Early reactions of brain-derived neurotrophic factor in plasma (pBDNF) and outcome to acute antidepressant treatment in patients with Major Depression

The Effect of EEG Biofeedback Training Frequency and Environmental Conditions on Simple and Complex Reaction Times

The objective of this study is to evaluate the impact of EEG biofeedback training under normoxic and normobaric hypoxic conditions on both simple and complex reaction times in judo athletes, and to identify the optimal training frequency and environmental conditions that substantially enhance reaction times in the examined athlete groups. The study comprised 20 male judo athlete members of the Polish national judo team in the middleweight and heavyweight categories. We randomly assigned participants to an experimental group and a control group. We conducted the research over four cycles, varying the frequency of EEG biofeedback sessions and environmental circumstances for both the experimental and control groups. Every research cycle had 15 training sessions. The results showed that the experimental group, following the theta/beta regimen, got significantly faster at complex reactions after a training cycle that included sessions every other day at normal oxygen levels. Following daily training sessions in normoxic circumstances, we noted enhancements in simple reaction speeds. Under normobaric hypoxia conditions, the judo athletes showed deterioration in both simple and complex reaction times. The control group showed no similar changes. Daily EEG training in normoxic settings markedly improved simple reaction time, but EEG-BF training conducted every other day greatly raised complicated reaction time. In contrast, training under normobaric hypoxia settings did not result in enhancements in basic or complicated reaction times following EEG training.

The Serum Brain-Derived Neurotrophic Factor Increases in Serotonin Reuptake Inhibitor Responders Patients with First-Episode, Drug-Naïve Major Depression

Brain-derived neurotrophic factor (BDNF) is a growth factor synthesized in the cell bodies of neurons and glia, which affects neuronal maturation, the survival of nervous system, and synaptic plasticity. BDNF play an important role in the pathophysiology of major depression (MD). The serum BDNF levels changed over time, or with the improvement in depressive symptoms. However, the change of serum BDNF during pharmacotherapy remains obscure in MDD. In particular, the changes in serum BDNF associated with pharmacotherapy have not yet been fully elucidated. The present study aimed to compare the changes in serum BDNF concentrations in first-episode, drug-naive patients with MD treated with antidepressants between treatment-response and treatment-nonresponse groups. The study included 35 inpatients and outpatients composed of 15 males and 20 females aged 36.7 ± 6.8 years at the Department of Psychiatry of our University Hospital. All patients met the DSM-5 diagnostic criteria for MD. The antidepressants administered included paroxetine, duloxetine, and escitalopram. Severity of depressive state was assessed using the 17-item HAMD before and 8 weeks after drug administration. Responders were defined as those whose total HAMD scores at 8 weeks had decreased by 50% or more compared to those before drug administration, while non-responders were those whose total HAMD scores had decreased by less than 50%. Here we showed that serum BDNF levels were not significantly different at any point between the two groups. The responder group, but not the non-responder group, showed statistically significant changes in serum BDNF 0 and serum BDNF 8. The results suggest that the changes of serum BDNF might differ between the two groups. The measurement of serum BDNF has the potential to be a useful predictor of pharmacotherapy in patients with first-episode, drug-naïve MD.

Development and validation of brain-derived neurotrophic factor measurement in human urine samples as a non-invasive effect biomarker

Background

Brain-derived neurotrophic factor (BDNF), a neurotrophic growth factor mainly expressed in the brain, has been proposed as a potential effect biomarker; that is, as a measurable biomarker whose values could be associated with several diseases, including neurological impairments. The European Human Biomonitoring Initiative (HBM4EU) has also recognized effect biomarkers as a useful tool for establishing link between exposure to environmental pollutants and human health. Despite the well-establish protocol for measuring serum BDNF, there is a need to validate its assessment in urine, a non-invasive sample that can be easily repeated over time. The aim of this study was to develop, standardize and validate a methodology to quantify BDNF protein levels in urine samples before its implementation in biomonitoring studies.

Methods

Different experimental conditions and non-competitive commercial enzyme-linked immunosorbent assay (ELISA) kits were tested to determine the optimal analytical procedure, trying to minimize the shortcomings of ELISA kits. The fine-tune protocol was validated in a pilot study using both upon awakening (n = 150) and prior to sleeping (n = 106) urine samples from the same Spanish adolescent males in a well-characterized study population (the Spanish INMA-Granada cohort).

Results

The best results were obtained in 0.6 ml of urine after the acidification and extraction (pre-concentration) of samples. The highest reproducibility was obtained with the ELISA kit from Raybiotech. Urinary BDNF concentrations of adolescent males were within the previously reported range (morning = 0.047-6.801 ng/ml and night = 0.047-7.404 ng/ml). Urinary BDNF levels in the awakening and pre-sleep samples did not follow a normal distribution and were not correlated.

Conclusion

The developed methodology offers good sensitivity and reproducibility. Having reliable markers in urine may facilitate both diagnosis and monitoring possible diseases (and treatment). Further studies are needed to implement urinary BDNF in biomonitoring studies to further elucidate its usefulness and biological significance for neurological impairments.

Acute Normobaric Hypoxia Lowers Executive Functions among Young Men despite Increase of BDNF Concentration

BACKGROUND

Decreased SpO2 during hypoxia can cause cognitive function impairment, and the effects of acute hypoxia on high-order brain functions such as executive processing remain unclear. This study's goal was to examine the impact of an acute normobaric hypoxia breathing session on executive function and biological markers.

METHODS

Thirty-two healthy subjects participated in a blind study performing two sessions of single 30 min breathing bouts under two conditions (normoxia (NOR) and normobaric hypoxia (NH), FIO2 = 0.135). The Stroop test was applied to assess cognitive function.

RESULTS

No significant difference was observed in the Stroop interference in the "reading" part of the test in either condition; however, there was a significant increase in the "naming" part under NH conditions (p = 0.003), which corresponded to a significant decrease in SpO2 (p < 0.001). There was a significant increase (p < 0.013) in the brain-derived neurotrophic factor (BDNF) level after NH conditions compared to the baseline, which was not seen in NOR. In addition, a significant drop (p < 0.001) in cortisol levels in the NOR group and a slight elevation in the NH group was noticed.

CONCLUSIONS

According to these findings, acute hypoxia delayed cognitive processing for motor execution and reduced the neural activity in motor executive and inhibitory processing. We also noted that this negative effect was associated with decreased SpO2 irrespective of a rise in BDNF.

Serum Mature BDNF Level Is Associated with Remission Following ECT in Treatment-Resistant Depression

The search for a biological marker predicting the future failure or success of electroconvulsive therapy (ECT) remains highly challenging for patients with treatment-resistant depression. Evidence suggests that Brain-Derived Neurotrophic Factor (BDNF), a protein known to be involved in brain plasticity mechanisms, can play a key role in both the clinical efficacy of ECT and the pathophysiology of depressive disorders. We hypothesized that mature BDNF (mBDNF), an isoform of BDNF involved in the neural plasticity and survival of neural networks, might be a good candidate for predicting the efficacy of ECT. Total BDNF (tBDNF) and mBDNF levels were measured in 23 patients with severe treatment-resistant depression before (baseline) they received a course of ECT. More precisely, tBDNF and mBDNF measured before ECT were compared between patients who achieved the criteria of remission after the ECT course (remitters, n = 7) and those who did not (non-remitters, n = 16). We found that at baseline, future remitters displayed significantly higher mBDNF levels than future non-remitters (p = 0.04). No differences were observed regarding tBDNF levels at baseline. The multiple logistic regression model controlled for age and sex revealed that having a higher baseline mBDNF level was significantly associated with future remission after ECT sessions (odd ratio = 1.38; 95% confidence interval = 1.07–2.02, p = 0.04). Despite the limitations of the study, current findings provide additional elements regarding the major role of BDNF and especially the mBDNF isoform in the clinical response to ECT in major depression.

