Which antidepressants have demonstrated superior efficacy? A review of the evidence

Supramolecular assemblies of citalopram and escitalopram in β-cyclodextrin dimeric cavity: Crystallographic and theoretical insights

Cyclodextrin (CD) encapsulation improves physicochemical and pharmacological properties of selective serotonin reuptake inhibitors (SSRIs), which are efficacious in treating depression, a global mental health problem. Here, we scrutinize β-CD inclusion complexes with racemate citalopram (rac-CTP; 1) and escitalopram ((S)-CTP; 2) by combined single-crystal X-ray diffraction and DFT full-geometry optimization. X-ray analysis unveiled that the 2:2 inclusion complexes of 1 and 2 with similar inclusion modes and topologies are stabilized by various intermolecular interactions of host-guest CH···π, host-host OH···O H-bonds, and guest-guest F···F in the tail-to-tail dimeric asymmetric unit. In the crystals, these dimers are stacked on top of each other, yielding similar channel structures of distinct crystal symmetries, triclinic, P1 (1) and monoclinic, P21 (2), which are further maintained by guest-guest π···π and CN···π interactions. The thermodynamic stabilities evaluated by DFT calculation indicate the vital role of weak intermolecular interactions in the formation and stabilization of the β-CD monomeric and dimeric inclusion complexes. This study provides crystallographic and theoretical evidence for the improved stability and the masked bitterness of CTP through β-CD encapsulation as patented previously and suggests the pharmaceutical implications in the drug delivery and enantioseparation.

Neuropsychological Effects of Antidepressants: Translational Studies

Pharmacological treatments that improve mood were first identified serendipitously, but more than half a century later, how these drugs induce their antidepressant effects remains largely unknown. With the help of animal models, a detailed understanding of their pharmacological targets and acute and chronic effects on brain chemistry and neuronal function has been achieved, but it remains to be elucidated how these effects translate to clinical efficacy. Whilst the field has been dominated by the monoamine and neurotrophic hypotheses, the idea that the maladaptive cognitive process plays a critical role in the development and perpetuation of mood disorders has been discussed since the 1950s. Recently, studies using objective methods to quantify changes in emotional processing found acute effects with conventional antidepressants in both healthy volunteers and patients. These positive effects on emotional processing and cognition occur without a change in the subjective ratings of mood. Building from these studies, behavioural methods for animals that quantify similar cognitive affective processes have been developed. Integrating these behavioural approaches with pharmacology and targeted brain manipulations, a picture is beginning to emerge of the underlying mechanisms that may link the pharmacology of antidepressants, these neuropsychological constructs and clinical efficacy. In this chapter, we discuss findings from animal studies, experimental medicine and patients investigating the neuropsychological effects of antidepressant drugs. We discuss the possible neural circuits that contribute to these effects and discuss whether a neuropsychological model of antidepressant effects could explain the temporal differences in clinical benefits observed with conventional delayed-onset antidepressants versus rapid-acting antidepressants.

Psychological status of patients with functional anorectal pain and treatment efficacy of paroxetine in alleviating the symptoms: a retrospective study

The aim of this study was to investigate the clinical characteristics, psychological status, sleep quality, and quality of life of patients with functional anorectal pain (FAP). The study also assessed the treatment efficacy of paroxetine in alleviating FAP symptoms. A retrospective comparative study of forty-three patients with FAP who were first treated with an anal plug compound glycolate suppository versus paroxetine combined with anal plug compound glycolate suppository between November 2021 and August 2022. Pain, quality of life, depression, anxiety and sleep quality were assessed before and after treatment by the Chinese version of the Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2), Health-related quality of life scale (The 12-Item Short-Form Health Survey, SF-12), 17-item Hamilton Depression Rating Scale (HDRS), 14-item Hamilton Anxiety Scale (HAMA), and Pittsburgh Sleep Quality Index (PSQI). A total of 46.5% of patients with FAP were found to have anxiety symptoms (HAMA ≥ 7), 37.2% of patients with FAP were found to have depressive symptoms (HDRS ≥ 8). A total of 32.6% of patients with FAP had sleep disorders (PSQI > 10). Within 1 week after drug withdrawal, the short-term efficacy rate of oral paroxetine was 95.5%. After treatment, the symptom pain score (VAS) and sleep score were lower than those before treatment (P < 0.01). In the areas of vitality (VT), Social Functioning (SF), and Mental Health (MH), the difference between the pre-treatment and 8 weeks posttreatment scores of the study group and the control group was statistically significant (P < 0.05). FAP patients have obvious symptoms of anxiety and depression, and the incidence of sleep disturbance is prevalent. Paroxetine, a typical serotonin reuptake inhibitor (SSRI), was able to alleviate depression, anxiety, and pain symptoms in FAP, which might have clinical application prospects.

Association between Plasma Metabolic Profiles of the Antidepressant Escitalopram and Clinical Response in Subjects with Depression

Liquid chromatography/electrospray ionization-mass spectrometry revealed plasma metabolic profiles for the antidepressant drug escitalopram (ECTP) and associated clinical responses in subjects with major depressive disorder (MDD). Metabolic profiles contribute to variations in responses to drug treatment of depression. To assess clinical responses and treatment outcomes, we quantified the levels of metabolites, including those of the parent drug, in plasma samples collected at different time points (days 0, 7, 14, and 42) during treatment of seven patients with MDD. Results showed that mean plasma levels of key metabolites and ECTP at day 7 were significantly associated with the clinical response at 42 days after treatment. Statistical analyses, including principal component analysis, of key metabolites and ECTP samples at different time points clearly distinguished the clinical responders from non-responder subjects. Although further validation with a larger cohort is necessary, our results indicate that early improvement and plasma levels of key metabolites and ECTP are predictive of therapeutic treatment outcomes and thus can be used to guide the use of ECTP.

Real-world characteristics of European patients receiving SNRIs as first-line treatment for major depressive disorder

BACKGROUND

Serotonin-norepinephrine reuptake inhibitors (SNRIs) are among the most frequently prescribed antidepressants (ADs) for major depressive disorder (MDD), with an increasing trend in the last decade. Given the relative dearth of information regarding rationales for their preferred use as first-line ADs in the broad clinical routine, the present study systematically investigated real-world characteristics of MDD patients prescribed either SNRIs or other AD substances across different countries and treatment settings.

METHODS

In the present secondary analyses based on a large European, multi-site, naturalistic and cross-sectional investigation with a retrospective assessment of treatment outcome, we firstly defined the proportion of MDD patients receiving SNRIs as first-line AD psychopharmacotherapy and secondly compared their sociodemographic and clinical characteristics to those patients prescribed alternative first-line ADs during their current major depressive episode (MDE).

RESULTS

Within the total sample of 1410 MDD patients, 336 (23.8 %) received first-line SNRIs. Compared to other ADs, SNRIs were significantly associated with inpatient care, suicidality and treatment resistance during the current MDE, and a longer lifetime duration of psychiatric hospitalizations. Moreover, greater severity of depressive symptoms at study entry, higher daily doses of the administered ADs, as well as more frequent prescriptions of psychopharmacotherapeutic add-on strategies in general and antipsychotic augmentation in particular, were significantly related to first-line SNRIs.

CONCLUSIONS

Considering the limitations of a cross-sectional and retrospective study design, our data point towards a preferred use of first-line SNRIs in a generally more severely ill MDD patients, although they did not lead to superior treatment outcomes compared to alternative ADs.

Novel Pharmacological Approaches to the Treatment of Depression

Major depressive disorder is one of the most prevalent mental health disorders. Monoamine-based antidepressants were the first drugs developed to treat major depressive disorder. More recently, ketamine and other analogues were introduced as fast-acting antidepressants. Unfortunately, currently available therapeutics are inadequate; lack of efficacy, adverse effects, and risks leave patients with limited treatment options. Efforts are now focused on understanding the etiology of depression and identifying novel targets for pharmacological treatment. In this review, we discuss promising novel pharmacological targets for the treatment of major depressive disorder. Targeting receptors including N-methyl-D-aspartate receptors, peroxisome proliferator-activated receptors, G-protein-coupled receptor 39, metabotropic glutamate receptors, galanin and opioid receptors has potential antidepressant effects. Compounds targeting biological processes: inflammation, the hypothalamic-pituitary-adrenal axis, the cholesterol biosynthesis pathway, and gut microbiota have also shown therapeutic potential. Additionally, natural products including plants, herbs, and fatty acids improved depressive symptoms and behaviors. In this review, a brief history of clinically available antidepressants will be provided, with a primary focus on novel pharmaceutical approaches with promising antidepressant effects in preclinical and clinical studies.

