Vascular Endothelial Growth Factor (VEGF) serum concentration during electroconvulsive therapy (ECT) in treatment resistant depressed patients

Unraveling epigenomic signatures and effectiveness of electroconvulsive therapy in treatment-resistant depression patients: a prospective longitudinal study

BACKGROUND

Electroconvulsive therapy (ECT) benefits patients with treatment-resistant depression (TRD), but the underlying biological processes are unclear. We conducted an epigenome-wide association study in 32 TRD patients undergoing ECT to depict ECT-associated methylation changes. Illness severity and ECT outcomes were assessed with the Montgomery-Åsberg Depression Rating Scale at baseline (T0) and 1 month after its end (T1). Methylation was profiled at T0 and T1 with the Illumina Infinium Methylation EPIC BeadChip array.

RESULTS

Longitudinal T0-T1 analyses showed 3 differentially methylated probes (DMPs) with nominal p values ≤ 10-5, with 2 annotated in the genes CYB5B and PVRL4. Including covariates, we found 4 DMPs for symptoms variation, annotated in FAM20C, EPB41, OTUB1 and ADARB1, and 3 DMPs for response status, with 2 annotated in IQCE and FAM20C. Regional analysis revealed 54 differentially methylated regions (DMRs) with nominal p value area ≤ 0.05, with 9 presenting adjusted p-value area ≤ 0.10, annotated in MCF2L, SLC25A24, RUNX3, MIR637, FOXK2, FAM180B, POU6F1, ALS2CL and CCRL2. Considering covariates, we found 21 DMRs for symptoms variation and 26 DMRs for response (nominal p value area ≤ 0.05), with 4 presenting adjusted p-value area ≤ 0.10 for response, annotated in SNORD34, NLRP6, GALNT2 and SFT2D3. None remained significant after false discovery rate correction. Notably, ADARB1 variants are associated with suicide attempt in patients with psychiatric disorders, and SLC25A24 relates to conduct disorder. Several DMPs and DMRs are annotated in genes associated with inflammatory/immune processes. Longitudinal analyses on females (n = 22) revealed statistically significant DMRs (adjusted p value area ≤ 0.05) and trend-significant DMRs (adjusted p value area ≤ 0.07) for symptoms variation and response status, annotated in genes related to psychiatric disorders (ZFP57, POLD4, TRIM10, GAS7, ADORA2A, TOLLIP), trauma exposure (RIPOR2) and inflammatory/immune responses (LAT, DLX4, POLD4, FAM30A, H19). Pathway analysis on females revealed enrichment for transcriptional activity, growth factors, DNA maintenance, and immune pathways including IRF7 and IRF2.

CONCLUSION

Although no significant results were found for the whole cohort, the study provides insights into ECT-associated methylation changes, highlighting DMPs and DMRs related to ECT outcomes. Analyses on females revealed significant DMRs and pathways related to psychiatric disorders and inflammatory/immune processes.

Correlation Between ECT Quality Measures and Likelihood to Transition From Acute to Continuation and Maintenance ECT

OBJECTIVES

To evaluate the association between 3 ECT quality measures (seizure duration, Postictal Suppression Index [PSI], and heart rate response) and therapeutic compliance as indicated by transitioning from acute to continuation to maintenance phases of ECT.

METHODS

This was a retrospective chart review of patients who received ECT between July 2016 and July 2019. ECT quality measures were lagged by 1 ECT session to examine the effect of the prior session's quality measure on progressing to a higher ECT phase at the subsequent ECT session. Associations with therapeutic compliance were analyzed using mixed-effects ordinal regression and mixed-effects partial proportional odds models.

RESULTS

Seizure duration was associated with 8% higher adjusted odds of progressing to out of the acute phase (95% confidence interval [CI]: 2% to 15%, P = 0.007) and 18% higher adjusted odds of progressing to the maintenance phase (95% CI: 10% to 28%, P < 0.001); PSI was associated with 9% higher adjusted odds of progressing out of the acute phase (95% CI: 3% to 16%, P = 0.005), whereas heart rate response was not statistically associated with therapeutic compliance. Greater therapeutic compliance was also associated with bilateral electrode placement and older age.

CONCLUSIONS

Longer seizure duration was associated with greater therapeutic compliance across all ECT phases, PSI was associated with progressing out of the acute phase, and heart rate response was not associated with therapeutic compliance. Our findings assist ECT psychiatrists in optimizing ECT quality measures to promote better compliance with ECT.

Suicidal behavior and all-cause mortality in depressed older adults aged 75+ treated with electroconvulsive therapy: A Swedish register-based comparison study

OBJECTIVES

Electroconvulsive therapy (ECT) is effective in treating late-life depression. There is limited research on suicidal behavior and all-cause mortality in the oldest old after ECT.

METHODS

Older adults aged 75 years and above who had been inpatients for moderate to severe depression between January 1, 2011, and December 31, 2017, were included in the study. We used exact and propensity score matching to balance groups. We compared suicidal behavior (fatal and non-fatal) and all-cause mortality in those who had received ECT and those with other depression treatments.

RESULTS

Of the study population, 1802 persons who received ECT were matched to 4457 persons with other treatments. There were no significant differences in the risk of suicidal behavior between groups, (within 3 months: odds ratio 0.73; 95% confidence intervals (CI), 0.44-1.23, within 4 months to 1 year: aOR 1.34; 95% CI, 0.84-2.13). All-cause mortality was lower among ECT recipients compared to those who had received other treatments, both within 3 months (aOR, 0.35; 95% CI, 0.23-0.52), and within 4 months to 1 year (aOR 0.65; 95% CI, 0.50-0.83).

CONCLUSIONS

Compared to other depression treatments, ECT is not associated with a higher risk of suicidal behavior in patients aged 75 and above. ECT is associated with lower all-cause mortality in this age group, but we advise caution regarding causal inferences.

Serum angioneurin levels following electroconvulsive therapy for mood disorders

OBJECTIVES

The efficacy of electroconvulsive therapy (ECT) in treating mood disorders (MDs) is hypothesized to be mediated by the induction of neurotrophic factors (denoted "angioneurins") that trigger neuronal plasticity. This study aimed to assess the effects of ECT on serum angioneurin levels in patients with MD.

METHODS

A total of 110 patients with MDs including 30 with unipolar depression, 25 with bipolar depression (BD), 55 with bipolar mania (BM), and 50 healthy controls were included in the study. Patients were subdivided into two groups: those who received ECT + medication (12 ECT sessions) and those who received only medication (no-ECT). Depressive and manic symptom assessments and measurements of vascular endothelial growth factor (VEGF), fibroblast growth factor-2, nerve growth factor (NGF), and insulin-like growth factor-1 levels in blood samples were performed at baseline and week 8.

RESULTS

Patients in the ECT group, specifically those with BD and BM, had significantly increased levels of VEGF compared to their baseline VEGF levels (p = 0.002). No significant changes in angioneurin levels were observed in the no-ECT group. Serum NGF levels were significantly associated with a reduction in depressive symptoms. Angioneurin levels were not associated with manic symptom reduction.

CONCLUSIONS

This study hints that ECT may increase VEGF levels with angiogenic mechanisms that amplify NGF signaling to promote neurogenesis. It may also contribute to changes in brain function and emotional regulation. However, further animal experiments and clinical validation are needed.

Systemic Inflammatory Response Index (SIRI) at Baseline Predicts Clinical Response for a Subset of Treatment-Resistant Bipolar Depressed Patients

Background: in a recent double-blind, placebo controlled RCT we demonstrated that selective inhibition of cyclo-oxygenase 2 (COX2) is an effective adjunctive strategy in treatment-resistant bipolar depression (TRBDD). To better clarify the mechanisms underlying TRBDD and treatment response, we conducted a retrospective exploratory analysis of the systemic inflammatory response index (SIRI = absolute neutrophils × absolute monocytes/absolute lymphocytes) in relation to other biomarkers and clinical outcomes after escitalopram (ESC), combined with the COX-2 inhibitor, celecoxib (CBX), versus placebo. Methods: Baseline measures of SIRI were compared between TRBDD and healthy controls (HC), and correlated with blood-based inflammatory cytokines, kynurenines, and growth factors. Post-treatment Hamilton Depression Rating Scale 17 (HAMD-17) total scores (clinical outcome) were modelled according to SIRI adjusting for demographics (including relevant interactions with SIRI), baseline depression, treatment arm, and treatment timepoint using multiple linear regression and robust linear mixed effects models. Results: Baseline SIRI did not distinguish TRBDD from HC groups. Baseline SIRI was significantly correlated with lower baseline MCP-1. The relationship between SIRI and HAMD-17 was significant at treatment week 8, in contrast to baseline. Finally, baseline SIRI predicted elevated post-treatment HAMD-17 scores, amongst patients with elevated depression scores at baseline. Significance: High pre-treatment SIRI may predict poorer depressive outcomes amongst TRBDD patients with baseline elevated depression.

