Distinct temporal pattern of the effects of the combined serotonin-reuptake inhibitor and 5-HT1A agonist EMD 68843 on the sleep EEG in healthy men

Nocturnal Delta Power is Associated With Lower Next-Day Pain But Not Pain Catastrophizing: Results From a Cohort of Female Participants With Temporomandibular Joint Pain

Existing data demonstrate reduced delta power during sleep in patients with depression and chronic pain. However, there has been little examination of the relationship between delta power and pain-reports, or pain-catastrophizing. We recruited female participants (n = 111) with insomnia and temporomandibular disorder, and measured nocturnal and daytime measures of pain and pain catastrophizing, and calculated relative nocturnal delta (0.5-4 Hz) power during sleep. We fit linear regression models, and further examined the moderating effect of depressive symptom severity. Lower relative delta power across the whole night was significantly associated with greater nocturnal pain (B = -20.276, P = .025, R2 = 0.214). Lower relative delta power during the first-third of the night, was associated with greater nocturnal pain (B = -17.807, p = 0.019, R2 = 0.217), next-day pain (B = 13.876, P = .039, R2 = 0.195), and next-morning pain (B = -15.751, P = .022, R2 = 0.198). Lower relative delta power during the final-third of the night was significantly associated with greater nocturnal (B = -17.602, P = .029, R2 = 0.207) and next-morning pain (3rd: B = -14.943, P = .042, R2 = 0.187). Depressive symptom severity did not moderate these relationships. Delta power was not significantly associated with nocturnal or daytime pain catastrophizing. These findings demonstrate that greater relative delta power during sleep is associated with lower nocturnal and next-day pain in patients with temporomandibular disorder. This data may guide the use of sleep interventions in clinical pain populations, with the aim of improving pain outcomes. PERSPECTIVE: This article presents data demonstrating an association between increased nocturnal delta power and reduced next-day pain. These findings may help promote interventions which aim to increase nocturnal delta power in clinical pain populations, with the goal of improving pain outcomes.

G-protein coupled receptors and synaptic plasticity in sleep deprivation

Insufficient sleep has been correlated to many physiological and psychoneurological disorders. Over the years, our understanding of the state of sleep has transcended from an inactive period of rest to a more active state involving important cellular and molecular processes. In addition, during sleep, electrophysiological changes also occur in pathways in specific regions of the mammalian central nervous system (CNS). Activity mediated synaptic plasticity in the CNS can lead to long-term and sometimes permanent strengthening and/or weakening synaptic strength affecting neuronal network behaviour. Memory consolidation and learning that take place during sleep cycles, can be affected by changes in synaptic plasticity during sleep disturbances. G-protein coupled receptors (GPCRs), with their versatile structural and functional attributes, can regulate synaptic plasticity in CNS and hence, may be potentially affected in sleep deprived conditions. In this review, we aim to discuss important functional changes that can take place in the CNS during sleep and sleep deprivation and how changes in GPCRs can lead to potential problems with therapeutics with pharmacological interventions.

Association of Sleep Architecture and Physiology with Depressive Disorder and Antidepressants Treatment

Sleep problems are frequently associated with the principal diagnostic criteria for many mental disorders. Alterations in the sleep of depressive patients are of high clinical significance because continuous sleep problems raise the chance of relapse, recurrence, or suicide, as well as the need for augmenting medications. Most antidepressants have been proven to influence the sleep architecture. While some classes of antidepressants improve sleep, others may cause sleep impairment. The successful treatment of depressive disorder also requires an understanding of the effects of antidepressants on sleep. This article briefly reviews the physiology of sleep and the typical alterations in the sleep architecture in depressive patients and updates the different effects of the majority of antidepressants including novel drugs in clinical practice on sleep. The summary of the updated scientific findings of the relationship between depression and sleep disturbances could be clinically beneficial in choosing the best medication for depressive patients with concurrent sleep disorders.

Sleep in pituitary insufficient patients compared to patients with depression and healthy controls at baseline and after challenge with CRH

Sleep disturbances are prevalent in both patients with pituitary insufficiency and with depression. The role of corticotropin releasing hormone (CRH), involved in sleep regulation, has not been fully clarified. Pituitary insufficiency is an ideal model for studying sleep-endocrine effects since no consecutive hormone releases and feedback effects occur after hormone administration. 11 male patients with a chronic insufficiency of the anterior pituitary gland (PI) and under stable hormonal substitution were studied during three consecutive nights in the sleep laboratory. The first night served for adapting to laboratory setting, during the second night placebo was administered and during the third night 4 × 50 μg CRH were injected in pulsatile fashion. Sleep parameters were additionally compared with those of 15 healthy male controls (C) and 15 male patients with depression (D). CRH administration was associated with a numerical increase of wake time (115 ± 15 to 131 ± 13 min) and a decrease of REM sleep (89 ± 8 to 80 ± 8 min), REM latency (69 ± 14 to 55 ± 9 min) and slow wave sleep (66 ± 16 to 57 ± 15 min). Yet, none of these changes reached statistical significance. PI showed a worse sleep profile as compared to both control groups, e.g. indicated by a significantly lower sleep efficiency index (PI:0.80 ± 0.03 vs. C:0.94 ± 0.01 vs. D:0.87 ± 0.03). In conclusion sleep-EEG changes after CRH in PI patients resemble those found in in part in patients with depression. Sleep in anterior pituitary insufficiency was impaired despite full hormonal substitution possibly suggesting an alteration of the receptor organisation of brain structures involved in sleep regulation.

