Agomelatine, a novel intriguing antidepressant option enhancing neuroplasticity: a critical review

A multicenter, randomized controlled study on the efficacy of agomelatine in ameliorating anhedonia, reduced motivation, and circadian rhythm disruptions in patients with major depressive disorder (MDD)

OBJECTIVE

To evaluate the clinical efficacy and safety of Agomelatine in improving symptoms in patients with major depressive disorder (MDD), providing more scientific evidence for the treatment of depression, and offering more effective therapeutic options for patients.

METHODS

A total of 180 MDD patients in acute phase from 10 psychiatric hospitals of Grade three in Zhejiang Province were enrolled in this 12-week study with the competitive and consecutive pattern, and they were randomized into two different groups treated with flexible-dosage antidepressants of selective serotonin reuptake inhibitors (SSRI) or agomelatine, respectively. The subjects were evaluated with psychological scales of HAMD-17, HAMA, SHAPS for anhedonia, MFI-20 for fatigue, PQSI for sleep quality and MEQ for disturbances in chronobiologic rhythms at baseline, 2, 4, 8 and 12-weekend points, and TESS was used for side-effect. The results were analyzed with repeated measurement analysis of variance.

RESULTS

The two groups each had 90 participants, and there were no significant differences at baseline. The scores of various assessment scales showed statistically significant time main effects during the visits (P < 0.01). The Agomelatine group demonstrated faster efficacy within 2 weeks, with better improvement in SHAPS, MEQ, and PSQI compared to the SSRIs group. However, the remission rate at 12 weeks was lower in the Agomelatine group than in the SSRIs group (63.3% and 72.2%), but the difference between the groups was not statistically significant. The Agomelatine group had fewer adverse reactions (14.4% and 16.7%), but there was a slightly higher incidence of liver function impairment (6.7% and 4.4%), with no statistically significant difference between the groups.

CONCLUSION

Agomelatine, as a novel antidepressant, shows certain advantages in improving depression and anxiety symptoms and is comparable to SSRIs in terms of safety. However, its long-term efficacy and safety on MDD or other depressive subtypes still require further observation and research.

Efficacy and safety of agomelatine in the treatment of patients with depressive disorder: A meta-analysis

OBJECTIVE

To systematically assess the efficacy and safety of agomelatine in the treatment of patients with depressive disorder.

METHODS

Randomized controlled trials (RCTs) related to agomelatine in the treatment of patients with depressive disorder published in PubMed, Web of Science, CNKI, VIP, and Wangfang were retrieved. Extracted data on the efficacy and safety of agomelatine and placebo in the treatment of depressive disorder, and the collected data were processed by RevMan5.4 software.

RESULTS

A total of 10 RCTs were included. Meta-analysis showed that the HAMD-17 total scores of agomelatine group were statistically different from those of placebo group (odds ratio [OR]: 2.04, 95% confidence intervals [CIs]: 1.71-2.43, P < .001). High heterogeneity was found between agomelatine groups and placebo groups (P < .0001, and I2 = 78%), so a subgroup analysis was further performed, and the heterogeneity became insignificant (P = .33, and I2 = 14%) after excluding the studies, of which course of treatment was 24 weeks or the sample size was relatively small. The adverse events between agomelatine and placebo groups were not statistically significant (OR: 1.15, 95% CIs: 0.69-1.92; P = .05).

CONCLUSION

Agomelatine was superior comparable to placebo in the treatment of patients with depressive disorder, and has fewer adverse events.

Apathy associated with antidepressant drugs: a systematic review

OBJECTIVES

Administration of antidepressant drugs - principally selective serotonin reuptake inhibitors (SSRIs) - may induce clinically significant 'apathy' which can affect treatment outcomes adversely. We aimed to review all relevant previous reports.

METHODS

We performed a PUBMED search of English-language studies, combining terms concerning psychopathology (e.g. apathy) and classes of antidepressants (e.g. SSRI).

RESULTS

According to certain inclusion (e.g. use of DSM/ICD diagnostic criteria) and exclusion (e.g. presence of a clinical condition that may induce apathy) criteria, 50 articles were eligible for review. Together, they suggest that administration of antidepressants - usually SSRIs - can induce an apathy syndrome or emotional blunting, i.e. a decrease in emotional responsiveness, to circumstances which would have triggered intense mood reactions prior to pharmacotherapy. The reported prevalence of antidepressant-induced apathy ranges between 5.8 and 50%, and for SSRIs ranges between 20 and 92%. Antidepressant-induced apathy emerges independently of diagnosis, age, and treatment outcome and appears dose-dependent and reversible. The main treatment strategy is dose reduction, though some data suggest the usefulness of treatment with olanzapine, bupropion, agomelatine or amisulpride, or the methylphenidate-modafinil-olanzapine combination.

CONCLUSION

Antidepressant-induced apathy needs careful clinical attention. Further systematic research is needed to investigate the prevalence, course, aetiology, and treatment of this important clinical condition.

A pilot study on improvements in attention function in major depressive disorder after 12 weeks of escitalopram monotherapy or combined treatment with agomelatine

Objective

This study aimed to explore both impairments in attention function in patients with major depressive disorder (MDD) and the efficacy of escitalopram monotherapy or combination therapy with agomelatine.

Methods

A total of 54 patients with MDD and 46 healthy controls (HCs) were included. Patients were treated with escitalopram for 12 weeks; those who presented with severe sleep impairments were also given agomelatine. Participants were evaluated using the Attention Network Test (ANT), which included tests of alerting, orienting, and executive control networks. Concentration, instantaneous memory, and resistance to information interference were tested using the digit span test, and the logical memory test (LMT) was used to evaluate abstract logical thinking. The Hamilton Depression Rating Scale-17 items, Hamilton Anxiety Rating Scale, and Pittsburgh Sleep Quality Index were used to assess depression, anxiety, and sleep quality, respectively. Patients with MDD were assessed at the end of weeks 0, 4, 8, and 12. HCs were assessed once at baseline.

Results

Compared with HCs, patients with MDD showed significantly different alerting, orienting, and executive control functions of attention networks. Treatment with escitalopram alone or combined with agomelatine significantly improved LMT scores at the end of weeks 4, 8, and 12 and restored scores to the level of HCs at the end of week 8. Total Toronto Hospital Test of Alertness scores in patients with MDD increased significantly after 4 weeks of treatment. The ANT executive control reaction time in patients with MDD decreased significantly after 4 weeks of treatment, with this decrease lasting until the end of week 12, but scores did not return to the levels of HCs. Combined treatment with escitalopram and agomelatine led to more improvement in ANT orienting reaction time and was accompanied by a greater reduction of total scores on the Hamilton Depression Rating Scale-17 items and Hamilton Anxiety Rating Scale compared with escitalopram monotherapy.

Conclusions

Patients with MDD showed overall impairments in three domains of attention networks as well as the LMT and a test of subjective alertness. Escitalopram monotherapy significantly improved the LMT scores and the executive control function scores in the ANT at the end of the fourth week of treatment, and the improvement was more extensive with combined escitalopram and agomelatine treatment.

Plasma acetyl-l-carnitine and l-carnitine in major depressive episodes: a case-control study before and after treatment

BACKGROUND

Major depressive disorder (MDD) is the main cause of disability worldwide, its outcome is poor, and its underlying mechanisms deserve a better understanding. Recently, peripheral acetyl-l-carnitine (ALC) has been shown to be lower in patients with major depressive episodes (MDEs) than in controls. l-Carnitine is involved in mitochondrial function and ALC is its short-chain acetyl-ester. Our first aim was to compare the plasma levels of l-carnitine and ALC, and the l-carnitine/ALC ratio in patients with a current MDE and healthy controls (HCs). Our second aim was to assess their changes after antidepressant treatment.

METHODS

l-Carnitine and ALC levels and the carnitine/ALC ratio were measured in 460 patients with an MDE in a context of MDD and in 893 HCs. Depressed patients were re-assessed after 3 and 6 months of antidepressant treatment for biology and clinical outcome.

RESULTS

As compared to HC, depressed patients had lower ALC levels (p < 0.00001), higher l-carnitine levels (p < 0.00001) and higher l-carnitine/ALC ratios (p < 0.00001). ALC levels increased [coefficient: 0.18; 95% confidence interval (CI) 0.12-0.24; p < 0.00001], and l-carnitine levels (coefficient: -0.58; 95% CI -0.75 to -0.41; p < 0.00001) and l-carnitine/ALC ratios (coefficient: -0.41; 95% CI -0.47 to -0.34; p < 0.00001), decreased after treatment. These parameters were completely restored after 6 months of antidepressant. Moreover, the baseline l-carnitine/ALC ratio predicted remission after 3 months of treatment (odds ratio = 1.14; 95% CI 1.03-1.27; p = 0.015).

CONCLUSIONS

Our data suggest a decreased mitochondrial metabolism of l-carnitine into ALC during MDE. This decreased mitochondrial metabolism is restored after a 6-month antidepressant treatment. Moreover, the magnitude of mitochondrial dysfunction may predict remission after 3 months of antidepressant treatment. New strategies targeting mitochondria should be explored to improve treatments of MDD.

