Ziprasidone Augmentation of Escitalopram for Major Depressive Disorder: Efficacy Results From a Randomized, Double-Blind, Placebo-Controlled Study

Ziprasidone population pharmacokinetics and co-medication effects in Chinese patients

Ziprasidone is widely used in the treatment of psychiatric disorders. Despite its prevalence, there is a notable lack of population pharmacokinetics (PPK) studies on ziprasidone in serum, both domestically and internationally. This study aimed to comprehensively investigate the various factors influencing the PPK characteristics of Ziprasidone, thereby providing a scientific basis for personalized treatment strategies in clinical settings. This is a retrospective study. A non-linear mixed-effects modeling method was used for data analysis, with the ziprasidone PPK model established using the Phoenix NLME 8.1 software. Model evaluation employed goodness-of-fit plots, visual predictive checks, and Bootstrap methods to ensure reliability and accuracy. To further validate the model's applicability, data from an additional 30 patients meeting the same inclusion criteria but not included in the final model were collected for external validation. Simulations were performed to explore the personalized dosage regimens. This retrospective analysis collected 547 drug concentration data points from 185 psychiatric disorder patients, along with related medical records. The data included detailed demographic information (such as age, gender, weight), dosing regimens, laboratory test results, and concomitant medication details. In the final model, Ka was fixed at 0.5 h-1 based on literature, and the population typical values for ziprasidone clearance (CL) and volume of distribution (V) were 18.74 L/h and 110.24 L, respectively. Co-administration of lorazepam and valproic acid significantly influenced the clearance of ziprasidone. Moreover, the model evaluation indicated good stability and predictive accuracy. A simple to use dosage regimen table was derived based on the results of simulations. This study successfully established and validated a PPK model for ziprasidone in Chinese patients with psychiatric disorders. The model provides a scientific reference for individualized dosing of ziprasidone and holds the potential to optimize treatment strategies, thereby enhancing therapeutic efficacy and safety.

Adjunctive cariprazine for major depressive disorder: a systematic review and meta-analysis

Converging evidence has suggested that treatment augmentation with a second-generation atypical antipsychotic (SGA) may improve treatment outcomes in major depressive disorder (MDD) patients after an incomplete response to a first-line antidepressant. Cariprazine is a recently approved SGA for MDD augmentation. Herein, we evaluate both continuous (ie, change in depressive symptom severity scores over time) and categorical (ie, remission and response rates) outcomes. Following a full-text review, four randomized controlled trials (RCTs) were included in our meta-analysis, while five studies were included for a qualitative review. Risk ratios (RRs) were calculated for all included randomized controlled studies to determine the relative response and remission rates of cariprazine compared to placebo augmentation. The RR for all-cause dropout was also determined as a proxy for overall acceptability. Two studies found a statistically significant treatment response using cariprazine augmentation. One study observed depressive symptom remission for cariprazine compared to placebo. Our random-effects model revealed moderate antidepressant effects of cariprazine, with a standardized mean difference (SMD) in Montgomery-Åsberg Depression Rating Scale (MADRS) scores of -1.79 (95% CI): -2.89, -0.69). Our pooled response RR and remission RR were calculated as 1.21 (95% CI: 1.05, 1.39, P=0.008) and 0.99 (95% CI: 0.84, 1.17, P=0.91), respectively. The RR for response was statistically significant (P<0.05). However, the RR for remission was not statistically significant. The findings from our meta-analysis include a variable magnitude of effects. Evidence suggests cariprazine may be an effective treatment for MDD; however, further results are needed to clarify this relation.

Pharmacotherapies for Treatment-Resistant Depression: How Antipsychotics Fit in the Rapidly Evolving Therapeutic Landscape

One in three adults with major depressive disorder (MDD) do not experience clinically significant improvement after multiple sequential courses of antidepressants and have treatment-resistant depression (TRD). The presence of TRD contributes to the morbidity and excess mortality associated with MDD and has been linked to significantly increased health care expenses. In the absence of a consensus definition of TRD, this report takes a broad approach by considering inadequate response to one or more courses of antidepressants and focuses on atypical antipsychotics that are approved by the U.S. Food and Drug Administration for treatment of depression (aripiprazole, brexpiprazole, cariprazine, extended-release quetiapine, and olanzapine-fluoxetine combination). While multiple acute-phase studies have demonstrated the efficacy of these medications in improving depressive symptoms, clinically meaningful improvement (i.e., remission) remains limited, with significant concerns about side effects (including weight gain, metabolic dysfunction, extrapyramidal symptoms, and tardive dyskinesia), especially with long-term use. With the rapidly evolving landscape of antidepressant treatments over the past few years, which has witnessed approval of rapid-acting antidepressants (e.g., esketamine nasal spray and dextromethorphan-bupropion combination) and several more in the late-stage pipeline (e.g., zuranolone and psilocybin), it remains to be seen whether the use of atypical antipsychotics will go the way of the older and rarely prescribed antidepressants (such as tricyclics and monoamine oxidase inhibitors). Pragmatic clinical trials are needed to compare the effectiveness of atypical antipsychotics with TRD-specific pharmacotherapies and neuromodulation treatments and to identify the optimal sequencing of these varied approaches for patients with MDD. When using atypical antipsychotics, clinicians and patients are encouraged to use a shared decision-making approach by personalizing treatment selection based on anticipated side effects, tolerability, cost, and feasibility.