Pregabalin augmentation of antidepressants in major depression - results from a European multicenter study

BACKGROUND

We aimed to investigate the prescription pattern of pregabalin augmentation of antidepressants in major depressive disorder (MDD) and to explore variables associated with add-on pregabalin treatment.

METHODS

1410 MDD patients participated in this naturalistic European multicenter study with retrospective assessment of treatment response. Analyses of covariance, chi-squared tests, and binary logistic regressions were accomplished to determine differences in socio-demographic and clinical characteristics between MDD patients with and without pregabalin augmentation.

RESULTS

Add-on pregabalin was established in 102 (7.23%) MDD patients. Compared to those without receiving pregabalin, pregabalin-treated patients were characterized by a significantly higher likelihood for older age (mean: 54.74 ± 13.08 vs 49.93 ± 14.13 years), unemployment (78.43% vs 51.23%), melancholic features (83.33% vs 58.94%), inpatient treatment (72.55% vs 31.65%), previous psychiatric hospitalizations (13.52 ± 24.82 vs 4.96 ± 19.93 weeks), any somatic comorbidity (68.63% vs 44.57%), comorbid hypertension (37.25% vs 17.51%), more severe depressive symptom severity at the onset of the current episode (mean MADRS: 37.55 ± 9.00 vs 33.79 ± 7.52), receiving augmentation/combination treatment strategies in general (mean number of psychotropic drugs: 3.64 ± 0.92 vs 2.07 ± 1.17), and with antidepressants (50.00% vs 27.91%) and antipsychotics (46.08% vs 24.08%) in particular.

LIMITATIONS

Due to its observational cross-sectional study design, our patient sample might not be fully representative for MDD patients in primary care settings.

CONCLUSIONS

Our findings suggest that add-on pregabalin is particularly administered in more severe/difficult-to-treat MDD conditions, whereas no association between the prescription of adjunctive pregabalin and comorbid anxiety symptoms could be determined.

The sociodemographic and clinical profile of patients with major depressive disorder receiving SSRIs as first-line antidepressant treatment in European countries

INTRODUCTION

Due to favorable antidepressant (AD) efficacy and tolerability, selective-serotonin reuptake inhibitors (SSRIs) are consistently recommended as substances of first choice for the treatment of major depressive disorder (MDD) in international guidelines. However, little is known about the real-world clinical correlates of patients primarily prescribed SSRIs in contrast to those receiving alternative first-line ADs.

METHODS

These secondary analyses are based on a naturalistic, multinational cross-sectional study conducted by the European Group for the Study of Resistant Depression at ten research sites. We compared the socio-demographic and clinical characteristics of 1410 patients with primary MDD, who were either prescribed SSRIs or alternative substances as first-line AD treatment, using chi-squared tests, analyses of covariance, and logistic regression analyses.

RESULTS

SSRIs were prescribed in 52.1% of MDD patients who showed lower odds for unemployment, current severity of depressive symptoms, melancholic features, suicidality, as well as current inpatient treatment compared to patients receiving alternative first-line ADs. Furthermore, patients prescribed SSRIs less likely received add-on therapies including AD combination and augmentation with antipsychotics, and exhibited a trend towards higher response rates.

CONCLUSION

A more favorable socio-demographic and clinical profile associated with SSRIs in contrast to alternative first-line ADs may have guided European psychiatrists' treatment choice for SSRIs, rather than any relevant pharmacological differences in mechanisms of action of the investigated ADs. Our results must be cautiously interpreted in light of predictable biases resulting from the open treatment selection, the possible allocation of less severely ill patients to SSRIs as well as the cross-sectional study design that does not allow to ascertain any causal conclusions.

Supramolecular Complexes of β-Cyclodextrin with Clomipramine and Doxepin: Effect of the Ring Substituent and Component of Drugs on Their Inclusion Topologies and Structural Flexibilities

Depression is a global threat. Tricyclic antidepressants (TCAs) are still efficacious in treating depression, albeit with more side effects. Cyclodextrins (CDs) with a suitable nanocavity are potential drug carriers and can enhance the drug bioavailability. Aiming for an atomistic understanding of the CD encapsulation facilitating the improvement of drug stability and the reduction of side effects, a comprehensive study series of the β-CD-TCA inclusion complexes through single crystal X-ray diffraction and density functional theory (DFT) calculation was undertaken. This work reports the supramolecular complexes of β-CD with two pivotal TCAs, clomipramine (CPM; 1) and doxepin (DXP; 2). The different inclusion topologies of the β-CD-TCA complexes were notable. X-ray analysis revealed that, in 1, the CPM B-ring (without chloro group) was entrapped in the β-CD cavity, whereas, in 2, the E-DXP A-ring and the Z-DXP B-ring were disordered in the cavity, yielding energetically favorable complexes primarily maintained by intermolecular C-H⋯π interactions, as indicated by DFT calculation. Because both wings of TCAs were similar, an alternative inclusion scenario of the A-ring was evidenced crystallographically in four other TCA complexes. The enhanced TCA thermodynamic stabilities via CD inclusion complexation helped to reduce the side effects and to increase the bioavailability. Moreover, the scrutinization of six TCAs in different lattice circumstances revealed the greater TCA structural flexibilities for their optimum pharmacological activity while binding with proteins.

Double blind, randomised trial to compare efficacy of escitalopram versus citalopram for interferon induced depression in hepatitis C patients

Objectives

The objective of the study was to compare the two antidepressant drugs citalopram and escitalopram on the basis of efficacy in depressed patients of Hepatitis C patients receiving interferons.

Methods

In this double blind randomized trial, the hepatitis C patients visited National institute of liver and Gastro intestinal diseases (NILGID), Dow University Hospital, were screened for depression before starting treatment with interferons. The Institutional review board approval was obtained and its letter reference no.is: IRB-682/DUHS/Approval/2016/169. Patients with previous history of depression were excluded from the study. The patients who started with Interferon therapy were assessed for depression on baseline and then on each visit. Those who developed depression were randomly assigned to receive either citalopram or escitalopram. Treatment groups were assessed with depression scale each time they visit the clinic. Two antidepressants were compared for their efficacy at an interval of 4 weeks, 8weeks and then 12 weeks.

Results

In the current study 80 patients were randomized to receive either citalopram or escitalopram. The study outcome was better in patients treated with escitalopram. The mean change in depression score from baseline to the end of the study was greater in escitalopram group i.e. 10.41 as compared to citalopram group i.e. 14.17. The difference in depression score was also calculated as 4.28 and.

3.76 (p < 0.001) for both the drugs at week 8 and week 12 respectively, which was statistically significant. Difference in depression score were also calculated for gender 0.576 (p = 0.497) and age 0.950 (p = 0.265), which were found to be non-significant, statistically.

Conclusion

The results demonstrated superiority of escitalopram over citalopram, the drug is twice as potent as the racemic mixture. Additionally the drug is well tolerated and exhibited better effects. Escitalopram proved to be a safer alternative to citalopram.

Position statement of the European Psychiatric Association (EPA) on the value of antidepressants in the treatment of unipolar depression

This position statement will address in an evidence-based approach some of the important issues and controversies of current drug treatment of depression such as the efficacy of antidepressants, their effect on suicidality and their place in a complex psychiatric treatment strategy including psychotherapy. The efficacy of antidepressants is clinically relevant. The highest effect size was demonstrated for severe depression. Based on responder rates and based on double-blind placebo-controlled studies, the number needed to treat (NNT) is 5–7 for acute treatment and four for maintenance treatment. Monotherapy with one drug is often not sufficient and has to be followed by other antidepressants or by comedication/augmentation therapy approaches. Generally, antidepressants reduce suicidality, but under special conditions like young age or personality disorder, they can also increase suicidality. However, under the conditions of good clinical practice, the risk–benefit relationship of treatment with antidepressants can be judged as favourable also in this respect. The capacity of psychiatrists to individualise and optimise treatment decisions in terms of ‘the right drug/treatment for the right patient’ is still restricted since currently there are no sufficient powerful clinical or biological predictors which could help to achieve this goal. There is hope that in future pharmacogenetics will contribute significantly to a personalised treatment. With regard to plasma concentration, therapeutic drug monitoring (TDM) is a useful tool to optimize plasma levels therapeutic outcome. The ideal that all steps of clinical decision-making can be based on the strict rules of evidence-based medicine is far away from reality. Clinical experience so far still has a great impact.