The antidepressant-like effect elicited by vitamin D3 is associated with BDNF/TrkB-related synaptic protein synthesis

Vitamin D₃ (cholecalciferol) has been shown to exert antidepressant-like responses, but the role BDNF/TrkB-related synaptic plasticity in this effect remains to be established. Thus, this study investigated the time-course antidepressant-like response of vitamin D₃ in female and male mice and the possible role of BDNF/TrkB signaling in this response. The repeated (7 and 21 days), but not acute (60 min), administration of vitamin D₃ (2.5 μg/kg, p.o.) exerted an antidepressant-like effect in female and male mice subjected to the tail suspension test, without altering the basal locomotor activity in the open-field test. Notably, vitamin D₃ caused a similar time-dependent antidepressant-like effect in male and female mice, suggesting that this behavioral response in the tail suspension test might not be affected by sex differences. Vitamin D₃ administration for 21 days, but not for 7 days or 1 h, augmented BDNF levels in the hippocampus and prefrontal cortex of mice. No effects on phospho-CREB/CREB levels were detected in the hippocampus and prefrontal cortex after chronic vitamin D₃ administration. Additionally, vitamin D₃ increased TrkB, GluA1, and PSD-95 levels in the prefrontal cortex, but not in the hippocampus. Furthermore, an upregulation of synapsin level was observed in both brain regions after vitamin D₃ administration. These findings reinforce and extend the notion that vitamin D₃ is effective to produce antidepressant-like responses in male and female mice and provide novel evidence that this effect could be associated with BDNF/TrkB-related synaptic protein synthesis. Finally, vitamin D₃ could be a feasible nutritional strategy for the management of depression.

Effects of Urban Forest Therapy Program on Depression Patients

Depression is a common serious mental health condition that can have negative personal and social consequences, and managing it is critical for treating depression patients. Forest therapy is emerging as a promising non-pharmacological intervention to improve mental health. However, although the effectiveness of forest therapy programs using forests far from the city has been proven, it is not well known that urban forests can be easily accessed in daily life. Therefore, this study aimed to examine the effects of an urban forest therapy program on depression symptoms, sleep quality, and somatization symptoms of depression patients. To evaluate this, a randomized controlled trial (RCT) design was employed. A total of 47 depression patients participated in this study (22 in the urban forest therapy program group and 25 in the control group). The Beck Depression Inventory (BDI), the Hamilton Rating Scale for Depression (HRSD), the Pittsburgh Sleep Quality Index (PSQI), and the Patient Health Questionnaire-15 (PHQ-15) were administered to each participant to assess the effects of the urban forest therapy program. The results of this study revealed that depression patients in the urban forest therapy program had significantly alleviated depression symptoms and improved sleep quality and somatization symptoms compared to the control group. In conclusion, this study demonstrates the possibility that the urban forest therapy program could be used as an effective non-pharmacological treatment to alleviate depression disorder.

Effects of CYP2D6*4 polymorphism on the steady-state concentration of paroxetine in patients diagnosed with depressive episode and comorbid alcohol use disorder

INTRODUCTION

Selective serotonin reuptake inhibitors have a common and increasing use for the treatment of patients diagnosed with depressive disorders. Some of them do not respond adequately to therapy, and numerous previous studies have indicated an increased risk of type A adverse drug reactions.

OBJECTIVE

The objective of our study was to evaluate the effect of 1846G>A polymorphism of CYP2D6 on the concentration/dose ratio of paroxetine.

MATERIAL AND METHODS

The study enrolled 267 patients with depressive episode (average age, 40.3 ± 14.3 years). Therapy included paroxetine in an average daily dose of 25.1 ± 9.5 mg per day. The efficacy and safety rates of treatment were evaluated using the international psychometric scales. For genotyping, we performed the real-time polymerase chain reaction. Therapeutic drug monitoring has been performed using high-performance liquid chromatography mass spectrometry (HPLC-MS/MS).

RESULTS

Our study revealed the statistically significant results in terms of treatment efficacy (Hamilton Depression Rating Scale scores): (GG) 2.0 [1.0; 3.0] and (GA) 4.0 [2.0; 5.0], p < 0.001; meanwhile, no statistically significant results were obtained for the safety profile (Udvalg for Kliniske Undersogelser (UKU) Scale scores): (GG) 3.0 [2.0; 3.0] and (GA) 3.0 [3.0; 4.0], p = 0.056. We revealed the statistically significant results for the concentration/dose ratio of paroxetine in patients with different genotypes: (GG) 2.803 [2.154; 4.098] and (GA) 5.098 [3.560; 7.241], p < 0.001.

CONCLUSION

The effect of CYP2D6*4 genetic polymorphism on the efficacy profile of paroxetine was demonstrated in a group of 267 patients with depressive disorder.

Neutrophil to-lymphocyte and platelet-to-lymphocyte ratios as biomarkers for suicidal behavior in children and adolescents with depression or anxiety treated with selective serotonin reuptake inhibitors

BACKGROUND

Both the neutrophil/lymphocyte ratio (NLR) and the platelet/lymphocyte ratio (PLR) have been proposed as biomarkers of suicidal risk in adults with depression. We examined whether these ratios may be considered biomarkers for suicidal behavior in young patients with major depressive or anxiety disorders before treatment with selective serotonin reuptake inhibitors (SSRIs), or as biomarkers for the adverse event of SSRI-associated suicidality.

METHODS

Children and adolescents meeting criteria for major depressive or anxiety disorder were recruited. Serum levels of three pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) were assessed; and NLR and PLR calculated, from blood samples collected at baseline and after 8 weeks treatment with SSRI. A Mann-Whitney test was performed to evaluate differences in NLR and PLR between children with and without a history of a suicide attempt prior to treatment. We compared hematological parameters before and after treatment, and between children who developed SSRI-associated suicidality versus children without treatment emergent suicidality.

RESULTS

Among 91 children and adolescents (aged 13.9 ± 2.4 years), baseline NLR and PLR were significantly higher among those with a history of a suicide attempt versus those without such history. Statistically significant correlations were found for the suicide ideation subscale in the Columbia suicide severity rating scale with both baseline NLR and PLR. Baseline NLR and PLR were similar in children who did and did not develop SSRI-associated suicidality after 8 weeks. In the final logistic regression model (χ2 = 18.504, df = 4, p value = 0.001), after controlling for sex, depression severity and IL-6 levels, NLR was significantly associated with a past suicide attempt (β = 1.247, p = 0.019; OR [95% CI] = 3.478 [1.230-9.841]), with a NLR cut-off value of = 1.76 (area under the curve = 0.75 (95% CI = 0.63-0.88, sensitivity = 73%, and specificity = 71%, p value = 0.003).

CONCLUSIONS

High NLR and PLR values may be associated with suicidal behavior in depressed and anxious children and adolescents. NLR appears as a better predictor of suicide attempt than PLR, and thus may be a useful biomarker of suicidality in young patients with depression or anxiety.

Magnitude and factors associated with treatment non-adherence among patients with depressive disorders at St. Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia, 2019: A cross sectional study

Background

Inadequate adherence to treatment is among the main underlying causes of depression becoming a chronic problem. In developing countries due to limited access to health care, inaccurate diagnoses, and scarcity of medications, poor adherence may become an even larger obstacle in the treatment of depression. The current study aims to assess the magnitude and factors related to treatment non-adherence among patients with depressive disorders.

Objective

To assess the magnitude and factors associated with treatment non adherence among patients with depressive disorders at St. Amanuel Mental Specialized Hospital, Addis Ababa, Ethiopia, 2019.

Methods

A hospital-based cross-sectional study was conducted among 415 respondents using systematic random sampling technique. Medication adherence was assessed by using Medication Adherence Rating Scale. Data was entered to Epi-data version 3.1 and analyzed using SPSS version 20. Binary logistic analysis was done and P-values less than 0.05 were considered statistically significant.

Results

The prevalence of treatment non-adherence among patients with depressive disorders was 26% (95%CI; 21.2, 32.5). Previous suicide attempt (AOR = 3.05, 95%CI; 1.82, 5.12), medication side effects (AOR = 2.46, 95%CI; 1.47, 4.11), moderate to high self-stigma (AOR = 2.60, 95%CI; 1.45, 4.66), and poor quality of life (AOR = 2.47, 95%CI; 1.42, 4.28) were significantly associated with treatment non-adherence among patients with depressive disorders.

Conclusion and recommendation

Treatment non-adherence is a common problem among patients being treated for depressive disorders. Previous suicide attempts, medication side effects, moderate to high self-stigma, and poor quality of life were significantly associated with treatment non-adherence. Appropriate interventions should be developed to promote measures to facilitate adherence in this group of patients, and address the associated factors when applicable.

Factors associated with sick leave duration in patients suffering from major depressive disorder initiating antidepressant treatment: a real-world evidence study in Germany and Spain

OBJECTIVE

To describe MDD patients starting antidepressant (AD) treatment by pharmacological approach and identify factors associated with a longer sick leave (SL) duration.