Seventy Years of Antipsychotic Development: A Critical Review

Since the mid-1950s discovery of the first effective antipsychotic medications (APM), we have only been able to improve the tolerability but not the overall efficacy of currently available APMs, as reflected by effectiveness trials in Europe and the United States. This inability to develop more effective APMs is attributable to multiple factors, including failure to create and use assessment tools to assess core symptom domains in schizophrenia, move beyond the dopaminergic hypothesis and to develop "me too" drugs, imposing ill-defined research domain criteria, and lacking federal funding for clinical trials. The classification of APMs is also confusing, including second-generation, partial agonists, and multimodal APMs in the same class of APMs, despite significant differences in their mechanisms of action. Other factors stagnating drug development include inadequate sample sizes to address heterogeneity, lack of statistical measures correlating with clinical significance, using the atheoretical basis of psychiatric diagnoses, failure to control placebo response, and high cost of newer and perhaps more tolerable APMs. Furthermore, there has been a failure to develop early predictors of antipsychotic response and various tools to optimize an APM response. Finally, some mental health providers are also responsible for the suboptimal use of APMs, by using excessive maintenance doses, often with irrational polypharmacy, further compromising effectiveness and medication adherence. However, some bright spots in antipsychotic development include improved tolerability of APMs and long-acting injectables to address the high prevalence of medication nonadherence. This review critically reviews 70 years of antipsychotic development, the reasons behind the failure to develop more effective APMs, and suggestions for future direction.

Recent advances in dopamine D2 receptor ligands in the treatment of neuropsychiatric disorders

Dopamine is a biologically active amine synthesized in the central and peripheral nervous system. This biogenic monoamine acts by activating five types of dopamine receptors (D_1-5 Rs), which belong to the G protein-coupled receptor family. Antagonists and partial agonists of D₂ Rs are used to treat schizophrenia, Parkinson's disease, depression, and anxiety. The typical pharmacophore with high D₂ R affinity comprises four main areas, namely aromatic moiety, cyclic amine, central linker and aromatic/heteroaromatic lipophilic fragment. From the literature reviewed herein, we can conclude that 4-(2,3-dichlorophenyl), 4-(2-methoxyphenyl)-, 4-(benzo[b]thiophen-4-yl)-1-substituted piperazine, and 4-(6-fluorobenzo[d]isoxazol-3-yl)piperidine moieties are critical for high D₂ R affinity. Four to six atoms chains are optimal for D₂ R affinity with 4-butoxyl as the most pronounced one. The bicyclic aromatic/heteroaromatic systems are most frequently occurring as lipophilic appendages to retain high D₂ R affinity. In this review, we provide a thorough overview of the therapeutic potential of D₂ R modulators in the treatment of the aforementioned disorders. In addition, this review summarizes current knowledge about these diseases, with a focus on the dopaminergic pathway underlying these pathologies. Major attention is paid to the structure, function, and pharmacology of novel D₂ R ligands, which have been developed in the last decade (2010-2021), and belong to the 1,4-disubstituted aromatic cyclic amine group. Due to the abundance of data, allosteric D₂ R ligands and D₂ R modulators from patents are not discussed in this review.

Augmentation strategies for treatment resistant major depression: A systematic review and network meta-analysis

OBJECTIVE

To compare the efficacy and discontinuation of augmentation agents in adult patients with treatment-resistant depression (TRD). We conducted a systematic review and network meta-analyses (NMA) to combine direct and indirect comparisons of augmentation agents.

METHODS

We included randomized controlled trials comparing one active drug with another or with placebo following a treatment course up to 24 weeks. Nineteen agents were included: stimulants, atypical antipsychotics, thyroid hormones, antidepressants, and mood stabilizers. Data for response/remission and all-cause discontinuation rates were analyzed. We estimated effect-size by relative risk using pairwise and NMA with random-effects model.