Spatio-temporal dynamics of EEG features during sleep in major depressive disorder after treatment with escitalopram: a pilot study

BACKGROUND

Previous studies have shown escitalopram is related to sleep quality. However, effects of escitalopram on dynamics of electroencephalogram (EEG) features especially during different sleep stages have not been reported. This study may help to reveal pharmacological mechanism underlying escitalopram treatment.

METHODS

The spatial and temporal responses of patients with major depressive disorder (MDD) to escitalopram treatment were analyzed in this study. Eleven MDD patients and eleven healthy control subjects who completed eight weeks' treatment of escitalopram were included in the final statistics. Six-channel sleep EEG signals were acquired during sleep. Power spectrum and nonlinear dynamics were used to analyze the spatio-temporal dynamics features of the sleep EEG after escitalopram treatment.

RESULTS

For temporal dynamics: after treatment, there was a significant increase in the relative energy (RE) of δ1 band (0.5 - 2 Hz), accompanied by a significant decrease in the RE of β2 band (20 - 30 Hz). Lempel-Ziv complexity and Co - complexity values were significantly lower. EEG changes at different sleep stages also showed the same regulation as throughout the night sleep. For spatio dynamics: after treatment, the EEG response of the left and right hemisphere showed asymmetry. Regarding band-specific EEG complexity estimations, δ1 and β2 in stage-1 and δ1 in stage-2 sleep stage in frontal cortex is found to be much more sensitive to escitalopram treatment in comparison to central and occipital cortices.

CONCLUSIONS

The sleep quality of MDD patients improved, EEG response occurred asymmetry in left and right hemispheres due to escitalopram treatment, and frontal cortex is found to be much more sensitive to escitalopram treatment. These findings may contribute to a comprehensive understanding of the pharmacological mechanism of escitalopram in the treatment of depression.

Molecular aspects of depression: A review from neurobiology to treatment

Major depressive disorder (MDD), also known as unipolar depression, is one of the leading causes of disability and disease worldwide. The signs and symptoms are low self‑esteem, anhedonia, feeling of worthlessness, sense of rejection and guilt, suicidal thoughts, among others. This review focuses on studies with molecular-based approaches involving MDD to obtain an integrated, more detailed and comprehensive view of the brain changes produced by this disorder and its treatment and how the Central Nervous System (CNS) produces neuroplasticity to orchestrate adaptive defensive behaviors. This article integrates affective neuroscience, psychopharmacology, neuroanatomy and molecular biology data. In addition, there are two problems with current MDD treatments, namely: 1) Low rates of responsiveness to antidepressants and too slow onset of therapeutic effect; 2) Increased stress vulnerability and autonomy, which reduces the responses of currently available treatments. In the present review, we encourage the prospection of new bioactive agents for the development of treatments with post-transduction mechanisms, neurogenesis and pharmacogenetics inducers that bring greater benefits, with reduced risks and maximized access to patients, stimulating the field of research on mood disorders in order to use the potential of preclinical studies. For this purpose, improved animal models that incorporate the molecular and anatomical tools currently available can be applied. Besides, we encourage the study of drugs that do not present "classical application" as antidepressants, (e.g., the dissociative anesthetic ketamine and dextromethorphan) and drugs that have dual action mechanisms since they represent potential targets for novel drug development more useful for the treatment of MDD.

Clinical factors associated with augmentation treatment with second-generation antipsychotics and lithium in major depression - Results from a European multicenter study

This cross-sectional European multicenter study with retrospective assessment of treatment response sought to determine variables associated with the administration of augmentation strategies with second-generation antipsychotics (SGAs) and lithium in the pharmacotherapy of major depressive disorder (MDD). In 349 DSM-IV-TR MDD patients, differences in socio-demographic, clinical, treatment, and pharmacological features between participants receiving add-on treatment of their antidepressants with either SGAs (n = 318) or lithium (n = 31) were investigated using analyses of covariance, chi-squared tests, and binary logistic regression analyses. As only significant between-group difference, we found SGA augmentation (compared with lithium augmentation) to be associated with high depressive symptom severity expressed by a higher mean Montgomery and Åsberg Depression Rating (MADRS) total score (27.19 ± 11.35 vs 18.87 ± 12.88, F = 14.82, p = < .0001) and a higher mean 21-item Hamilton Rating Scale for Depression (HAM-D) total score (21.27 ± 9.30 vs 13.74 ± 9.11, F = 18.60, p = < .0001). No significant differences for socio-demographic features, psychotic symptoms, suicidality, psychiatric and somatic comorbidities, antidepressant pharmacotherapy, and other add-on medications could be seen. Even if there was no significant superiority of one augmentation strategy with regard to treatment response pattern, a trend whereupon adjunctive SGAs were more likely dispensed in treatment-resistant and difficult-to-treat MDD conditions could be observed. In terms of the prescription pattern, we could demonstrate that lithium is less frequently used than SGAs in the clinical routine care which may reflect the need of continuous plasma level determinations and the anticipation of adverse effects.

A Systematic Review and Meta-Analysis of Applicability of Web-Based Interventions for Individuals with Depression and Quality of Life Impairment

OBJECTIVE

The purpose of this meta-analysis was to determine the applicability of web-based treatment programs for individuals with depression and quality of life impairments.

METHODS

We conducted database and manual searches using imprecise search-term strategy and inclusion criteria. Research published from 2005 to December 2015 was included in this study. Upon review, a total of 12 published papers on web-based intervention for individuals with depression were assessed eligible for this meta-analysis. Effect sizes were estimated for depression and quality of life.

RESULTS

The mean effect size of web-based treatment on depressive symptoms was 0.72. However, unlike the result showing medium to large effect size, the analysis on the quality of life did not yield adequate effects of web-based interventions.

CONCLUSION

Our results suggest robust benefits of employing web-based treatments for depressive symptoms. However, the adequacy of these relatively new intervention tools for individuals who suffer severe impairments of quality of life was found insufficient. The current study demonstrates the need to further develop web-based intervention techniques to improve overall functioning, as well as the clinical symptoms of patients with mental disorders.

Dose Escalation of Antidepressants in Unipolar Depression: A Meta-Analysis of Double-Blind, Randomized Controlled Trials

BACKGROUND

As many patients with unipolar depression do not respond sufficiently to initial antidepressant monotherapy, a dose increase of the current administered antidepressant (dose escalation, high-dose treatment) is frequently carried out as next treatment measure.

METHODS

We conducted a meta-analysis which included all double-blind randomized controlled trials (RCTs) comparing a dose increase of antidepressants directly to continuation of standard-dose treatment in unipolar depressive patients who were non- responders to standard-dose pharmacotherapy. A mean change in the Hamilton Rating Scale for Depression (HAM-D) total score was the primary outcome. Secondary outcomes were response rates and discontinuation rates due to any reason, inefficacy, and adverse effects. Hedges g and risk ratios were calculated as effect sizes.

RESULTS

Seven double-blind RCTs (8 study arms) representing 1,208 participants were included. Fluoxetine (N [number of studies] = 2, n [number of patients] = 448), sertraline (N = 2, n = 272), paroxetine (N = 2, n = 146), duloxetine (N = 1, n = 255), and maprotiline (N = 1, n = 87) were investigated. Dose escalation was not more efficacious in HAM-D total score reduction than maintaining standard-dose treatment, neither for the pooled antidepressant group (N = 7, n = 999; Hedges g = -0.04, 95% CI: -0.20 to 0.12; p = 0.63) nor the individual antidepressants. No differences could be determined for response rates, all-cause discontinuation, and drop-outs due to inefficacy. Significantly more patients in the dose escalation group dropped out due to adverse effects than in the standard-dose continuation group. The metaregressions indicate no influence of baseline symptom severity or amounts of dose increments on effect sizes.

CONCLUSIONS

According to our meta-analytic findings, dose escalation after initial non-response to standard-dose pharmacotherapy cannot be regarded as general evidence-based treatment option in unipolar depression.