METHODS

Retrospective study on IQVIA German Disease Analyser (specialists) and Spanish Longitudinal Patient Database (general practitioners and specialists). MDD patients initiating AD treatment between July 2016-June 2018 were grouped by therapeutic approach (AD monotherapy vs. combination/switch/add-on) and their characteristics were analysed descriptively. Multiple logistic regression models were run to evaluate factors affecting SL duration (i.e., >30 days).

RESULTS

One thousand six hundred and eighty-five patients (monotherapy: 58%; combination/switch/add-on: 42%) met inclusion criteria for Germany, and 1817 for Spain (monotherapy: 83%; combination/switch/add-on: 17%). AD treatment influenced SL duration: combination/switch/add-on patients had a 2-fold and a 4-fold risk of having >30 days of SL than monotherapy patients, respectively in Germany and Spain. Patients with a gap of time between MDD diagnosis and AD treatment initiation had a higher likelihood of experiencing a longer SL both in Germany and Spain (38% higher likelihood and 6-fold risk of having >30 days of SL, respectively).

CONCLUSIONS

A careful and timely selection of AD treatment approach at the time of MDD diagnosis may improve functional recovery and help to reduce SL, minimising the socio-economic burden of the disease.Key pointsThe major depressive disorder has a substantial impact on work absenteeism.The present study aimed to describe MDD patients starting antidepressant (AD) treatment depending on the pharmacological approach and to identify factors associated with longer sick leave (SL) duration.Patients receiving AD monotherapy had a lower likelihood of having more than 30 days of sick leave than those receiving AD combination/switch/add-on.Patients for whom a gap of time between MDD diagnosis and initiation of AD treatment was observed, showed a higher likelihood of having more than 30 days of sick leave.Because findings from this analysis relied on secondary data, the authors would like to claim the urgency of conducting prospective observational studies that further investigate the effect that different AD therapeutic approaches and timely initiation of treatment might exert on patients' recovery.

Natural Products for the Treatment of Post-stroke Depression

Post-stroke depression (PSD) is the most frequent and important neuropsychiatric consequence of stroke. It is strongly associated with exacerbated deterioration of functional recovery, physical and cognitive recoveries, and quality of life. However, its mechanism is remarkably complicated, including the neurotransmitters hypothesis (which consists of a monoaminergic hypothesis and glutamate-mediated excitotoxicity hypothesis), inflammation hypothesis, dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, and neurotrophic hypothesis and neuroplasticity. So far, the underlying pathogenesis of PSD has not been clearly defined yet. At present, selective serotonin reuptake inhibitors (SSRIs) have been used as the first-line drugs to treat patients with PSD. Additionally, more than SSRIs, a majority of the current antidepressants complied with multiple side effects, which limits their clinical application. Currently, a wide variety of studies revealed the therapeutic potential of natural products in the management of several diseases, especially PSD, with minor side effects. Accordingly, in our present review, we aim to summarize the therapeutic targets of these compounds and their potential role in-clinic therapy for patients with PSD.

Impact of 5-HT7 receptor inverse agonism of lurasidone on monoaminergic tripartite synaptic transmission and pathophysiology of lower risk of weight gain

A part of atypical antipsychotics exert mood-stabilising effects via modulation of various monoamine receptors and intracellular signalling. Recent pharmacodynamic studies suggested that tripartite-synaptic transmission can be involved in pathophysiology of mood-disorders, schizophrenia, their associated cognitive impairments, and several adverse-reactions to atypical antipsychotics. Therefore, to explore mechanisms underlying antidepressive mood-stabilising and antipsychotic effects of lurasidone, we determined concentration-dependent effects of acute and subchronic lurasidone administrations on astroglial L-glutamate release, and expression of connexin43, ERK, AKT, adenosine monophosphate activated protein kinase (AMPK), 5-HT1A (5-HT1AR) and 5-HT7 (5-HT7R) receptors in cultured astrocytes using ultra-high-pressure liquid-chromatography with mass-spectrometry and capillary-immunoblotting systems. Therapeutically-relevant lurasidone concentration suppressed astroglial L-glutamate release through activated connexin43-containing hemichannel by decreasing connexin43 expression in plasma-membrane. Subchronic lurasidone administration downregulated 5-HT1AR and 5-HT7R in astroglial plasma-membrane concentration-dependently. Subchronic lurasidone administration attenuated ERK and AMPK signallings concentration-dependently without affecting AKT signalling. These results suggest that effects of subchronic lurasidone administration on astroglial L-glutamate release, 5-HT receptor, and intracellular signalling are similar to vortioxetine and different from mood-stabilising atypical antipsychotics, clozapine. Therefore, inhibitory effects of subchronic lurasidone administration on astroglial L-glutamate release through activated connexin43-containing hemichannel probably contribute to pathophysiology of antidepressive mood-stabilising effects of lurasidone. Furthermore, inhibitory effects of subchronic lurasidone administration on ERK and AMPK activities (without affecting AKT activity) induced by downregulation of 5-HT7R could result in clinical advantages of lurasidone, lower risk of weight gain.

Association between lithium levels in drinking water and suicide rates: Role of affective disorders

OBJECTIVE

The study aimed to assess the association between lithium levels in drinking water from public supplies and suicide rates in different municipalities of Lithuania in relation with incidence of affective disorders.

METHODS

53 drinking water samples were analysed from the main public drinking water systems of the country's municipalities. Lithium levels were determined using the ion chromatography method. Information on all registered affective disorders across all age groups and gender within the 5-year period was obtained from the Department of Statistics, and was averaged across the investigation time period. For the statistical analysis, lithium levels were averaged per municipality and plotted against suicide standardized mortality rates per 100,000 populations, within the 5-year period.

RESULTS

We found that lithium levels in drinking water are positively associated with the incidence of affective disorders. Our findings suggest higher incidence rates of affective disorders in the municipalities with a lithium level in drinking water above median compared to those in the municipalities with a lithium level below median and with the same socio-demographic and psychiatric characteristics. Suicide mortality rates are inversely associated with lithium levels in drinking water only in municipalities with higher lithium levels (above median) and with a high rate of affective disorders.

CONCLUSION

Based on our study results and insights we generate the following hypothesis for the further research, that lithium level in drinking water might have an important protective effect against suicide rates in the population with affective disorders.

Intramuscular ketamine vs. escitalopram and aripiprazole in acute and maintenance treatment of patients with treatment-resistant depression: A randomized double-blind clinical trial

OBJECTIVE

Ketamine, an N-methyl D-aspartate (NMDA) receptor antagonist, can promote rapid action in the management of individuals with treatment-resistant depression (TRD) at sub-anesthetic doses. However, few studies have investigated the long-term use of ketamine administered intravenously (IV) and intranasally (IN). We report the design and rationale of a therapeutic trial for assessing the efficacy, safety, and tolerability of repeated-dose intramuscular (IM) ketamine vs. active treatment (escitalopram and aripiprazole) in TRD patients.

METHODS

A comparative, parallel-group, randomized double-blind trial assessing the efficacy, safety, and tolerability of acute (4 weeks) and maintenance (24 weeks) use of IM ketamine (0.75 mg/kg) vs. active control (escitalopram 15 mg and aripiprazole 5 mg) in individuals with moderate-severe intensity TRD (no psychotic symptoms) with or without suicide risk will be conducted. Patients with TRD (18-40 years) will be randomized and blinded to receive ketamine IM or active treatment at a 1:1 ratio for 4 weeks (active treatment) and 24 weeks (maintenance treatment). Subjects will be assessed using clinical scales, monitored for vital signs (VS) after application of injectable medication, and undergo neuropsychological tests. The primary outcome will be changed on the Montgomery-Åsberg Depression Rating Scale (MADRS) during the course of the trial. The study is in running.

RESULTS

This study can potentially yield evidence on the use of IM ketamine in the treatment of depressive disorders as an ultra-rapid low-cost therapy associated with less patient discomfort and reduced use of medical resources, and can elucidate long-term effects on different outcomes, such as neuropsychological aspects.

CONCLUSIONS

The trial can help promote the introduction of a novel accessible approach for the treatment of complex disease (TRD) and also allow refinement of its long-term use.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/ct2/show/NCT04234776, identifier: NCT04234776.

Effects of 31 recombinant CYP2C19 variants on clomipramine metabolism in vitro

BACKGROUND

CYP2C19 is an important member of the cytochrome P450 enzyme superfamily. We recently identified 31CYP2C19 alleles in the Han Chinese population; studying the effects of CYP2C19 on drug metabolism can help reduce adverse drug reactions and therapeutic failure.

AIM

The aim of this study was to assess the catalytic activities of 31 allelic isoforms and their effects on the metabolism of clomipramine in vitro.

METHODS

The wild-type and 30 CYP2C19 variants were expressed in insect cells, and each variant was characterized using clomipramine as the substrate. Reactions were performed at 37°C with 5-150 μmol/L substrate for 30 min. By using ultra-high-performance liquid chromatography-mass spectrometry to detect the products, the kinetic parameters Km, Vmax, and intrinsic clearance (Vmax/Km) of N-desmethyl clomipramine were determined.