Intricate role of sleep deprivation in modulating depression: focusing on BDNF, VEGF, serotonin, cortisol, and TNF-α

In this review article, we aimed to discuss intricate roles of SD in modulating depression in preclinical and clinical studies. Decades of research have shown the inconsistent effects of SD on depression, focusing on SD duration. However, inconsistent role of SD seems to be more complicated, and SD duration cannot be the only one factor. Regarding this issue, we chose some important factors involved in the effects of SD on cognitive functions and mood including brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), serotonin, cortisol, and tumor necrosis factor-alpha (TNF-α). It was concluded that SD has a wide-range of inconsistent effects on BDNF, VEGF, serotonin, and cortisol levels. It was noted that BDNF diurnal rhythm is significantly involved in the modulatory role of SD in depression. Furthermore, the important role of VEGF in blood-brain barrier permeability which is involved in modulating depression was discussed. It was also noted that there is a negative correlation between cortisol and BDNF that modulates depression. Eventually, it was concluded that TNF-α regulates sleep/wake cycle and is involved in the vulnerability to cognitive and behavioral impairments following SD. TNF-α also increases the permeability of the blood-brain barrier which is accompanied by depressive behavior. In sum, it was suggested that future studies should focus on these mechanisms/factors to better investigate the reasons behind intricate roles of SD in modulating depression.

Association between electroconvulsive therapy and depressive disorder from 2012 to 2021: Bibliometric analysis and global trends

Background

Depressive disorder is a chronic mental illness that is vulnerable to relapse, imposes a huge economic burden on society and patients, and is a major global public health problem. Depressive disorders are characterized by depressed mood, decreased energy and interest, and suicidal ideation and behavior in severe cases. They can be treated through pharmacotherapy and psychotherapy or physical treatments such as electroconvulsive therapy (ECT). In patients with suicidal ideation, behavior, or refractory depressive disorder ECT has a faster onset of action and better efficacy than pharmacotherapy. This study used bibliometric and visual analyses to map the current state of global research on ECT for depressive disorder and to predict future research trends in this area.

Materials and methods

A literature search was performed for studies on ECT and depressive disorder in the Web of Science Core Collection (WoSCC) database. All studies considered for this paper were published between 2012 and 2021. Bibliometric and co-occurrence analyses were performed using the CiteSpace software.

Results

In total, 2,184 publications were retrieved. The number of publications on ECT and depressive disorder have been increasing since 2012, with China being a emerging hub with a growing influence in the field. Zafiris J. Daskalakis is the top author in terms of number of publications, and The Journal of ECT is not only the most published journal but also the most co-cited journal in the field. Co-occurrence analysis showed that electroconvulsive therapy, treatment-resistant depression, bipolar disorder, hippocampus, efficacy, and electrode placement are current research hotspots. Molecular biomarkers, neuroimaging predictors, and late-life depression will become research hotspots in the future.

Conclusion

Our analysis made it possible to observe an important growth of the field since 2012, to identify key scientific actors in this growth and to predict hot topics for future research.

Electroconvulsive shock increases neurotrophy and neurogenesis: Time course and treatment session effects

Increasing evidence suggests that hippocampal neurotrophy may be related to the development of major depressive disorders. Neurogenesis, which can be regulated by neurotrophic factors, is also involved in antidepressant efficacy. This paper reviewed literature on neurotrophic signaling and cell proliferation after electroconvulsive shock (ECS) treatment. All articles were from PubMed, Web of Science, and Scopus databases between 2000 and 2020. The keywords used in the literature search are: "ECS," "ECT," "electroconvulsive seizure," "electroconvulsive shock," "electroconvulsive therapy," "neurotrophic factor," "nerve growth factor," "neurotrophins," "neurogenesis," and "cell proliferation." Eighty-two articles were included in the final analysis. It was shown that compared with acute ECS, repeated ECS increased neurotrophin expression in more brain regions at higher levels and was maintained for a longer time. Similarly, ECS increased cell proliferation in a dose- and time-dependent manner. The increase in cell proliferation was positively correlated with the amount of ECS administered and the newly born cells survived for a long time. The effects of ECS in inducing increases in neurotrophin levels and neurogenesis may contribute to brain function changes and antidepressant effects. Future research may focus on optimal sessions of ECT treatment to obtain the best therapeutic effect.

Investigating the Role of Leukocyte Telomere Length in Treatment-Resistant Depression and in Response to Electroconvulsive Therapy

Psychiatric disorders seem to be characterized by premature cell senescence. However, controversial results have also been reported. In addition, the relationship between accelerated aging and treatment-resistance has scarcely been investigated. In the current study, we measured leukocyte telomere length (LTL) in 148 patients with treatment-resistant depression (TRD, 125 with major depressive disorder, MDD, and 23 with bipolar disorder, BD) treated with electroconvulsive therapy (ECT) and analyzed whether LTL was associated with different response profiles. We also compared LTL between patients with TRD and 335 non-psychiatric controls. For 107 patients for which genome-wide association data were available, we evaluated whether a significant overlap among genetic variants or genes associated with LTL and with response to ECT could be observed. LTL was negatively correlated with age (Spearman’s correlation coefficient = −0.25, p < 0.0001) and significantly shorter in patients with treatment-resistant MDD (Quade’s F = 35.18, p < 0.0001) or BD (Quade’s F = 20.84, p < 0.0001) compared to controls. Conversely, baseline LTL was not associated with response to ECT or remission. We did not detect any significant overlap between genetic variants or genes associated with LTL and response to ECT. Our results support previous findings suggesting premature cell senescence in patients with severe psychiatric disorders and suggest that LTL could not be a predictive biomarker of response to ECT.

Molecular Biomarkers of Electroconvulsive Therapy Effects and Clinical Response: Understanding the Present to Shape the Future

Electroconvulsive therapy (ECT) represents an effective intervention for treatment-resistant depression (TRD). One priority of this research field is the clarification of ECT response mechanisms and the identification of biomarkers predicting its outcomes. We propose an overview of the molecular studies on ECT, concerning its course and outcome prediction, including also animal studies on electroconvulsive seizures (ECS), an experimental analogue of ECT. Most of these investigations underlie biological systems related to major depressive disorder (MDD), such as the neurotrophic and inflammatory/immune ones, indicating effects of ECT on these processes. Studies about neurotrophins, like the brain-derived neurotrophic factor (BDNF) and the vascular endothelial growth factor (VEGF), have shown evidence concerning ECT neurotrophic effects. The inflammatory/immune system has also been studied, suggesting an acute stress reaction following an ECT session. However, at the end of the treatment, ECT produces a reduction in inflammatory-associated biomarkers such as cortisol, TNF-alpha and interleukin 6. Other biological systems, including the monoaminergic and the endocrine, have been sparsely investigated. Despite some promising results, limitations exist. Most of the studies are concentrated on one or few markers and many studies are relatively old, with small sample sizes and methodological biases. Expression studies on gene transcripts and microRNAs are rare and genetic studies are sparse. To date, no conclusive evidence regarding ECT molecular markers has been reached; however, the future may be just around the corner.

Electroconvulsive therapy increases temporarily plasma vascular endothelial growth factor in patients with major depressive disorder

OBJECTIVES

Vascular endothelial growth factor (VEGF) has been related to the etiology of major depressive disorder (MDD). The findings involving the effects of electroconvulsive therapy (ECT) on the VEGF levels have been conflicting. The aim was to examine the possible changes in the VEGF levels and their associations with clinical outcome in patients with MDD during ECT.

METHODS

The study comprised 30 patients suffering from MDD. Their plasma VEGF levels were measured at baseline and 2 and 4 hr after the first, fifth, and last ECT session. The severity of depression was quantified by the Montgomery-Asberg Depression Rating Scale (MADRS).

