], p-value < 0.0001. Additionally, subgroup analysis revealed a statistically significant difference in serum and plasma levels (p-value=0.01). Performing univariate meta-regression, disease duration and the proportion of males had, respectively, a significant negative and positive correlation with BDNF levels.

CONCLUSION

Circulating levels of BDNF are decreased in MS. Future studies should investigate the role of BDNF as a biomarker of disease severity and/or progression for a personalized approach to MS.

Impact of duration of untreated psychosis in short-term response to treatment and outcome in antipsychotic naïve first-episode psychosis

AIM

Duration of untreated psychosis (DUP) is one of the few potentially modifiable outcome predictors in psychosis. Previous studies have associated a longer DUP with a poor prognosis, but few of them were performed in countries with low and middle level of income. This study aimed to investigate the DUP in a Brazilian sample of antipsychotic-naïve first-episode psychosis (AN-FEP) patients and its association with clinical characteristics and treatment outcomes in a short-term follow-up.

METHODS

One hundred forty-five AN-FEP patients between 16 and 40 years were enrolled and were reassessed 10 weeks after risperidone treatment. We investigated the association between DUP and symptom severity, functionality and response to treatment, using the Positive and Negative Syndrome Scale (PANSS), the Clinical Global Impression-Severity Scale (CGI) and the Global Assessment of Functionality (GAF) scale. DUP was defined as the period between the onset of the first psychotic symptoms and the first effective antipsychotic treatment. For the analysis, we performed multivariate linear regressions.

RESULTS

The DUP's median was 61 days. At baseline, we did not find any significant association between DUP and clinical characteristics. After treatment, the longer DUP predicted worse positive and negative symptom dimensions, worse total PANSS, GAF and CGI scores and poorer response to treatment.

CONCLUSION

Our results showed that DUP is associated with worse outcomes after short treatment, but it does not modify the baseline clinical profile of the AN-FEP patients. Such results reinforce the need to develop early intervention strategies, reducing DUP.

Hippocampal subfield volumes and change in body mass over 12 months of treatment in first-episode schizophrenia spectrum disorders

In this study, we explored the relationship between baseline hippocampal subfield volumes and change in body mass over 12 months of treatment in 90 first-episode schizophrenia spectrum disorder patients (66 males, 24 females; mean age= 24.7 ± 6.8 years). Body mass index was assessed in patients at baseline, and at months 3, 6, 9 and 12. Hippocampal subfields of interest were assessed at baseline using a segmentation algorithm included in the FreeSurfer 6.0 software program. Linear regression revealed a significant interactive effect between sex and anterior hippocampus size as predictors of change in body mass over 12 months, adjusting for age, substance use, and treatment duration. In an exploratory post-hoc sub-analysis, partial correlations showed a significant association between weight gain and smaller CA1, CA3 and subiculum volumes in females, but not males, adjusting for age and substance use, with similar trends evident for the CA4 and presubiculum subfields. In conclusion, our findings suggest that smaller anterior hippocampal subfields at baseline are associated with the development of weight gain over the course of treatment in first-episode schizophrenia spectrum disorders in a sex-specific fashion. This may be related to the greater increase in body mass evident for female patients in our study.

A Longitudinal Study of Serum Brain-Derived Neurotrophic Factor Levels in First-Episode Schizophrenia

BACKGROUND

Biomarkers identified for psychosis might allow for early diagnosis, more accurate prognosis, and tailored individualized interventions. Brain-derived neurotrophic factor (BDNF) is suggested to be a likely candidate biomarker for the diagnosis and treatment evaluation in psychosis. The aims of present study were to examine the levels of serum BDNF in both patients with first-episode psychosis (FEP) and in healthy controls for a year, and to investigate the association between BDNF with symptom severity and remission status.

METHODS

A sample of 31 healthy controls and 29 patients with FEP were included in this study. Diagnoses were ascertained on the Structured Clinical Interview for DSM-IV-TR. Symptom severity was assessed on the Positive and Negative Syndrome Scale. Serum levels of BDNF were measured using enzyme-linked immunosorbent assay method at recruitment and at 3-, 6-, and 12-month time points.

RESULTS

Serum BDNF levels in both groups did not differ significantly over time. Baseline BDNF levels in patients with FEP did not correlate with symptom severity and neither baseline BDNF level nor its relative change at 3-month predicted remission status at 6- and 12-month follow-up visits. Of note, we observe similar fluctuations in serum BDNF levels in both patients and healthy controls over the 12-month period.

