Brain-derived Neurotrophic Factor and High Sensitive C-reactive Protein in Bipolar Depression and Unipolar Depression: The Practical Usage as a Discriminatory Tool

miRNAs in Major Depression: Possible Association of miR-17 and miR-92 with Childhood Traumas

Objective

Psychosocial and genetic factors are considered to play roles in the etiological mechanisms of major depressive disorder (MDD). The involvement of miRNAs in the etiopathogenesis of depression and childhood traumas is still unclear. This study aims to reveal potential differences in miRNA levels between patients with depression and healthy individuals and assess their connection to childhood traumas.

Methods

This study included fifty patients with MDD and 33 healthy controls. The targeting of the 3'UTR regions of the BDNF, SLC6A4/SERT/5-HTT, HTR1a, and HTR2a genes by 8 miRNAs was analyzed to explore their potential involvement in depression and childhood traumas. The Hamilton Depression Rating Scale, the Hamilton Anxiety Rating Scale, and the Childhood Trauma Questionnaire-28 were administered to the participants.

Results

Patients with MDD exhibited significantly lower expression levels of miR-335 and miR-4775, as well as significantly higher expression levels of miR-15, miR-16, miR-17, miR-92, miR-182, and miR-206, when compared to healthy controls using the 2-(ΔΔCt) method. Only miR-17 and miR-92 were associated with childhood traumas in the patients with depression.

Conclusion

Our research reveals a possible involvement of miRNAs in the pathophysiology of depression and highlights a potential relationship between childhood traumas and specific miRNAs in depressed patients.

Microglial NLRP3 inflammasome-mediated neuroinflammation and therapeutic strategies in depression

Previous studies have demonstrated a bidirectional relationship between inflammation and depression. Activation of the nucleotide-binding oligomerization domain, leucine-rich repeat, and NLR family pyrin domain-containing 3 (NLRP3) inflammasomes is closely related to the pathogenesis of various neurological diseases. In patients with major depressive disorder, NLRP3 inflammasome levels are significantly elevated. Understanding the role that NLRP3 inflammasome-mediated neuroinflammation plays in the pathogenesis of depression may be beneficial for future therapeutic strategies. In this review, we aimed to elucidate the mechanisms that lead to the activation of the NLRP3 inflammasome in depression as well as to provide insight into therapeutic strategies that target the NLRP3 inflammasome. Moreover, we outlined various therapeutic strategies that target the NLRP3 inflammasome, including NLRP3 inflammatory pathway inhibitors, natural compounds, and other therapeutic compounds that have been shown to be effective in treating depression. Additionally, we summarized the application of NLRP3 inflammasome inhibitors in clinical trials related to depression. Currently, there is a scarcity of clinical trials dedicated to investigating the applications of NLRP3 inflammasome inhibitors in depression treatment. The modulation of NLRP3 inflammasomes in microglia holds promise for the management of depression. Further investigations are necessary to ascertain the efficacy and safety of these therapeutic approaches as potential novel antidepressant treatments.

Brain-derived neurotrophic factor and C-reactive protein (CRP) biomarkers in suicide attempter and non-attempter major depression disorder (MDD) patients

BACKGROUND

In the available literature, levels of BDNF and CRP have been reported to correlate with suicide in depressive patients but there are inconsistencies in the results. We aimed to evaluate and compare BDNF and CRP concentrations in MDD patients with(MDD + SA) and without suicide attempts (MDD-SA) and healthy controls.

METHODS

30 (MDD + SA) patients, 30 (MDD-SA) patients, and 26 healthy controls were enrolled in the study. Age, sex, and BMI of patients were recorded. Blood sample was obtained for measurement of BDNF and CRP. Smoking and drug history, family history of suicide, and history of self-harm were also documented. Data were analyzed with SPSS version 22 and R version 4.1.1.