New Treatment Options for Depression: A Primer for Internists

Depression continues to be a challenging condition to treat despite the myriad treatment options available. Primary care providers are increasingly tasked with providing second- and third-line treatments for major depressive disorder, and thus, should be familiar with newer medication therapies that are available. In this article, we aim to provide the general internist and other providers who treat depression in their practice with a succinct review of recent developments in the treatment of depression.

Depression and Sleep

Impaired sleep is both a risk factor and a symptom of depression. Objective sleep is assessed using the sleep electroencephalogram (EEG). Characteristic sleep-EEG changes in patients with depression include disinhibition of rapid eye movement (REM) sleep, changes of sleep continuity, and impaired non-REM sleep. Most antidepressants suppress REM sleep both in healthy volunteers and depressed patients. Various sleep-EEG variables may be suitable as biomarkers for diagnosis, prognosis, and prediction of therapy response in depression. In family studies of depression, enhanced REM density, a measure for frequency of rapid eye movements, is characteristic for an endophenotype. Cordance is an EEG measure distinctly correlated with regional brain perfusion. Prefrontal theta cordance, derived from REM sleep, appears to be a biomarker of antidepressant treatment response. Some predictive sleep-EEG markers of depression appear to be related to hypothalamo-pituitary-adrenocortical system activity.

Sleep-endocrine effects of growth hormone-releasing hormone (GHRH) in patients with schizophrenia

Changes in sleep-EEG after endocrine stimulation tests in patients with schizophrenia include reduced sleep efficiency, prolonged sleep latency and increased awaking after sleep onset Findings on sleep associated growth hormone (GH) secretion were ambiguous. The aim of this study was to elucidate the sleep-endocrine activity especially in the GH system of patients with schizophrenia after repeated administration of GHRH. The effect of repetitive injections of 4 × 50 μg GHRH between 22.00 and 01.00 h on sleep endocrine parameters was investigated in 9 patients diagnosed for schizophrenia. Patients did not receive any medication for one week. Concentrations of ACTH, cortisol, prolactin and GH were determined. Patients spent three consecutive nights in the sleep laboratory. Blood was taken every 20min. Results were compared with matched healthy controls. A non-significant prolonged sleep onset latency and increased time awake was found in patients compared to controls. Sleep stage 2 was significantly reduced in patients. No significant difference in ACTH and cortisol was detected, whereas the GH secretion in patients following GHRH stimulation was significantly elevated compared to controls. Our results in drug free patients confirm already known changes in sleep-EEG in these patients. The GH response to GHRH-stimulation indicates a different regulatory sensitivity of the system between daytime and night-time.

The serotonin hallucinogen 5-MeO-DMT alters cortico-thalamic activity in freely moving mice: Regionally-selective involvement of 5-HT1A and 5-HT2A receptors

5-MeO-DMT is a natural hallucinogen acting as serotonin 5-HT_1A/5-HT_2A receptor agonist. Its ability to evoke hallucinations could be used to study the neurobiology of psychotic symptoms and to identify new treatment targets. Moreover, recent studies revealed the therapeutic potential of serotonin hallucinogens in treating mood and anxiety disorders. Our previous results in anesthetized animals show that 5-MeO-DMT alters cortical activity via 5-HT_1A and 5-HT_2A receptors. Here, we examined 5-MeO-DMT effects on oscillatory activity in prefrontal (PFC) and visual (V1) cortices, and in mediodorsal thalamus (MD) of freely-moving wild-type (WT) and 5-HT_2A-R knockout (KO2A) mice. We performed local field potential multi-recordings evaluating the power at different frequency bands and coherence between areas. We also examined the prevention of 5-MeO-DMT effects by the 5-HT_1A-R antagonist WAY-100635. 5-MeO-DMT affected oscillatory activity more in cortical than in thalamic areas. More marked effects were observed in delta power in V1 of KO2A mice. 5-MeO-DMT increased beta band coherence between all examined areas. In KO2A mice, WAY100635 prevented most of 5-MeO-DMT effects on oscillatory activity. The present results indicate that hallucinatory activity of 5-MeO-DMT is likely mediated by simultaneous alteration of prefrontal and visual activities. The prevention of these effects by WAY-100635 in KO2A mice supports the potential usefulness of 5-HT_1A receptor antagonists to treat visual hallucinations. 5-MeO-DMT effects on PFC theta activity and cortico-thalamic coherence may be related to its antidepressant activity. This article is part of the Special Issue entitled 'Psychedelics: New Doors, Altered Perceptions'.