RESULTS

The VEGF levels increased between the 2-hr and 4-hr measurements during the first (p = .003) and the fifth (p = .017) sessions. The baseline VEGF levels between individual ECT sessions remained unchanged during the ECT series. No correlations were found between the increased VEGF levels and the clinical outcome.

CONCLUSIONS

Electroconvulsive therapy increased the VEGF levels repeatedly at the same time point in two different ECT sessions. These increases had no association with the response to ECT. Consequently, VEGF may act as a mediator in the mechanism of action of ECT.

Brain stimulation effects on serum BDNF, VEGF, and TNFα in treatment-resistant psychiatric disorders

Resistance to pharmacological treatment poses a notable challenge for psychiatry. Such cases are usually treated with brain stimulation techniques, including repetitive transcranial magnetic stimulation (rTMS) and electroconvulsive therapy (ECT). Empirical evidence links treatment resistance to insufficient brain plasticity and chronic inflammation. Therefore, this study encompasses analysis of neurotrophic and inflammatory factors in psychiatric patients undergoing rTMS and ECT in order to refine the selection of patients and predict clinical outcomes. This study enrolled 25 drug-resistant depressive patients undergoing rTMS and 31 drug-resistant schizophrenia patients undergoing ECT. Clinical efficacy of brain stimulation therapies was gauged using MADRS and HAM-D scales in the depression group and PANSS scale in the schizophrenia group. Blood-derived BDNF, VEGF, and TNFα were analysed during the treatment course. For reference, 19 healthy control subjects were also enrolled. After statistical analysis, no significant differences were detected in BDNF, VEGF, and TNFα concentrations among healthy, depressive, and schizophrenic subject groups before the treatment. However, depressive patient treatment with rTMS has increased BDNF concentration, while schizophrenic patient treatment with ECT has lowered the concentration of TNFα. Our findings suggest that a lower initial TNFα concentration could be a marker for treatment success in depressed patients undergoing rTMS, whereas in schizophrenic patient group treated with ECT, a higher concentration of VEGF correlates to milder symptoms post-treatment, especially in the negative scale.

Cytokines changes associated with electroconvulsive therapy in patients with treatment-resistant depression: a Meta-analysis

One third of depressive patients do not achieve remission after several steps of treatment and are considered as treatment resistant. Electroconvulsive therapy (ECT) improves symptoms in 70 to 90% of such cases. Resistant depression is associated with a dysregulation of the immune system with a dysbalance between the pro- and the anti-inflammatory cytokines. Therefore, we aimed to measure the kinetic of cytokines levels before, during and at the end of ECT. To test this hypothesis, we performed a meta-analysis assessing cytokines plasma levels before, during and after ECT in patients with major depressive disorders. After a systematic database search, means and standard deviations were extracted to calculate standardized mean differences. We found that IL-6 levels increased after 1 or 2 ECT session (p = 0.01) then decrease after 4 ECT sessions (p < 0.01) with no difference at the end of ECT (p = 0.94). A small number of studies were included and there was heterogeneity across them. The present meta-analysis reveals that ECT induces an initial increase of IL-6 levels and a potential decrease of TNF-α levels. No changes on IL-4 and IL-10 levels were found. Further work is necessary to clarify the impact of ECT on peripheral cytokines.

Association of plasma VEGF levels and the antidepressant effects of ketamine in patients with depression

AIMS

Growing evidence suggests that vascular endothelial growth factor (VEGF) may be involved in the neuronal mechanisms underlying both depression aetiology and the response to ketamine treatments. The aim of this study was to examine whether changes in plasma VEGF levels are associated with the antidepressant effects of repeated ketamine infusions in patients with depression.

METHODS

Ninety-six patients with depression were enrolled and received six ketamine infusions during a 12-day period. Depressive symptom severity and plasma VEGF levels were measured by the Montgomery-Åsberg Depression Rating Scale (MADRS) and an enzyme-linked immunosorbent assay (ELISA) respectively, at baseline, 13 days and 26 days.

RESULTS

Despite a significant improvement in MADRS scores after patients received six ketamine infusions (p < 0.001), no changes in plasma VEGF levels were observed at 13 days when compared with baseline. Moreover, no significant difference in plasma VEGF levels at baseline and 13 days was found between ketamine responders and nonresponders. No association was found between the antidepressant effects of repeated ketamine treatments and plasma VEGF levels.

CONCLUSION

This study indicated that VEGF may not be a potential predictor of antidepressant response to repeated intravenous administration of ketamine in patients with depression.

Peripheral vascular endothelial growth factor changes after transcranial magnetic stimulation in treatment-resistant depression

OBJECTIVES

To determine if vascular endothelial growth factor (VEGF) changes with transcranial magnetic stimulation (TMS) in treatment-resistant major depressive disorder (MDD).

METHODS

Serum from a naturalistic population of 15 patients with MDD was collected at baseline and after standard TMS treatment. VEGF concentration was determined via ELISA. Inventory of Depressive Symptomatology Self Report and Patient Health Questionnaire were used as a measure of depression symptom severity, clinical response and remission. Mann-Whitney U and Kendall's Tau Correlation were used for continuous variables.

RESULTS

VEGF increased from pre- to post-TMS (+30.3%) in remitters whereas VEGF decreased in non-remitters (-9.87%) (P < 0.05). This same pattern was observed when comparing mean %change in VEGF between responders (+14.7%) and non-responders (-14.9%) (P = 0.054). Correlation was present between change in VEGF concentration (baseline to post) and change in Inventory of Depressive Symptomatology-Self Report at Tx30 (r = -0.371, P < 0.054), reflecting greater increases in VEGF linked to greater improvement in depressive symptoms following the standard 6-week course of TMS.

CONCLUSION

Patients with a successful treatment with TMS had significantly greater increase in VEGF from baseline to after treatment compared to non-responders/non-remitters and a larger increase in VEGF was associated with greater improvement in depressive symptoms after TMS. This is the first report examining VEGF levels in depressed patients receiving TMS. This study provides correlative data supporting further investigation into VEGF's role as an important mediator in the processes underpinning TMS' antidepressant effects and as a potential biomarker of clinical outcomes.

Vascular endothelial growth factor in major depressive disorder, schizophrenia, and bipolar disorder: A network meta-analysis

The peripheral levels of vascular endothelial growth factor (VEGF) have been studied in major psychiatric diseases compared with healthy controls (HCs), but the results were inconsistent. Moreover, few studies have compared VEGF levels between these psychiatric diseases. The aim of the present study was to compare blood VEGF levels in major depressive disorder (MDD), schizophrenia (SCZ), bipolar disorder either in a manic episode, a depressive episode, or a euthymic state, and HC. We supposed that VEGF levels may be elevated in some of these diseases as a potential biomarker. In this study, forty-four studies with 6343 participants were included, and network meta-analysis was used to synthesize evidence from both direct and indirect comparisons. The main analysis showed that no significant differences were found between these groups. Subgroup analysis found that patients with MDD may have higher blood VEGF levels than patients with SCZ when the levels were measured through ELISA, and VEGF levels were increased in medication-treated MDD patients compared with HCs. Taken together, blood VEGF levels may be unaltered in these psychiatric disorders, while detection of VEGF in blood by ELISA may a feasible way to distinguish MDD and SCZ. Further replicated studies with larger samples are needed.

Blues in the Brain and Beyond: Molecular Bases of Major Depressive Disorder and Relative Pharmacological and Non-Pharmacological Treatments

Despite the extensive research conducted in recent decades, the molecular mechanisms underlying major depressive disorder (MDD) and relative evidence-based treatments remain unclear. Various hypotheses have been successively proposed, involving different biological systems. This narrative review aims to critically illustrate the main pathogenic hypotheses of MDD, ranging from the historical ones based on the monoaminergic and neurotrophic theories, through the subsequent neurodevelopmental, glutamatergic, GABAergic, inflammatory/immune and endocrine explanations, until the most recent evidence postulating a role for fatty acids and the gut microbiota. Moreover, the molecular effects of established both pharmacological and non-pharmacological approaches for MDD are also reviewed. Overall, the existing literature indicates that the molecular mechanisms described in the context of these different hypotheses, rather than representing alternative ones to each other, are likely to contribute together, often with reciprocal interactions, to the development of MDD and to the effectiveness of treatments, and points at the need for further research efforts in this field.