Early Enhancement of Neuroplasticity Index, the Ratio of Serum Brain-Derived Neurotrophic Factor Level to HAMD-24 Score, in Predicting the Long-Term Antidepressant Efficacy

Background: Current mainstream treatment of major depressive disorder (MDD) has a disadvantage in delayed onset of efficacy, making detection of early signatures predicative of the long-term treatment efficacy urgent.

Methods: MDD patients were scored with HAMD-24 and serum brain-derived neurotrophic factor (BDNF) levels were measured at different times in two independent trials: a single-arm observation of Yueju pill, a clinically approved traditional multiherbal medicine, and a two-arm random placebo-controlled trial for Yueju vs escitalopram. The ratio of the BDNF level to HAMD-24 score, or neuroplasticity index (NI), and its derived parameters were used for correlation analysis and receiver operating characteristic (ROC) analysis.

Results: On both the early (4th) and final (28th) days, Yueju and escitalopram significantly reduced HAMD-24 scores, compared to baselines, but only Yueju increased BDNF at both times. For either Yueju or escitalopram treatment, NI, but not BDNF, at baseline was correlated to NIs at the early or final treatment day. NI at early time was significantly correlated to early NI enhancement from the baseline for both Yueju and escitalopram, and to final NI enhancement from the baseline for Yueju in both trials. ROC analysis supported the predictability of Yueju’s final treatment efficacy from early NI enhancement.

Limitations: The small sample size and 28 days of treatment time may lead to the impossibility of ROC analysis of escitalopram.

Conclusion: Early NI enhancement is useful for prediction of long-term efficacy of Yueju and presumably some other antidepressants.

Clinical Trial Registration: [www.ClinicalTrials.gov], identifier [ChiCTR1900021114].

Downregulation of connexin43 potentiates noradrenaline-induced expression of brain-derived neurotrophic factor in primary cultured cortical astrocytes

Decreased expression of brain-derived neurotrophic factor (BDNF) is involved in the pathology of depressive disorders. Astrocytes produce BDNF following antidepressant treatment or stimulation of adrenergic receptors. Connexin43 (Cx43) is mainly expressed in central nervous system astrocytes and its expression is downregulated in patients with major depression. How changes in Cx43 expression affect astrocyte function, including BDNF production, is poorly understood. The current study examined the effect of Cx43 knockdown on BDNF expression in cultured cortical astrocytes after stimulation of adrenergic receptors. The expression of Cx43 in rat primary cultured cortical astrocytes was downregulated with RNA interference. Levels of messenger RNAs (mRNAs) or proteins were measured by real-time PCR and western blotting, respectively. Knockdown of Cx43 potentiated noradrenaline (NA)-induced expression of BDNF mRNA in cultured astrocytes. NA treatment induced proBDNF protein expression in astrocytes transfected with small interfering RNA (siRNA) targeting Cx43, but not with control siRNA. This potentiation was mediated by the Src tyrosine kinase-extracellular signal-regulated kinase (ERK) pathway through stimulation of adrenergic α1 and β receptors. Furthermore, the Gq/11 protein-Src-ERK pathway and the G-protein coupled receptor kinase 2-Src-ERK pathway were involved in α1 and β adrenergic receptor-mediated potentiation of BDNF mRNA expression, respectively. The current studies demonstrate a novel mechanism of BDNF expression in cortical astrocytes mediated by Cx43, in which downregulation of Cx43 increases, through adrenergic receptors, the expression of BDNF. The current findings indicate a potentially novel mechanism of action of antidepressants, via regulation of astrocytic Cx43 expression and subsequent BDNF expression.

The role of BDNF exon I region methylation in the treatment of depression with sertraline and its clinical diagnostic value

Background

Brain‐derived neurotrophic factor (BDNF) is considered to be one of the best candidate genes for depression. However, whether sertraline treatment affects the methylation level of this gene remains unknown.

Methods

Fifty‐three patients with depression and 51 healthy controls were included in the study. The methylation level of BDNF exon I was determined in blood samples from these subjects. The Hamilton Depression Scale was used to evaluate the depression status of patients. Single nucleotide polymorphism detection was used for genotyping, and a receiver operating characteristic (ROC) curve was used to evaluate the predictive value of the methylation level of this locus in patients with depression.

Results

There was a significant difference in the methylation level of BDNF exon I between the control and depression groups. No effect of sertraline monotherapy on BDNF methylation was found in subjects with depression. Moreover, no interaction was found between BDNF genotype and the per cent methylation of BDNF exon I. However, methylation at this site was positively correlated with diurnal variation and retardation scores. Blood homocysteine concentrations were significantly reduced by sertraline treatment. No influence of genotype on serum BDNF concentration was found in subjects with depression. The ROC curve showed that methylation of BDNF exon I may be used to distinguish patients from healthy people, to a certain extent.

Conclusion

Methylation of BDNF exon I may be used as a biomarker of depression and may be a therapeutic target for previously untreated depression.

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.

Effect of Acute Normobaric Hypoxia Exposure on Executive Functions among Young Physically Active Males

Background: On the one hand, hypoxic exposure may result in progressive brain metabolism disturbance, causing subsequent cognitive impairments. On the other hand, it might also enhance neurogenesis and brain vascularization as well as accelerate cerebral blood flow, leading to cognitive function improvement. The aim of this study was to investigate whether progressive stages of normobaric hypoxia (NH) (FIO₂ = 13%, FIO₂ = 12%, and FIO₂ = 11%) differentially affect post-exposure cognitive performance. Methods: Fifteen physically active men (age = 23.1 ± 2.1) participated in the study. The Stroop test (ST) was applied to assess cognitive function. To generate NH conditions, a hypoxic normobaric air generator was used. Results: We observed an executive function impairment (“naming” interference p < 0.05) after NH exposure (FIO₂ = 13%). After exposure at FIO₂ = 12% and FIO₂ = 11%, no changes were observed in the Stroop test. Also, changes in SpO₂ during subsequent NH exposure were observed. Conclusions: The current investigation shows that executive functions deteriorate after acute NH exposure and this post-exposure deterioration is not proportional to the normobaric hypoxia stages among young physically active males.

A Load to Find Clinically Useful Biomarkers for Depression

Depression is heterogeneous and complex disease with diverse symptoms. Its neurobiological underpinning is still not completely understood. For now, there are still no validated, easy obtainable, clinically useful noninvasive biomarker(s) or biomarker panel that will be able to confirm a diagnosis of depression, its subtypes and improve diagnostic procedures. Future multimodal preclinical and clinical research that involves (epi)genetic, molecular, cellular, imaging, and other studies is necessary to advance our understanding of the role of monoamines, GABA, HPA axis, neurotrophins, metabolome, and glycome in the pathogenesis of depression and their potential as diagnostic, prognostic, and treatment response biomarkers. These studies should be focused to include the first-episode depression and antidepressant drug-naïve patients with large sample sizes to reduce variability in different biological and clinical parameters. At present, metabolomics study revealed with high precision that a neurometabolite panel consisting of plasma metabolite biomarkers (GABA, dopamine, tyramine, kynurenine) might represent clinically useful biomarkers of MDD.