Vilazodone for the Treatment of Depression: An Update

Vilazodone is a novel antidepressant having a selective serotonin (5-HT) reuptake inhibitor and 5-HT1A receptor partial agonist profile, so it has been regarded as a serotonin partial agonist-reuptake inhibitor (SPARI). We aimed to provide Vilazodone's clinical implications mainly by reviewing published clinical trials. Vilazodone has been speculated to have three potential benefits including faster onset of action, greater efficacy, and better tolerability owning to its SPARI properties. However, no studies conducted so far have directly proven the above speculations. Five initial phase II trials failed to distinguish vilazodone from placebo in the treatment of MDD, but 4 randomized clinical trials (RCT), 3 post-hoc or pooled analysis, 1 long-term open label study, and a meta-analysis showed vilazodone's superior efficacy over placebo. The studies also showed vilazodone is generally safe and tolerable. However, diarrhea, nausea, headache, dizziness, dry mouth, and insomnia warrant close attention in clinical practice because they have been constantly noted throughout the clinical studies. 2 RCTs recently documented the efficacy and safety of vilazodone in patients with generalized anxiety disorder, which could be a start of broadening vilazodone's usage or FDA approval in diverse anxiety disorders.

Effect of dopamine D4 receptor agonists on sleep architecture in rats

Dopamine plays a key role in the regulation of sleep-wake states, as revealed by the observation that dopamine-releasing agents such as methylphenidate have wake-promoting effects. However, the precise mechanisms for the wake-promoting effect produced by the enhancement of dopamine transmission are not fully understood. Although dopamine D1, D2, and D3 receptors are known to have differential effects on sleep architecture, the role of D4 receptors (D4Rs), and particularly the influence of D4R activation on the sleep-wake state, has not been studied so far. In this study, we investigated for the first time the effects of two structurally different D4R agonists, Ro 10-5824 and A-412997, on the sleep-wake states in rats. We found that both D4R agonists generally increased waking duration, and conversely, reduced non-rapid eye movement (NREM) sleep duration in rats. The onset of NREM sleep was also generally delayed. However, only the A-412997 agonist (but not the Ro 10-5824) influenced rapid eye movement sleep onset and duration. Furthermore, these effects were accompanied with an enhancement of EEG spectral power in the theta and the gamma bands. Our results suggest the involvement of dopamine D4R in the regulation of sleep-wake states. The activation of the D4R could enhance the arousal states as revealed by the behavioral and electrophysiological patterns in this study. Dopamine D4R may contribute to the arousal effects of dopamine-releasing agents such as methylphenidate.

Vilazodone for the treatment of major depressive disorder: focusing on its clinical studies and mechanism of action

We tried to review and update clinical and preclinical studies evaluating vilazodone's role as an antidepressant for patients with major depressive disorder (MDD). In terms of its mechanism of actions, we sought to elaborate them mainly through preclinical animal studies. A data search was conducted in November 1, 2013, using the key terms "vilazodone" or "Viibryd," in PubMed and Medline databases. All published and unpublished studies are included and citations from publications were also reviewed for additional references. Five unpublished, phase-II and two pivotal published phase-III clinical trials with nearly identical design (8-week, double-blind, randomized, and placebo-controlled) investigated efficacy of vilazodone, were found for the treatment of patients with MDD. Two post-hoc studies and one long-term open study were also included. Data were thoroughly reviewed to incorporate the pharmacology, action mechanism, efficacy and safety for the vilazodone in the treatment of major depressive disorder. Vilazodone is an antidepressant with novel mechanism of action because its chemical structure is unrelated to conventional antidepressant, and it has a selective serotonin (5-HT) reuptake inhibitor and 5-HT1A receptor partial agonist profile. Vilazodone is an effective and safe treatment option with its novel action mechanisms for patients with depression. Its putative benefits compared with other antidepressants must be thoroughly studied in adequately-powered and well-designed future clinical trials.

The Neurobiological Mechanisms and Treatments of REM Sleep Disturbances in Depression

Most depressed patients suffer from sleep abnormalities, which are one of the critical symptoms of depression. They are robust risk factors for the initiation and development of depression. Studies about sleep electroencephalograms have shown characteristic changes in depression such as reductions in non-rapid eye movement sleep production, disruptions of sleep continuity and disinhibition of rapid eye movement (REM) sleep. REM sleep alterations include a decrease in REM sleep latency, an increase in REM sleep duration and REM sleep density with respect to depressive episodes. Emotional brain processing dependent on the normal sleep-wake regulation seems to be failed in depression, which also promotes the development of clinical depression. Also, REM sleep alterations have been considered as biomarkers of depression. The disturbances of norepinephrine and serotonin systems may contribute to REM sleep abnormalities in depression. Lastly, this review also discusses the effects of different antidepressants on REM sleep disturbances in depression.

A review of current evidence for vilazodone in major depressive disorder

OBJECTIVES

This review is to inform clinicians of currently available data on vilazodone for treating patients with major depressive disorder (MDD), focusing on its differential action mechanism and extended clinical utility.

METHODS

A data search was conducted in June 2012 using the PubMed/ MEDLINE/relevant clinical trial databases with the key terms "vilazodone" or "Viibryd."