CONCLUSIONS

Findings from our study did not support a role for serum BDNF as a biomarker for patients with FEP. Because of the polygenic nature of psychosis, we recommend a comprehensive multimarker profile consisting of markers from representative components of mediated neuronal nutrition, neuroimmunology, and neurologic functional deficit to allow for better predictive power.

Brain-derived neurotrophic factor and mental disorders

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that modulates neuroplasticity in the brain, and is one of the most widely investigated molecule in psychiatric disorders. The researches of BDNF emcompassed the advance of investigative techniques of past decades. BDNF researches ranged from protein quantilization, to RNA expression measurements, to DNA sequencing, and lately but not lastly, epigenetic studies. In this review, we will briefly address findings on BDNF protein levels, mRNA expression, Val66Met polymorphism, and epigenetic modifications, in schizophrenia, major depressive disorder (MDD), and bipolar disorder.

Does metabolic status affect serum levels of BDNF and MMP-9 in patients with schizophrenia?

The purpose of the article: Brain-derived neurotrophic factor (BDNF) and matrix metalloproteinase-9 (MMP-9) are involved in the processes of neurogenesis, synaptic plasticity, learning and memory. Growing number of studies shows a relationship between BDNF or MMP-9 and schizophrenia. Also, BDNF and MMP-9 levels may be affected by metabolic parameters, such as obesity or dyslipidemia. Our hypothesis is that alterations of BDNF or MMP-9 levels in schizophrenia might be secondary to metabolic abnormalities, often found among schizophrenia patients. Materials and methods: We have compared BDNF and MMP-9 between patients with schizophrenia (n = 64, age 49 ± 8.2 y) and healthy controls (n = 32, age 51 ± 8.9 y) in the context of cardio-metabolic parameters. Serum levels of BDNF and MMP-9 were measured using ELISA test, body composition parameters were determined using bioelectric impedance analysis. Results and conclusions: Our results showed significantly lowered serum BDNF concentration in the schizophrenia group (schizophrenia: 23.8 ± 7.83 ng/mL, control: 27.69 ± 8.11 ng/mL, p = 0.03). Serum MMP-9 concentration in schizophrenia group did not differ compared with the control group (schizophrenia: 456.8 ± 278.4 ng/mL, control: 341.5 ± 162.4 ng/mL, p = 0.07). After adjusting for age, all anthropometric parameters, body composition and laboratory tests BDNF were still significantly lower in the schizophrenia group. However, MMP-9 became significantly elevated in the schizophrenia group after adjusting for several anthropometric and body composition covariates. Our results confirmed reduced serum BDNF concentration in patients with schizophrenia. Also, this reduction seems to be independent of metabolic abnormalities. On the other hand, our hypothesis that MMP-9 level in schizophrenia is altered due to metabolic abnormalities might be true.

Brain-derived neurotrophic factor (BDNF) and bipolar disorder

Brain-derived neurotrophic factor (BDNF) is deemed to be associated with the psychopathology of bipolar I disorder (BD). However, studies focusing on accuracy of BDNF levels to differentiate these patients from healthy controls (HCs) are scarce. Over a discrete twelve-year period, we investigated serum BDNF levels in patients with BD and compared them to age-, sex- and body mass index (BMI)-matched HCs. There were lower serum BDNF levels in 83 samples with BD than in 222 HCs samples (5.7 ± 4.2 ng/ml vs. 12.2 ± 7.5 ng/ml, F = 46.784). Pearson's correlation test showed significant positive correlations between Young Mania Rating Scale scores and the BDNF levels among 61 manic patients (γ = 0.339). The receiver operating characteristic curve analysis showed BDNF levels demonstrated a moderate accuracy of being able to differentiate BD patients from HCs (AUC = 0.801). The most adequate cut-off points of the BDNF level were 6.74 ng/ml (sensitivity = 82.0%, specificity = 63.9%). Our results support that BDNF demonstrated moderate accuracy to distinguish BD patients from HCs. In the future, greater samples would be required to prove these results.

Accuracy of brain-derived neurotrophic factor levels for differentiating between Taiwanese patients with major depressive disorder or schizophrenia and healthy controls

Objectives

Brain-derived neurotrophic factor (BDNF) has been associated with the psychopathology of both major depressive disorder (MDD) and schizophrenia (SZ). However, studies focusing on the accuracy of BDNF levels to differentiate between these patients and healthy controls (HCs) have been rare.