Predicting treatment effects in unipolar depression: A meta-review

There is increasing interest in clinical prediction models in psychiatry, which focus on developing multivariate algorithms to guide personalized diagnostic or management decisions. The main target of these models is the prediction of treatment response to different antidepressant therapies. This is because the ability to predict response based on patients' personal data may allow clinicians to make improved treatment decisions, and to provide more efficacious or more tolerable medications to the right patient. We searched the literature for systematic reviews about treatment prediction in the context of existing treatment modalities for adult unipolar depression, until July 2019. Treatment effect is defined broadly to include efficacy, safety, tolerability and acceptability outcomes. We first focused on the identification of individual predictor variables that might predict treatment response, and second, we considered multivariate clinical prediction models. Our meta-review included a total of 10 systematic reviews; seven (from 2014 to 2018) focusing on individual predictor variables and three focusing on clinical prediction models. These identified a number of sociodemographic, phenomenological, clinical, neuroimaging, remote monitoring, genetic and serum marker variables as possible predictor variables for treatment response, alongside statistical and machine-learning approaches to clinical prediction model development. Effect sizes for individual predictor variables were generally small and clinical prediction models had generally not been validated in external populations. There is a need for rigorous model validation in large external data-sets to prove the clinical utility of models. We also discuss potential future avenues in the field of personalized psychiatry, particularly the combination of multiple sources of data and the emerging field of artificial intelligence and digital mental health to identify new individual predictor variables.

Early changes of serum BDNF and SSRI response in adolescents with major depressive disorder

BACKGROUND

Recent evidence suggests that brain-derived neurotrophic factor (BDNF) levels and their early changes may predict antidepressant response in adults with major depressive disorder (MDD). However, in adolescents, BDNF levels in depression and their changes during antidepressant treatment are relatively unknown. We aimed to investigate whether pre-treatment BDNF levels and their early changes predict antidepressant response in depressed adolescents.

METHODS

The study included 83 MDD adolescents and 52 healthy controls aged 12 to 17 years. All depressed adolescents were treated with escitalopram in an 8 week, open-label trial. Depression severity and serum BDNF level at baseline, and weeks 2 and 8 were measured with the Children's Depression Rating Scale-Revised (CDRS-R) and ELISA, respectively.

RESULTS

Responders showed a significant decrease in BDNF levels at week 2 but non-responders and healthy controls had no changes in BDNF levels at week 2. The early decrease (baseline - week 2) of BDNF levels predicted SSRI response with moderate sensitivity and specificity. Logistic regression analysis revealed that early BDNF decrease predicted SSRI response at week 8 after controlling for other demographic and clinical variables.

LIMITATIONS

The follow-up duration of the study was limited in 8 weeks. It remains possible that serum BDNF levels would have changed with longer treatment.

CONCLUSIONS

This is the first longitudinal study to investigate the effect of antidepressants on BDNF levels in adolescents with MDD. Our findings suggest that a decrease of serum BDNF levels in early phase of SSRI treatment may be associated later SSRI response in adolescents with MDD.

The genetics of bipolar disorder

Bipolar disorder (BD) is one of the most heritable mental illnesses, but the elucidation of its genetic basis has proven to be a very challenging endeavor. Genome-Wide Association Studies (GWAS) have transformed our understanding of BD, providing the first reproducible evidence of specific genetic markers and a highly polygenic architecture that overlaps with that of schizophrenia, major depression, and other disorders. Individual GWAS markers appear to confer little risk, but common variants together account for about 25% of the heritability of BD. A few higher-risk associations have also been identified, such as a rare copy number variant on chromosome 16p11.2. Large scale next-generation sequencing studies are actively searching for other alleles that confer substantial risk. As our understanding of the genetics of BD improves, there is growing optimism that some clear biological pathways will emerge, providing a basis for future studies aimed at molecular diagnosis and novel therapeutics.

The Relationship between DNA Methylation and Antidepressant Medications: A Systematic Review

Major depressive disorder (MDD) is the leading cause of disability worldwide and is associated with high rates of suicide and medical comorbidities. Current antidepressant medications are suboptimal, as most MDD patients fail to achieve complete remission from symptoms. At present, clinicians are unable to predict which antidepressant is most effective for a particular patient, exposing patients to multiple medication trials and side effects. Since MDD’s etiology includes interactions between genes and environment, the epigenome is of interest for predictive utility and treatment monitoring. Epigenetic mechanisms of antidepressant medications are incompletely understood. Differences in epigenetic profiles may impact treatment response. A systematic literature search yielded 24 studies reporting the interaction between antidepressants and eight genes (BDNF, MAOA, SLC6A2, SLC6A4, HTR1A, HTR1B, IL6, IL11) and whole genome methylation. Methylation of certain sites within BDNF, SLC6A4, HTR1A, HTR1B, IL11, and the whole genome was predictive of antidepressant response. Comparing DNA methylation in patients during depressive episodes, during treatment, in remission, and after antidepressant cessation would help clarify the influence of antidepressant medications on DNA methylation. Individuals’ unique methylation profiles may be used clinically for personalization of antidepressant choice in the future.

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.

Effects of Dance Exergaming on Depressive Symptoms, Fear of Falling, and Musculoskeletal Function in Fallers and Nonfallers Community-Dwelling Older Women

The aim of this study was to evaluate the effects of a pop dance exergaming protocol on fall risk factors-depressive symptoms, fear of falling, and musculoskeletal function-in community-dwelling older female fallers and nonfallers. There were 47 community-dwelling older women assigned to the intervention group (IG) [fallers (n = 10, 69.8 ± 4.3 years); nonfallers (n = 12, 68.9 ± 3.3 years)] and the control group (CG) [fallers (n = 12, 73.6 ± 5.4 years); nonfallers (n = 13, 68.7 ± 4.8 years)]. The CG maintained their lifestyle and the IG performed a videogame dance training three times per week for 12 weeks. The Dance Central game for Xbox 360® and Kinect motion sensor were used. The primary outcomes were geriatric depressive symptoms, fear of falling, and concentric and eccentric isokinetic peak torque (PT) of quadriceps and hamstrings. Secondary outcomes included cross-sectional area of quadriceps and hamstring muscles, functionality (Timed Up and Go test, gait speed, the Five Times Sit-to-Stand test), and a fall circumstances and outcomes recording. The depressive symptoms decreased in the Intervention Fallers Group. The eccentric hamstrings PT at 180°/s increased in the Intervention Nonfallers Group. There were no significant differences between groups for the other variables analyzed. The training attendance was 83% for the Intervention Fallers Group and 88% for the Intervention Nonfallers Group. Dance exergaming can be indicated to decrease depressive symptoms in fallers and increase the PT in nonfallers among community-dwelling older women.