RESULTS

Among the CYP2C19 variants tested, CYP2C19*29, L16F, and T130M showed extremely increased intrinsic clearance of clomipramine, CYP2C19*3C, and N277K showed similar intrinsic clearance (Vmax/Km) values with CYP2C19*1, while the intrinsic clearance values of other variants were significantly decreased (from 0.65% to 63.28%). In addition, CYP2C19*3 and 35FS could not be detected because they have no detectable enzyme activity.

CONCLUSIONS

As the first report of 31 CYP2C19 alleles for clomipramine metabolism, our study could provide corresponding reference for clomipramine for further studies in vivo and offer valuable information relevant to the personalized medicine for CYP2C19-metabolized drug.

Efficacy of amisulpride for depressive symptoms in individuals with mental disorders: A systematic review and meta-analysis

BACKGROUND

Depressive symptoms occur in several psychiatric disorders, often in the absence of a formal diagnosis of depression. We aimed to evaluate the efficacy and the tolerability of amisulpride, both alone and as augmentation therapy, in the treatment of depressive symptoms in individuals with any major psychiatric disorder.

METHODS

We searched PubMed, Embase, PsycINFO, GreyLit, OpenGrey and ProQuest up to March 2020 for randomised controlled trials focussing on the treatment of an acute depressive episode in any major psychiatric disorder. A random-effect meta-analysis was performed to synthesize the findings on depressive symptoms (primary outcome), response rate and tolerability.

RESULTS

We retrieved 11 studies including 2065 patients with a diagnosis of dysthymia (eight studies), major depression (one study) or schizophrenia (two studies). Amisulpride 50 mg/day was associated with a larger reduction of depressive symptoms compared to placebo (standardised mean difference [SMD] = -0.70, CI 95% -0.92, -0.49; I²  = 0.0%), and was found to be comparable to selective serotonin reuptake inhibitors (SSRIs; SMD = -0.08, CI 95% -0.23, 0.06, I²  = 0.0%), amineptine, imipramine and amitriptyline in the treatment of dysthymia (three studies, not pooled). In individuals with schizophrenia, amisulpride administered at higher doses (>400 mg/day) was comparable to olanzapine and risperidone (two studies, not pooled). In terms of tolerability, amisulpride was superior to placebo for dysthymia (odds ratio [OR] = 3.94, CI 95% 1.07, 14.48; I²  = 0.0) and comparable with SSRIs (OR = 0.94, CI 95% 0.55, 1.62; I²  = 0.0%).

CONCLUSION

Treatment with amisulpride could be a valid choice for selected individuals with dysthymia or depressive symptoms in the context of schizophrenia. More studies on the efficacy and tolerability of amisulpride are needed to draw firm conclusions on its potential benefits in other psychiatric disorders.

MicroRNA Regulates Early-Life Stress–Induced Depressive Behavior via Serotonin Signaling in a Sex-Dependent Manner in the Prefrontal Cortex of Rats

Background

The underlying neurobiology of early-life stress (ELS)-induced major depressive disorder is not clearly understood.

Methods

In this study, we used maternal separation (MS) as a rodent model of ELS and tested whether microRNAs (miRNAs) target serotonin genes to regulate ELS-induced depression-like behavior and whether this effect is sex dependent. We also examined whether environmental enrichment prevents susceptibility to depression- and anxiety-like behavior following MS and whether enrichment effects are mediated through serotonin genes and their corresponding miRNAs.

Results

MS decreased sucrose preference, which was reversed by enrichment. Males also exhibited greater changes in forced swim climbing and escape latency tests only following enrichment. Slc6a4 and Htr1a were upregulated in the frontal cortex following MS. In male MS rats, enrichment slightly reversed Htr1a expression to levels similar to control rats. miR-200a-3p and miR-322-5p, which target SLC6A4, were decreased by MS, but not significantly. An HTR1A-targeting miRNA, miR-320-5p, was also downregulated by MS and showed slight reversal by enrichment in male animals. miR-320-5p targeting of Htr1a was validated in vitro using SHSY neuroblastoma cell lines.

Conclusions

Altogether, this study implicates miRNA interaction with the serotonin pathway in ELS-induced susceptibility to depression-related reward deficits. Furthermore, because of its recovery by enrichment in males, miR-320 may represent a viable sex-specific target for reward-related deficits in major depressive disorder.

Agomelatine: A novel melatonergic antidepressant. Method validation and first exploratory pharmacokinetic study in fasted and fed dogs

Agomelatine is a novel melatonergic antidepressant, with a non-monoaminergic mechanism of action. The aim of this study was to evaluate its plasma concentrations after a single oral dose of 300 mg/dog in fasted and fed status. The research was carried out in 6 adult healthy Labrador dogs according to a randomized open, single-dose, two-treatment, two-phase, paired 2 × 2 cross-over study. At the end of the study all the animals had received the drug in fasted and fed conditions. The drug concentrations were detected in plasma by a validated LC-MS/MS analytical method. The plasma concentrations of agomelatine were found to be extremely variable in both groups as well as the pharmacokinetic profiles. Due to these variable findings the only reliable pharmacokinetic parameters were assessed as C_max (31.8 vs 15.7 ng/mL), T_max (0.75 vs 4 h) and AUC (155 vs 52 ng h/mL) in fasted and fed status, respectively. Unfortunately, as a pioneer study, the small animal sample size used along with the unanticipated variability did not allow to neither statistically estimate if food can affect the pharmacokinetics of agomelatine nor recommend agomelatine for off-label therapies in canine species. Further studies are warranted to clarify this issue.

Anomalous functional connectivity within the default-mode network in treatment-naive patients possessing first-episode major depressive disorder

BACKGROUND AND OBJECTIVE

Previous studies have shown that the default-mode network (DMN) has a substantial role in patients with major depressive disorder (MDD). However, there is a shortage of information regarding variations in the functional connectivity (FC) of the DMN of treatment-naive patients with first-episode MDD. The present study aims to explore the FC of the DMN in such patients.

METHODS

The study population consisted of 33 patients and 35 controls, paired regarding age, gender, education level, and health condition. Depression severity was assessed through the Hamilton Depression Scale (HAM-D), and subjects underwent evaluation during the resting-state through functional magnetic resonance imaging (rs-fMRI). To assess the result, we used FC and ICA. We used Spearman's correlation test to detect potential correlations between anomalous FC and severity of HAM-D scores.

RESULTS

We have found a decreased FC in the left medial orbitofrontal gyrus (MOFG) and right marginal gyrus (SMG) in depressive patients compared to controls. There was a negative correlation between abnormal FC in the right SMG and HAM-D scores. We have not found any increase in FC of the DMN in treatment-naive, first-episode of MDD patients.

CONCLUSIONS

Our study provided evidence of a negative correlation between abnormal FC in the DMN and severity of depression symptoms measured by HAM-D in treatment-naive MDD patients. This finding could shed some light on the relevance of DMN for understanding the pathophysiology of cognitive impairment in MDD.

Immunoregulation and antidepressant effect of ketamine

Major depressive disorder (MDD) is a common mental health disorder that brings severe disease burden worldwide. Traditional antidepressants are mainly targeted at monoamine neurotransmitters, with low remission rates and high recurrence rates. Ketamine is a noncompetitive glutamate N-methyl-d-aspartate receptor (NMDAR) antagonist, and its rapid and powerful antidepressant effects have come to light. Its antidepressant mechanism is still unclarified. Research found that ketamine had not only antagonistic effect on NMDAR but also strong immunomodulatory effect, both of which were closely related to the pathophysiology of MDD. Although there are many related studies, they are relatively heterogeneous. Therefore, this review mainly describes the immune mechanisms involved in MDD and how ketamine plays an antidepressant role by regulating peripheral and central immune system, including peripheral inflammatory cytokines, central microglia, and astrocytes. This review summarizes the related research, finds out the deficiencies of current research, and provides ideas for future research and the development of novel antidepressants.

Using a machine learning approach to investigate factors associated with treatment-resistant depression among adults with chronic non-cancer pain conditions and major depressive disorder

OBJECTIVE

Presence of chronic non-cancer pain conditions (CNPC) among adults with major depressive disorder (MDD) may reduce benefits of antidepressant therapy, thereby increasing the possibility of treatment resistance. This study sought to investigate factors associated with treatment-resistant depression (TRD) among adults with MDD and CNPC using machine learning approaches.

METHODS

This retrospective cohort study was conducted using a US claims database which included adults with newly diagnosed MDD and CNPC (January 2007-June 2017). TRD was identified using a clinical staging algorithm for claims data. Random forest (RF), a machine learning method, and logistic regression was used to identify factors associated with TRD. Initial model development included 42 known and/or probable factors that may be associated with TRD. The final refined model included 20 factors.