Vascular endothelial growth factor and pigment epithelial-derived factor in the peripheral response to ketamine

BACKGROUND

Ketamine is a rapid-acting antidepressant but its mechanism remains unclear. Vascular endothelial growth factor growth factor (VEGF) has been reported in the antidepressant action of ketamine in rodents. VEGF and pigment epithelial-derived factor (PEDF) signalling are closely linked and both are dysregulated in depression. We explored the effect of a single infusion of ketamine, with midazolam as comparison, on peripheral whole blood mRNA levels of vascular endothelial growth factor A (VEGFA) and PEDF, and the VEGFA/PEDF ratio, in patients with depression.

METHODS

Twenty-five patients with depression were randomised to either ketamine (0.5 mg/kg) or midazolam (0.045 mg/kg) infusions over 40 min. Blood plasma samples were taken 1 h before the first infusion and 4 h after the infusion start. mRNA was extracted and qRT-PCR performed to analyse gene expression.

RESULTS

Single infusions of ketamine and midazolam both decreased depression scores (F(1,21) = 102.40, p < 0.000). There was a significant group × time interaction for VEGFA mRNA levels (F(1, 21) = 5.207, p = 0.029), with ketamine increasing VEGFA levels. There was no significant effect of either ketamine or midazolam on PEDF levels. There was a significant group × time interaction for VEGFA/PEDF mRNA ratio, with ketamine alone increasing this ratio (F(1, 11) = 12.085, p = 0.005).

LIMITATIONS

Patients were on psychotropic medication and continued treatment as usual throughout the study.

CONCLUSIONS

These preliminary results support a role for VEGF in the action of ketamine and suggest a novel role for VEGF/PEDF in the molecular response to ketamine.

Sustained Ultrastructural Changes in Rat Hippocampal Formation After Repeated Electroconvulsive Seizures

BACKGROUND

Electroconvulsive therapy (ECT) is a highly effective and fast-acting treatment for depression used in the clinic. Its mechanism of therapeutic action remains uncertain. Previous studies have focused on documenting neuroplasticity in the early phase following electroconvulsive seizures (ECS), an animal model of ECT. Here, we investigate whether changes in synaptic plasticity and nonneuronal plasticity (vascular and mitochondria) are sustained 3 months after repeated ECS trials.

METHODS

ECS or sham treatment was given daily for 1 day or 10 days to a genetic animal model of depression: the Flinders Sensitive and Resistant Line rats. Stereological principles were employed to quantify numbers of synapses and mitochondria as well as length of microvessels in the hippocampus 24 hours after a single ECS. Three months after 10 ECS treatments (1 per day for 10 days) and sham-treatment, brain-derived neurotrophic factor and vascular endothelial growth factor protein levels were quantified with immunohistochemistry.

RESULTS

A single ECS treatment significantly increased the volume of hippocampal CA1-stratum radiatum, the total length of microvessels, mitochondria number, and synapse number. Observed changes were sustained as shown in the multiple ECS treatment group analyzed 3 months after the last of 10 ECS treatments.

CONCLUSION

A single ECS caused rapid effects of synaptic plasticity and nonneuronal plasticity, while repeated ECS induced long-lasting changes in the efficacy of synaptic plasticity and nonneuronal plasticity at least up to 3 months after ECS.

Structural changes induced by electroconvulsive therapy are associated with clinical outcome

BACKGROUND

Electroconvulsive therapy (ECT) is the most effective treatment option for major depressive disorder, so understanding whether its clinical effect relates to structural brain changes is vital for current and future antidepressant research.

OBJECTIVE

To determine whether clinical response to ECT is related to structural volumetric changes in the brain as measured by structural magnetic resonance imaging (MRI) and, if so, which regions are related to this clinical effect. We also determine whether a similar model can be used to identify regions associated with electrode placement (unilateral versus bilateral ECT).

METHODS

Longitudinal MRI and clinical data (Hamilton Depression Rating Scale) was collected from 10 sites as part of the Global ECT-MRI research collaboration (GEMRIC). From 192 subjects, relative changes in 80 (sub)cortical areas were used as potential features for classifying treatment response. We used recursive feature elimination to extract relevant features, which were subsequently used to train a linear classifier. As a validation, the same was done for electrode placement. We report accuracy as well as the structural coefficients of regions included in the discriminative spatial patterns obtained.

RESULTS

A pattern of structural changes in cortical midline, striatal and lateral prefrontal areas discriminates responders from non-responders (75% accuracy, p < 0.001) while left-sided mediotemporal changes discriminate unilateral from bilateral electrode placement (81% accuracy, p < 0.001).

CONCLUSIONS

The identification of a multivariate discriminative pattern shows that structural change is relevant for clinical response to ECT, but this pattern does not include mediotemporal regions that have been the focus of electroconvulsive therapy research so far.

Electroconvulsive therapy modulates grey matter increase in a hub of an affect processing network

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We here present a structural neuroimaging study reporting on a large multi-site patient sample with unipolar depression that underwent ECT.

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Patients showed grey matter increases in the medial temporal lobe.

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Connectivity modeling revealed that this altered brain region was involved in networks related to affect processing and memory.

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This provides a potential explanation, how these structural changes during ECT are involved in both main and side effects of the treatment.

A growing number of recent studies has suggested that the neuroplastic effects of electroconvulsive therapy (ECT) might be prominent enough to be detected through changes of regional gray matter volumes (GMV) during the course of the treatment. Given that ECT patients are difficult to recruit for imaging studies, most publications, however, report only on small samples. Addressing this challenge, we here report results of a structural imaging study on ECT patients that pooled patients from five German sites.

Whole-brain voxel-based morphometry (VBM) analysis was performed to detect structural differences in 85 patients with unipolar depression before and after ECT, when compared to 86 healthy controls. Both task-independent and task-dependent physiological whole-brain functional connectivity patterns of these regions were modeled using additional data from healthy subjects. All emerging regions were additionally functionally characterized using the BrainMap database.

Our VBM analysis detected a significant increase of GMV in the right hippocampus/amygdala region in patients after ECT compared to healthy controls. In healthy subjects this region was found to be enrolled in a network associated with emotional processing and memory. A region in the left fusiform gyrus was additionally found to have higher GMV in controls when compared with patients at baseline. This region showed minor changes after ECT.

Our data points to a GMV increase in patients post ECT in regions that seem to constitute a hub of an emotion processing network. This appears as a plausible antidepressant mechanism and could explain the efficacy of ECT not only in the treatment of unipolar depression, but also of affective symptoms across heterogeneous disorders.

Association between hippocampal volume change and change in memory following electroconvulsive therapy in late-life depression

OBJECTIVE

Electroconvulsive therapy (ECT)-induced hippocampal volume change (HVC) has been repeatedly described in recent years. The similar time course of HVC and ECT-related cognitive effects suggest a relation, that is to date, understudied. This study investigates whether HVC following ECT predicts the change in memory performance six months after the end of the ECT treatment.

METHODS

Hippocampal volume (HV) was measured via high-resolution 3D T1-weighted images in 88 patients with late-life depression, within 1 week before and after ECT. Memory performance was assessed before and six months after ECT. Multiple linear regression was used to examine whether change in memory performance could be predicted based on ECT-induced changes in HV.

RESULTS

Larger right absolute HVC predicts less pronounced improvement on the VAT (visual memory) in the whole sample. For the 8-Word Test (verbal memory), Category Fluency Test (semantic memory), and MMSE, the effect is only present in patients who switched from right unilateral to bitemporal stimulation after six ECT sessions. Absolute HVC in the left hemisphere was not significantly related to cognitive change.

CONCLUSION

A larger absolute change in right HV during ECT is associated with less improvement in memory performance up to 6 months post-ECT.

BDNF Genotype and Baseline Serum Levels in Relation to Electroconvulsive Therapy Effectiveness in Treatment-Resistant Depressed Patients

OBJECTIVES

Electroconvulsive therapy (ECT) represents one of the most effective therapies for treatment-resistant depression (TRD). The brain-derived neurotrophic factor (BDNF) is a neurotrophin implicated in major depressive disorder and in the effects of different therapeutic approaches, including ECT. Both BDNF peripheral levels and Val66Met polymorphism have been suggested as biomarkers of treatment effectiveness. The objective of this study was to test the potential of serum BDNF levels and Val66Met polymorphism in predicting ECT outcome in TRD patients.