BDNF Plasma Levels and BDNF Exon IV Promoter Methylation as Predictors for Antidepressant Treatment Response

Major problems of current antidepressant pharmacotherapy are insufficient response rates and difficulties in response prediction. We recently provided preliminary evidence in a small study that patients with major depressive disorder (MDD) with a hypomethylation of the CpG-87 site of the promoter IV region of the brain-derived neurotrophic factor (BDNF) gene are less likely to benefit from antidepressants. Here, we aimed at replicating this finding in a secondary analysis of 561 MDD patients (mean age 40.0 ± 11.9 years, 56% female) included into the Early Medication Change study (EMC). We measured BDNF exon IV promoter and p11 gene methylation at Baseline (BL) as well as BDNF-plasma-levels (pBDNF) at BL and day 14 and related them to treatment outcome. Although we were not able to replicate the predictor function of hypomethylation of the BDNF exon IV promoter, a subgroup of patients with severe depression (Hamilton Depression Rating Scale [HAMD-17] ≥ 25) (n = 199) and hypermethylation at CpG-87 of the BDNF exon IV promoter had significantly higher remission rates than patients without a methylation (p = 0.032). We also found that 421 (75%) of 561 patients showed an early improvement (≥ 20% HAMD-17 reduction after 2 weeks), which was associated with a 4.24-fold increased likelihood to remit at study end compared to the 140 patients without early improvement. However, specificity of response prediction of early improvement was low (34%) and false positive rate high (66%). The combination of early improvement with a pBDNF increase between BL and day 14, however, increased the specificity of response prediction from 34 to 76%, and the combination with methylation of the CpG-87 site of the BDNF exon IV promoter from 34 to 62%. Thus, the combined markers reduced false positives rates from 66 to 24% and 38%, respectively. Methylation at other sites or p11 promoter methylation failed to increase specificity of early improvement prediction. In sum, the results add to previous findings that BDNF, BDNF promoter methylation and the combination of clinical and biological markers may be interesting candidates for therapy response prediction which has to be confirmed in further studies. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT00974155, identifier: NCT00974155.

Early improvement as a resilience signal predicting later remission to antidepressant treatment in patients with Major Depressive Disorder: Systematic review and meta-analysis

Early improvement of depressive symptoms during the first two weeks of antidepressant treatment has been discussed to be a resilience signal predicting a later positive treatment outcome in patients with Major Depressive Disorder (MDD). However, the predictive value of early improvement varies between studies, and the use of different antidepressants may explain heterogeneous results. The objective of this review was to assess the predictive value of early improvement on later response and remission and to identify antidepressants with the highest chance of early improvement. We included 17 randomized controlled trials investigating early improvement in 14,779 adult patients with MDD comparing monotherapy with an antidepressant against placebo or another antidepressant drug. 62% (range: 35-85%) of patients treated with an antidepressant and 47% (range: 21-69%) with placebo were early improver, defined as a >20%/25% symptom reduction after two weeks of treatment. Early improvement predicted response and remission after 5-12 weeks of treatment with high sensitivity (85%; 95%-CI: 84.3 to 85.7) and low to moderate specificity (54%; 95%-CI: 53.1 to 54.9). Early improver had a 8.37 fold (6.97-10.05) higher likelihood to become responder and a 6.38 fold (5.07-8.02) higher likelihood to be remitter at endpoint than non-improver. The highest early improver rates were achieved in patients treated with mirtazapine or a tricyclic antidepressant. This finding of a high predictive value of early improvement on treatment outcome may be important for treatment decisions in the early course of antidepressant treatment. Further studies should test the efficacy of such early treatment decisions.

The Comparison of Effectiveness of Various Potential Predictors of Response to Treatment With SSRIs in Patients With Depressive Disorder

The substantial non-response rate in depressive patients indicates a continuing need to identify predictors of treatment outcome. The aim of this 6-week, open-label study was (1) to compare the efficacy of a priori defined predictors: ≥20% reduction in MADRS score at week 1, ≥20% reduction in MADRS score at week 2 (RM ≥ 20% W2), decrease of cordance (RC), and increase of serum and plasma level of brain-derived neurotrophic factor at week 1; and (2) to assess whether their combination yields higher efficacy in the prediction of response to selective serotonin re-uptake inhibitors (SSRIs) than when used singly. Twenty-one patients (55%) achieved a response to SSRIs. The RM ≥20% W2 (areas under curve-AUC = 0.83) showed better predictive efficacy compared to all other predictors with the exception of RC. The identified combined model (RM ≥ 20% W2 + RC), which predicted response with an 84% accuracy (AUC = 0.92), may be a useful tool in the prediction of response to SSRIs.

Brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) levels in post-mortem brain tissue from patients with depression compared to healthy individuals - a proof of concept study

The neurotrophic factors (NTF) hypothesis of depression was postulated nearly a decade ago and is nowadays widely acknowledged. Previous reports suggest that cerebral concentrations of NTF may be reduced in suicide victims who received minimal or no antidepressant pharmacotherapy. Recent evidence suggests that antidepressant treatment may improve or normalise cerebral concentrations of neurotrophic factors. Therefore, we examined the concentration of brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3) in different brain regions (cortex, cingulate gyrus, thalamus, hippocampus, putamen and nucleus caudatus) of 21 individuals - 7 patients of which 4 patients with major depressive disorder (MDD) and overall age 86.8±5 years who received antidepressant pharmacotherapy (selective serotonin re-uptake inhibitors [SSRI]; tricyclic antidepressants [TCA]), 3 patients with MDD without antidepressant treatment and overall age 84.3±5 years versus 14 unaffected subjects at age 70.3±13.8. We detected significant elevation of BDNF (parietal cortex) and NT3 (parietal, temporal and occipital cortex, cingulate gyrus, thalamus, putamen and nucleus caudatus regions) in MDD patients who received antidepressant medication compared to MDD untreated patients and controls. Moreover, we detected a significant decrease of NT3 levels in the parietal cortex of patients suffering from MDD non-treated patients without treatment compared to healthy individuals. Although the limited statistical power due to the small sample size in this proof of concept study corroborates data from previous studies, which show that treatment with antidepressants mediates alterations in neuroplasticity via the action of NTF. However, more research using post-mortem brain tissue with larger samples needs to be carried out as well as longitudinal studies to further verify these results.

Recent advances in predicting responses to antidepressant treatment

Major depressive disorder is one of the leading causes of disability in the world since depression is highly frequent and causes a strong burden. In order to reduce the duration of depressive episodes, clinicians would need to choose the most effective therapy for each individual right away. A prerequisite for this would be to have biomarkers at hand that would predict which individual would benefit from which kind of therapy (for example, pharmacotherapy or psychotherapy) or even from which kind of antidepressant class. In the past, neuroimaging, electroencephalogram, genetic, proteomic, and inflammation markers have been under investigation for their utility to predict targeted therapies. The present overview demonstrates recent advances in all of these different methodological areas and concludes that these approaches are promising but also that the aim to have such a marker available has not yet been reached. For example, the integration of markers from different systems needs to be achieved. With ongoing advances in the accuracy of sensing techniques and improvement of modelling approaches, this challenge might be achievable.

Meta-analyses of comparative efficacy of antidepressant medications on peripheral BDNF concentration in patients with depression

Background

Brain derived neurotrophic factor (BDNF) is one of the most important regulatory proteins in the pathophysiology of major depressive disorder (MDD). Increasing numbers of studies have reported the relationship between serum/plasma BDNF and antidepressants (ADs). However, the potential effects of several classes of antidepressants on BDNF concentrations are not well known. Hence, our meta-analyses aims to review the effects of differential antidepressant drugs on peripheral BDNF levels in MDD and make some recommendations for future research.

Methods

Electronic databases including PubMed, EMBASE, the Cochrane Library, Web of Science, and PsycINFO were searched from 1980 to June 2016. The change in BDNF levels were compared between baseline and post-antidepressants treatment by use of the standardized mean difference (SMD) with 95% confidence intervals (CIs). All statistical tests were two-sided.

Results

We identified 20 eligible trials of antidepressants treatments for BDNF in MDD. The overall effect size for all drug classes showed that BDNF levels were elevated following a course of antidepressants use. For between-study heterogeneity by stratification analyses, we detect that length of treatment and blood samples are significant effect modifiers for BDNF levels during antidepressants treatment. While both SSRIs and SNRIs could increase the BDNF levels after a period of antidepressant medication treatment, sertraline was superior to other three drugs (venlafaxine, paroxetine or escitalopram) in the early increase of BDNF concentrations with SMD 0.53(95% CI = 0.13–0.93; P = 0.009).