RESULTS

Included in the sample were 23,645 patients (73% female mean age: 55 years; 78% with ≥2 CNPC, and 91% with joint pain/arthritis). Overall, 11.4% adults (N = 2684) met selected criteria for TRD. The five leading factors associated with TRD were the following: mental health specialist visits, polypharmacy (≥5 medications), psychotherapy use, anxiety, and age. Cross-validated logistic regression model indicated that those with TRD were younger, more likely to have anxiety, mental health specialist visits, polypharmacy, and psychotherapy use with adjusted odds ratios (AORs) ranging from 1.93 to 1.27 (all ps < .001).

CONCLUSION

Machine learning identified several factors that warrant further investigation and may serve as potential targets for clinical intervention to improve treatment outcomes in patients with TRD and CNPC.

Potential clinical value of circular RNAs as peripheral biomarkers for the diagnosis and treatment of major depressive disorder

Background

circular RNAs (circRNAs) are expressed abundantly in the brain and are implicated in the pathophysiology of neuropsychiatric disease. However, the potential clinical value of circRNAs in major depressive disorder (MDD) remains unclear.

Methods

RNA sequencing was conducted in whole-blood samples in a discovery set (7 highly homogeneous MDD patients and 7 matched healthy controls [HCs]). The differential expression of circRNAs was verified in an independent validation set. The interventional study was conducted to assess the potential effect of the antidepressive treatment on the circRNA expression.

Findings

in the validation set, compared with 52 HCs, significantly decreased circFKBP8 levels (Diff: -0.24; [95% CI -0.39 ~ -0.09]) and significantly elevated circMBNL1 levels (Diff: 0.37; [95% CI 0.09 ~ 0.64]) were observed in 53 MDD patients. The expression of circMBNL1 was negatively correlated with 24-item Hamilton Depression Scale (HAMD-24) scores in 53 MDD patients. A mediation model indicated that circMBNL1 affected HAMD-24 scores through a mediator, serum brain-derived neurotrophic factor. In 53 MDD patients, the amplitude of low-frequency fluctuations in the right orbital part middle frontal gyrus was positively correlated with circFKBP8 and circMBNL1 expression. Furthermore, the interventional study of 53 MDD patients demonstrated that antidepressive treatment partly increased circFKBP8 expression and the change in expression of circFKBP8 was predictive of further reduced HAMD-24 scores.

Interpretation

whole-blood circFKBP8 and circMBNL1 may be potential biomarkers for the diagnosis of MDD, respectively, and circFKBP8 may show great potential for the antidepressive treatment.

Efficacy of dextromethorphan for the treatment of depression: a systematic review of preclinical and clinical trials

INTRODUCTION

The large percentage of adults with major depressive disorder (MDD) insufficiently responding and/or tolerating conventional monoamine-based antidepressants invites the need for mechanistically novel treatments. Convergent evidence implicates glutamatergic signaling as a potential therapeutic target in MDD.

AREAS COVERED

The synthesis herein of preclinical and clinical studies indicates that dextromethorphan (DXM) is well tolerated and exhibits clinically significant antidepressant effects; DXM combined with bupropion has demonstrated replicated and relatively rapid onset efficacy in adults with MDD. DXM efficacy has been preliminarily reported in adults with bipolar depression. The combination of DXM and bupropion represents a pharmacokinetic and pharmacodynamic synergy which may account for the rapidity of action in MDD.

EXPERT OPINION

The combination of DXM and bupropion is a safe, well tolerated and efficacious treatment option in adults with MDD. Priority questions are whether DXM/bupropion is uniquely effective across discrete domains of psychopathology (e.g. anhedonia, reward processing, general cognitive systems) and/or whether it is able to significantly improve patient-reported outcomes (e.g. quality of life, psychosocial functioning). The availability of ketamine/esketamine and DXM/bupropion instantiates the relevance of glutamate as a treatment target in MDD. Studies in bipolar depression with DXM/bupropion are warranted as well as in MDD with suicidality.

Neuroprogression as an Illness Trajectory in Bipolar Disorder: A Selective Review of the Current Literature

Bipolar disorder (BD) is a chronic and disabling psychiatric condition that is linked to significant disability and psychosocial impairment. Although current neuropsychological, molecular, and neuroimaging evidence support the existence of neuroprogression and its effects on the course and outcome of this condition, whether and to what extent neuroprogressive changes may impact the illness trajectory is still poorly understood. Thus, this selective review was aimed toward comprehensively and critically investigating the link between BD and neurodegeneration based on the currently available evidence. According to the most relevant findings of the present review, most of the existing neuropsychological, neuroimaging, and molecular evidence demonstrates the existence of neuroprogression, at least in a subgroup of BD patients. These studies mainly focused on the most relevant effects of neuroprogression on the course and outcome of BD. The main implications of this assumption are discussed in light of specific shortcomings/limitations, such as the inability to carry out a meta-analysis, the inclusion of studies with small sample sizes, retrospective study designs, and different longitudinal investigations at various time points.

The use of antidepressant medications for Bipolar I and II disorders

Given that the patterns and clinical correlates related to antidepressant drugs (ADs) prescription for Bipolar Disorder (BD) remain generally unclear, this study aimed to compare socio-demographic and clinical features of BD patients treated vs. not treated with ADs. The sample consists of 287 currently euthymic bipolar patients. Among participants (mean age=51.9±15.02), 157 54.7% were receiving ADs. Based on the main findings, subjects given ADs were older and more frequently retired than those without receiving ADs. Moreover, patients given ADs were more likely to have had a first major depressive episode. Lifetime substance abuse/dependence history was less frequently reported among patients given ADs. Furthermore, ADs given patients had a higher number of affective episodes, and longer duration of their illness. Additionally, subjects treated with ADs reported higher hopelessness levels, and lower positive reinterpretations than those who were not treated with ADs. Factors associated with ADs-use by multivariate modeling were reduced personal autonomy (OR=.070), and hopelessness levels (OR=1.391). These results may help clinicians to better understand the clinical correlates of BD subtypes and improve their differential management. Additional studies are needed to replicate these findings, and facilitate the differential trajectories of BD patients based on socio-demographic/clinical profiles.

International Union of Basic and Clinical Pharmacology. CX. Classification of Receptors for 5-hydroxytryptamine; Pharmacology and Function

5-HT receptors expressed throughout the human body are targets for established therapeutics and various drugs in development. Their diversity of structure and function reflects the important role 5-HT receptors play in physiologic and pathophysiological processes. The present review offers a framework for the official receptor nomenclature and a detailed understanding of each of the 14 5-HT receptor subtypes, their roles in the systems of the body, and, where appropriate, the (potential) utility of therapeutics targeting these receptors. SIGNIFICANCE STATEMENT: This review provides a comprehensive account of the classification and function of 5-hydroxytryptamine receptors, including how they are targeted for therapeutic benefit.

Ketamine, but not guanosine, as a prophylactic agent against corticosterone-induced depressive-like behavior: Possible role of long-lasting pro-synaptogenic signaling pathway

Ketamine has been reported to exert a prophylactic effect against stress-induced depressive-like behavior by modulating the guanosine-based purinergic system. However, the molecular pathways underlying its prophylactic effect and whether guanosine also elicits a similar effect remain to be determined. Here, we investigated the prophylactic effect of ketamine and guanosine against corticosterone (CORT – 20 mg/kg, p.o.)-induced depressive-like behavior in mice. Furthermore, we characterized if the prophylactic response may be associated with mTORC1-driven signaling in the hippocampus and prefrontal cortex. A single administration of ketamine (5 mg/kg, i.p.), but not guanosine (1 or 5 mg/kg, p.o.), given 1 week before the pharmacological stress prevented CORT-induced depressive-like behavior in the tail suspension test (TST) and splash test (SPT). Fluoxetine treatment for 3 weeks did not prevent CORT-induced behavioral effects. A single administration of subthreshold doses of ketamine (1 mg/kg, i.p.) plus guanosine (5 mg/kg, p.o.) partially prevented the CORT-induced depressive-like behavior in the SPT. Additionally, CORT reduced Akt (Ser⁴⁷³) and GSK-3β (Ser⁹) phosphorylation and PSD-95, GluA1, and synapsin immunocontent in the hippocampus, but not in the prefrontal cortex. No alterations on mTORC1/p70S6K immunocontent were found in both regions in any experimental group. CORT-induced reductions on PSD-95, GluA1, and synapsin immunocontent were prevented only by ketamine treatment. Collectively, these findings suggest that ketamine, but not guanosine, exerts a prophylactic effect against depressive-like behavior, an effect associated with the stimulation of long-lasting pro-synaptogenic signaling in the hippocampus.

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CORT induces depressive-like behavior and hippocampal synaptogenic markers deficits.

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Ketamine prevents CORT-induced behavioral and hippocampal synaptogenic alterations.

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Guanosine or fluoxetine are unable to prevent the alterations induced by CORT.

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Ketamine plus guanosine partially prevent CORT-induced reduced self-care behavior.