Methods

Over a discrete ten-year period, we investigated serum BDNF levels in patients with MDD or SZ and compared them to HCs.

Results

We found serum BDNF levels in 224 samples with SZ to be lower than those in 390 HCs samples (p = 0.007), but not lower than those in the 273 samples with MDD. Male MDD patients tended to have lower BDNF levels compared to male HCs (p = 0.083). The receiver operating characteristic curve analysis demonstrated that BDNF levels were moderately accurate in differentiating male MDD patients and female patients with SZ from HCs (AUC = 0.652 and 0.623, respectively). The most adequate cut-off points for BDNF level were 5.11 ng/ml (sensitivity = 81.1%, specificity = 48.5%) and 5.88 ng/ml (sensitivity = 74.1%, specificity = 57.4%), respectively.

Conclusions

Our results support that BDNF demonstrated moderate accuracy in distinguishing male patients with MDD and female patients with SZ from HCs. In the future, greater samples would be required to further confirm these results.

Association between serum levels of glutamate and neurotrophic factors and response to clozapine treatment

Clozapine is the only available therapy for about 30% of schizophrenia patients otherwise refractory to antipsychotics. Unfortunately, the mechanism of action of the drug is still unknown and there are no biomarkers that can predict a positive response to clozapine. We aimed to examine serum neurotrophins and glutamate levels as putative biomarkers for clozapine response based on the hypothesized mode-of-action of the compound. Blood samples of 89 chronic schizophrenia patients maintained on clozapine were analyzed in a cross-sectional design. Serum brain derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), neurotrophic growth factor (NGF), glial derived neurotrophic factor (GDNF) and glutamate were determined. Differences between responders and non-responders to clozapine and correlation between clinical and biological measures were analyzed. Our sample consisted of 54 (61%) responders and 35 (39%) non-responders. Responders had higher mean BDNF levels than non-responders (2066±814 vs. 1668±820pg/ml, p<0.05. respectively) and higher serum glutamate levels (1.61±2.2 vs. 0.66±0.9pg/ml, respectively, p<0.05). Furthermore, there was a significant correlation between serum glutamate levels and positive symptoms among the clozapine-responder group (rho=0.47, p<0.005). High serum levels of BDNF and glutamate were associated with response to clozapine, while glutamate levels correlated with the psychosis severity in clozapine responders only. Large-scale, prospective longitudinal studies are needed to support these findings and the assumption that serum glutamate and BDNF can discriminate between clozapine responders and non-responders.

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.

The Efficacy of Non-Pharmacological Interventions on Brain-Derived Neurotrophic Factor in Schizophrenia: A Systematic Review and Meta-Analysis

Several studies have investigated the relationship between non-pharmacological interventions (NPIs) and peripheral brain-derived neurotrophic factor (BDNF) in schizophrenia patients. We conducted a systematic review and meta-analysis to review the efficacy of NPIs on peripheral serum and plasma BDNF in subjects with schizophrenia (including schizoaffective disorder). Meta-analyses were conducted to examine the effects of NPIs on blood BDNF levels by using the standardized mean differences (SMDs) between the intervention groups and controls. In total, six randomized controlled trials with 289 participants were included. Of them, five studies used exercise, physical training or diet products. One study used cognitive training. Overall, the BDNF levels in the NPI group increased significantly compared with the control groups (SMD = 0.95, 95% confidence interval (CI) = 0.07 to 1.83, p = 0.03). Subgroup analyses indicated beneficial effects of a non-exercise intervention on peripheral BDNF levels (SMD = 0.41, 95% CI = 0.08 to 0.74, p = 0.01). Meta-regression analyses showed that the completion rate influenced the variation in SMD (p = 0.01). Despite insufficient evidence to draw a conclusion, our results suggest that use of NPIs as adjunctive treatments, specifically non-exercise interventions, may affect positively serum or plasma BDNF in patients with schizophrenia.

BDNF serum levels in schizophrenic patients during treatment augmentation with sarcosine (results of the PULSAR study)

AIM

Finding a relationship between schizophrenia symptoms severity and initial level of BDNF and its changes during augmentation of antipsychotic treatment with sarcosine.