RESULTS

The efficacy, safety, and tolerability of vilazodone have been demonstrated in two pivotal 8-week, randomized, double-blinded, placebo-controlled studies. Certain pharmacological characteristics of vilazodone were observed, including early onset of action, fewer sexual side effects, the absence of known cardiac toxicity, and minimal effect on weight gain, that may provide potential clinical advantages compared with currently available antidepressants. However, such possibilities should be replicated and confirmed in more well-designed and adequately powered clinical trials. Vilazodone requires dose titration up to 2 weeks to reach a target dose of 40 mg/d due to high rate of gastrointestinal side effects. No direct comparative studies with other antidepressants are currently available to confirm the aforementioned potential clinical utility.

CONCLUSION

Vilazodone is a newer antidepressant possessing different action mechanisms compared to currently available antidepressants but whether it has superiority to other class of antidepressants in terms of efficacy and safety should still warrant further evaluation through more well-controlled and direct comparison clinical trials.

Vilazodone for major depressive disorder: a systematic review of the efficacy and safety profile for this newly approved antidepressant - what is the number needed to treat, number needed to harm and likelihood to be helped or harmed?

OBJECTIVE

To describe the efficacy and safety of vilazodone for the treatment of major depressive disorder (MDD).

DATA SOURCES

The pivotal registration trials were accessed by querying http://www.ncbi.nlm.nih.gov/pubmed/, http://www.fda.gov and http://www.clinicaltrials.gov for the search term 'vilazodone'. Product labeling provided additional information.

STUDY SELECTION

  All available clinical reports of studies were identified.

DATA EXTRACTION

Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the available study reports and other sources of information.

DATA SYNTHESIS

Vilazodone is a specific serotonin reuptake inhibitor and serotonin 5HT1A receptor partial agonist. In needs to be administered with food to ensure adequate bioavailability. Approval for the treatment of MDD was based on a clinical development programme that included two 8-week placebo-controlled randomised clinical trials in outpatients with MDD where vilazodone was titrated to a target dose of 40 mg/d over the first 2 weeks. Both trials evidenced efficacy for vilazodone as measured by the Montgomery Asberg Depression Rating Scale. NNT for response vs. placebo was 8 (95% CI 6-16) and for remission was 14 (95% CI 8-55). NNH vs. placebo for discontinuation because of an adverse event (AE) was 27 (95% CI 15-104). The most commonly encountered AEs (incidence ≥ 5% and at least twice the rate of placebo) were diarrhoea, nausea, vomiting and insomnia, with NNH values vs. placebo of 6 (95% CI 5-8), 6 (95% CI 5-8), 30 (95% CI 18-82) and 26 (95% CI 16-78), respectively. NNH vs. placebo for any sexual AE was 12 (95% CI 9-18), but systematically collected data using rating scales of sexual function did not reveal treatment associated effects. Vilazodone was not associated with clinically relevant weight change in the short-term trials. In an open-label 1-year study of vilazodone, mean weight increased by 1.7 kg among the observed cases.

CONCLUSIONS

Vilazodone represents another option for the treatment of MDD. Vilazodone appears to have a favourable weight-gain profile based on short-term studies. Sexual side-effects were not consistently demonstrated when assessed using clinical rating scales but spontaneously reported AEs related to sexual functioning were observed. Additional controlled data regarding long-term efficacy and effectiveness will help characterise this new agent when used in maintenance treatment.

Clinical utility of vilazodone for the treatment of adults with major depressive disorder and theoretical implications for future clinical use

BACKGROUND

Vilazodone is the latest approved antidepressant available in the United States. Its dual mechanism of action combines the inhibition of serotonin transporters while simultaneously partially agonizing serotonin-1a (5-HT1A) receptors. This combined activity results in serotonin facilitation across the brain's serotonergic pathways, which has been termed by the authors as that of a serotonin partial agonist and reuptake inhibitor, or SPARI.

OBJECTIVE

The authors to review laboratory, animal model data, and human trial data to synthesize a working theory regarding the mechanism of antidepressant action of this agent and regarding its potential for additional indications.

METHODS

A MEDLINE and Internet search was conducted and the resultant evidence reviewed.

RESULTS

Vilazodone has randomized, controlled empirical data which has garnered it an approval for treating major depressive disorder. It combines two well-known pharmacodynamic mechanisms of serotonergic action into a novel agent. Although no head-to-head studies against other antidepressants are published, the efficacy data for vilazodone appears comparable to other known antidepressants, with associated gastrointestinal side effects similar to serotonin selective reuptake inhibitor and serotonin norepinephrine reuptake inhibitor antidepressants, but potentially with a lower incidence of sexual side effects and weight gain.

DISCUSSION

As a new option for the treatment of major depressive disorder, vilazodone, due to its unique SPARI mechanism of action, may hold promise for patients who cannot tolerate or have not responded to previous antidepressant monotherapies. Additionally, its use may extend to the treatment of other mental health conditions similar to those treated by serotonin selective reuptake inhibitors.