METHODS

Seventy-four TRD patients scheduled to undergo ECT were included in the study. Illness severity was assessed through the Montgomery and Asberg Depression Rating Scale before beginning ECT (T0), the day after the end of ECT (T1), and 1 month after the end of ECT (T2). At T1, patients were classified as responders/nonresponders and remitters/nonremitters, whereas at T2, they were classified as sustained responders/nonresponders and sustained remitters/nonremitters. Serum concentrations of BDNF were measured at T0, and the BDNF Val66Met polymorphism was genotyped.

RESULTS

No difference in BDNF concentrations was observed in responders versus nonresponders, in remitters versus nonremitters, in sustained responders versus sustained nonresponders, and in sustained remitters versus sustained nonremitters. No association of Val66Met polymorphism was detected with both the response and the remission status.

CONCLUSIONS

Baseline serum BDNF levels and the BDNF Val66Met polymorphism showed no clinical utility in predicting ECT outcome in TRD patients.

Reduced vascular endothelial growth factor levels in the cerebrospinal fluid in patients with treatment resistant major depression and the effects of electroconvulsive therapy-A pilot study

BACKGROUND

Several lines of evidence are pointing towards an involvement of the vascular endothelial growth factor (VEGF) in the pathophysiology of depression. There are studies analyzing blood levels of VEGF in patients with depression compared to controls, but a data on cerebrospinal fluid (CSF) levels of VEGF in patients with depression are lacking.

METHOD

CSF VEGF levels were measured in patients (n = 12) with a severe, treatment-resistant depressive episode before and after the antidepressant treatment by a course of electroconvulsive therapy (ECT) and compared to age- and sex-matched controls (n = 20).

RESULTS

The patients with depression showed lower mean VEGF levels in the CSF prior to ECT than the controls (p = 0.041). Regarding the patients, CSF VEGF concentration at baseline and after the complete ECT treatment did not differ from each other (p = 0.78).

LIMITATIONS

Major limitations of this study are the small sample size and that data from corresponding serum levels cannot be provided. Another limitation is that the controls were not completely healthy, as they were recruited from a memory clinic with subjective complaints. The timing of the second sample might have been suboptimal, when taking into account that there might be an on-going phase of re-equilibrating after ECT.

CONCLUSIONS

CSF VEGF concentrations were lower in a clinical sample of patients with treatment-resistant depression compared with matched controls. Additionally, no change in CSF VEGF levels during a course of ECT could be detected.

Peripheral blood E2F1 mRNA in depression and following electroconvulsive therapy

The E2F transcription factors are a group of proteins that bind to the promotor region of the adenovirus E2 gene. E2F1, the first family member to be cloned, is linked to functions including cell proliferation and apoptosis, DNA repair, cell senescence and metabolism. We recently performed a deep sequencing study of micro-RNA changes in whole blood following ECT. Two micro-RNAs (miR-126-3p and miR-106a-5p) were identified and gene targeting analysis identified E2F1 as a shared target of these miRNAs. To our knowledge, no studies have examined E2F1 mRNA levels in patients with depression. Peripheral blood E2F1 mRNA levels were therefore examined in patients with depression, compared to healthy controls, and the effects of a course of ECT on peripheral blood E2F1 mRNA was investigated. Depressed patient and healthy control groups were balanced on the basis of age and sex. E2F1 mRNA levels were significantly lower in depressed patients in comparison to controls (p = .009) but did not change with ECT. There was no relationship between baseline E2F1 levels and depression severity, response to treatment, presence of psychosis or polarity of depression. There were no significant correlations between E2F1 levels and mood scores based on the HAM-D24. These results indicate that reduced peripheral blood E2F1 mRNA could be a trait feature of depression.

Elevated serum vascular endothelial growth factor in treatment-resistant schizophrenia treated with electroconvulsive therapy: Positive association with therapeutic effects

OBJECTIVES

As the name implies, vascular endothelial growth factor (VEGF) enhances angiogenesis, promotes vascular permeability, and stimulates neurogenesis in the adult brain. Furthermore, animal model studies have shown that electroconvulsive therapy (ECT), which is primarily utilised in cases of treatment-resistant schizophrenia (TRS), regulates the expression of VEGF. The current study focuses largely on the effect of ECT on VEGF serum concentration, and the relationship between VEGF and therapeutic effects in patients diagnosed with TRS.

METHODS

Participants comprised 40 TRS patients and 43 healthy controls. Clinical severity was assessed (i.e. 1 day before commencement of ECT and 1 day following ECT) using the positive and negative syndrome scale (PANSS). Blood samples were also collected for VEGF measurements at corresponding time points.

RESULTS

Pre-treatment serum VEGF levels were significantly lower in TRS patients compared to healthy controls. VEGF concentrations increased significantly following ECT, whereas no difference was found in controls. Moreover, there was a positive correlation between the change in VEGF and therapeutic effects.

CONCLUSIONS

Elevated serum VEGF in TRS treated with ECT is positively associated with therapeutic effects, suggesting that alterations in VEGF levels may constitute an index by which to evaluate the improvement in clinical condition.

The Involvement of Sortilin/NTSR3 in Depression as the Progenitor of Spadin and Its Role in the Membrane Expression of TREK-1

The molecular identification of sortilin, also called neurotensin receptor-3, from three different biochemical approaches already predicted the involvement of the protein in numerous biological and cellular functions. The first important observation was that sortilin is synthesized as a precursor that is converted to a mature protein after cleavage by the protein convertase furin in late Golgi compartments. This maturation leads to the formation of a 44 amino acid peptide, the propeptide (PE). The release of this peptide when matured sortilin reached the plasma membrane remained to be demonstrated. Sortilin has been also shown to be shedded by matrix metalloproteases releasing a large extracellular fragment identified as soluble sortilin. Therefore, sortilin has been shown to interact with several proteins and receptors confirming its role in the sorting of cellular components to the plasma membrane and/or to the lysosomal pathway. Interestingly, sortilin physically interacts with the two pore domain potassium channel TREK-1 and the PE as well as its synthetic analog spadin is able to block the activation of TREK-1 highlighting their role in the depression pathology. The present review describes the advance of research that led to these results and how both the soluble form of sortilin and the sortilin-derived PE have been detected in human serum and whose levels are affected in patients with major depressive disorder (MDD). The use of spadin as an antidepressant and the further role of soluble sortilin and of sortilin-derived PE as potential biomarkers during depression statement and/or remission of the pathology are considered and discussed in this review.

Vascular endothelial growth factor plasma levels in depression and following electroconvulsive therapy

Both animal and human studies have implicated the neurotrophic and angiogenic mediator vascular endothelial growth factor (VEGF) in depression, with meta-analyses, indicating that protein levels are raised in patients with depression. In line with this, we have previously shown that VEGFA mRNA levels are higher in whole blood from patients with depression compared to controls, in particular in patients with psychotic unipolar depression, and that treatment with electroconvulsive therapy (ECT) alters VEGFA mRNA levels. The aim of the present study was, therefore, to extend this previous work by assessing plasma VEGF protein levels in patients with depression compared to healthy controls, and in patients following treatment with ECT. We found that there was no difference between controls and patients with depression with regard to plasma VEGF (p = 0.59), and that VEGF levels were unaltered by ECT (p = 0.09) after correction for potential covariates. We found no correlation between VEGF protein and mRNA levels. Within the subgroup of patients receiving treatment with bitemporal ECT (n = 34), we identified a moderate negative correlation (ρ = - 0.54, p = 0.001) between the change in VEGF and the change in depression severity following treatment; however, no other association between VEGF and mood, responder/remitter status, polarity of depression, or presence of psychosis were found. Overall, our results indicate that the measurement of VEGF protein is not a useful marker for depression or response to treatment, and suggest that the measurement of VEGFA mRNA may prove more useful.

Volume of the Human Hippocampus and Clinical Response Following Electroconvulsive Therapy

BACKGROUND

Hippocampal enlargements are commonly reported after electroconvulsive therapy (ECT). To clarify mechanisms, we examined if ECT-induced hippocampal volume change relates to dose (number of ECT sessions and electrode placement) and acts as a biomarker of clinical outcome.