METHOD

57 individuals with schizophrenia with predominantly negative symptoms completed a 6-month RCT prospective study. The patients received 2g of sarcosine (n=27) or placebo (n=30) daily. At the beginning, after 6 weeks and 6 months BDNF levels were measured. Severity of symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS) and Calgary Depression Scale for Schizophrenia (CDSS).

RESULTS

BDNF serum levels were stable after 6 weeks and 6 months in both groups. We noted improvement in negative symptoms, general psychopathology and total PANSS score in sarcosine group comparing to placebo, however there was no correlations between serum BDNF concentrations and PANSS scores in all assessments. Initial serum BDNF concentrations cannot be used as a predictor of the improvement resulting from adding sarcosine.

CONCLUSIONS

Our results indicate that either BDNF is not involved in the NMDA-dependent mechanism of sarcosine action or global changes in BDNF concentrations induced by amino-acid cannot be detected in blood assessments.

Aerobic Exercise in People with Schizophrenia: Neural and Neurocognitive Benefits

Schizophrenia is characterized by extensive neurocognitive deficits, which are linked to greater disability, poorer functional outcome, and have been suggested to impact daily functioning more than clinical symptoms. Aerobic exercise (AE) has emerged as a potential intervention. This review examines the impact of AE on brain structure and function along with neurocognitive performance in individuals with schizophrenia. Preliminary evidence indicates that AE can increase hippocampal volume and cortical thickness, in addition to exerting a neuroprotective effect against hippocampal volume decrease and cortical thinning. There is also evidence that AE is able to significantly increase serum brain-derived neurotrophic factor (BDNF) levels, which are implicated in neurogenesis, neuroplasticity, and cognitive improvement. Finally, evidence suggests that AE plays a significant role in improving overall cognition, including improvements in processing speed, working memory, and visual learning. The authors discuss the implications of the findings and provide recommendations for future research and areas of inquiry.

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.

Is schizophrenia a neurodegenerative disease? Evidence from age-related decline of brain-derived neurotrophic factor in the brains of schizophrenia patients and matched nonpsychiatric controls

BACKGROUND

Brain-derived neurotrophic factor (BDNF) protein levels decline in the brain during senescence and are also shown to be reduced in schizophrenia patients. BDNF is present in both the gray and white matters of the brain. It is unclear whether BDNF abnormalities in schizophrenia are specific to gray and/or white matter.

OBJECTIVE

We hypothesized that the age-related BDNF decline is abnormal and contributes to the reduced BDNF in schizophrenia.

METHODS

We tested this hypothesis by measuring BDNF protein levels in postmortem gray and white matter, using the prefrontal cortex (PFC) and the genu of the corpus callosum as regions of interests, from 20 schizophrenia patients and 20 matched nonpsychiatric controls. Samples were selected across the adult lifespan--from 20 to 80 years of age.

RESULTS

PFC gray matter BDNF protein levels were significantly lower in older age in both nonpsychiatric comparisons and patients, while BDNF in white matter did not decrease significantly with age in either group. PFC BDNF was linearly lower from 20 to 80 years of age in nonpsychiatric comparisons. In schizophrenia, the age effect was similarly linear in younger patients but a decline did not occur in older patients.

CONCLUSION

PFC BDNF does not follow a normative linear age effect in schizophrenia patients as they grow older, which may represent a 'floor effect' due to earlier decline or a survivor cohort of older patient donors who are less susceptible to a schizophrenia-related pathological aging process.

Serum brain-derived neurotrophic factor (BDNF) and its association with remission status in Chinese patients with schizophrenia

The neurotrophin, brain-derived neurotrophic factor (BDNF), characterises a probable neurobiochemical explanation of maldevelopments in schizophrenia and is a candidate biomarker of the illness. A paucity of studies examining neurobiochemical predictors of remission in schizophrenia exists. In this study, we seek to examine if serum BDNF level is associated with remission status in a sample of Chinese patients with schizophrenia. This study did not find a significant relationship between serum BDNF and remission in patients with schizophrenia. Identification of a suitable biomarker for diagnosis, management, and prognostic outcome is crucial and warrants further study.

Methodological considerations to determine the effect of exercise on brain-derived neurotrophic factor levels

OBJECTIVES

Physical exercise up-regulates brain-derived neurotrophic factor (BDNF) in the brain and blood. However, there is yet no consensus about the adequate blood processing conditions to standardize its assessment. We aimed to find a reliable blood sample processing method to determine changes in BDNF due to exercise.