Melatonin's Antineoplastic Potential Against Glioblastoma

Glioblastoma (GBM) is one of the most intransigent and aggressive brain tumors, and its treatment is extremely challenging and ineffective. To improve patients’ expectancy and quality of life, new therapeutic approaches were investigated. Melatonin is an endogenous indoleamine with an incredible variety of properties. Due to evidence demonstrating melatonin’s activity against several cancer hallmarks, there is growing interest in its use for preventing and treating cancer. In this review, we report on the potential effects of melatonin, alone or in combination with anticancer drugs, against GBM. We also summarize melatonin targets and/or the intracellular pathways involved. Moreover, we describe melatonin’s epigenetic activity responsible for its antineoplastic effects. To date, there are too few clinical studies (involving a small number of patients) investigating the antineoplastic effects of melatonin against GBM. Nevertheless, these studies described improvement of GBM patients’ quality of life and did not show significant adverse effects. In this review, we also report on studies regarding melatonin-like molecules with the tumor-suppressive properties of melatonin together with implemented pharmacokinetics. Melatonin effects and mechanisms of action against GBM require more research attention due to the unquestionably high potential of this multitasking indoleamine in clinical practice.

Recent Stressful Life Events in Euthymic Major Depressive Disorder Patients: Sociodemographic and Clinical Characteristics

BACKGROUND

Stressful life events (SLE) may influence the illness course and outcome. This study aimed to characterize socio-demographic and clinical features of euthymic major depressive disorder (MDD) outpatients with SLE compared with those without.

METHODS

The present sample included 628 (mean age=55.1 ± 16.1) currently euthymic MDD outpatients of whom 250 (39.8%) reported SLE and 378 (60.2%) did not.

RESULTS

After univariate analyses, outpatients with SLE were most frequently widowed and lived predominantly with friends/others. Moreover, relative to outpatients without SLE, those with SLE were more likely to have a family history of suicidal behavior, manifested melancholic features, report a higher Coping Orientation to the Problems Experienced (COPE) positive reinterpretation/growth and less likely to have a comorbid panic disorder, residual interepisodic symptoms, use previous psychiatric medications, and currently use of antidepressants. Having a family history of suicide (OR=9.697; p=≤.05), history of psychotropic medications use (OR=2.888; p=≤.05), and reduced use of antidepressants (OR=.321; p=.001) were significantly associated with SLE after regression analyses. Mediation analyses showed that the association between current use of antidepressants and SLE was mediated by previous psychiatric medications.

CONCLUSION

Having a family history of suicide, history of psychotropic medications use, and reduced use of antidepressants is linked to a specific "at risk" profile characterized by the enhanced vulnerability to experience SLE.

The burden of suicidal ideation across Europe: a cross-sectional survey in five countries

BACKGROUND

Suicidal ideation (SI) is an associated risk of depression, affecting 30-40% of the depressed population. However, there is a paucity of studies investigating the impact of SI in Europe. This retrospective observational study examined the burden of SI among adults with major depressive disorder (MDD) in the 2017 National Health and Wellness Survey in five European countries: France, Germany, Italy, Spain, and the UK.

METHODS

Bivariate analyses evaluated group differences between respondents with MDD with and without SI according to demographic characteristics, self-reported health-related quality of life, work productivity and activity impairment (WPAI), and healthcare resource utilization (HRU). Generalized linear models examined group differences country-wise, after controlling for relevant confounders.

RESULTS

Among 52,060 respondents, 3,308 individuals were diagnosed with MDD, comprising SI (n=905) and non-SI (nSI) (n=2403) patients. Adjusted differences (ADs), compared to the general population, were observed using the Medical Outcomes Study Short Form Survey (SF-12v2) mental component summary scores (AD: SI=-20.02, nSI=-10.77), physical component summary scores (AD: SI=-4.49, nSI=-2.50), and EuroQoL-5 Dimensions (AD: SI=-0.34, nSI=-0.15) (for all, p<0.001). Significantly greater WPAI and higher HRU were associated with SI compared to nSI.

CONCLUSION

The results illustrate the unique impact of SI within the MDD population and the need to reduce the burden.

Confining the Concept of Vascular Depression to Late-Onset Depression: A Meta-Analysis of MRI-Defined Hyperintensity Burden in Major Depressive Disorder and Bipolar Disorder

Background: The vascular depression hypothesis emphasizes the significance of vascular lesions in late-life depression. At present, no meta-analytic model has investigated whether a difference in hyperintensity burden compared to controls between late-life and late-onset depression is evident. By including a substantial number of studies, focusing on a meaningful outcome measure, and considering several moderating and control variables, the present meta-analysis investigates the severity of hyperintensity burden in major depressive disorder (MDD) and bipolar disorder (BD). A major focus of the present meta-analysis refers to the role of age at illness onset. It is analyzed whether late-onset rather than late-life depression characterizes vascular depression. Method: In total, 68 studies were included in the meta-analysis and a multilevel random effects model was calculated using Hedges' g as the effect size measure. Results: The severity of hyperintensity burden was significantly greater in the patient group compared to the control group. This effect was evident regarding the whole patient group (g = 0.229) as well as both depression subgroups, with a significantly greater effect in BD (g = 0.374) compared to MDD (g = 0.189). Hyperintensity burden was more pronounced in late-onset depression than in early-onset depression or late-life depression. A considerable heterogeneity between the included studies was observed, which is reflected by the large variability in effects sizes. Conclusion: In conclusion, the present meta-analysis underscores the association of hyperintensities with MDD and BD. Especially late-onset depression is associated with an increased hyperintensity burden, which is in line with the vascular depression hypothesis. The results suggest that it might be more feasible to confine the concept of vascular depression specifically to late-onset depression as opposed to late-life depression. Further research is needed to understand the causal mechanisms that might underlie the relation between hyperintensity burden and depression.

The Missing Link: How Exosomes and miRNAs can Help in Bridging Psychiatry and Molecular Biology in the Context of Depression, Bipolar Disorder and Schizophrenia

MicroRNAs (miRNAs) only recently have been recognized as promising molecules for both fundamental and clinical neuroscience. We provide a literature review of miRNA biomarker studies in three most prominent psychiatric disorders (depression, bipolar disorder and schizophrenia) with the particular focus on depression due to its social and healthcare importance. Our search resulted in 191 unique miRNAs across 35 human studies measuring miRNA levels in blood, serum or plasma. 30 miRNAs replicated in more than one study. Most miRNAs targeted neuroplasticity and neurodevelopment pathways. Various limitations do not allow us to make firm conclusions on clinical potential of studied miRNAs. Based on our results we discuss the rationale for future research investigations of exosomal mechanisms to overcome methodological caveats both in studying etiology and pathogenesis, and providing an objective back-up for clinical decisions.

Melatonin receptor stimulation by agomelatine prevents Aβ-induced tau phosphorylation and oxidative damage in PC12 cells

Purpose

As a novel antidepressant drug, agomelatine has good therapeutic effect on the mood disorder and insomnia in Alzheimer's disease (AD). Recent studies have shown the neuroprotective function of agomelatine, including anti-oxidative and anti-apoptosis effect. However, it remains unclear whether agomelatine exerts neuroprotection in AD. Thus, the neuroprotective effect of agomelatine against amyloid beta _25-35 (Aβ_25-35)-induced toxicity in PC12 cells was evaluated in this study.

Methods

The concentration of malondialdehyde (MDA), LDH, and ROS was investigated to evaluate oxidative damage. The expression of P-tau, tau, PTEN, P-Akt, Akt, P-GSK3β, and GSK3β proteins was assessed by Western blotting. Our results demonstrated that Aβ_25-35 significantly increased the content of MDA, LDH, and ROS. Meanwhile, Aβ_25-35 upregulated the expression of P-tau and PTEN as well as downregulated P-Akt and P-GSK3β expression. These effects could be blocked by agomelatine pretreatment. Furthermore, luzindole, the melatonin receptor (MT) antagonist, could reverse the neuroprotective effect of agomelatine.

Conclusion

The results demonstrated that antidepressant agomelatine might prevent the tau protein phosphorylation and oxidative damage induced by Aβ_25-35 in PC12 cells by activating MT-PTEN/Akt/GSK3β signaling. This study provided a novel therapeutic target for AD in the future.

Complex effects of childhood abuse, affective temperament, and subjective social status on depressive symptoms of adult volunteers from the community

BACKGROUND

How subjective social status is associated with childhood abuse and affective temperament in the mechanism of depressive symptom exacerbation remains unknown. In this study, we investigated how the complex effects of subjective social status, childhood abuse, and affective temperament influence depressive symptoms in adulthood.

METHODS

Self-report questionnaires were distributed to 853 adult volunteers between January and August 2014. Of them, 404 people gave full consent and returned complete anonymous responses. The following five questionnaires were analyzed: demographic information, Patient Health Questionnaire-9, subjective social status, Child Abuse and Trauma Scale, and Temperament Evaluation of Memphis, Pisa, Paris and San Diego autoquestionnaire. The associations between the scores were analyzed by structural equation modeling. This study was conducted with approval from the ethics committees of Tokyo Medical University and Hokkaido University Hospital.