METHODS

Longitudinal neuroimaging and clinical data from 10 independent sites participating in the Global ECT-Magnetic Resonance Imaging Research Collaboration (GEMRIC) were obtained for mega-analysis. Hippocampal volumes were extracted from structural magnetic resonance images, acquired before and after patients (n = 281) experiencing a major depressive episode completed an ECT treatment series using right unilateral and bilateral stimulation. Untreated nondepressed control subjects (n = 95) were scanned twice.

RESULTS

The linear component of hippocampal volume change was 0.28% (SE 0.08) per ECT session (p < .001). Volume change varied by electrode placement in the left hippocampus (bilateral, 3.3 ± 2.2%, d = 1.5; right unilateral, 1.6 ± 2.1%, d = 0.8; p < .0001) but not the right hippocampus (bilateral, 3.0 ± 1.7%, d = 1.8; right unilateral, 2.7 ± 2.0%, d = 1.4; p = .36). Volume change for electrode placement per ECT session varied similarly by hemisphere. Individuals with greater treatment-related volume increases had poorer outcomes (Montgomery-Åsberg Depression Rating Scale change -1.0 [SE 0.35], per 1% volume increase, p = .005), although the effects were not significant after controlling for ECT number (slope -0.69 [SE 0.38], p = .069).

CONCLUSIONS

The number of ECT sessions and electrode placement impacts the extent and laterality of hippocampal enlargement, but volume change is not positively associated with clinical outcome. The results suggest that the high efficacy of ECT is not explained by hippocampal enlargement, which alone might not serve as a viable biomarker for treatment outcome.

Baseline serum vascular endothelial growth factor levels predict treatment response to antipsychotic medication in patients with schizophrenia

Vascular endothelial growth factor (VEGF) is implicated in angiogenesis, blood flow, and neuroplasticity, which have previously been shown to contribute to schizophrenia and the mechanisms of action of antipsychotic medication. The aim of the present study was to investigate whether baseline serum VEGF levels predict treatment responses to antipsychotic medication. Drug-free adults with schizophrenia were administered monotherapy with atypical antipsychotic drugs for 6 weeks. Participants' psychiatric symptoms were assessed using the positive and negative symptom scale (PANSS) before and after treatment. Blood samples for VEGF measurements were collected from 201 participants comprising 83 healthy controls and 118 patients (i.e. only on admission). Baseline VEGF levels in adults with schizophrenia were significantly lower than those in the control group (t = 3.656, df = 199, P < 0.001). In particular, pretreatment VEGF levels were significantly higher in patients responding to drug treatment at follow-up (≥ 50% reduction in initial PANSS total) (t = 4.743, df = 116, P < 0.001). The predictive power of serum VEGF levels was investigated using receiver operating characteristic curves. The area under the curve was 0.774 (95% confidence interval 0.688-0.846); for fixed specificity of 78.8%, the corresponding sensitivity was 63.5%. Results from this preliminary experiment suggest high baseline serum concentrations of VEGF may predict a better response to antipsychotic medications in adults with schizophrenia. Further studies using larger sample sizes are needed to verify the findings.

Towards a multi protein and mRNA expression of biological predictive and distinguish model for post stroke depression

Previous studies suggest that neurotrophic factors participate in the development of stroke and depression. So we investigated the utility of these biomarkers as predictive and distinguish model for post stroke depression (PSD). 159 individuals including PSD, stroke without depression (Non-PSD), major depressive disorder (MDD) and normal control groups were recruited and examined the protein and mRNA expression levels of vascular endothelial growth factor (VEGF), vascular endothelial growth factor receptors (VEGFR2), placental growth factor (PIGF), insulin-like growth factor (IGF-1) and insulin-like growth factor receptors (IGF-1R). The chi-square test was used to evaluate categorical variable, while nonparametric test and one-way analysis of variance were applied to continuous variables of general characteristics, clinical and biological changes. In order to explore the predictive and distinguish role of these factors in PSD, discriminant analysis and receiver operating characteristic curve were calculated. The four groups had statistical differences in these neurotrophic factors (all P < 0.05) except VEGF concentration and IGF-1R mRNA (P = 0.776, P = 0.102 respectively). We identified these mRNA expression and protein analytes with general predictive performance for PSD and Non-PSD groups [area under the curve (AUC): 0.805, 95% CI, 0.704-0.907, P < 0.001]. Importantly, there is an excellent predictive performance (AUC: 0.984, 95% CI, 0.964-1.000, P < 0.001) to differentiate PSD patients from MDD patients. This was the first study to explore the changes of neurotrophic factors family in PSD patients, the results intriguingly demonstrated that the combination of protein and mRNA expression of biological factors could use as a predictive and discriminant model for PSD.

Increased serum levels of sortilin-derived propeptide after electroconvulsive therapy in treatment-resistant depressed patients

PURPOSE

Sortilin-derived propeptide (PE) and its synthetic analog spadin show strong antidepressant activity in rodents and, therefore, could be used as a biomarker to evaluate the clinical efficacy of antidepressant treatments. The aim of this study was to determine whether electroconvulsive therapy (ECT) modulates serum PE concentration in patients with treatment-resistant depression (TRD).

PATIENTS AND METHODS

Forty-five patients with major depressive disorder, who met the Diagnostic and Statistical Manual of Mental Disorders-IV criteria, were selected for this study.

RESULTS

We did not observe any difference in the PE levels between TRD patients and controls (z=0.10, P=0.92), but we found a strong significant increase between the PE levels measured just before (T0) and about 1 month (T2) after ECT (z=-2.82, P=0.005). A significant difference between T0 and T2 was observed only in responders (z=-2.59, P=0.01), whereas no effect was found in nonresponders (z=-1.27, P=0.20). Interestingly, we found a significant correlation between the increase in PE levels and decrease in Montgomery -Åsberg Depression Rating Scale scores for the total patient sample (P=0.03).

CONCLUSION

This study indicates for the first time that ECT affects serum PE concentration in responders and, therefore, could contribute to the evaluation of the therapy success.

Growth Factor Proteins and Treatment-Resistant Depression: A Place on the Path to Precision

Background: Since the neurotrophic hypothesis of depression was formulated, conflicting results have been reported regarding the role of growth factor proteins in depressed patients, including whether there are state or trait alterations found in patients compared to controls and whether they represent predictors of treatment response. Recently it has been hypothesized that heterogeneity of findings within this literature might be partly explained by participants' history of treatment-resistant depression. This study aimed to investigate the role of growth factor proteins in patients with treatment-resistant depression (TRD) undergoing an inpatient intervention. Methods: Blood samples were collected from 36 patients with TRD and 36 matched controls. Patients were assessed both at admission and discharge from a specialist inpatient program. We examined serum biomarker differences between patients and non-depressed matched controls, longitudinal changes after inpatient treatment and relationship to clinical outcomes. Additionally, the influence of potential covariates on biomarker levels were assessed. Results: Patients displayed lower serum levels of brain-derived neurotrophic factor (OR = 0.025; 95% CI = 0.001, 0.500) and vascular endothelial growth factor-C (VEGFC; OR = 0.083, 95% CI = 0.008, 0.839) as well as higher angiopoietin-1 receptor (Tie2; OR = 2.651, 95% CI = 1.325, 5.303) compared to controls. Patients were stratified into responders (56%) and non-responders (44%). Lower VEGFD levels at admission predicted subsequent non-response (OR = 4.817, 95% CI = 1.247, 11.674). During treatment, non-responders showed a decrease in VEGF and VEGFC levels, while responders showed no significant changes. Conclusion: TRD patients demonstrate a deficit of peripheral growth factors and our results suggest that markers of the VEGF family might decline over time in chronically depressed patients in spite of multidisciplinary treatment. The action of angiogenic proteins may play an important role in the pathophysiology of TRD, and pending comprehensive investigation may provide important insights for the future of precision psychiatry.

Vascular endothelial growth factor: Potential predictor of treatment response in major depression

OBJECTIVES

The aim of the study was to evaluate baseline plasma VEGF levels as a potential predictor of response to antidepressant pharmacotherapy. The study also sought to determine whether baseline plasma VEGF would be useful in predicting treatment outcome when two pharmacodynamically diverse agents with established antidepressant efficacy, escitalopram and quetiapine, were administered monotherapeutically to MDD patients.

METHODS

Two groups of qualifying MDD subjects were enrolled. One group was treated with escitalopram and the other with quetiapine. Plasma concentrations of VEGF were measured using Randox Technologies at baseline, and at weeks 8 and 12 of treatment.