Translatability scoring in drug development: eight case studies

Translational medicine describes the transfer of basic in vitro and in vivo data into human applications. In the light of low rates of market approvals for new medical entities, better strategies to predict the risk of drug development should be used to increase output and reduce costs. Recently, a scoring system to assess the translatability of early drug projects has been proposed. Here eight drugs from different therapeutic areas have been subjected to a retrospective test-run in this system fictively located at the phase II-III transition. The scores gained here underline the importance of biomarker quality which is pivotal to decrease the risk of the project in all cases. This is particularly evident for gefitinib. The EGFR mutation status is a breakthrough biomarker to predict therapeutic success which made this compound clinically acceptable, and this is plausibly reflected by a considerable increase of the translatability score. For psychiatric and Alzheimer's drugs, and for a CETP-inhibitor, the lack of suitable biomarkers and animal models is reflected by a low translatability score, well correlating with the excessive translational risk in these areas. These case studies document the apparent utility of the scoring system, at least under retrospective conditions, as the scores correlate with the outcomes at the level of market approval. Prospective validation is still missing, but these case studies are encouraging.

Clinical relevance of disturbances of sleep and vigilance in major depressive disorder: a review

OBJECTIVE

The primary objective of this article is to provide a concise review of the clinical relevance of sleep and vigilance in major depressive disorder.

DATA SOURCES

PubMed was reviewed (1990-2009) and English-language articles were identified using the key words sleep and depression and sleep and antidepressants. Secondary searches included articles cited in sources identified by the primary search.

STUDY SELECTION

The narrative review provides brief descriptions of the normal physiology of sleep and changes associated with depression, as well as the impact of various treatments on these processes.

DATA SYNTHESIS

Although it has long been known that sleep disturbances are an important characteristic of depression, relatively few studies have been conducted with the newer-generation antidepressants. Neither of the most widely used classes of antidepressants, the selective serotonin reuptake inhibitors and the serotonin-norepinephrine reuptake inhibitors, have particularly beneficial effects on sleep and, among the medications that reliably improve sleep efficiency, including mirtazapine and the tricyclic antidepressants, problems with daytime sedation can offset therapeutic benefit. Despite relatively widespread use, trazodone has not been demonstrated to be an effective and safe hypnotic in patients taking other antidepressants. For many patients, ongoing concomitant treatment with benzodiazepines and related drugs is the preferred option, again without convincing empirical support of longer-term efficacy. Among newer and investigational antidepressants, agomelatine shows promise with respect to both overall safety and effects on insomnia, although possible negative effects on liver function warrant further study.

CONCLUSIONS

Sleep disturbances are a significant aspect of depressive syndromes, and relief of insomnia remains an important unmet need in antidepressant therapeutics. Development of a well-tolerated antidepressant medication that rapidly improves sleep maintenance without daytime sedation is a priority for drug development.

Changes in the sleep electroencephalogram (EEG) during male to female transgender therapy

Steroids, including estrogens, participate in sleep regulation. For example estrogen replacement therapy improved sleep quality in postmenopausal women. Patients, who undergo a cross-gender hormone therapy, receive high doses of estrogens. The effects of this treatment on sleep are unknown. To clarify this issue, we examined seven male to female transsexual patients (age range 31-44 years, mean±SD 35.9±4.2 years). The patients spent two nights on 2 separate occasions in our sleep laboratory. The first night of each session served for adaptation to laboratory conditions. In the second night sleep electroencephalogram [EEG] was recorded from 2300h to 0700h. The first examination was performed before and the second about 3 months after initiation of cross-gender hormone therapy with a dose of 80-100mg estrogen applied every 2 weeks. Additionally patients were treated with a starting dose of the anti-androgen cyproteronacetate of 100mg/day and after about 6 weeks with a maintenance therapy of 50mg/d in order to suppress androgenic effects. Statistical analysis was performed with the Wilcoxon rank test. Under this estrogen therapy we found a significant increase in stage 1 sleep during the whole night (at baseline [b]: 33.29±9.94min; treatment [t]: 51.57±24.26min; p<0.05) Beta activity in nonREM sleep was significantly increased (p=0.02) during hormone therapy compared to before treatment. Other sleep EEG parameters showed no significant changes. Administration of estrogen and anti-androgens in male to female transsexual patients had only a small influence on sleep EEG, with an increase in the duration of shallow sleep.

Vilazodone: in major depressive disorder

Vilazodone, a novel antidepressant agent that combines selective serotonin reuptake inhibitor (SSRI) activity and serotonin 5-HT(1A) receptor partial agonist activity in a single molecule, is indicated for the treatment of major depressive disorder (MDD) in the US. It is administered orally, once daily, with food. At the recommended dosage of 40 mg/day, vilazodone was effective in the short-term treatment of MDD in adults, as evidenced by significant improvements versus placebo on multiple measures of depression, including the Montgomery-Åsberg Depression Rating Scale (MADRS) and the 17-item Hamilton Rating Scale for Depression (HAM-D-17), in two pivotal, 8-week, randomized, double-blind, phase III studies. Significant differences between vilazodone and placebo on the MADRS and HAM-D-17 were seen after 1 week of treatment (first efficacy timepoint) in one of the two studies. Long-term treatment with vilazodone 40 mg/day was associated with an improvement from baseline in depressive symptoms in a 52-week, noncompar-ative, phase III study. Vilazodone was generally well tolerated in the short- and long-term treatment of MDD, with diarrhoea and nausea being the most frequently occurring treatment-emergent adverse events. Vilazodone had a minimal impact on sexual functioning in the three phase III studies.

Vilazodone for the Treatment of Depression

Objective:

To evaluate the clinical literature on and potential clinical role of vilazodone for the treatment of major depressive disorder.