Pharmacological Characterization of H05, a Novel Serotonin and Noradrenaline Reuptake Inhibitor with Moderate 5-HT2A Antagonist Activity for the Treatment of Depression

Multitarget antidepressants selectively inhibiting monoaminergic transporters and 5-hydroxytryptamine (5-HT) 2A receptor have demonstrated higher efficacy and fewer side effects than selective serotonin reuptake inhibitors. In the present study, we synthesized a series of novel 3-(benzo[d][1,3]dioxol-4-yloxy)-3-arylpropyl amine derivatives, among which compound H05 was identified as a lead, exhibiting potent inhibitory effects on both serotonin (K_i = 4.81 nM) and norepinephrine (NE) (K_i = 6.72 nM) transporters and moderate 5-HT_2A antagonist activity (IC₅₀ = 60.37 nM). H05 was able to dose-dependently reduce the immobility duration in mouse forced swimming test and tail suspension test, with the minimal effective doses lower than those of duloxetine, and showed no stimulatory effect on locomotor activity. The administration of H05 (5, 10, and 20 mg/kg, by mouth) significantly shortened the immobility time of adrenocorticotropin-treated rats that serve as a model of treatment-resistant depression, whereas imipramine (30 mg/kg, by mouth) and duloxetine (30 mg/kg, by mouth) showed no obvious effects. Chronic treatment with H05 reversed the depressive-like behaviors in a rat model of chronic unpredictable mild stress and a mouse model of corticosterone-induced depression. Microdialysis analysis revealed that the administration of H05 at either 10 or 20 mg/kg increased the release of 5-HT and NE from the frontal cortex. The pharmacokinetic (PK) and brain penetration analyses suggest that H05 has favorable PK properties with good blood-brain penetration ability. Therefore, it can be concluded that H05, a novel serotonin and NE reuptake inhibitor with 5-HT_2A antagonist activity, possesses efficacious activity in the preclinical models of depression and treatment-resistant depression, and it may warrant further evaluation for clinical development.

Disturbances of diurnal phase markers, behavior, and clock genes in a rat model of depression; modulatory effects of agomelatine treatment

Major depressive disorder (MDD) is a growing problem worldwide. Though, the etiology remains unresolved, circadian rhythm disturbances are frequently observed in MDD and thus is speculated to play a key role herein. The present study focuses on circadian rhythm disturbances in the chronic mild stress (CMS) animal model of depression and examined whether the atypical antidepressant, agomelatine, which is mediating its action via melatonergic and serotonergic receptors, is capable of resynchronizing the perturbed rhythm. Melatonin is often used as a marker of the circadian phase, but the functional and behavioral output is dictated on a cellular level by the molecular clock, driven by the clock genes. We applied in situ hybridization histochemistry to measure the expression levels of the core clock genes, period (Per) 1 and 2 and bone and muscle ARNT-like protein 1 (Bmal1), in multiple brain regions believed to be implicated in depression. Agomelatine showed an antidepressant-like effect in the sucrose consumption test and an anxiolytic-like profile in the elevated zero maze. We found that CMS increased nighttime melatonin release in rats and that agomelatine attenuated this effect. Stress was shown to have a time and region-specific effect on clock gene expression in the brain. Treatment with agomelatine failed to normalize clock gene expression, and the observed modifying effect on gene expression did not associate with the antidepressant-like effect. This suggests that the antidepressant actions of agomelatine are mainly independent of circadian rhythm synchronization and, in this regard, not superior to traditional antidepressants tested in our model.

The comparative effectiveness of electroencephalographic indices in predicting response to escitalopram therapy in depression: A pilot study

BACKGROUND

This study aims to compare the effectiveness of EEG frequency band activity including interhemispheric asymmetry and prefrontal theta cordance in predicting response to escitalopram therapy at 8-weeks post-treatment, in a multi-site initiative.

METHODS

Resting state 64-channel EEG data were recorded from 44 patients with a diagnosis of major depressive disorder (MDD) as part of a larger, multisite discovery study of biomarkers in antidepressant treatment response, conducted by the Canadian Biomarker Integration Network in Depression (CAN-BIND). Clinical response was measured at 8-weeks post-treatment as change from baseline Montgomery-Asberg Depression Rating Scale (MADRS) score of 50% or more. EEG measures were analyzed at (1) pre-treatment baseline (2) 2 weeks post-treatment and (3) as an ''early change" variable defined as change in EEG from baseline to 2 weeks post-treatment.

RESULTS

At baseline, treatment responders showed elevated absolute alpha power in the left hemisphere while non-responders showed the opposite. Responders further exhibited a cortical asymmetry in the parietal region. Groups also differed in pre-treatment relative delta power with responders showing greater power in the right hemisphere over the left while non-responders showed the opposite. At 2 weeks post-treatment, responders exhibited greater absolute beta power in the left hemisphere relative to the right and the opposite was noted for non-responders. A reverse pattern was noted for absolute and relative delta power at 2 weeks post-treatment. Responders exhibited early reductions in relative alpha power and early increments in relative theta power. Non-responders showed a significant early increase in prefrontal theta cordance.

CONCLUSIONS

Hemispheric asymmetries in the alpha and delta bands at baseline and at 2 weeks post-treatment have moderately strong predictive utility in predicting response to antidepressant treatment.

Antidepressant-Like Actions of Inhibitors of Poly(ADP-Ribose) Polymerase in Rodent Models

BACKGROUND

Many patients suffering from depressive disorders are refractory to treatment with currently available antidepressant medications, while many more exhibit only a partial response. These factors drive research to discover new pharmacological approaches to treat depression. Numerous studies demonstrate evidence of inflammation and elevated oxidative stress in major depression. Recently, major depression has been shown to be associated with elevated levels of DNA oxidation in brain cells, accompanied by increased gene expression of the nuclear base excision repair enzyme, poly(ADP-ribose) polymerase-1. Given these findings and evidence that drugs that inhibit poly(ADP-ribose) polymerase-1 activity have antiinflammatory and neuroprotective properties, the present study was undertaken to examine the potential antidepressant properties of poly(ADP-ribose) polymerase inhibitors.

METHODS

Two rodent models, the Porsolt swim test and repeated exposure to psychological stressors, were used to test the poly(ADP-ribose) polymerase inhibitor, 3-aminobenzamide, for potential antidepressant activity. Another poly(ADP-ribose) polymerase inhibitor, 5-aminoisoquinolinone, was also tested.

RESULTS

Poly(ADP-ribose) polymerase inhibitors produced antidepressant-like effects in the Porsolt swim test, decreasing immobility time, and increasing latency to immobility, similar to the effects of fluoxetine. In addition, 3-aminobenzamide treatment increased sucrose preference and social interaction times relative to vehicle-treated control rats following repeated exposure to combined social defeat and unpredictable stress, mediating effects similar to fluoxetine treatment.

CONCLUSIONS

The poly(ADP-ribose) polymerase inhibitors 3-aminobenzamide and 5-aminoisoquinolinone exhibit antidepressant-like activity in 2 rodent stress models and uncover poly(ADP-ribose) polymerase as a unique molecular target for the potential development of a novel class of antidepressants.

The impact of comorbid post-traumatic stress disorder in patients with major depressive disorder on clinical features, pharmacological treatment strategies, and treatment outcomes - Results from a cross-sectional European multicenter study

This international, multicenter, cross-sectional study comprising 1346 adult in- and outpatients with major depressive disorder (MDD) investigated the association between MDD as primary diagnosis and comorbid post-traumatic stress disorder (PTSD). In a cross-sectional data collection process, the presence of comorbid PTSD was determined by the Mini International Neuropsychiatric Interview (MINI) and the patients' socio-demographic, clinical, psychopharmacological, and response information were obtained. Clinical features between MDD with and without concurrent PTSD were compared using descriptive statistics, analyses of covariance (ANCOVA), and binary logistic regression analyses. 1.49% of the MDD patients suffered from comorbid PTSD. Significantly more MDD + comorbid PTSD patients exhibited atypical features, comorbid anxiety disorders (any comorbid anxiety disorder, panic disorder, agoraphobia, and social phobia), comorbid bulimia nervosa, current suicide risk, and augmentation treatment with low-dose antipsychotic drugs. In the binary logistic regression analyses, the presence of atypical features (odds ratio (OR) = 4.49, 95%CI:1.01-20.12; p≤.05), any comorbid anxiety disorder (OR = 3.89, 95%CI:1.60-9.44; p = .003), comorbid panic disorder (OR = 6.45, 95%CI:2.52-16.51; p = .001), comorbid agoraphobia (OR = 6.51, 95%CI:2.54-16.68; p≤.001), comorbid social phobia (OR = 6.16, 95%CI:1.71-22.17; p≤.001), comorbid bulimia nervosa (OR = 10.39, 95%CI:1.21-88.64; p = .03), current suicide risk (OR = 3.58, 95%CI:1.30-9.91; p = .01), and augmentation with low-potency antipsychotics (OR = 6.66, 95%CI:2.50-17.77; p<.001) were associated with concurrent PTSD in predominant MDD. Major findings of this study were (1.) the much lower prevalence rate of comorbid PTSD in predominant MDD compared to the reverse prevalence rates of concurrent MDD in primary PTSD, (2.) the high association to comorbid anxiety disorders, and (3.) the increased suicide risk due to concurrent PTSD.