Conclusions

There is some evidence that treatment of antidepressants appears to be effective in the increase of peripheral BDNF levels. More robust evidence indicates that different types of antidepressants appear to induce differential effects on the BDNF levels. Since sertraline makes a particular effect on BDNF concentration within a short amount of time, there is potential value in exploring its relationship with BDNF and its pharmacological mechanism concerning peripheral blood BDNF. Further confirmatory trials are required for both observations.

Antidepressant-like activity of the neuropeptide Y Y5 receptor antagonist Lu AA33810: behavioral, molecular, and immunohistochemical evidence

RATIONALE

It has recently been found that chronic treatment with the highly selective, brain-penetrating Y5 receptor antagonist, Lu AA33810 [N-[[trans-4-[(4,5-dihydro [1] benzothiepino[5,4-d] thiazol-2-yl) amino] cyclohexyl]methyl]-methanesulfonamide], produces antidepressant-like effects in the rat chronic mild stress model.

OBJECTIVE

In the present study, we investigated the possible antidepressant-like activity of Lu AA33810 in rats subjected to glial ablation in the prefrontal cortex (PFC) by the gliotoxin L-AAA, which is an astroglial degeneration model of depression.

RESULTS

We observed that Lu AA33810 administered intraperitoneally at a single dose of 10 mg/kg both reversed depressive-like behavioral changes in the forced swim test (FST) and prevented degeneration of astrocytes in the mPFC. The mechanism of antidepressant and glioprotective effects of Lu AA33810 has not been studied, so far. We demonstrated the contribution of the noradrenergic rather than the serotonergic pathway to the antidepressant-like action of Lu AA33810 in the FST. Moreover, we found that antidepressant-like effect of Lu AA33810 was connected with the influence on brain-derived neurotrophic factor (BDNF) protein expression. We also demonstrated the antidepressant-like effect of Lu AA33810 in the FST in rats which did not receive the gliotoxin. We found that intracerebroventricular injection of the selective MAPK/ERK inhibitor U0126 (5 μg/2 μl) and the selective PI3K inhibitor LY294002 (10 nmol/2 μl) significantly inhibited the anti-immobility effect of Lu AA33810 in the FST in rats, suggesting that MAPK/ERK and PI3K signaling pathways could be involved in the antidepressant-like effect of Lu AA33810.

CONCLUSION

Our results indicate that Lu AA33810 exerts an antidepressant-like effect and suggest the Y5 receptors as a promising target for antidepressant therapy.

Estrogen therapy increases BDNF expression and improves post-stroke depression in ovariectomy-treated rats

The present study investigated the effect of exogenous estrogen on post-stroke depression. Rats were exposed to chronic mild stress following middle cerebral artery occlusion. The occurrence of post-stroke depression was evaluated according to the changes in preference for sucrose and performance in a forced swimming test. Estrogen therapy significantly improved these neurological symptoms, indicating that estrogen is effective in treating post-stroke depression. Increased brain-derived neurotrophic factor (BDNF) expression was reported in the hippocampus of rats that had been treated with estrogen for two weeks, suggesting that BDNF expression may be an important contributor to the improvement of post-stroke depression that is observed following estrogen therapy.

Prediction of treatment outcomes in psychiatry--where do we stand ?

Psychiatric treatment relies on a solid armamentarium of pharmacologic and nonpharmacologic treatment modalities that perform reasonably well for many patients but leave others in a state of chronic disability or troubled by problematic side effects. Treatment planning in psychiatry remains an art that depends on considerable trial and error. Thus, there is an urgent need for better tools that will provide a means for matching individual patients with the most effective treatments while minimizing the risk of adverse events. This review will consider the current state of the science in predicting treatment outcomes in psychiatry. Genetic and other biomarkers will be considered alongside clinical diagnostic, and family history data. Problems inherent in prediction medicine will also be discussed, along with recent developments that support the hope that psychiatry can do a better job in quickly identifying the best treatments for each patient.

Regulation of fear extinction versus other affective behaviors by discrete cortical scaffolding complexes associated with NR2B and PKA signaling

In patients suffering from post-traumatic stress disorder (PTSD), fear evoked by trauma-related memories lasts long past the traumatic event and it is often complicated by general anxiety and depressed mood. This poses a treatment challenge, as drugs beneficial for some symptoms might exacerbate others. For example, in preclinical studies, antagonists of the NR2B subunit of N-methyl-d-aspartate receptors and activators of cAMP-dependent protein kinase (PKA) act as potent antidepressants and anxiolytics, but they block fear extinction. Using mice, we attempted to overcome this problem by interfering with individual NR2B and PKA signaling complexes organized by scaffolding proteins. We infused cell-permeable Tat peptides that displaced either NR2B from receptor for activated C kinase 1 (RACK1), or PKA from A-kinase anchor proteins (AKAPs) or microtubule-associated proteins (MAPs). The infusions were targeted to the retrosplenial cortex, an area involved in both fear extinction of remotely acquired memories and in mood regulation. Tat-RACK1 and Tat-AKAP enhanced fear extinction, all peptides reduced anxiety and none affected baseline depression-like behavior. However, disruption of PKA complexes distinctively interfered with the rapid antidepressant actions of the N-methyl-D-aspartate receptors antagonist MK-801 in that Tat-MAP2 blocked, whereas Tat-AKAP completely inverted the effect of MK-801 from antidepressant to depressant. These effects were unrelated to the MK-801-induced changes of brain-derived neurotrophic factor messenger RNA levels. Together, the findings suggest that NR2B-RACK1 complexes specifically contribute to fear extinction, and may provide a target for the treatment of PTSD. AKAP-PKA, on the other hand, appears to modulate fear extinction and antidepressant responses in opposite directions.

Epigenetic mechanisms underlying the role of brain-derived neurotrophic factor in depression and response to antidepressants

Major depressive disorder (MDD) is a devastating neuropsychiatric disorder encompassing a wide range of cognitive and emotional dysfunctions. The prevalence of MDD is expected to continue its growth to become the second leading cause of disease burden (after HIV) by 2030. Despite an extensive research effort, the exact etiology of MDD remains elusive and the diagnostics uncertain. Moreover, a marked inter-individual variability is observed in the vulnerability to develop depression, as well as in response to antidepressant treatment, for nearly 50% of patients. Although a genetic component accounts for some cases of MDD, it is now clearly established that MDD results from strong gene and environment interactions. Such interactions could be mediated by epigenetic mechanisms, defined as chromatin and DNA modifications that alter gene expression without changing the DNA structure itself. Some epigenetic mechanisms have recently emerged as particularly relevant molecular substrates, promoting vulnerability or resilience to the development of depressive-like symptoms. Although the role of brain-derived neurotrophic factor (BDNF) in the pathophysiology of MDD remains unclear, its modulation of the efficacy of antidepressants is clearly established. Therefore, in this review, we focus on the epigenetic mechanisms regulating the expression of BDNF in humans and in animal models of depression, and discuss their role in individual differences in vulnerability to depression and response to antidepressant drugs.