Data Sources:

Searches were conducted on MEDLINE (1948-February 2011), Iowa Drug Information Service (1988-February 2011), EBSCO Academic Search Premier (1975-February 2011), Google Scholar (1992-February 2011), PsycINFO (1980-February 2011), and PsycARTICLES (1985-February 2011), and on general Internet search engines including Google and Bing (no lower limit-February 2011). Search terms were vilazodone, EMD 68843, depression, and major depressive disorder. Potential prior marketers of vilazodone, including Merck KGaA in Germany and Genaissance Pharmaceuticals, were contacted for any available unpublished Phase 1, Phase 2, Phase 3 studies, or preclinical information.

Study Selection and Data Extraction:

All applicable full-text English-language articles, abstracts, and professional poster presentations found were evaluated and included in the review, as well as marketing and Securities and Exchange Commission filings available from the patent holders.

Data Synthesis:

Vilazodone is an antidepressant recently approved by the Food and Drug Administration (FDA) that is first in a new class regarding mechanism of action. It has demonstrated efficacy in the primary outcome of the Montgomery-Asberg Depression Rating Scale (MADRS) response in an 8-week pivotal Phase 3 trial. Phase 2 trials did not demonstrate efficacy for primary outcomes of the 17-item Hamilton Rating Scale for Depression but showed statistically significant improvements in select secondary outcomes such as Clinical Global Impressions severity and MADRS. Long-term efficacy data are still forthcoming. An emerging aspect to vilazodone's development has been the identification and assessment of potential genetic biomarkers associated with both therapeutic response and more serious adverse effects. Initial studies into biomarkers have been inconclusive.

Conclusions:

Vilazodone is a new agent recently approved by the FDA for treating major depressive disorder. Response rates seen with vilazodone are similar to those of currently available antidepressants.

Vilazodone: a brief pharmacological and clinical review of the novel serotonin partial agonist and reuptake inhibitor

BACKGROUND

Vilazodone is the latest US Food and Drug Administration approved antidepressant agent available in the USA. Its putative mechanism of antidepressant action enhances the release of serotonin across the brain's serotonergic pathways specifically by inhibiting the serotonin transporter, similar to a selective serotonin reuptake inhibitor (SSRI), and simultaneously stimulating serotonin-1a receptors via partial agonism, similar to the anxiolytic bus-pirone. This combined activity in the single vilazodone agent has been termed by the authors as being a serotonin partial agonist and reuptake inhibitor or (SPARI).

METHODS

A MEDLINE and Internet search was conducted and the resultant preclinical and clinical evidence was reviewed. The authors attempt to review laboratory data, animal model data and human trial data to develop a translational theory on the mechanism of antidepressant action of this agent and also its adverse effect potential.

RESULTS

Randomized, controlled empirical data for vilazodone have gained it approval for treating major depressive disorder. It combines two well known pharmacodynamic mechanisms of serotonergic action into a novel agent. Although no head-to-head studies against other antidepressants have been published, the efficacy data for vilazodone appear comparable to other known antidepressants, with similar gastrointestinal side effects to SSRI or serotonin norepinephrine reuptake inhibitor (SNRI) antidepressants, but possibly with a lower incidence of sexual side effects and weight gain.

DISCUSSION

Vilazodone will lend itself to the current armamentarium in the treatment of major depressive disorder and may hold promise for patients who cannot tolerate other antide-pressants. Its unique SPARI mechanism of action could also be efficacious for patients who do not respond to SSRI or SNRI antidepressant monotherapies.

Wake and sleep EEG provide biomarkers in depression

Both wake and sleep electroencephalogram (EEG) provide biomarkers of depression and antidepressive therapy, respectively. For a long time it is known that EEG activity is altered by drugs. Quantitative EEG analysis helps to delineate effects of antidepressants on brain activity. Cordance is an EEG measure with a superior correlation with regional brain perfusion. Prefrontal quantitative EEG cordance appears to be a predictor of the response to antidepressants. Sleep EEG shows characteristic changes in depression as impaired sleep continuity, desinhibition of REM sleep and changes of nonREM sleep. Elevated REM density (a measure for frequency of rapid eye movements) characterizes an endophenotype in family studies of depression. REM-sleep changes including a more distinct REM rebound after sleep deprivation are found in animal models of depression. Most antidepressants suppress REM sleep in depressed patients, normal controls and laboratory animals. REM suppression appears to be a distinct, but not an absolute requirement for antidepressive effects of a compound. Sleep-EEG variables like REM latency or certain clusters of variables were shown to predict the response to the treatment with a certain antidepressant or even the course of the disorder for several years. Some of these predictive sleep-EEG markers of the longterm course of depression appear to be closely related to hypothalamo-pituitary-adrenocortical system activity.