RESULTS

Covariance structure analysis demonstrated that childhood abuse and subjective social status did not have a direct effect on adulthood depressive symptoms. Childhood abuse had direct effects on subjective social status and affective temperament and childhood abuse indirectly affected adulthood depressive symptoms through subjective social status and affective temperament. Subjective social status also affected depressive symptoms through an effect on affective temperament. This model explained 43% of the variability in depressive symptoms and the fitness of this model was good.

CONCLUSION

Regarding childhood abuse and adulthood depressive symptoms, subjective social status as well as affective temperament may be mediators. The results of this study are expected to contribute to the elucidation of the mechanism of depression.

The Effect of Agomelatine Treatment on Diabetes-Induced Cognitive Impairments in Rats: Concomitant Alterations in the Hippocampal Neuron Numbers

Researches that are related to the central nervous system complications of diabetes have indicated higher incidence of cognitive disorders in patients. Since the variety of nootropic drugs used in clinics is limited and none of them consistently improves the outcomes, new and effective drug alternatives are needed for the treatment of diabetes-induced cognitive disorders. Based on the nootropic potential of agomelatine, the promising efficacy of this drug on cognitive impairments of diabetic rats was investigated in the current study. Experimental diabetes model was induced by streptozotocin. After development of diabetes-related cognitive impairments in rats, agomelatine (40 and 80 mg/kg) was administrated orally for two weeks. Cognitive performance was assessed by Morris water-maze and passive avoidance tests. Then, the total numbers of neurons in both dentate gyrus and Cornu Ammonis (CA) 1–3 subfields of the hippocampus were estimated by the optical fractionator method. Agomelatine treatment induced notable enhancement in the learning and memory performance of diabetic rats. Moreover, it reversed the neuronal loss in the hippocampal subregions of diabetic animals. Obtained results suggest that agomelatine has a significant potential for the treatment of diabetes-induced cognitive impairments. However, therapeutic efficacy of this drug in diabetic patients suffering from cognitive dysfunctions needs to be confirmed by further clinical trials.

Functional neuroanatomy in panic disorder: Status quo of the research

AIM

To provide an overview of the current research in the functional neuroanatomy of panic disorder.

METHODS

Panic disorder (PD) is a frequent psychiatric disease. Gorman et al (1989; 2000) proposed a comprehensive neuroanatomical model of PD, which suggested that fear- and anxiety-related responses are mediated by a so-called “fear network” which is centered in the amygdala and includes the hippocampus, thalamus, hypothalamus, periaqueductal gray region, locus coeruleus and other brainstem sites. We performed a systematic search by the electronic database PubMed. Thereby, the main focus was laid on recent neurofunctional, neurostructural, and neurochemical studies (from the period between January 2012 and April 2016). Within this frame, special attention was given to the emerging field of imaging genetics.

RESULTS

We noted that many neuroimaging studies have reinforced the role of the “fear network” regions in the pathophysiology of panic disorder. However, recent functional studies suggest abnormal activation mainly in an extended fear network comprising brainstem, anterior and midcingulate cortex (ACC and MCC), insula, and lateral as well as medial parts of the prefrontal cortex. Interestingly, differences in the amygdala activation were not as consistently reported as one would predict from the hypothesis of Gorman et al (2000). Indeed, amygdala hyperactivation seems to strongly depend on stimuli and experimental paradigms, sample heterogeneity and size, as well as on limitations of neuroimaging techniques. Advanced neurochemical studies have substantiated the major role of serotonergic, noradrenergic and glutamatergic neurotransmission in the pathophysiology of PD. However, alterations of GABAergic function in PD are still a matter of debate and also their specificity remains questionable. A promising new research approach is “imaging genetics”. Imaging genetic studies are designed to evaluate the impact of genetic variations (polymorphisms) on cerebral function in regions critical for PD. Most recently, imaging genetic studies have not only confirmed the importance of serotonergic and noradrenergic transmission in the etiology of PD but also indicated the significance of neuropeptide S receptor, CRH receptor, human TransMEMbrane protein (TMEM123D), and amiloride-sensitive cation channel 2 (ACCN2) genes.

CONCLUSION

In light of these findings it is conceivable that in the near future this research will lead to the development of clinically useful tools like predictive biomarkers or novel treatment options.

Transcriptomic profiling of human hippocampal progenitor cells treated with antidepressants and its application in drug repositioning

Current pharmacological treatments for major depressive disorder (MDD) are ineffective in a significant proportion of patients, and the identification of new antidepressant compounds has been difficult. 'Connectivity mapping' is a method that can be used to identify drugs that elicit similar downstream effects on mRNA levels when compared to current treatments, and thus may point towards possible repositioning opportunities. We investigated genome-wide transcriptomic changes to human hippocampal progenitor cells treated with therapeutically relevant concentrations of a tricyclic antidepressant (nortriptyline) and a selective serotonin reuptake inhibitor (escitalopram). We identified mRNA changes common to both drugs to create an 'antidepressant mRNA signature'. We used this signature to probe the Library of Integrated Network-based Cellular Signatures (LINCS) and to identify other compounds that elicit similar changes to mRNA in neural progenitor cells. Results from LINCS revealed that the tricyclic antidepressant clomipramine elicited mRNA changes most similar to our mRNA signature, and we identified W-7 and vorinostat as functionally relevant drug candidates, which may have repositioning potential. Our results are encouraging and represent the first attempt to use connectivity mapping for drug repositioning in MDD.

High-frequency repetitive transcranial magnetic stimulation over the left DLPFC for major depression: Session-dependent efficacy: A meta-analysis

Background

Depression is a major debilitating psychiatric disorder. Current antidepressant drugs are often associated with side effects or treatment resistance. The aim of this meta-analysis was to evaluate therapeutic effects of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) in major depression (MD).

Methods

The medical data bases of PubMed, Medline, Embase and Cochrane Central Register were searched for randomized controlled trials (RCTs) reporting the therapeutic effects of high-frequency rTMS for depression, which were published in English between January 1990 and June 2016. The index terms were “depress*”, “depression” and “transcranial magnetic stimulation”. Depression outcome data of different sessions (5, 10, 15, and 20 sessions of rTMS treatment) were extracted and synthesized by calculating standardized mean difference (SMD) with 95% confidence intervals (CI) by using a random-effect model. Within each session group, the subgroup analyses based on the number of pulses (≤ 1000, 1200–1500, 1600–1800, and 2000–3000) were also conducted.

Results

Thirty RCTs with a total of 1754 subjects including 1136 in the rTMS group and 618 in the sham group were included in this meta-analysis. rTMS had a significant overall therapeutic effect on depression severity scores (SMD = −0.73, P < 0.00001). The five, 10, 15, 20 sessions of rTMS treatments yielded the significant mean effect sizes of −0.43, −0.60, −1.13, and −2.74, respectively. In the four groups (5, 10, 15, 20 sessions), the maximal mean effect size was all obtained in the subgroup of 1200–1500 pulses per day (−0.97, −1.14, −1.91, −5.47; P < 0.05).

Conclusions

The increasing of HF-rTMS sessions is associated with the increased efficacy of HF-rTMS in reducing depressed patients’ symptom severity. A total number of pulses of 1200–1500 per day appear to deliver the best antidepressant effects of HF-rTMS.

Is there an association between diet and depression in children and adolescents? A systematic review

This review critically evaluates previous studies investigating the association between dietary intake of children and young people and depression and related mental health problems. A systematic literature search was conducted using electronic databases such as PsycINFO, MEDLINE, PubMed and Cochrane. A total of twenty studies were identified that met inclusion criteria and were subsequently rated for quality. The studies used a range of methods to measure dietary intake and mental health. Important potential confounding variables (e.g. socio-economic status) were often not included or controlled. There were also inconsistencies in the use of key constructs, which made comparisons between studies difficult. Despite some contradictory results, overall there was support for an association between healthy dietary patterns or consumption of a high-quality diet and lower levels of depression or better mental health. Similarly, there was a relationship between unhealthy diet and consumption of low-quality diet and depression or poor mental health. However, where significant relationships were reported, effect sizes were small. Future research on the relationship between diet and mental health in young people should use more clearly defined constructs to define diet and include or control for important confounders.

Investigational drugs for treating major depressive disorder

INTRODUCTION

Treatment of patients suffering from major depression could be highly challenging for psychiatrists. Intractability as well as relapse is commonly seen among these patients, leading to functional impairment and poor quality of life. The present review discusses some of the novel investigational drugs that are under pre-clinical or clinical phases in the treatment of major depression. Areas covered: Molecules belonging to different classes such as triple reuptake inhibitors, opioid receptors, ionotropic and metabotropic glutamate receptors, and neurotrophin in the treatment of major depression are covered in this article. Expert opinion: Although the historical discovery of earlier antidepressant molecules (iproniazid and imipramine) is through serendipitous discovery, the present research focuses on discovering novel molecules based on our current pathophysiological knowledge of the disease condition. The fast-acting antidepressant property of N-methyl-d-aspartate (NMDA) receptor molecules, including ketamine is an exciting area of research. Other drug molecules such as amitifadine (triple reuptake inhibitor), ALKS-5461 (kappa receptor antagonist and mu opioidergic receptor agonist), rapastinel (NMDA glutamatergic receptor modulator) are under Phase-III clinical trials and could be approved in the near future for the treatment of major depression.