RESULTS

A total of 65 studies (N = 12,415) with 19 augmentation agents were included in the NMA. Our findings from the NMA for response rates, compared to placebo, were significant for: liothyronine, nortriptyline, aripiprazole, brexpiprazole, quetiapine, lithium, modafinil, olanzapine (fluoxetine), cariprazine, and lisdexamfetamine. For remission rates, compared to placebo, were significant for: thyroid hormone(T4), aripiprazole, brexpiprazole, risperidone, quetiapine, and olanzapine (fluoxetine). Compared to placebo, ziprasidone, mirtazapine, and cariprazine had statistically significant higher discontinuation rates. Overall, 24% studies were rated as having low risk of bias (RoB), 63% had moderate RoB and 13% had high RoB.

LIMITATIONS

Heterogeneity in TRD definitions, variable trial duration and methodological clinical design of older studies and small number of trials per comparisons.

CONCLUSIONS

This NMA suggests a superiority of the regulatory approved adjunctive atypical antipsychotics, thyroid hormones, dopamine compounds (modafinil and lisdexamfetamine) and lithium. Acceptability was lower with ziprasidone, mirtazapine, and cariprazine. Further research and head-to-head studies should be considered to strengthen the best available options for TRD.

Key considerations in the pharmacological management of treatment-resistant depression

Introduction: Treatment-resistant depression (TRD) is a complex, multifactorial, and biologically heterogeneous disorder with debilitating outcomes. Understanding individual reasons why patients do not respond to treatment is necessary for improving clinical recommendations regarding medication regimens, augmentation strategies, and alternative treatments.Areas covered: This manuscript reviews evidence-based treatment strategies for the clinical management of TRD. Current developments in the field and potential future recommendations for personalized treatment of TRD are also discussed.Expert opinion: Treatment guidelines for TRD are limited by the heterogeneous nature of the disorder. Furthermore, current strategies reflect this heterogeneity by emphasizing disease characteristics as well as drug trial response or failure. Developing robust biomarkers that could one day be integrated into clinical practice has the potential to advance specific treatment targets and ultimately improve treatment and remission outcomes.

Efficacy and Tolerability of Combination Treatments for Major Depression: Antidepressants plus Second-Generation Antipsychotics vs. Esketamine vs. Lithium

BACKGROUND

Successful treatment of major depressive disorder (MDD) can be challenging, and failures ("treatment-resistant depression" [TRD]) are frequent. Steps to address TRD include increasing antidepressant dose, combining antidepressants, adding adjunctive agents, or using nonpharmacological treatments. Their relative efficacy and tolerability remain inadequately tested. In particular, the value and safety of increasingly employed second-generation antipsychotics (SGAs) and new esketamine, compared to lithium as antidepressant adjuncts remain unclear.

METHODS

We reviewed randomized, placebo-controlled trials and used random-effects meta-analysis to compare odds ratio (OR) versus placebo, as well as numbers-needed-to-treat (NNT) and to-harm (NNH), for adding SGAs, esketamine, or lithium to antidepressants for major depressive episodes.

RESULTS

Analyses involved 49 drug-placebo pairs. By NNT, SGAs were more effective than placebo (NNT = 11 [CI: 9-15]); esketamine (7 [5-10]) and lithium (5 [4-10]) were even more effective. Individually, aripiprazole, olanzapine+fluoxetine, risperidone, and ziprasidone all were more effective (all NNT < 10) than quetiapine (NNT = 13), brexpiprazole (16), or cariprazine (16), with overlapping NNT CIs. Risk of adverse effects, as NNH for most-frequently reported effects, among SGAs versus placebo was 5 [4-6] overall, and highest with quetiapine (NNH = 3), lowest with brexpiprazole (19), 5 (4-6) for esketamine, and 9 (5-106) with lithium. The risk/benefit ratio (NNH/NNT) was 1.80 (1.25-10.60) for lithium and much less favorable for esketamine (0.71 [0.60-0.80]) or SGAs (0.45 [0.17-0.77]).

CONCLUSIONS

Several modern antipsychotics and esketamine appeared to be useful adjuncts to antidepressants for acute major depressive episodes, but lithium was somewhat more effective and better tolerated.

LIMITATIONS

Most trials of adding lithium involved older, mainly tricyclic, antidepressants, and the dosing of adjunctive treatments were not optimized.

Ziprasidone, a second-generation antipsychotic, affects core clock gene mRNA expression in mice

Some psychiatric diseases are associated with disruptions in the circadian clock system. Ziprasidone (ZIP), a second-generation antipsychotic, is widely used for psychiatry-related pharmacotherapy but its mechanism has not been clearly elucidated. We measured clock gene fluctuation patterns in the hippocampus and the amygdala in ZIP-treated mice. ZIP significantly increased Per1, Per2, and Bmal1 mRNA 2 h after the lights were turned off (ZT14) in the hippocampus, but not in the amygdala. These results suggest that ZIP might affect clock gene regulation, which could represent the pathway underlying symptom amelioration.