Evidence-based pharmacotherapy of treatment-resistant unipolar depression

Treatment resistance to the antidepressive pharmacotherapy represents one of the most important clinical challenges in the pharmacological management of unipolar depression. In this review, we aimed to summarise the evidence for various pharmacological treatment options in therapy-resistant unipolar depression derived from clinical trials, systematic reviews, meta-analyses and treatment guidelines. The first measure in case of insufficient response to the initial antidepressant monotherapy contains the debarment of 'pseudo-resistance', potentially caused by inadequate dose and treatment duration of the antidepressant, insufficient plasma levels, non-compliance of the patient regarding medication intake or relevant psychiatric and/or somatic comorbidities. Applying a dose escalation of the current antidepressant cannot be generally recommended as evidence-based treatment option and the efficacy depends on the class of antidepressants. There is no compelling evidence for a switch to another, new antidepressant compound after insufficient response to a previous antidepressant. The combination of two antidepressants should be preferentially established with antidepressants characterised by different mechanisms of action (e.g. reuptake inhibitors together with presynaptic autoreceptor inhibitors). At present, the most convincing body of evidence exists for the augmentation of antidepressants with second-generation antipsychotic drugs and lithium. Hence, both strategies are consistently advised by treatment guidelines as pharmacological first-line strategy in treatment-resistant depression.

Pharmacological treatment strategies in unipolar depression in European tertiary psychiatric treatment centers - A pharmacoepidemiological cross-sectional multicenter study

This multicenter, cross-sectional study with retrospective assessment of treatment response evaluated the current prescription trends and pharmacological treatment strategies applied in European university/academic psychiatric centers in unipolar depression. Altogether, 1181 adult in- and outpatients with major depressive disorder (MDD) were enrolled in 9 academic sites in 8 European countries. Socio-demographic, clinical, and medication information were retrieved and the present symptom severity was assessed by the Montgomery and Åsberg Depression Rating Scale (MADRS). The symptom improvement during the current MDD episode was covered by retrospective MADRS measurements. Beyond descriptive statistics, analyses of variance (ANOVA) and Spearman correlation analyses were accomplished to determine the influence of symptom severity and treatment response on the prescription patterns. 53.4% of all MDD patients received a selective serotonin reuptake inhibitor (SSRI) and 23.6% a serotonin-norepinephrine reuptake inhibitor (SNRI) as first-line treatment. The majority of participants (59.4%) were treated with polypharmaceutical strategies (median: 2 psychiatric compounds per patient) and for the number of individual drugs we found a significant correlation with the current MADRS total score and the MADRS total score change during the present depressive episode. Benzodiazepines (33.2% of patients), antidepressants (29.0%), antipsychotics (24.2%), and mood stabilizers (10.1%) were the most frequently prescribed adjunctive agents. There were no significant differences between the different psychopharmacological classes used as augmentors in terms of symptom severity and treatment response. In summary, this international cross-sectional study revealed the widespread use of polypharmaceutical treatment strategies in European tertiary psychiatric treatment centers for the management of MDD.

Social defeat protocol and relevant biomarkers, implications for stress response physiology, drug abuse, mood disorders and individual stress vulnerability: a systematic review of the last decade

INTRODUCTION

Social defeat (SD) in rats, which results from male intraspecific confrontations, is ethologically relevant and useful to understand stress effects on physiology and behavior.

METHODS

A systematic review of studies about biomarkers induced by the SD protocol and published from 2002 to 2013 was carried out in the electronic databases PubMed, Web of Knowledge and ScienceDirect. The search terms were: social defeat, rat, neurotrophins, neuroinflammatory markers, and transcriptional factors.

RESULTS

Classical and recently discovered biomarkers were found to be relevant in stress-induced states. Findings were summarized in accordance to the length of exposure to stress: single, repeated, intermittent and continuous SD. This review found that the brain-derived neurotrophic factor (BDNF) is a distinct marker of stress adaptation. Along with glucocorticoids and catecholamines, BDNF seems to be important in understanding stress physiology.

CONCLUSION

The SD model provides a relevant tool to study stress response features, development of addictive behaviors, clinic depression and anxiety, as well as individual differences in vulnerability and resilience to stress.

In vivo investigation of escitalopram's allosteric site on the serotonin transporter

Escitalopram is a commonly prescribed antidepressant of the selective serotonin reuptake inhibitor class. Clinical evidence and mapping of the serotonin transporter (SERT) identified that escitalopram, in addition to its binding to a primary uptake-blocking site, is capable of binding to the SERT via an allosteric site that is hypothesized to alter escitalopram's kinetics at the SERT. The studies reported here examined the in vivo role of the SERT allosteric site in escitalopram action. A knockin mouse model that possesses an allosteric-null SERT was developed. Autoradiographic studies indicated that the knockin protein was expressed at a lower density than endogenous mouse SERT (approximately 10-30% of endogenous mouse SERT), but the knockin mice are a viable tool to study the allosteric site. Microdialysis studies in the ventral hippocampus found no measurable decrease in extracellular serotonin response after local escitalopram challenge in mice without the allosteric site compared to mice with the site (p=0.297). In marble burying assays there was a modest effect of the absence of the allosteric site, with a larger systemic dose of escitalopram (10-fold) necessary for the same effect as in mice with intact SERT (p=0.023). However, there was no effect of the allosteric site in the tail suspension test. Together these data suggest that there may be a regional specificity in the role of the allosteric site. The lack of a robust effect overall suggests that the role of the allosteric site for escitalopram on the SERT may not produce meaningful in vivo effects.

Evidence-based guidelines for treating depressive disorders with antidepressants: A revision of the 2008 British Association for Psychopharmacology guidelines

A revision of the 2008 British Association for Psychopharmacology evidence-based guidelines for treating depressive disorders with antidepressants was undertaken in order to incorporate new evidence and to update the recommendations where appropriate. A consensus meeting involving experts in depressive disorders and their management was held in September 2012. Key areas in treating depression were reviewed and the strength of evidence and clinical implications were considered. The guidelines were then revised after extensive feedback from participants and interested parties. A literature review is provided which identifies the quality of evidence upon which the recommendations are made. These guidelines cover the nature and detection of depressive disorders, acute treatment with antidepressant drugs, choice of drug versus alternative treatment, practical issues in prescribing and management, next-step treatment, relapse prevention, treatment of relapse and stopping treatment. Significant changes since the last guidelines were published in 2008 include the availability of new antidepressant treatment options, improved evidence supporting certain augmentation strategies (drug and non-drug), management of potential long-term side effects, updated guidance for prescribing in elderly and adolescent populations and updated guidance for optimal prescribing. Suggestions for future research priorities are also made.

Learning from the past and looking to the future: Emerging perspectives for improving the treatment of psychiatric disorders

Modern neuropsychopharmacology commenced in the 1950s with the serendipitous discovery of first-generation antipsychotics and antidepressants which were therapeutically effective yet had marked adverse effects. Today, a broader palette of safer and better-tolerated agents is available for helping people that suffer from schizophrenia, depression and other psychiatric disorders, while complementary approaches like psychotherapy also have important roles to play in their treatment, both alone and in association with medication. Nonetheless, despite considerable efforts, current management is still only partially effective, and highly-prevalent psychiatric disorders of the brain continue to represent a huge personal and socio-economic burden. The lack of success in discovering more effective pharmacotherapy has contributed, together with many other factors, to a relative disengagement by pharmaceutical firms from neuropsychiatry. Nonetheless, interest remains high, and partnerships are proliferating with academic centres which are increasingly integrating drug discovery and translational research into their traditional activities. This is, then, a time of transition and an opportune moment to thoroughly survey the field. Accordingly, the present paper, first, chronicles the discovery and development of psychotropic agents, focusing in particular on their mechanisms of action and therapeutic utility, and how problems faced were eventually overcome. Second, it discusses the lessons learned from past successes and failures, and how they are being applied to promote future progress. Third, it comprehensively surveys emerging strategies that are (1), improving our understanding of the diagnosis and classification of psychiatric disorders; (2), deepening knowledge of their underlying risk factors and pathophysiological substrates; (3), refining cellular and animal models for discovery and validation of novel therapeutic agents; (4), improving the design and outcome of clinical trials; (5), moving towards reliable biomarkers of patient subpopulations and medication efficacy and (6), promoting collaborative approaches to innovation by uniting key partners from the regulators, industry and academia to patients. Notwithstanding the challenges ahead, the many changes and ideas articulated herein provide new hope and something of a framework for progress towards the improved prevention and relief of psychiatric and other CNS disorders, an urgent mission for our Century.