Apathy and APOE4 are associated with reduced BDNF levels in Alzheimer's disease

Reduced brain-derived neurotrophic factor (BDNF) signaling is considered as a pathogenic event in early Alzheimer's disease (AD), but the influence of apathy and apolipoprotein E ε4 allele (APOE4) on serum BDNF values was not previously investigated in AD. We evaluated serum BDNF levels in AD, amnestic mild cognitive impairment (MCI), and control subjects. Baseline BDNF levels were similar in AD, MCI, and controls. AD patients having apathy showed lower BDNF values than patients without apathy (p < 0.05). After correction for the influence of apathy, APOE4 carriers showed lower BDNF levels (p < 0.01) and MMSE scores (p < 0.01) than non-APOE4 carriers in the subgroup of AD females, but not in males. Significant (p < 0.05) positive correlations between BDNF values and MMSE scores were only observed in subgroups of AD males and of AD patients without apathy. These results are showing the association of apathy and APOE4 with reduced serum BDNF levels in AD, and are suggesting that BDNF reductions might contribute to the worse cognitive performance exhibited by AD apathetic patients and female APOE4 carriers.

Chronic depression is associated with a pronounced decrease in serum brain-derived neurotrophic factor over time

One of the leading neurobiological hypotheses on depression states that decreased expression of brain-derived neurotrophic factor (BDNF) contributes to depression. This is supported by consistent findings of low serum BDNF levels in depressed patients compared with non-depressed controls. Whereas it has been generally assumed that this is a state characteristic of depression, strong inferences about state or trait effects require a longitudinal study design. To investigate the longitudinal association between serum BDNF and depression, we measured serum BDNF, (current and past) depression status, use of antidepressants, and all potential covariates at baseline and after 2 years in 1751 individuals, consisting of patients with an incident (n=153), remitted (n=420) and persistent depression (n=310) and non-depressed controls (n=868). We analyzed change/differences in serum BDNF across these four groups with analyses of covariance adjusted for covariates and baseline BDNF value, together with the effects of starting and stopping antidepressant treatment. Our analyses revealed a significant difference for the depression course groups (P=0.007). Compared with non-depressed controls, persistently depressed and remitted patients had a steeper decrease of BDNF levels over time (-1.33 (P=0.001) and -0.97 ng ml(-1) (P=0.011), respectively), whereas BDNF reductions in patients with incident depression were similar to those in healthy controls. Initiation or discontinuation of antidepressants was not associated with BDNF change (P=0.72). These findings suggest that BDNF not only contributes to depression, but that depression in turn may also contribute to low BDNF.

Inflammation and neuronal plasticity: a link between childhood trauma and depression pathogenesis

During the past two decades, there has been increasing interest in understanding and characterizing the role of inflammation in major depressive disorder (MDD). Indeed, several are the evidences linking alterations in the inflammatory system to Major Depression, including the presence of elevated levels of pro-inflammatory cytokines, together with other mediators of inflammation. However, it is still not clear whether inflammation represents a cause or whether other factors related to depression result in these immunological effects. Regardless, exposure to early life stressful events, which represent a vulnerability factor for the development of psychiatric disorders, act through the modulation of inflammatory responses, but also of neuroplastic mechanisms over the entire life span. Indeed, early life stressful events can cause, possibly through epigenetic changes that persist over time, up to adulthood. Such alterations may concur to increase the vulnerability to develop psychopathologies. In this review we will discuss the role of inflammation and neuronal plasticity as relevant processes underlying depression development. Moreover, we will discuss the role of epigenetics in inducing alterations in inflammation-immune systems as well as dysfunction in neuronal plasticity, thus contributing to the long-lasting negative effects of stressful life events early in life and the consequent enhanced risk for depression. Finally we will provide an overview on the potential role of inflammatory system to aid diagnosis, predict treatment response, enhance treatment matching, and prevent the onset or relapse of Major Depression.

BDNF as a biomarker for successful treatment of mood disorders: a systematic & quantitative meta-analysis

BACKGROUND

Peripheral brain-derived neurotrophic factor (BDNF) is decreased in acute major depressive disorder (MDD) and bipolar disorder (BD) and recovered after treatment. Here we validated on a meta-analytical level whether BDNF restores differentially according to treatment response and whose measurements could be used as a biomarker, plasma or serum.

METHODS

Using strict inclusion criteria, we compared BDNF in healthy controls and patients with MDD (38 studies, n=6619), and BD (17 studies, n=1447). Pre- and post-treatment BDNF levels were meta-analyzed according to treatment response in patients from 21 MDD studies (n=735) and 7 BD studies (n=88). Serum and plasma subgroups were analyzed, publication bias was assessed and heterogeneity was investigated.

RESULTS

Serum and plasma BDNF were decreased in acute MDD and BD, and did not differ in euthymia in comparison with control subjects. Antidepressive treatment increased serum BDNF levels in MDD in responders (Cohen׳s d (d)=1.27, p=4.4E-07) and remitters (d=0.89, p=0.01), significantly more than in non-responders (d=0.11, p=0.69). For plasma BDNF in MDD and for BD, the evidence was insufficient for a meta-analysis. Although no significant difference was found between serum and plasma ES, variance of plasma ES was higher.

LIMITATIONS

Between-study heterogeneity was explained only partially; signs of publication bias in serum studies.

CONCLUSION

Serum BDNF might be regarded as a biomarker for the successful treatment of MDD. Serum measurements seem more reliable than plasma ones. Further research should focus on defining optimal time points for BDNF measurements and increase evidence for the usage of BDNF as a predictive biomarker in BD.

The effectiveness of prefrontal theta cordance and early reduction of depressive symptoms in the prediction of antidepressant treatment outcome in patients with resistant depression: analysis of naturalistic data

Current studies suggest that an early improvement of depressive symptoms and the reduction of prefrontal theta cordance value predict the subsequent response to antidepressants. The aim of our study was (1) to compare the predictive abilities of early clinical improvement defined as ≥ 20 % reduction in Montgomery and Åsberg Depression Rating Scale (MADRS) total score at week 1 and 2, and the decrease of prefrontal theta cordance at week 1 in resistant depressive patients and (2) to assess whether the combination of individual predictors yields more robust predictive power than either predictor alone. Eighty-seven subjects were treated (≥ 4 weeks) with various antidepressants chosen according to the judgment of attending psychiatrists. Areas under curve (AUC) were calculated to compare predictive effect of defined single predictors (≥ 20 % reduction in MADRS total score at week 1 and 2, and the decrease of cordance at week 1) and combined prediction models. AUCs of all three predictors were not statistically different (pair-wise comparison). The model combining all predictors yielded an AUC value 0.91 that was significantly higher than AUCs of each individual predictor. The results indicate that the combined predictor model may be a useful and clinically meaningful tool for the prediction of antidepressant response in patients with resistant depression.

Brain-derived neurotrophic factor as a suicide factor in mental disorders

OBJECTIVE

Brain-derived neurotrophic factor (BDNF) plays a critical role in brain plasticity processes and serum levels have been demonstrated to be altered in patients with different mental disorder including suicidal behaviour. The objective of this study was to examine the association between serum BDNF levels as a possible peripheral indicator of suicide behaviour in subjects suffering from depression, personality disorders (PDs) and adjustment disorders (ADs) with or without suicide attempt.

METHODS

The research included 172 randomly selected individuals suffering from recurrent depressive disorder (RDD; F 33.2), emotionally unstable PD (F 60.3) and AD (F 43.2), with or without attempted suicide according to the criteria of the ICD-10 (International Statistical Classification of Diseases and Related Health Problems 10th Revision) and 60 phenotypically health control subjects. In the group of patients, 73% subjects took some form of psychopharmacotherapy. Serum BDNF levels were measured by enzyme linked immunosorbent assay.