RESULTS

We stratified the MDD patients into those who remitted and those who failed to respond. Mean baseline VEGF for the remitters and non-responders was 9.61  and 5.40 pg/ml, respectively (P < 0.0005). Using optimal data analysis a cut score of 7.49 pg/ml for baseline plasma VEGF distinguished remitters from non-responders with a 63% overall accuracy. The remission rate was comparable for both drugs (73 and 81% for quetiapine and escitalopram, respectively). VEGF levels did not significantly change following antidepressant treatment with either escitalopram or quetiapine when measured at 8 and 12 weeks; this result held true for both remitters and non-responders.

CONCLUSIONS

Our results suggest that VEGF may predict response to antidepressant treatment and may ultimately prove to be a potential biomarker that can be measured with a routine blood draw at the point of service.

Peripheral blood microRNA and VEGFA mRNA changes following electroconvulsive therapy: implications for psychotic depression

OBJECTIVE

MicroRNAs are short, non-coding molecules that regulate gene expression. Here, we investigate the role of microRNAs in depression and electroconvulsive therapy (ECT).

METHODS

We performed three studies: a deep sequencing discovery-phase study of miRNA changes in whole blood following ECT (n = 16), followed by a validation study in a separate cohort of patients pre-/post-ECT (n = 37) and matched healthy controls (n = 34). Changes in an experimentally validated gene target (VEGFA) were then analysed in patients pre-/post-ECT (n = 97) and in matched healthy controls (n = 53).

RESULTS

In the discovery-phase study, we found no statistically significant differences in miRNA expression from baseline to end of treatment in the group as a whole, but post hoc analysis indicated a difference in patients with psychotic depression (n = 3). In a follow-up validation study, patients with psychotic depression (n = 7) had elevated baseline levels of miR-126-3p (t = 3.015, P = 0.006) and miR-106a-5p (t = 2.598, P = 0.025) compared to healthy controls. Following ECT, these differences disappeared. Baseline VEGFA levels were significantly higher in depressed patients compared to healthy controls (F(1,144) = 27.688, P = <0.001). Following ECT, there was a significant change in VEGFA levels in the psychotic group only (t = 2.915, P = 0.010).

CONCLUSION

Molecular differences (miRNA and VEGFA) may exist between psychotic and non-psychotic depression treated with ECT.

Mouse repeated electroconvulsive seizure (ECS) does not reverse social stress effects but does induce behavioral and hippocampal changes relevant to electroconvulsive therapy (ECT) side-effects in the treatment of depression

Electroconvulsive therapy (ECT) is an effective treatment for depression, but can have negative side effects including amnesia. The mechanisms of action underlying both the antidepressant and side effects of ECT are not well understood. An equivalent manipulation that is conducted in experimental animals is electroconvulsive seizure (ECS). Rodent studies have provided valuable insights into potential mechanisms underlying the antidepressant and side effects of ECT. However, relatively few studies have investigated the effects of ECS in animal models with a depression-relevant manipulation such as chronic stress. In the present study, mice were first exposed to chronic social stress (CSS) or a control procedure for 15 days followed by ECS or a sham procedure for 10 days. Behavioral effects were investigated using an auditory fear conditioning (learning) and expression (memory) test and a treadmill-running fatigue test. Thereafter, immunohistochemistry was conducted on brain material using the microglial marker Iba-1 and the cholinergic fibre marker ChAT. CSS did not increase fear learning and memory in the present experimental design; in both the control and CSS mice ECS reduced fear learning and fear memory expression. CSS induced the expected fatigue-like effect in the treadmill-running test; ECS induced increased fatigue in CSS and control mice. In CSS and control mice ECS induced inflammation in hippocampus in terms of increased expression of Iba-1 in radiatum of CA1 and CA3. CSS and ECS both reduced acetylcholine function in hippocampus as indicated by decreased expression of ChAT in several hippocampal sub-regions. Therefore, CSS increased fatigue and reduced hippocampal ChAT activity and, rather than reversing these effects, a repeated ECS regimen resulted in impaired fear learning-memory, increased fatigue, increased hippocampal Iba-1 expression, and decreased hippocampal ChAT expression. As such, the current model does not provide insights into the mechanism of ECT antidepressant function but does provide evidence for pathophysiological mechanisms that might contribute to important ECT side-effects.

How Electroconvulsive Therapy Works?: Understanding the Neurobiological Mechanisms

Electroconvulsive therapy (ECT) is a time tested treatment modality for the management of various psychiatric disorders. There have been a lot of modifications in the techniques of delivering ECT over decades. Despite lots of criticisms encountered, ECT has still been used commonly in clinical practice due to its safety and efficacy. Research evidences found multiple neuro-biological mechanisms for the therapeutic effect of ECT. ECT brings about various neuro-physiological as well as neuro-chemical changes in the macro- and micro-environment of the brain. Diverse changes involving expression of genes, functional connectivity, neurochemicals, permeability of blood-brain-barrier, alteration in immune system has been suggested to be responsible for the therapeutic effects of ECT. This article reviews different neurobiological mechanisms responsible for the therapeutic efficacy of ECT.

Interactions between the vascular endothelial growth factor gene polymorphism and life events in susceptibility to major depressive disorder in a Chinese population

BACKGROUND

Recent studies suggest that vascular endothelial growth factor (VEGF) is involved in the development of major depressive disorder. The aim of this study is to investigate the interaction between vascular endothelial growth factor (VEGF) polymorphism (+405G/C, rs2010963) and negative life events in the pathogenesis of major depressive disorder (MDD).

METHODS

DNA genotyping was performed on peripheral blood leukocytes in 274 patients with MDD and 273 age-and sex-matched controls. The frequency and severity of negative life events were assessed by the Life Events Scale (LES). A logistics method was employed to assess the gene-environment interaction (G×E).

RESULTS

Differences in rs2010963 genotype distributions were observed between MDD patients and controls. Significant G×E interactions between allelic variation of rs2010963 and negative life events were observed. Individuals carrying the C alleles were susceptible to MDD only when exposed to high-negative life events.

CONCLUSIONS

These results indicate that interactions between the VEGF rs2010963 polymorphism and environment increases the risk of developing MDD.

Environmental enrichment ameliorates chronic immobilisation stress-induced spatial learning deficits and restores the expression of BDNF, VEGF, GFAP and glucocorticoid receptors

Severe and prolonged stress is the main environmental factor that precipitates depression, anxiety and cognitive dysfunctions. On the other hand, exposure to environmental enrichment (EE) has been shown to induce progressive plasticity in the brain and improve learning and memory in various neurological and psychiatric disorders. It is not known whether exposure to enriched environment could ameliorate chronic immobilisation stress-induced cognitive deficits and altered molecular markers. Hence, in the present study we aimed to evaluate the effect of enriched environment on chronic immobilisation stress (CIS) associated changes in spatial learning and memory, behavioural measures of anxiety, depression and molecular markers as well as structural alterations. Male Wistar rats were subjected to chronic immobilisation stress for 2h/day/10days followed by 2weeks of exposure to EE. CIS resulted in weight loss, anhedonia, increased immobility, spatial learning and memory impairment, enhanced anxiety, and reduced expression of BDNF, VEGF, GFAP and glucocorticoid receptors (GR) in discrete brain regions. Interestingly, stressed rats exposed to enrichment ameliorated behavioural depression, spatial learning and memory impairment and reduced anxiety behaviour. In addition, EE restored BDNF, VEGF, GFAP and GR expression and normalized hypotrophy of dentate gyrus and hippocampus in CIS rats. In contrast, EE did not restore hypertrophy of the amygdalar complex. Thus, EE ameliorates stress-induced cognitive deficits by modulating the neurotrophic factors, astrocytes and glucocorticoid receptors in the hippocampus, frontal cortex and amygdala.

Potential Mechanisms Underlying the Therapeutic Effects of Electroconvulsive Therapy

In spite of the extensive application of electroconvulsive therapy (ECT), how it works remains unclear. So far, researchers have made great efforts in figuring out the mechanisms underlying the effect of ECT treatment via determining the levels of neurotransmitters and cytokines and using genetic and epigenetic tools, as well as structural and functional neuroimaging. To help address this question and provide implications for future research, relevant clinical trials and animal experiments are reviewed.