[Treatment of endogenous depression with venflaxine: clinical action, tolerability and personalized treatment options]

OBJECTIVE

To specify clinical action of venflaxine during the course treatment of patients with different depressive states of endogenous nature.

MATERIAL AND METHODS

An open naturalistic study of 32 patients with different nosological forms of endogenous depression (manic-depressive psychosis, cyclothymia, schizophrenia) was carried out. Duration of the course treatment with venflaxine (velaxin) administered in daily dose of 37,5-300 mg was 56 days. Clinical and psychometric methods were used.

RESULTS

Venflaxine was a highly effective antidepressant. In the end of treatment, a "good" therapeutic effect with >50% reduction in total scores on the Hamilton scale (HAMD-D) was achieved in 84,4% of patients, a "marked" effect up to complete recovery with >80% reduction in HAMD-D scores was in 78,1% of cases.

CONCLUSION

Due to its clinical characteristics, venflaxine may be regarded as a multiprofile antidepressant with the distinct balanced action. In the spectrum of its antidepressant activity, a thymoleptic effect is most pronounced compared to anxiolytic and stimulating effects. This provides a high efficacy of the drug in different types of endogenous depression (anxiety, apatho-adynamic and, in particular, melancholic).

[Evidence-based choice and antidepressants treatment in psychiatry]

Depression is a severe and usually recurrent mental disorder which leads to a prominent impairment of physical and social functioning, a reduced quality of life of the patients, implies as well an increased morbidity and mortality. Reducing the social-economic depression burden is possible in the optimization of decision-making process of antidepressant choice (including SSRIs and SNRIs) based on the evidence-based risk/benefit ratio and resource saving potential treatment involving target psychosocial interventions and monitoring of long-term treatment adherence.

Comparison of vortioxetine versus venlafaxine XR in adults in Asia with major depressive disorder: a randomized, double-blind study

OBJECTIVE

This randomized, double-blind 8 week study compared the efficacy and tolerability of fixed-dose treatment with vortioxetine (10 mg/day) and venlafaxine extended release (XR) (150 mg/day) in major depressive disorder (MDD) patients.

RESEARCH DESIGN AND METHODS

Patients aged 18-65 years with a primary diagnosis of recurrent MDD, a Montgomery-Åsberg Depression Rating Scale (MADRS) total score ≥26 and a Clinical Global Impression-Severity (CGI-S) score ≥4 were randomized (1:1) to treatment with either vortioxetine or venlafaxine XR. The primary endpoint was change from baseline to Week 8 in MADRS total score (analysis of covariance [ANCOVA], full-analysis set [FAS], last observation carried forward [LOCF]), using a non-inferiority margin of +2.5 points. Pre-specified secondary endpoints included MADRS response and remission rates, anxiety symptoms (HAM-A), CGI, overall functioning (SDS), and health-related quality of life (Q-LES-Q).

CLINICAL TRIAL REGISTRATION

This study (SOLUTION) has the www.ClinicalTrials.gov identifier: NCT01571453.

RESULTS

On the primary efficacy endpoint at Week 8, non-inferiority was established with a difference of -1.2 MADRS points in favor of vortioxetine (95% CI: -3.0 to 0.6). The MADRS total score decreased (improved) from 32.3 ± 4.6 at baseline to 13.6 ± 9.6 (vortioxetine: n = 209) and from 32.3 ± 4.5 to 14.8 ± 10.4 (venlafaxine XR: n = 215) (FAS, LOCF). At Week 8, the HAM-A and SDS total scores, CGI and Q-LES-Q scores, and response and remission rates demonstrated similar improvement for vortioxetine and venlafaxine XR, with remission rates (MADRS ≤10) of 43.1% (vortioxetine) versus 41.4% (venlafaxine XR) (LOCF). Fewer vortioxetine than venlafaxine XR patients withdrew for any reason (18.0% versus 27.4%) or for adverse events (6.6% versus 13.7%). The most frequent adverse events (≥5%) for both treatments were nausea, dizziness, headache, and dry mouth. In addition, accidental overdose, decreased appetite, constipation and insomnia were reported by (≥5%) of patients treated with venlafaxine XR.

LIMITATIONS

The inclusion and exclusion criteria may limit the generalizability of the study. Since patients with a history of lack of response to venlafaxine XR were excluded from this study, there is a selection bias in favor of venlafaxine XR.

CONCLUSION

Vortioxetine was at least as efficacious as venlafaxine XR and was safe and better tolerated than venlafaxine XR.

Curcumin as a putative antidepressant

Due to inadequate efficacy of antidepressants, various new chemical entities and agents of natural origin have been tested for therapeutic efficacy both alone and to augment existing antidepressants, producing varied clinical results. This article summarizes the basic properties of curcumin and its mechanisms of action, with specific emphasis on the etiopathogenesis of depression, preclinical and current clinical evidence, and future research directions, to better understand the possible role of curcumin in treating depression. Curcumin may have antidepressant activities with diverse mechanisms of action involving primarily neurotransmitters, transcription pathways, neurogenesis, the hypothalamic-pituitary-adrenal axis and inflammatory and immune pathways, as demonstrated in various animal and human studies. Current published randomized clinical trials suggest a small, non-significant benefit of curcumin for major depression. More adequately-powered and methodologically improved studies are mandatory.

On 'polypharmacy' and multi-target agents, complementary strategies for improving the treatment of depression: a comparative appraisal

Major depression is a heterogeneous disorder, both in terms of symptoms, ranging from anhedonia to cognitive impairment, and in terms of pathogenesis, with many interacting genetic, epigenetic, developmental and environmental causes. Accordingly, it seems unlikely that depressive states could be fully controlled by a drug possessing one discrete mechanism of action and, in the wake of disappointing results with several classes of highly selective agent, multi-modal treatment concepts are attracting attention. As concerns pharmacotherapy, there are essentially two core strategies. First, multi-target antidepressants that act via two or more complementary mechanisms and, second, polypharmacy, which refers to co-administration of two distinct drugs, usually in separate pills. Both multi-target agents and polypharmacy ideally couple a therapeutically unexploited action to a clinically established mechanism in order to enhance efficacy, moderate side-effects, accelerate onset of action and treat a broader range of symptoms. The melatonin MT1/MT2 agonist and 5-HT(2C) antagonist, agomelatine, which is effective in the short- and long-term treatment of depression, exemplifies the former approach, while evidence-based polypharmacy is illustrated by the adjunctive use of second-generation antipsychotics with serotonin reuptake inhibitors for treatment of resistant depression. Histone acetylation and methylation, ghrelin signalling, inflammatory modulators, metabotropic glutamate-7 receptors and trace amine-associated-1 receptors comprise attractive substrates for new multi-target and polypharmaceutical strategies. The present article outlines the rationale underpinning multi-modal approaches for treating depression, and critically compares and contrasts the pros and cons of established and potentially novel multi-target vs. polypharmaceutical treatments. On balance, the former appear the most promising for the elaboration, development and clinical implementation of innovative concepts for the more effective management of depression.

Impact of acute administration of escitalopram on the processing of emotional and neutral images: a randomized crossover fMRI study of healthy women

BACKGROUND

Acute neural effects of antidepressant medication on emotion processing biases may provide the foundation on which clinical outcomes are based. Along with effects on positive and negative stimuli, acute effects on neutral stimuli may also relate to antidepressant efficacy, yet these effects are still to be investigated. The present study therefore examined the impact of a single dose of the selective serotonin reuptake inhibitor escitalopram (20 mg) on positive, negative and neutral stimuli using pharmaco-fMRI.

METHODS

Within a double-blind, randomized, placebo-controlled crossover design, healthy women completed 2 sessions of treatment administration and fMRI scanning separated by a 1-week washout period.

RESULTS

We enrolled 36 women in our study. When participants were administered escitalopram relative to placebo, left amygdala activity was increased and right inferior frontal gyrus (IFG) activity was decreased during presentation of positive pictures (potentiation of positive emotion processing). In contrast, escitalopram was associated with decreased left amygdala and increased right IFG activity during presentation of negative pictures (attenuation of negative emotion processing). In addition, escitalopram decreased right IFG activity during the processing of neutral stimuli, akin to the effects on positive stimuli (decrease in negative appraisal).