DESIGN AND METHODS

Twelve healthy university students performed an incremental cycling test to exhaustion. At baseline, immediately after exercise, and 30 and 60 min of recovery, venous blood was drawn and processed under different conditions, i.e. whole blood, serum coagulated for 10 min and 24 h, total plasma, and platelet-free plasma. BDNF concentration was measured by ELISA.

RESULTS

Exercise increased BDNF in whole blood and in serum coagulated for 24 h when corrected by hemoconcentration. We did not find effects of exercise on BDNF in serum coagulated for 10 min or in plasma samples. Plasma shows heterogeneous BDNF values in response to exercise that are not prevented when platelets are eliminated while homogeneous BDNF levels were found in whole blood or serum coagulated for 24 hour samples.

CONCLUSIONS

In exercise studies, BDNF levels should be adjusted by hemoconcentration. Our data highlight the importance of blood sample selection since the differences between each one affect significantly the BDNF factor changes due to exercise.

Changes in serum levels of brain derived neurotrophic factor and nerve growth factor-beta in schizophrenic patients before and after treatment

Schizophrenia is one of the most debilitating diseases among psychiatric disorders. Recent studies suggest the existence of effective immunological changes in the pathophysiology of this disease. The purpose of the current study was to determine the changes in serum levels of Brain Derived Neurotrophic Factor (BDNF) and Nerve Growth Factor-beta (NGF) in schizophrenic patients before treatment and 40 days after treatment. In this case-control study, serum levels of BDNF and NGF were measured by ELISA in 26 patients with schizophrenia and 26 healthy controls. All patients were treated with clozapine or risperidone for 40 days. A positive and negative syndrome scale (PANSS) questionnaire has been used to recognize the severity of the disease and to assess the response to treatment. Neurotrophin concentrations were compared before and after the treatment and with control groups using paired t-test and ANOVA test. BDNF and NGF levels in the case group were more than levels after treatment, but these differences were significant only for NGF. Concentrations in both neurotrophins were higher than the control group. The statistically significant difference was observed between changes in the NGF levels in the case and the control group, while no significant difference was seen in changes of BDNF. The main conclusion to be drawn from this study was that the increase in BDNF and particularly NGF may have an important role in causing schizophrenia. And possibly drugs clozapine and risperidone help to treat the disease by reducing the concentration of Neurotrophins.

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.

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.

Putative neuroprotective agents in neuropsychiatric disorders

In many individuals with major neuropsychiatric disorders including depression, bipolar disorder and schizophrenia, their disease characteristics are consistent with a neuroprogressive illness. This includes progressive structural brain changes, cognitive and functional decline, poorer treatment response and an increasing vulnerability to relapse with chronicity. The underlying molecular mechanisms of neuroprogression are thought to include neurotrophins and regulation of neurogenesis and apoptosis, neurotransmitters, inflammatory, oxidative and nitrosative stress, mitochondrial dysfunction, cortisol and the hypothalamic-pituitary-adrenal axis, and epigenetic influences. Knowledge of the involvement of each of these pathways implies that specific agents that act on some or multiple of these pathways may thus block this cascade and have neuroprotective properties. This paper reviews the potential of the most promising of these agents, including lithium and other known psychotropics, aspirin, minocycline, statins, N-acetylcysteine, leptin and melatonin. These agents are putative neuroprotective agents for schizophrenia and mood disorders.

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.

Associations of serum brain-derived neurotrophic factor with cognitive impairments and negative symptoms in schizophrenia

Brain-derived neurotrophic factor (BDNF) may be involved in the pathophysiology of schizophrenia. The aim of this study was to examine the associations of serum BDNF levels with the cognition and clinical characteristics in patients with schizophrenia. Sixty-three patients with schizophrenia and 52 age- and sex-matched healthy controls were examined with neuropsychological tests. Serum BDNF levels were determined by enzyme-linked immunosorbent assay (ELISA). There were no significant differences in serum BDNF levels between normal controls and patients with schizophrenia. Serum BDNF levels of normal controls showed negative correlations with verbal working memory, but this was not the case with schizophrenic patients. Meanwhile, serum BDNF levels of schizophrenic patients showed positive correlations with the scores of the Scale for the Assessment of Negative Symptoms (SANS) and the Information subtest scores of Wechsler Adult Intelligence Scale Revised (WAIS-R). Serum BDNF levels are related with the impairment of verbal working memory and negative symptoms in patients with schizophrenia.

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.