NPAS3 Regulates Transcription and Expression of VGF: Implications for Neurogenesis and Psychiatric Disorders

Neuronal PAS domain protein 3 (NPAS3) and VGF (VGF Nerve Growth Factor (NGF) Inducible) are important for neurogenesis and psychiatric disorders. Previously, we have demonstrated that NPAS3 regulates VGF at the transcriptional level. In this study, VGF (non-acronymic) was found regulated by NPAS3 in neuronal stem cells. However, the underlying mechanism of this regulation remains unclear. The aim of this study was to explore the correlation of NPAS3 and VGF, and their roles in neural cell proliferation, in the context of psychiatric illnesses. First, we focused on the structure of NPAS3, to identify the functional domain of NPAS3. Truncated NPAS3 lacking transactivation domain was also found to activate VGF, which suggested that not only transactivation domain but other structural motifs were also involved in the regulation. Second, Mutated enhancer box (E-box) of VGF promoter showed a significant response to this basic helix-loop-helix (bHLH) transcription factor, which suggested an indirect regulatory mechanism for controlling VGF expression by NPAS3. κB site within VGF promoter was identified for VGF activation induced by NPAS3, apart from direct binding to E-box. Furthermore, ectopically expressed NPAS3 in PC12 cells produced parallel responses for nuclear factor kappa-light-chain-enhancer of activated B cells [NF-κB (P65)] expression, which specifies that NPAS3 regulates VGF through the NF-κB signaling pathway. Over-expression of NPAS3 also enhances the cell proliferation, which can be blocked by knockdown of VGF. Finally, NPAS3 was found to influence proliferation of neural cells through VGF. Therefore, downstream signaling pathways that are responsible for NPAS3-VGF induced proliferation via glutamate receptors were explored. Combining this work and published literature, a potential network composed by NPAS3, NF-κB, Brain-Derived Neurotrophic Factor (BDNF), NGF and VGF, was proposed. This network collectively detailed how NPAS3 connects with VGF and intersected neural cell proliferation, synaptic activity and psychiatric disorders.

Efficacy and safety of multiple doses of levomilnacipran extended-release for the treatment of major depressive disorder

OBJECTIVE

The aim of this meta-analysis was to evaluate the efficacy and safety of levomilnacipran extended-release (ER) in the treatment of major depressive disorder (MDD).

METHODS

Randomized controlled trials were searched by electronic databases. Unpublished data were also searched by the relevant websites. Weighted mean difference (WMD) and risk ratio (RR) with 95% confidence interval (CI) were calculated and pooled using fixed-effects model or random-effects model.

RESULTS

Five randomized placebo-controlled trials including 2,637 patients were analyzed. Compared with placebo, levomilnacipran ER had a greater reduction in the Montgomery-Åsberg Depression Rating Scale (MADRS) total score and Sheehan Disability Scale (SDS) total score (MADRS: WMD -3.49 [95% CI -4.28, -2.70; P<0.00001]; SDS: WMD -2.41 [95% CI -3.05, -1.77; P<0.00001]). Significantly more patients in levomilnacipran ER achieved MADRS response rate (RR 1.35 [95% CI 1.23, 1.47; P<0.00001]) and MADRS remission rate (RR 1.30 [95% CI 1.06, 1.59; P=0.01]). In terms of safety, more patients discontinued due to adverse events (AEs) in levomilnacipran ER compared with placebo (RR 3.15 [95% CI 2.26, 4.39; P<0.00001]), but it was generally well tolerated in each eligible trial. The most common AEs were nausea, delay in ejaculation, erectile dysfunction, tachycardia, headache and increase in heart rate.

CONCLUSION

Levomilnacipran ER is a safe and effective short-term treatment for MDD (≤10 weeks). Long-term and head-to-head trials comparing levomilnacipran ER with other antidepressants are needed to confirm the conclusion.

Effects of Duloxetine Treatment on Cognitive Flexibility and BDNF Expression in the mPFC of Adult Male Mice Exposed to Social Stress during Adolescence

Early stress is a significant risk factor for the onset of mood disorders such as depression during adulthood. Impairments in cognitive flexibility mediated by prefrontal cortex (PFC) dysfunction are increasingly recognized as important etiological and pathological factors in the development of depression. Our previous study demonstrated that social defeat stress during early adolescence produced delayed deficits in cognitive flexibility in adult mice. The potential molecular mechanisms underlying these long-term consequences remain unclear. One candidate molecule is brain-derived neurotrophic factor (BDNF), which plays a vital role in neural development and synaptic plasticity. In this study, we initially examined the effects of adolescent social stress on cognitive flexibility and PFC BDNF expression within a week after the last stress exposure and 6 weeks later during adulthood. Adolescent (PND 28) male mice were subjected to stress or control manipulation for 10 days. The attentional set-shifting task (AST) was used to assess cognitive flexibility. Levels of BDNF mRNA and protein in the PFC were examined after behavioral testing. The results demonstrated that previously stressed mice exhibited delayed extra-dimensional set-shifting deficits in AST when tested as adults but not when tested as adolescents. Consistent with the cognitive alterations, adolescent stress induced dynamic alterations in BDNF expression in the medial PFC (mPFC), with a transient increase observed shortly after the stress, followed by a decrease 6 weeks later during adulthood. Next, we further determined the effects of chronic treatment with the antidepressant duloxetine during early adulthood on cognitive and molecular alterations induced by adolescent stress. Compared with the controls, duloxetine treatment reversed the cognitive deficits and increased the BDNF protein expression in the mPFC during adulthood in previously stressed mice. These findings demonstrated that BDNF expression in the mPFC was sensitive to adolescent social stress, which may contribute to the disturbance of the development and later functioning of this brain region.

Recent Advances in Neurogenic Small Molecules as Innovative Treatments for Neurodegenerative Diseases

The central nervous system of adult mammals has long been considered as a complex static structure unable to undergo any regenerative process to refurbish its dead nodes. This dogma was challenged by Altman in the 1960s and neuron self-renewal has been demonstrated ever since in many species, including humans. Aging, neurodegenerative, and some mental diseases are associated with an exponential decrease in brain neurogenesis. Therefore, the controlled pharmacological stimulation of the endogenous neural stem cells (NSCs) niches might counteract the neuronal loss in Alzheimer’s disease (AD) and other pathologies, opening an exciting new therapeutic avenue. In the last years, druggable molecular targets and signalling pathways involved in neurogenic processes have been identified, and as a consequence, different drug types have been developed and tested in neuronal plasticity. This review focuses on recent advances in neurogenic agents acting at serotonin and/or melatonin systems, Wnt/β-catenin pathway, sigma receptors, nicotinamide phosphoribosyltransferase (NAMPT) and nuclear erythroid 2-related factor (Nrf2).

Insomnia and dementia: is agomelatine treatment helpful? Case report and review of the literature

The treatment of sleep disorders in Alzheimer's disease (AD) may be quite challenging in elderly patients because of drug side effects or interactions and comorbid local or systemic diseases. Here, we report a patient with AD, who was suffering from severe insomnia and depression. We ordered agomelatine for the treatment of insomnia in this patient, and it was quite helpful not only for insomnia but also for depression and for the cognitive symptoms related with dementia. Our aim was to share these observations for similar patients.

Agomelatine Improves Apathy in Frontotemporal Dementia

BACKGROUND/AIMS

Apathy is the most common initial symptom of frontotemporal dementia (FTD) and has been linked to frontal-subcortical dopaminergic system dysfunction. No pharmacological therapy has been approved for the treatment of apathy, but, on the basis of its physiopathological mechanism, we suspected that increasing prefrontal dopaminergic innervation could improve this disabling symptom.

METHODS

We evaluated a group of 24 nondepressed patients with a diagnosis of the behavioral variant of FTD, in order to determine the effectiveness on apathy of agomelatine, an antidepressant with MT1 and MT2 receptor agonism and 5-HT2C receptor antagonism; the latter leads to an increase in prefrontal dopaminergic and noradrenergic tone. To try to tease out the effects of 5-HT2C antagonism on apathy, patients were randomized, using a cross-over design, to receive either agomelatine 50 mg/day or sustained release melatonin 10 mg/day for 10 weeks in a double-blind procedure. At the end of the follow-up period, subjects receiving melatonin switched to agomelatine for the following 10 weeks.

RESULTS

Agomelatine, but not melatonin, was associated with a significant reduction of apathy in FTD subjects and of caregiver distress due to patients' apathy. The switch from melatonin to agomelatine was associated with a reduction in apathetic behavior. Agomelatine was well-tolerated by all enrolled subjects.

CONCLUSIONS

Our data, albeit preliminary, suggest that agomelatine could represent a novel useful approach to the treatment of apathy in FTD patients.