Vilazodone: a 5-HT1A receptor agonist/serotonin transporter inhibitor for the treatment of affective disorders

Vilazodone (EMD 68843; 5-{4-[4-(5-cyano-3-indolyl)-butyl]-1-piperazinyl}-benzofuran-2-carboxamide hydrochloride) is a combined serotonin specific reuptake inhibitor (SSRI) and 5-HT1A receptor partial agonist currently under clinical evaluation for the treatment of major depression. This molecule was designed based on the premise that negative feedback circuitry, mediated via 5-HT1 receptors, limits the acute SSRI-induced enhancements in serotonergic neurotransmission. If the hypothesis is correct, combination of SSRI with 5-HT1A partial agonism should temporally enhance the neuroplastic adaptation and subsequently hasten therapeutic efficacy compared to current treatments. Preclinical in vitro evaluation has confirmed vilazodone's primary pharmacological profile both in clonal and native systems, that is, serotonin reuptake blockade and 5-HT1A partial agonism. However, in vivo and in contrast to combination of 8-OH-DPAT and paroxetine, vilazodone selectively enhanced serotonergic output in the prefrontal cortex of rats. Behavioral evaluations, in the ultrasonic vocalization model of anxiety in rats, demonstrated anxiolytic efficacy. In the forced swim test (a putative model of depression), vilazodone also showed efficacy but at a single dose only. In man, vilazodone abolished REM sleep and demonstrated clinical antidepressant efficacy equivalent to an SSRI. Ongoing clinical evaluations will hopefully reveal whether the founding hypothesis was valid and if vilazodone will produce a more rapid onset of antidepressant efficacy.

Vilazodone, a novel dual-acting serotonergic antidepressant for managing major depression

Major depressive disorder (MDD) affects <or= 15% of the general population and imparts a significant economic and psychosocial burden. Despite the availability of a wide range of drugs for treating MDD, the majority of patients fail to achieve complete and sustained remission of symptoms. Vilazodone is a novel dual-acting serotonergic antidepressant currently in clinical development for the treatment of MDD. Vilazodone combines the effects of a selective serotonin reuptake inhibitor with 5-HT(1A) receptor partial agonist activity. In a recent Phase III clinical trial, vilazodone showed significant antidepressant efficacy compared to placebo with a statistically significant onset of effect at 1 week. Overall dropout rates were low. Diarrhea, nausea and headache were the most common adverse events reported. In addition, there was no significant difference between placebo and vilazodone in terms of sexual dysfunction as measured by the Arizona Sexual Experiences Scale. A unique feature of the vilazodone clinical program is the concurrent development of biomarkers that may predict treatment response and common side effects. Vilazodone offers a dual mechanism of action, good general tolerability with the potential for less impairment of sexual function than selective serotonin reuptake inhibitors and the possibility of personalized treatment for MDD.

HPA axis and sleep: identifying subtypes of major depression

It is increasingly acknowledged that the diagnosis of major depression encompasses patients who do not necessarily share the same disease biology. Though the diagnostic criteria allow the specification of different subtypes, e.g. melancholic and atypical features, a consensus still has to be reached with regard to the clinical symptoms that clearly delineate these subtypes. Beside clinical characteristics, biological markers may help to further improve identification of biologically distinct endophenotypes and, ultimately, to devise more specific treatment strategies. Alterations of the hypothalamus-pituitary-adrenal (HPA) axis and sleep architecture are not only commonly observed in patients with major depression, but the nature and extent of these alterations can help to identify distinct subtypes. Thus, a HPA overdrive, due to enhanced secretion of corticotropin-releasing hormone (CRH) and an impaired negative feedback via glucocorticoid receptors, seems to be most consistently observed in patients with melancholic features. These patients also show the clearest sleep-electroencephalogram (EEG) alterations, including disrupted sleep, low amounts of slow wave sleep (SWS), a short rapid eye movement (REM) latency and a high REM density. In contrast, patients with atypical features are characterized by reduced activity of the HPA axis and ascending noradrenergic neurons in the locus coeruleus. Though sleep-EEG alterations have been less thoroughly examined in these patients, there are data to suggest that SWS is not reduced and that REM sleep parameters are not consistently altered. While the atypical and melancholic subtypes of major depression may represent the extremes of a spectrum, the distinct clinical features provide an opportunity to further explore biological markers, as well as environmental factors, contributing to these clinical phenotypes. Moreover, dysregulations of the HPA axis and sleep-EEG alterations can also be induced in rodents, thereby allowing alignment of critical biological aspects of a human disease subtype with an animal model. Such "Translational Research" efforts should help to develop targeted therapies for distinct patient populations.

Changes of sleep architecture, spectral composition of sleep EEG, the nocturnal secretion of cortisol, ACTH, GH, prolactin, melatonin, ghrelin, and leptin, and the DEX-CRH test in depressed patients during treatment with mirtazapine