LIMITATIONS

Although we used a women-only sample to reduce heterogeneity, our results may not generalize to men. Potential unblinding, which was related to the subjective occurrence of side effects, occurred in the study; however, manipulation check analyses demonstrated that results were not impacted.

CONCLUSION

These novel findings demonstrate that a single dose of the commonly prescribed escitalopram facilitates a positive information processing bias. These findings provide an important lead for better understanding effects of antidepressant medication.

A comparative review of escitalopram, paroxetine, and sertraline: Are they all alike?

It is known that newer antidepressants, such as the selective serotonin reuptake inhibitors (SSRIs), provide advantages in tolerability over antidepressants such as the tricyclics. However, even within the SSRI class, differences in efficacy or tolerability exist between the individual drugs. Among the three most widely prescribed SSRIs are paroxetine, sertraline, and escitalopram. Escitalopram is commonly referred to as an SSRI, but also has well-documented allosteric properties, and thus can be further classed as an allosteric serotonin reuptake inhibitor. All three antidepressants are efficacious compared with placebo, but there is evidence that escitalopram is more effective than a range of other antidepressants. There are no direct data to regard either paroxetine or sertraline as a superior antidepressant. Escitalopram is superior compared with paroxetine, which has a less favorable tolerability profile. Paroxetine is associated with cholinergic muscarinic antagonism and potent inhibition of CYP2D6, and sertraline has moderate drug interaction issues in comparison with escitalopram. Overall, as an allosteric serotonin reuptake inhibitor that is somewhat different from classical SSRIs, escitalopram is the first choice judged by combined efficacy and tolerability, and nonclinical data have offered possible mechanisms through which escitalopram could be more efficacious, based on its interaction with orthosteric and allosteric binding sites at the serotonin transporter.

Evidence-based, pharmacological treatment guideline for depression in Korea, revised edition

This paper aims to introduce, summarize, and emphasize the importance of the 'Evidence-Based, Pharmacological Treatment Guideline for Depression in Korea, Revised Edition'. The guideline broadly covers most aspects of the pharmacological treatment of patients in Korea diagnosed with moderate to severe major depression according to the DSM-IV TR. The guideline establishment process involved determining and answering a number of key questions, searching and selecting publications, evaluating recommendations, preparing guideline drafts, undergoing external expert reviews, and obtaining approval. A guideline adaptation process was conducted for the revised edition. The guideline strongly recommends pharmacological treatment considered appropriate to the current clinical situation in Korea, and should be considered helpful when selecting the appropriate pharmacological treatment of patients diagnosed with major depressive disorder. Therefore, the wide distribution of this guideline is recommended.

Multi-modality: a new approach for the treatment of major depressive disorder

Effective treatment with antidepressants is currently limited by factors that affect treatment compliance, including delay in onset of therapeutic effects and intolerable side-effects. Recent data suggest that use of antidepressant combinations with different mechanisms of action may be a better first-line strategy prior to augmentation with other drug classes. The rationale for this approach is that combining multiple pharmacological actions affecting multiple monoamine targets produces greater efficacy. Several new multi-modal compounds are in development and early results for the most advanced agents indicate shorter onset of therapeutic effects and improved tolerability. By modulating multiple receptors and transmitter systems, it is hoped that these new agents may also treat some of the associated symptoms of major depressive disorder, such as anxiety and cognitive dysfunction.

Antidepressant monotherapy compared with combinations of antidepressants in the treatment of resistant depressive patients: a randomized, open-label study

OBJECTIVE

This randomized, 6-week, open-label study compared efficacy of CAD and antidepressant monotherapies (ADM) that had been chosen according to clinical judgment of the attending psychiatrist.

METHODS

A total of 60 inpatients (intent-to-treat analysis) with depressive disorder (≥ 1 unsuccessful antidepressant treatment) were randomly assigned to the interventions. The responders who completed the acute phase of study, were evaluated for relapse within 2 months of follow-up treatment. The primary outcome measure was change in the Montgomery-Åsberg Depression Rating Scale (MADRS) and response was defined as a ≥ 50% reduction of MADRS score.

RESULTS

Mean changes in total MADRS score from baseline to week 6 for patients in both treatment modalities were not different (ADM = 13.2 ± 8.6 points; CAD = 14.5 ± 9.5 points; P = 0.58). The analysis of covariance performed for significantly higher value of imipramine equivalent dose in CAD group showed only a non-significant between-group difference for total MADRS change (P = 0.17). There were also no differences between groups in response rate (ADM = 48%; CAD = 58%) and number of drop-outs in acute treatment as well as proportion of responders' relapses in the follow-up.

CONCLUSION

Both treatment modalities produced clinically relevant reduction of depressive symptomatology in acute treatment of patients with resistant depression and their effect was comparable.

The neurobiology of depression and antidepressant action

We present a comprehensive overview of the neurobiology of unipolar major depression and antidepressant drug action, integrating data from affective neuroscience, neuro- and psychopharmacology, neuroendocrinology, neuroanatomy, and molecular biology. We suggest that the problem of depression comprises three sub-problems: first episodes in people with low vulnerability ('simple' depressions), which are strongly stress-dependent; an increase in vulnerability and autonomy from stress that develops over episodes of depression (kindling); and factors that confer vulnerability to a first episode (a depressive diathesis). We describe key processes in the onset of a 'simple' depression and show that kindling and depressive diatheses reproduce many of the neurobiological features of depression. We also review the neurobiological mechanisms of antidepressant drug action, and show that resistance to antidepressant treatment is associated with genetic and other factors that are largely similar to those implicated in vulnerability to depression. We discuss the implications of these conclusions for the understanding and treatment of depression, and make some strategic recommendations for future research.

5-HT2 ligands in the treatment of anxiety and depression

INTRODUCTION

One third of depressed patients do not respond adequately to conventional antidepressants including the selective serotonin reuptake inhibitors (SSRIs). Therefore, multi-target drugs or augmentation strategies have been developed for the management of SSRIs-resistant patients. In this context, the 5-HT(2) receptor subtypes represent promising targets but their precise roles have yet to be determined.

AREAS COVERED

The aim of this review is to shed some light on the preclinical evidence supporting the use of 5-HT(2A) and/or 5-HT(2C) receptor antagonists such as antipsychotics, as potential effective adjuncts in SSRIs-resistant depression. This review synthesizes the current literature about the behavioral, electrophysiological and neurochemical effects of 5-HT(2) receptors ligands on the monoaminergic systems but also on adult hippocampal neurogenesis.

EXPERT OPINION

Although studies support the hypothesis that the inactivation of 5-HT(2A) and/or 5-HT(2C) receptors might be of interest to reinforce different facets of the therapeutic activity of SSRIs, this pharmacological strategy remains debatable notably because of the lack of chronic data in relevant animal models. Conversely, emerging evidence suggests that the activation of 5-HT(2B) receptor is required for antidepressant-like activity, opening the way to new therapeutic approaches. However, the potential risks related to the enhancement of monoaminergic neurotransmissions could represent a major concern.

Low gene expression of bone morphogenetic protein 7 in brainstem astrocytes in major depression

The noradrenergic locus coeruleus (LC) is the principal source of brain norepinephrine, a neurotransmitter thought to play a major role in the pathology of major depressive disorder (MDD) and in the therapeutic action of many antidepressant drugs. The goal of this study was to identify potential mediators of brain noradrenergic dysfunction in MDD. Bone morphogenetic protein 7 (BMP7), a member of the transforming growth factor-β superfamily, is a critical mediator of noradrenergic neuron differentiation during development and has neurotrophic and neuroprotective effects on mature catecholaminergic neurons. Real-time PCR of reversed transcribed RNA isolated from homogenates of LC tissue from 12 matched pairs of MDD subjects and psychiatrically normal control subjects revealed low levels of BMP7 gene expression in MDD. No differences in gene expression levels of other members of the BMP family were observed in the LC, and BMP7 gene expression was normal in the prefrontal cortex and amygdala in MDD subjects. Laser capture microdissection of noradrenergic neurons, astrocytes, and oligodendrocytes from the LC revealed that BMP7 gene expression was highest in LC astrocytes relative to the other cell types, and that the MDD-associated reduction in BMP7 gene expression was limited to astrocytes. Rats exposed to chronic social defeat exhibited a similar reduction in BMP7 gene expression in the LC. BMP7 has unique developmental and trophic actions on catecholamine neurons and these findings suggest that reduced astrocyte support for pontine LC neurons may contribute to pathology of brain noradrenergic neurons in MDD.