RESULTS

86 patients in three groups were evaluated (mean age: 28.45 ± 9.27 years, 56.71% female). Baseline and demographic parameters except for self-harm (40%, 3.3%, and 0% for MDD + SA, MDD-SA, and healthy controls, respectively, p = 0.001) did not differ between groups. CRP level was not significantly different between groups. BDNF showed a significant difference between groups (17.35, 16.45, and 19.43 for three groups, respectively, p < 0.001). An increase in BDNF decreased the odds of both depression and suicide. Roc curve showed excellent power for BDNF in discriminating MDD groups With healthy group.Roc can notdicrimiate MDD + SA and MDD-SA.

CONCLUSION

In our study, the concentration of BDNF differed significantly between depressed patients with/without suicide attempts and healthy controls which shows the association of BDNF with depression development and not suicide attempts. We could not find any association between CRP level and suicide attempt but still larger cohorts are needed for a definite conclusion.

Brain functional networks and structures that categorize type 2 bipolar disorder and major depression

BACKGROUND

Distinguishing between type 2 bipolar disorder (BD II) and major depressive disorder (MDD) poses a significant clinical challenge due to their overlapping symptomatology. This study aimed to investigate neurobiological markers that differentiate BD II from MDD using multimodal neuroimaging techniques.

METHODS

Fifty-nine individuals with BD II, 114 with MDD, and 117 healthy controls participated in the study, undergoing structural and functional magnetic resonance imaging. Functional connectivity (FC) analysis used regions from Shen's whole-brain FC-based atlas. Feature selection was carried out using independent t-tests and ReliefF algorithms, followed by classification using Support Vector Machine and wide neural network.

RESULTS

Significant differences in brain structure and function were observed among patients with BD II, MDD, and healthy controls. Both structural and functional alterations were more pronounced in BD II compared to MDD, particularly in regions associated with sensory processing, motor function, and the cerebellum. Classification based on neurobiological markers achieved a mean testing accuracy of 88.24%, with the t-test selected features outperforming those selected by ReliefF. Dysconnectivity patterns correlated with symptom severity and functioning in BD II but not MDD.

CONCLUSION

Our findings suggest that neurobiological markers derived from multimodal imaging techniques can effectively differentiate patients with BD II from those with MDD. The identified alterations in brain structure and function, particularly in sensory-motor processing networks, may serve as potential biomarkers for distinguishing between these mood disorders. However, the influence of psychotropic medications and daily functioning severity on these neurobiological markers warrants further investigation.

Brain-derived neurotrophic factor levels across psychiatric disorders: A systemic review and network meta-analysis

As an important neurotrophic factor in the central nervous system, Brain-derived Neurotrophic Factor (BDNF) has been implicated in the pathophysiology of psychiatric disorders in many studies. However, its value as a biomarker for the diagnosis and differential diagnosis of mental disorders is still controversial, and its change patterns among different mental disorders have not been compared. We conducted a network meta-analysis of BDNF levels in different psychiatric disorders including schizophrenia(SCZ), major depressive disorder(MDD), bipolar disorder(BD), panic disorder(PD), post-traumatic stress disorder(PTSD), obsessive-compulsive disorder(OCD), generalized anxiety disorder(GAD) and insomnia. Studies were identified by searching electronic databases through 31/05/2023. BDNF levels decreased in patients with BD, MDD, OCD, PD, SCZ compared with controls, while significantly increased in patients with PTSD. According to the network meta-analysis, BDNF levels were significantly decreased in MDD and SCZ compared with BD (-2.6, 95% CIs [-5.32 to -0.15] and - 2.68 95% CIs [-5.18 to -0.23] respectively). However, in the traditional meta-analysis, there was a trend towards lower BDNF levels in SCZ compared to BD, with no significant difference (SMD = -0.20, 95% CIs [-0.49 to 0.08]). In conclusion, abnormal BDNF levels have been found in psychiatric disorders, and the changes in peripheral BDNF levels in patients with psychiatric disorders were reconfirmed in this study, which suggests BDNF exhibits promising clinical utility and may hold diagnostic value in distinguishing between MDD and BD.