RESULTS

Subjects with PD and AD with suicide attempts had significantly lower serum BDNF levels than those without suicide attempts. In groups of subjects with PD and AD, those taking psychopharmacotherapy had higher serum BDNF levels. In the group of subjects with RDD, there were no differences with respect to suicide attempts or psychopharmacotherapy. Logistical regression analysis was indicated that psychopharmacotherapy and serum BDNF levels statistically correlated with suicide attempts.

CONCLUSION

The lower levels of BDNF in subjects suffering from PD and AD with suicide attempts, suggest that the serum BDNF level is a potential marker of suicidal behaviour, independent of mental disorders.

Applications of blood-based protein biomarker strategies in the study of psychiatric disorders

Major psychiatric disorders such as schizophrenia, major depressive and bipolar disorders are severe, chronic and debilitating, and are associated with high disease burden and healthcare costs. Currently, diagnoses of these disorders rely on interview-based assessments of subjective self-reported symptoms. Early diagnosis is difficult, misdiagnosis is a frequent occurrence and there are no objective tests that aid in the prediction of individual responses to treatment. Consequently, validated biomarkers are urgently needed to help address these unmet clinical needs. Historically, psychiatric disorders are viewed as brain disorders and consequently only a few researchers have as yet evaluated systemic changes in psychiatric patients. However, promising research has begun to challenge this concept and there is an increasing awareness that disease-related changes can be traced in the peripheral system which may even be involved in the precipitation of disease onset and course. Converging evidence from molecular profiling analysis of blood serum/plasma have revealed robust molecular changes in psychiatric patients, suggesting that these disorders may be detectable in other systems of the body such as the circulating blood. In this review, we discuss the current clinical needs in psychiatry, highlight the importance of biomarkers in the field, and review a representative selection of biomarker studies to highlight opportunities for the implementation of personalized medicine approaches in the field of psychiatry. It is anticipated that the implementation of validated biomarker tests will not only improve the diagnosis and more effective treatment of psychiatric patients, but also improve prognosis and disease outcome.

High baseline BDNF serum levels and early psychopathological improvement are predictive of treatment outcome in major depression

RATIONALE

Major depressive disorder has been associated with low serum levels of brain-derived neurotrophic factor (sBDNF), which is functionally involved in neuroplasticity. Although sBDNF levels tend to normalize following psychopathological improvement with antidepressant treatment, it is unclear how closely sBDNF changes are associated with treatment outcome.

OBJECTIVES

To examine whether baseline sBDNF or early changes in sBDNF are predictive of response to therapy.

METHODS

Twenty-five patients with major depressive disorder underwent standardized treatment with duloxetine. Severity of depression, measured by the Hamilton Depression Rating Scale, and sBDNF were assessed at baseline, and after 1, 2, and 6 weeks of treatment. Therapy outcome after 6 weeks was defined as response (≥50 % reduction in baseline Hamilton Depression Rating score) and remission (Hamilton Depression Rating score <8). The predictive values for treatment outcome of baseline sBDNF, and early (i.e., ≤2 weeks) changes in sBDNF and Hamilton Depression Rating score were also assessed.

RESULTS

At baseline, sBDNF correlated with Hamilton Depression Rating scores. Treatment response was associated with a higher baseline sBDNF concentration, and a greater Hamilton Depression Rating score reduction after 1 and 2 weeks. A greater early rise in sBDNF correlated with a decreased early Hamilton Depression Rating score reduction.

CONCLUSIONS

Even though higher baseline sBDNF levels are associated with more severe depression, they may reflect an increased capacity to respond to treatment. In contrast, changes in sBDNF over the full course of treatment are not associated with psychopathological improvement.

Association between baseline serum vascular endothelial growth factor levels and response to electroconvulsive therapy

OBJECTIVE

Several studies have shown that vascular endothelial growth factor (VEGF) is implicated in different neuronal processes involved in major depressive disorder (MDD) and in the mechanisms of action of antidepressants. The aim of this study was to investigate whether VEGF serum levels before treatment might be associated with the antidepressant response.

METHOD

Two groups of patients were enrolled. One was composed of 50 MDD patients receiving an antidepressant drug treatment. Illness severity was measured before the treatment (T0) and after 12 weeks (T1). The second group was composed of 67 treatment-resistant depressed (TRD) patients undergoing electroconvulsive therapy (ECT). Illness severity was assessed before the treatment (T0) and 1 month after the end of ECT (T1). Blood samples for VEGF measurements were collected for both groups at the baseline (T0).

RESULTS

A significant correlation was observed between baseline VEGF serum levels and the percentage reduction in depressive symptomatology after ECT (P = 0.003). In particular, VEGF levels at baseline were significantly lower in patients showing no response to ECT at follow-up (P = 0.008). No correlation between T0 VEGF concentrations and drug treatment outcome was found.

CONCLUSION

Our results suggest that VEGF plays a role in the mechanism of response to ECT.

The Missing Work of Collaboration: Using Assemblages to Rethink Antidepressant Action

How do antidepressants work? This often-asked question continues to attract debate. The depressed individual features in many debates about antidepressants' action. With this focus, discussion oscillates over whether antidepressants work to remedy chemical imbalances in the brains of depressed people, or produce inauthentic states of being. This article argues shifting the analytic focus away from the depressed individual and onto the collective body, or assemblage, moves debates about how antidepressants work into more productive terrain. This provides a new way of looking at how antidepressants work to facilitate recovery from depression through a series of collaborative connections or relationships. Drawing on the charts, photos, and narratives from research encounters with people who take antidepressants, the article illustrates how medication facilitates the creation of active associations in an assemblage of forces. The article concludes by discussing the new ways of thinking about depression, medication and recovery suggested by this understanding of antidepressant action.

Serum Levels of Brain-Derived Neurotrophic Factor at 4 Weeks and Response to Treatment with SSRIs

OBJECTIVE

It is important to predict a response to an antidepressant in early time after starting the antidepressant. We previously reported that serum brain-derived neurotrophic factor (BDNF) levels in responders to treatment with antidepressants were increased, whereas, those in nonresponders were not. Therefore, we hypothesized that the changes in serum levels of BDNF from baseline (T0) to 4 weeks (T4) after treatment with selective serotonin reuptake inhibitors (SSRIs) predict the response to the treatment at 8 weeks (T8) in depressed patients. To confirm the hypothesis, we measured serum BDNF at T0, T4, and T8 during the treatment with SSRIs (paroxetine, sertraline, and fluvoxamine).

METHODS

One hundred fifty patients (M/F; 51/99, age; 50.4±15.1 years) met major depressive disorder (MDD) using by DSM-IV-TR enrolled in the present study. We measured serum BDNF concentrations at T0, T4, and T8 in patients with MDD treated with SSRIs.

RESULTS

The changes in serum BDNF, age, sex, dose of SSRIs, and HAMD-17 score did not predict the response to SSRIs at T8.

CONCLUSION

These results suggest that the changes in serum BDNF levels from T0 to T4 could not predict the subsequent responses to SSRIs at T8.

Use of mental health telemetry to enhance identification and predictive value of early changes during augmentation treatment of major depression

Standard clinical trial methodology in depression does not allow for careful examination of early changes in symptom intensity. The purpose of this study was to use daily "Mental Health Telemetry" (MHT) to prospectively record change in depressive and anxiety symptoms for depressed patients receiving augmentation treatment, and determine the extent and predictive capacity of early changes. We report results of a 6-week, open-label study of the addition of quetiapine XR (range, 50-300 mg) for adult patients (n = 26) with major depressive disorder who were nonresponsive to antidepressant treatment. In addition to regular study visits, all participants completed daily, wirelessly transmitted self-report ratings of symptoms on a Smartphone. Daily and 3-day moving average mean scores were calculated, and associations between early symptom change and eventual response to treatment were determined. Improvement in depressive and anxiety symptoms was identified as early as day 1 of treatment. Of the total decline in depression severity over 6 weeks, 9% was present at day 1, 28% at day 2, 39% at days 3 and 4, 65% at day 7, and 80% at day 10. Self-report rating of early improvement (≥20%) in depressive symptoms at day 7 significantly predicted responder status at week 6 (P = 0.03). Clinician-rated depressive and anxiety symptoms only became significantly associated with responder status at day 14. In conclusion, very early changes in depressive symptoms were identified using MHT, early changes accounted for most of total change, and MHT-recorded improvement as early as day 7 significantly predicted response to treatment at study end point.