Combining escitalopram with gaboxadol provides no additional benefit in the treatment of patients with severe major depressive disorder

The aim of this proof-of-concept study was to compare the efficacy of escitalopram (20 mg/d) in combination with fixed doses of gaboxadol to escitalopram (20 mg) in the treatment of patients with severe major depressive disorder (MDD). Adult patients were randomized to 8 wk of double-blind treatment with fixed doses of placebo (n=71), escitalopram (20 mg, n=140), escitalopram (20 mg)+gaboxadol (5 mg) (n=139), or escitalopram (20 mg)+gaboxadol (10 mg) (n=140). The pre-defined primary analysis of efficacy was an analysis of covariance (ANCOVA) of change from baseline to endpoint (week 8) in Montgomery-Åsberg Depression Rating Scale (MADRS) total score using last observation carried forward (LOCF). There was no statistically significant difference in the mean change from baseline in MADRS total score between the 20 mg escitalopram+10 mg gaboxadol group and the 20 mg escitalopram group [difference=-0.45 MADRS points (95% CI -2.5 to 1.6, p=0.6619, full analysis set (FAS), LOCF, ANCOVA)] at week 8. The mean treatment differences to placebo at week 8 were -5.6 (95% CI -8.0 to -3.1, p<0.0001) (20 mg escitalopram), -5.1 (95% CI -7.5 to -2.7, p<0.0001) (20 mg escitalopram+5 mg gaboxadol), and -6.0 (95% CI -8.4 to -3.6, p<0.0001) (20 mg escitalopram+10 mg gaboxadol). The most common adverse events reported in the active treatment groups for which the incidence was higher than that in the placebo group, comprised nausea, anxiety and insomnia. There were no clinically relevant efficacy differences between a combination of escitalopram and gaboxadol compared to escitalopram alone in the treatment of severe MDD. All active treatment groups were superior in efficacy to placebo and were well tolerated.

Increase of antipsychotic medication in depressive inpatients from 2000 to 2007: results from the AMSP International Pharmacovigilance Program

While international guidelines recommend monotherapy with antidepressants for depressed patients, recent investigation has demonstrated augmenting effects of antipsychotics (APs) in patients with major depression. We set out to investigate the use of APs in a European sample of depressed inpatients and the possible changes in their prescription over the period from 2000 to 2007. On two reference days in the years 2000 (32 psychiatric institutions, N=1078) and 2007 (54 psychiatric institutions, N=1826), the following data were recorded for all depressed inpatients (ICD-10: F32.00, F32.01, F32.1, F32.10, F32.11, F32.2, F33.0, F33.00, F33.01, F33.1, F33.10, F33.11, F33.2), monitored as part of the AMSP (Arzneimittelsicherheit in der Psychiatrie) surveillance programme: age, sex, ICD-10 diagnosis and all medication applied on that day. Depressed inpatients with psychotic symptoms were excluded. We found a significant increase in the number of AP-treated inpatients from 37.9% in 2000 to 45.8% in 2007 (χ²=17.257, p<0.001). The number of inpatients who received an atypical AP rose significantly between 2000 and 2007, from 12.8% to 28.3% (χ²=93.37, p<0.001). On the contrary, the percentage of inpatients receiving typical APs showed a significant decrease from 30.2% to 24.1% over the same period (χ²=13.179, p<0.001). Examining only the subgroup of severely depressed inpatients we found an increase in the number of AP-treated inpatients, but this was not statistically significant (χ²=2.047, p=0.15). Our study revealed a significant increase in the usage of atypical APs. However, this effect was not only due to augmentation strategies for severely depressed inpatients. Further studies are needed to examine possible putative effects of AP augmentation treatment in mild to moderate depression.

Executive summary of the report by the WPA section on pharmacopsychiatry on general and comparative efficacy and effectiveness of antidepressants in the acute treatment of depressive disorders

Current gold standard in the treatment of depression includes pharmacotherapeutic and psychotherapeutic strategies together with social support. Due to the actually discussed controversies concerning the differential efficacy of antidepressants, a contribution to a comprehensive clarification seems to be necessary to avert further deterioration and uncertainty from patients, relatives, and their treating psychiatrists and general practitioners. Both efficacy and clinical effectiveness of antidepressants in the treatment of depressive disorders can be confirmed. Clinically meaningful antidepressant treatment effects were confirmed in different types of studies. Methodological issues of randomized controlled studies, meta-analyses, and effectiveness studies will be discussed. Furthermore, actual data about the differential efficacy and effectiveness of antidepressants with distinct pharmacodynamic properties and about outcome differences in studies using antidepressants and/or psychotherapy are discussed. This is followed by a clinically oriented depiction-the differential clinical effectiveness of different pharmacodynamic modes of action of antidepressants in different subtypes of depressive disorders. It can be summarized that the spectrum of different antidepressant treatments has broadened during the last decades. The efficacy and clinical effectiveness of antidepressants is statistically significant and clinically relevant and proven repeatedly. For further optimizing antidepressant treatment plans, clearly structured treatment algorithms and the implementation of psychotherapy seem to be useful. A modern individualized antidepressant treatment in most cases is a well-tolerated and efficacious tool to minimize the negative impact of the otherwise devastating and life-threatening outcome of depressive disorders.

Escitalopram, an antidepressant with an allosteric effect at the serotonin transporter--a review of current understanding of its mechanism of action

RATIONALE

Escitalopram is a widely used antidepressant for the treatment of patients with major depression. It is the pure S-enantiomer of racemic citalopram. Several clinical trials and meta-analyses indicate that escitalopram is quantitatively more efficacious than many other antidepressants with a faster onset of action.

OBJECTIVE

This paper reviews current knowledge about the mechanism of action of escitalopram.

RESULTS

The primary target for escitalopram is the serotonin transporter (SERT), which is responsible for serotonin (or 5-hydroxytryptamine [5-HT]) reuptake at the terminals and cell bodies of serotonergic neurons. Escitalopram and selective serotonin reuptake inhibitors bind with high affinity to the 5-HT binding site (orthosteric site) on the transporter. This leads to antidepressant effects by increasing extracellular 5-HT levels which enhance 5-HT neurotransmission. SERT also has one or more allosteric sites, binding to which modulates activity at the orthosteric binding site but does not directly affect 5-HT reuptake by the transporter. In vitro studies have shown that through allosteric binding, escitalopram decreases its own dissociation rate from the orthosteric site on the SERT. R-citalopram, the nontherapeutic enantiomer in citalopram, is also an allosteric modulator of SERT but can inhibit the actions of escitalopram by interfering negatively with its binding. Both nonclinical studies and some clinical investigations have demonstrated the cellular, neurochemical, neuroadaptive, and neuroplastic changes induced by escitalopram with acute and chronic administration.

CONCLUSIONS

The findings from binding, neurochemical, and neurophysiological studies may provide a mechanistic rationale for the clinical difference observed with escitalopram compared to other antidepressant therapies.

PET kinetics of radiolabeled antidepressant, [N-methyl-11C]mirtazapine, in the human brain

Background

We compared six kinetic models with and without the requirement of arterial cannulation for estimating the binding potential of [N-methyl-¹¹C]mirtazapine in the living human brain.

Methods

Distribution volumes of [N-methyl-¹¹C]mirtazapine in brain regions were estimated using single- and two-tissue compartment models as well as a graphical plasma input model. The two-tissue compartment model provided a direct estimate of the binding potentials of [N-methyl-¹¹C]mirtazapine in brain regions, while binding potentials of the single-tissue compartment model and the graphical plasma input model were estimated indirectly from ratios of distribution volumes in brain regions. We obtained also direct estimates of binding potentials using a graphical reference tissue model and two nonlinear reference tissue models.

Results

The two-tissue compartment model required several fits with different initial guesses for avoiding negative values of parameters. Despite the extra fits, estimates of distribution volumes and binding potentials of [N-methyl-¹¹C]mirtazapine obtained by the two-tissue compartment model were far more variable than those produced by the other methods. The graphical plasma input method and the graphical reference tissue method provided estimates of the binding potential that correlated closely, but differed in magnitude. The single-tissue compartment model provided relatively low estimates of binding potentials with curves that failed to fit the data as well as the three other methods that used the entire series of positron emission tomography data. The reference tissue method and the simplified reference tissue method provided similar, consistent estimates of binding potentials. However, certain assumptions of the simplified reference tissue method may not be fulfilled by the radioligand.

Conclusion

The reference tissue method is appropriate for estimating the binding potential of [N-methyl-¹¹C]mirtazapine in regions of the human brain so that the binding potential of [N-methyl-¹¹C]mirtazapine can be estimated without arterial cannulation.