The noradrenergic and specific serotoninergic antidepressant mirtazapine improves sleep, modulates hormone secretion including blunting of hypothalamic-pituitary-adrenocortical (HPA) activity, and may prompt increased appetite and weight gain. The simultaneous investigation of sleep electroencephalogram (EEG) and hormone secretion during antidepressive treatment helps to further elucidate these effects. We examined sleep EEG (for later conventional and quantitative analyses) and the nocturnal concentrations of cortisol, adrenocorticotropin (ACTH), growth hormone (GH), prolactin, melatonin and the key factors of energy balance, ghrelin, and leptin before and after 28 days of treatment of depressed patients (seven women, three men, mean age 39.9+/-4.2 years) with mirtazapine. In addition, a sleep EEG was recorded at day 2 and the dexamethasone-corticotropin-releasing hormone (DEX-CRH) test was performed to assess HPA activity at days -3 and 26. Psychometry and mirtazapine plasma concentrations were measured weekly. Already at day 2, sleep continuity was improved. This effect persisted at day 28, when slow-wave sleep, low-delta, theta and alpha activity, leptin and (0300-0700) melatonin increased, and cortisol and ghrelin decreased. ACTH and prolactin remained unchanged. The first two specimens of GH collected after the start of quantitative EEG analysis were reduced at day 28. The DEX-CRH test showed, at day 26, a blunting of the overshoot of ACTH and cortisol found at day -3. The Hamilton Depression score decreased from 32.1+/-7.3 to 15.5+/-6.7 between days -1 and 28. A weight gain of approximately 3 kg was observed. This unique profile of changes is compatible with the action of mirtazapine at 5-HT-2 receptors, at presynaptic adrenergic alpha 2 receptors, at the HPA system, and on ghrelin and leptin.

Changes in sleep electroencephalogram and nocturnal hormone secretion after administration of the antidyskinetic agent sarizotan in healthy young male volunteers

RATIONALE

Sarizotan is a 5-HT(1A) agonist with high affinity to D(3) and D(4) receptors. In animal experiments, the drug shows a strong anti-cataleptic effect and suppresses effectively dyskinesias in animal models of L: -dopa-induced dyskinesia and of tardive dyskinesia. Data from an open pilot study in patients with Parkinson's disease show clear indication of a treatment effect against L: -dopa-induced dyskinesia.

OBJECTIVE

CNS-active drugs are known to modulate sleep electroencephalogram (EEG) and sleep-related hormone secretion. 5-HT(1A) agonists suppress rapid-eye movement (REM) sleep and enhance the secretion of ACTH, cortisol, prolactin and growth hormone (GH) at daytime. We hypothesised that sarizotan shares these effects. Furthermore, we were interested in the influence of sarizotan on leptin, which participates in the regulation of the energy balance and is enhanced after various psychoactive drugs.

METHODS

Ten healthy male subjects were investigated twice in a double-blind, placebo-controlled crossover design. Sleep EEG and nocturnal hormone secretion of ACTH, cortisol, prolactin, GH and leptin were examined after oral administration of either placebo or 20 mg of sarizotan at night.

RESULTS

After administration of sarizotan, a significant reduction of REM sleep and total sleep time in conventional sleep EEG and a significant reduction of sigma- and theta-power in spectral analysis were observed. The main effect on nocturnal hormone secretion was a significant elevation of prolactin and of ACTH in the first half of the night.

CONCLUSIONS

While REM sleep was suppressed, the endocrine effects of 20 mg sarizotan at night were weak. Its sleep-endocrine profile is comparable to the effects provoked by selective 5-HT reuptake inhibitors.

Rapid tryptophan depletion reverses phenelzine-induced suppression of REM sleep

Treatment with the monoamine oxidase inhibitor phenelzine completely suppressed rapid eye movement (REM) sleep in five depressed patients. Hypothesizing that increased serotonergic neurotransmission eliminated REM sleep, we administered a tryptophan-free amino acid drink (TFD) known to reduce plasma tryptophan and brain levels of serotonin. The TFD reversed the REM sleep suppression, while the control drink (TFD plus tryptophan) had virtually no effect on sleep. Neither TFD nor control drink affected mood, total sleep time, sleep efficiency or the all-night electroencephalogram power spectra in non-rapid eye movement (NREM) sleep. We report the first non-disruptive, double-blind method for studying human subjects overnight with and without REM sleep. It opens up a novel strategy for investigating the functions of REM sleep, and the roles of serotonin and REM sleep in the regulation of NREM sleep and mood.

State markers of depression in sleep EEG: dependency on drug and gender in patients treated with tianeptine or paroxetine

Tianeptine enhances while paroxetine inhibits serotonin reuptake into neurons; however, both show an antidepressive action. A subgroup of 38 depressed patients from a drug trial comparing the efficacy of tianeptine with that of paroxetine was studied with regard to their effects on sleep regulation, especially in relation to treatment response. We recorded sleep EEGs at day 7 and day 42 after the start of treatment with either compound, which allows measurement of changes due to the antidepressive medication in relation to the duration of treatment. Spectral analysis of the non-REM sleep EEG revealed a strong decline in the higher sigma frequency range (14-16 Hz) in male treatment responders independent of medication, whereas nonresponders did not show marked changes in this frequency range independent of gender. The patients receiving paroxetine showed less REM sleep and more intermittent wakefulness compared to the patients receiving tianeptine. REM density after 1 week of treatment was a predictor of treatment response in the whole sample. Psychopathological features with regard to the score in single items of the HAMD revealed predictive markers for response, some of which were opposite in the gender groups, especially those related to somatic anxiety. Changes in REM density were inversely correlated to the changes in HAMD in the paroxetine, but not the tianeptine, group. Our data suggest the importance of taking gender into account in the study of the biological effects of drugs. The study further points to the importance of the higher sigma frequency range in the sleep EEG of non-REM sleep and REM density as a marker of treatment response.