Serum levels of brain-derived neurotrophic factor are unchanged after transcranial direct current stimulation in treatment-resistant depression

BACKGROUND

Brain-derived neurotrophic factor (BDNF) plays an important role in differentiation and repair of neurons in the adult brain. BDNF serum levels have been found to be lower in depressed patients than in healthy subjects. In a couple of studies, effective antidepressant treatment including electroconvulsive therapy led to an increase in BDNF serum levels. As transcranial direct current stimulation (tDCS) is currently discussed as novel therapeutic intervention in major depression, we investigated BDNF serum levels during tDCS in therapy-resistant depression.

METHODS

Twenty-two patients with a major depressive episode participated in a double-blind placebo-controlled trial and received randomized cross over treatment with 2 weeks active and 2 weeks sham tDCS (1 or 2 mA for 20 min, anode over the left dorsolateral prefrontal cortex, cathode right supraorbital cortex).

RESULTS

Clinical assessment only showed a modest and non-significant improvement in HAMD, BDI and CGI in both groups. BDNF serum levels were measured at baseline, after 2 and after 4 weeks. There was neither a significant change of BDNF levels following active tDCS, nor were severity of depressive symptoms and BDNF levels correlated.

LIMITATIONS

The small sample size, its heterogeneity, the short observation period and a cross-over design without an interval between both conditions.

CONCLUSIONS

tDCS did not change BDNF serum levels unlike other established antidepressant interventions in this treatment resistant sample. However, larger studies are needed.

No influence of brain-derived neurotrophic factor (BDNF) polymorphisms on treatment response in a naturalistic sample of patients with major depression

The role of the brain-derived neurotrophic factor (BDNF) in the pathophysiology of major depressive disorder (MDD) remains to be elucidated. Recent post hoc analyses indicated a potential association of three polymorphisms in the BDNF gene with worse treatment outcome in patients with the subtype of melancholic depression. We aimed at replicating these findings in a German naturalistic multicenter follow-up. Three polymorphisms in the BDNF gene (rs7103411, rs6265 (Val66Met) and rs7124442) were genotyped in 324 patients with MDD and 470 healthy controls. We applied univariate tests and logistic regression models stratifying for depression subtype and gender. The three polymorphisms were not associated with MDD as diagnosis. Further, no associations were found in univariate tests. With logistic regression, we only found a tendency towards an association of the rs6265 (Val66Met) polymorphism with overall response to treatment (response rates: GG (val/val) < GA (val/met) < AA (met/met); p = 0.0129) and some gender differences for the rs6265 (Val66Met) and rs7103411 polymorphisms. Treatment outcome stratified for subtypes of depression did not differ significantly between the investigated polymorphisms or using haplotype analyses. However, results showed a tendency towards significance. At this stage, we cannot support an influence of these three polymorphisms. Further studies in larger patient samples to increase sample sizes of subgroups are warranted.

Interplay between pro-inflammatory cytokines and growth factors in depressive illnesses

The development of depressive disorders had long been attributed to monoamine variations, and pharmacological treatment strategies likewise focused on methods of altering monoamine availability. However, the limited success achieved by treatments that altered these processes spurred the search for alternative mechanisms and treatments. Here we provide a brief overview concerning a possible role for pro-inflammatory cytokines and growth factors in major depression, as well as the possibility of targeting these factors in treating this disorder. The data suggest that focusing on one or another cytokine or growth factor might be counterproductive, especially as these factors may act sequentially or in parallel in affecting depressive disorders. It is also suggested that cytokines and growth factors might be useful biomarkers for individualized treatments of depressive illnesses.

Effects of intermittent hypoxia on cognitive performance and quality of life in elderly adults: a pilot study

BACKGROUND

Physical exercise has a positive effect on cognitive performance and quality of life (QoL). One reason for this is the upregulation of brain-derived neurotrophic factor, which improves brain plasticity. Intermittent hypoxia promotes first the proliferation of endogenous neuroprogenitors which leads to an increased number of newborn neurons and second the expression of brain-derived neurotrophic factor in the adult hippocampus. Intermittent hypoxia may, therefore, support synaptic plasticity, the process of learning and provoke antidepressant-like effects. Hence, intermittent hypoxia might also lead to improved cognitive functioning and QoL.

OBJECTIVE

This study aims to evaluate to what extent physical activity with preceded intermittent hypoxic training is more effective than solely strength-endurance training on cognitive performance and QoL.

METHODS

34 retired people aged between 60 and 70 years were randomly assigned to a control group or intervention group. Contrarily to the control group, which was supplied with a placebo air mixture, the intervention group was supplied with an intermittent hypoxic training prior to a strength-endurance exercise program. The cognitive performance of individuals was examined using the d2 test and the Number Combination Test (ZVT) both before and after the exercise program. We assessed QoL with the Medical Outcomes Study Short-Form 36-Item Health Survey (SF-12) and Pittsburgh Sleep Quality Index (PSQI) and the strength-endurance capacity using the Spring test.

RESULTS

Regarding the d2 test, a time × group effect was observed. Speed of cognitive performance in seconds was measured using ZVT. Here, no interaction effect was discovered. An interaction effect was not found in the Physical Component Summary scores (SF-12). Regarding the Mental Component Summary, an interaction effect just failed to become statistically significant. Furthermore, we determined sleep quality with the PSQI. Here, an interaction effect was observed. The analysis of the strength-endurance test revealed no interaction effects.

CONCLUSION

The data of the current study suggest that an additional intermittent hypoxic training combined with physical exercise augments the positive effects of exercise on cognitive performance and QoL in elderly humans.

Plasma brain-derived neurotrophic factor levels predict the clinical outcome of depression treatment in a naturalistic study

Remission is the primary goal of treatment for major depressive disorder (MDD). However, some patients do not respond to treatment. The main purpose of this study was to determine whether brain-derived neurotrophic factor (BDNF) levels are correlated with treatment outcomes. In a naturalistic study, we assessed whether plasma BDNF levels were correlated with clinical outcomes by measuring plasma BDNF in patients with depressive syndrome (MADRS score ≥18), and subsequently comparing levels between the subgroup of patients who underwent remission (MADRS score ≤8) and the subgroup who were refractory to treatment (non-responders). Patients with depressive syndrome who underwent remission had significantly higher plasma BDNF levels (p<0.001), regardless of age or sex. We also found a significant negative correlation between MADRS scores and plasma BDNF levels within this group (ρ = –0.287, p = 0.003). In contrast, non-responders had significantly lower plasma BDNF levels (p = 0.029). Interestingly, plasma BDNF levels in the non-responder group were significantly higher than those in the remission group in the initial stage of depressive syndrome (p = 0.002). Our results show that plasma BDNF levels are associated with clinical outcomes during the treatment of depression. We suggest that plasma BDNF could potentially serve as a prognostic biomarker for depression, predicting clinical outcome.