Study on exosomes for identifying bipolar disorder in early stage: A cross-sectional and validation study protocol

BACKGROUND

The difficulty is remained to accurately distinguish bipolar disorder (BD) from major depressive disorder (MDD) in early stage, with a delayed diagnosis for 5-10 years. BD patients are often treated with antidepressants systematically due to being diagnosed with MDD, affecting the disease course and clinical outcomes. The current study aims to explore the role of plasma exosomes as biomarker to distinguish BD from MDD in early stage.

METHODS

Two stages are included. The first stage is a cross-sectional study, comparing the concentrations of plasma exosome microRNA and related proteins among BD group, MDD group, and healthy controls (HC) group (n = 40 respectively), to identify target biomarkers preliminarily. The "Latent Class Analysis" and "Receiver Operating Characteristic" analysis will be performed to determine the optimal concentration range for each biomarker. The second stage is to validate target markers in subjects, coming from an ongoing study focusing on patients with a first depressive episode. All target biomarkers will be test in plasma samples reserved at the initial stage to detect whether the diagnosis indicated by biomarker level is consistent with the diagnosis by DSM-5. Furthermore, the correlation between specific biomarkers and the manic episode, suicidal ideation, and adverse reactions will also be observed.

DISCUSSION

Exosome-derived microRNA and related proteins have potential in serving as a good medium for exploring mental disorders because it can pass through the blood-brain barrier bidirectionally and convey a large amount of information stably. Improving the early diagnosis of BD would help implement appropriate intervention strategy as early as possible and significantly reduce the burden of disease.

[Growth factors PDGF-AA, PDGF-BB and BDNF as potential differentiating biomarkers of unipolar and bipolar depression]

OBJECTIVE

To establish the differences and identify the prognostic value of biological markers - platelet growth factors PDGF-AA, PDGF-BB and brain-derived neurotrophic growth factor (BDNF) - for the differential diagnosis of patients with unipolar and bipolar depression using machine learning.

MATERIAL AND METHODS

The study included 79 patients aged 48 [34; 57] years, including 35 people with bipolar depression (ICD-10. F31) and 44 people with unipolar depression (F32-33). Clinical assessment of the patients' condition was carried out using the Hamilton Depression Rating Scale (HDRS-17) and the Hamilton Anxiety Rating Scale (HARS). The concentration of growth factors in the blood serum of patients was determined using multiplex analyzers Magpix and Luminex 200 (Luminex, USA). To build a predictive model, the support vector machine was used.

RESULTS

Patients with bipolar depression showed statistically significant higher concentrations of PDGF-AA and PDGF-BB, as well as lower concentrations of BDNF. When constructing a predictive model, it was possible to separate patients with unipolar and bipolar depression according to all three biomarkers; the sensitivity and specificity of the model were 0.96±0.06 and 0.95±0.05, respectively.

CONCLUSIONS

The study of concentrations of BDNF and platelet-derived growth factors shows statistically significant differences in indicators in the case of unipolar and bipolar depression, which can potentially be used as prognostic biomarkers for differential diagnosis in appropriate clinical cases.

Can Brain-Derived Neurotrophic Factor Be Considered a Biomarker for Bipolar Disorder? An Analysis of the Current Evidence

Brain-derived neurotrophic factor (BDNF) plays a key role in brain development, contributing to neuronal survival and neuroplasticity. Previous works have found that BDNF is involved in several neurological or psychiatric diseases. In this review, we aimed to collect all available data on BDNF and bipolar disorder (BD) and assess if BDNF could be considered a biomarker for BD. We searched the most relevant medical databases and included studies reporting original data on BDNF circulating levels or Val66Met polymorphism. Only articles including a direct comparison with healthy controls (HC) and patients diagnosed with BD according to international classification systems were included. Of the 2430 identified articles, 29 were included in the present review. Results of the present review show a reduction in BDNF circulating levels during acute phases of BD compared to HC, which increase after effective therapy of the disorders. The Val66Met polymorphism was related to features usually associated with worse outcomes. High heterogeneity has been observed regarding sample size, clinical differences of included patients, and data analysis approaches, reducing comparisons among studies. Although more studies are needed, BDNF seems to be a promising biomarker for BD.