Growth factors as clinical biomarkers of prognosis and diagnosis in psychiatric disorders

The psychiatric disorders are one of the most disabling illnesses in the world and represent a major problem for public health. These disorders are characterized by neuroanatomical or biochemical changes and it has been suggested that such changes may be due to inadequate neurodevelopment. Diverse alterations in the gene expression and/or serum level of specific growth factors have been implicated in the etiology, symptoms and progression of some psychiatric disorders. Herein, we summarize the latest information regarding the role of brain-derived neurotrophic factor (BDNF), epidermal growth factor (EGF), fibroblast growth factor (FGF), Insulin-like growth factor (IGF-1), neuroregulin-1 (NGR-1), erythropoietin (EPO), vascular growth factor (VEGF), transforming growth factor beta (TGF-β), nerve growth factor (NGF) and others cytokines in the pathogenesis of schizophrenia, depression, bipolar and anxiety disorders. Focusing on the role of these growth factors and their relationship with the main impairments (cognitive, emotional and social) of these pathologies. Some of these signaling molecules may be suitable biological markers for diagnosis and prognosis in cognitive, mood and social disabilities across different mental disorders.

Genetic polymorphisms and the adequacy of brain stimulation: state of the art

INTRODUCTION

Heterogeneity of therapeutic response to brain stimulation techniques has inspired scientists to uncover the secrets to success or failure of these projects. Genetic polymorphisms are one of the major causes of this heterogeneity.

AREAS COVERED

More than twenty genetic variants within more than ten genes (e.g. BDNF, COMT, DRD2, TRPV1, 5-HT1A, 5-HHT, P2RX7, VEGF, TPH1, TPH2, ACE, APOE, GNB3, NET, NMDA receptors, and RGS4) have been investigated, among which the BDNF gene and its polymorphism, Val66Met, is the best documented variant. We review the genotypic combinations, which are reported to interact with the work of brain stimulation, of which the DRD2 C957T polymorphism is the most prominent type. Finally, implications of transcranial magnetic stimulation in deciphering the interaction between genetic background (e.g. SCN1A and 5-HTT) and drugs (e.g. carbamazepine and citalopram) at the cortical excitability level is explained. Expert commentary: Studies are ongoing to find missing factors responsible for heterogeneity of response to brain stimulation techniques. Further knowledge about genetic factors affecting the therapeutic response to brain stimulation techniques might provide helpful guidelines for choosing ideal candidates for treatment.

Influence of GRIK4 genetic variants on the electroconvulsive therapy response

Several lines of evidence have shown the involvement of the glutamatergic system in the function of electroconvulsive therapy (ECT). In particular, patients with treatment resistant depression (TRD) and chronic depression have lower levels of glutamate/glutamine than controls, and ECT can reverse this deficit. Genetic factors might contribute to modulating the mechanisms underlying ECT. This study aimed to evaluate the relationship between three polymorphisms (rs1954787, rs4936554 and rs11218030) of the glutamate receptor ionotropic kainate 4 (GRIK4) gene and responsiveness to ECT treatment in a sample of one hundred individuals, TRD or depressive Bipolar Disorder patients resistant to pharmacological treatments. The results revealed that GRIK4 variants were significantly associated with the response to ECT. In particular, we found that patients carrying the G allele of the GRIK4 rs11218030 had a significantly poorer response to ECT (p=2.71×10(-4)), showing five times the risk of relapse after ECT compared to the AA homozygotes. Analogously, patients carrying the GG rs1954787 genotype and rs4936554A allele carriers presented a double risk of lack of response after ECT (p=0.013 and p=0.040, respectively). In conclusion, the current study provides new evidence, indicating that some GRIK4 variants modulate the response to ECT in patients with depression resistant to treatment, suggesting a role for kainate receptor modulation.

Are morphological changes necessary to mediate the therapeutic effects of electroconvulsive therapy?

The neurotrophic hypothesis has become the favorite model to explain the antidepressant properties of electroconvulsive therapy (ECT). It is based on the assumption that a restoration of previously defective neural networks drives therapeutic effects. Recent data in rather young patients suggest that neurotrophic effects of ECT might be detectable by diffusion tensor imaging. We here aimed to investigate whether the therapeutic response to ECT necessarily goes along with mesoscopic effects in gray matter (GM) or white matter (WM) in our patients in advanced age. Patients (n = 21, 15 males and 7 females) suffering from major depressive disorder were treated with ECT. Before the start of treatment and after the completion of the index series, they underwent magnetic resonance imaging, including a diffusion-weighed sequence. We used voxel-based morphometry to assess GM changes and tract-based spatial statistics and an SPM-based whole-brain analysis to detect WM changes in the course of treatment. Patients significantly improved clinically during the course of ECT. This was, however, not accompanied by GM or WM changes. This result challenges the notion that mesoscopic brain structure changes are an obligatory prerequisite for the antidepressant effects of ECT.

Electroconvulsive seizures (ECS) do not prevent LPS-induced behavioral alterations and microglial activation

Background

Long-term neuroimmune activation is a common finding in major depressive disorder (MDD). Literature suggests a dual effect of electroconvulsive therapy (ECT), a highly effective treatment strategy for MDD, on neuroimmune parameters: while ECT acutely increases inflammatory parameters, such as serum levels of pro-inflammatory cytokines, there is evidence to suggest that repeated ECT sessions eventually result in downregulation of the inflammatory response. We hypothesized that this might be due to ECT-induced attenuation of microglial activity upon inflammatory stimuli in the brain.

Methods

Adult male C57Bl/6J mice received a series of ten electroconvulsive seizures (ECS) or sham shocks, followed by an intracerebroventricular (i.c.v.) lipopolysaccharide (LPS) or phosphate-buffered saline (PBS) injection. Brains were extracted and immunohistochemically stained for the microglial marker ionized calcium-binding adaptor molecule 1 (Iba1). In addition, a sucrose preference test and an open-field test were performed to quantify behavioral alterations.

Results

LPS induced a short-term reduction in sucrose preference, which normalized within 3 days. In addition, LPS reduced the distance walked in the open field and induced alterations in grooming and rearing behavior. ECS did not affect any of these parameters. Phenotypical analysis of microglia demonstrated an LPS-induced increase in microglial activity ranging from 84 to 213 % in different hippocampal regions (CA3 213 %; CA1 84 %; dentate gyrus 131 %; and hilus 123 %). ECS-induced alterations in microglial activity were insignificant, ranging from −2.6 to 14.3 % in PBS-injected mice and from −20.2 to 6.6 % in LPS-injected mice.

Conclusions

We were unable to demonstrate an effect of ECS on LPS-induced microglial activity or behavioral alterations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12974-015-0454-x) contains supplementary material, which is available to authorized users.

Peripheral vascular endothelial growth factor as a novel depression biomarker: A meta-analysis

BACKGROUND

The neurotrophic hypothesis of major depressive disorder (MDD) postulates that the pathology of this illness incorporates a down-regulation of neurotrophin signaling. Brain-derived neurotrophic factor (BDNF) is the most studied neurotrophic mediator regarding the neurobiology of MDD. Nevertheless, emerging evidence has implicated the multi-competent angiogenic and neurogenic molecule - vascular endothelial growth factor (VEGF) - in hippocampal neurogenesis and depression pathophysiology.

OBJECTIVE

To compare peripheral levels of VEGF between individuals with MDD and healthy controls.

METHODS

We performed a systematic review and meta-analysis of original studies measuring peripheral levels of VEGF in participants with MDD compared to healthy controls. We searched the Pubmed/MEDLINE, EMBASE and PsycInfo databases for studies published in any language through December 16th, 2014.

RESULTS

Fourteen studies met eligibility criteria (N=1633). VEGF levels were significantly elevated in individuals with MDD when compared to healthy controls (Hedges's g=0.343; 95% CI: 0.146-0.540; P<0.01). Funnel plot inspection and the Egger's test did not provide evidence of publication bias. A significant degree of heterogeneity was observed (Q=38.355, df=13, P<0.001; I(2)=66.1%), which was explored through meta-regression and subgroup analyses. Overall methodological quality, sample for assay (plasma versus serum), as well as the matching of MDD and control samples for age and gender emerged as significant sources of heterogeneity.

CONCLUSIONS

Taken together, extant data indicate that VEGF shows promise as a biomarker for MDD, and supports that this mediator may be involved in neuroplasticity mechanisms underlying the pathophysiology of MDD.