Pharmacological Treatments for Patients with Treatment-Resistant Depression

Over a third of patients with major depressive disorder (MDD) do not have an adequate response to first-line antidepressant treatments, i.e., they have treatment-resistant depression (TRD). These patients tend to have a more severe course of illness and are at an increased risk of suicide. Next step treatment options for patients with TRD, include switching to a different antidepressant, combining more than one antidepressant, or augmenting an antidepressant with another (non-antidepressant) medication. It is unclear which of these treatment approaches should be applied to a given patient, and in what order. Due to this ambiguity, comparing antidepressants and augmentation agents on the basis of their efficacy, tolerability, and speed of symptom relief would be beneficial for clinicians. To accomplish this, a systematic search was conducted following PRISMA guidelines. Only randomized controlled trials were included in this qualitative synthesis, resulting in 66 articles. This review identified several effective pharmaco-therapeutic strategies that are currently available for patients with TRD. Ketamine and esketamine appear to be effective for the treatment of TRD. Augmentation with certain second generation antipsychotics, such as quetiapine or aripiprazole is likewise effective, and may be preferred over switching to antidepressant monotherapy. While the combination of olanzapine and fluoxetine was one of the first pharmacotherapy approved for TRD, and its use may be limited by metabolic side-effects. Other effective strategies include augmentation with lithium, liothyronine (T3), lamotrigine, or combination of antidepressants including bupropion, tricyclics, or mirtazapine. There is insufficient research to demonstrate the efficacy of ziprasidone or levothyroxine (T4). A shared decision-making approach is recommended to guide treatment selection to address each patient’s individual needs.

The identification, assessment and management of difficult-to-treat depression: An international consensus statement

BACKGROUND

Many depressed patients are not able to achieve or sustain symptom remission despite serial treatment trials - often termed "treatment resistant depression". A broader, perhaps more empathic concept of "difficult-to-treat depression" (DTD) was considered.

METHODS

A consensus group discussed the definition, clinical recognition, assessment and management implications of the DTD heuristic.

RESULTS

The group proposed that DTD be defined as "depression that continues to cause significant burden despite usual treatment efforts". All depression management should include a thorough initial assessment. When DTD is recognized, a regular reassessment that employs a multi-dimensional framework to identify addressable barriers to successful treatment (including patient-, illness- and treatment-related factors) is advised, along with specific recommendations for addressing these factors. The emphasis of treatment, in the first instance, shifts from a goal of remission to optimal symptom control, daily psychosocial functional and quality of life, based on a patient-centred approach with shared decision-making to enhance the timely consideration of all treatment options (including pharmacotherapy, psychotherapy, neurostimulation, etc.) to optimize outcomes when sustained remission is elusive.

LIMITATIONS

The recommended definition and management of DTD is based largely on expert consensus. While DTD would seem to have clinical utility, its specificity and objectivity may be insufficient to define clinical populations for regulatory trial purposes, though DTD could define populations for service provision or phase 4 trials.

CONCLUSIONS

DTD provides a clinically useful conceptualization that implies a search for and remediation of specific patient-, illness- and treatment obstacles to optimizing outcomes of relevance to patients.

Pharmacological interventions for treatment-resistant depression in adults

BACKGROUND

Although antidepressants are often a first-line treatment for adults with moderate to severe depression, many people do not respond adequately to medication, and are said to have treatment-resistant depression (TRD). Little evidence exists to inform the most appropriate 'next step' treatment for these people.

OBJECTIVES

To assess the effectiveness of standard pharmacological treatments for adults with TRD.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register (CCMDCTR) (March 2016), CENTRAL, MEDLINE, Embase, PsycINFO and Web of Science (31 December 2018), the World Health Organization trials portal and ClinicalTrials.gov for unpublished and ongoing studies, and screened bibliographies of included studies and relevant systematic reviews without date or language restrictions.

SELECTION CRITERIA

Randomised controlled trials (RCTs) with participants aged 18 to 74 years with unipolar depression (based on criteria from DSM-IV-TR or earlier versions, International Classification of Diseases (ICD)-10, Feighner criteria or Research Diagnostic Criteria) who had not responded to a minimum of four weeks of antidepressant treatment at a recommended dose. Interventions were: (1) increasing the dose of antidepressant monotherapy; (2) switching to a different antidepressant monotherapy; (3) augmenting treatment with another antidepressant; (4) augmenting treatment with a non-antidepressant. All were compared with continuing antidepressant monotherapy. We excluded studies of non-standard pharmacological treatments (e.g. sex hormones, vitamins, herbal medicines and food supplements).

DATA COLLECTION AND ANALYSIS

Two reviewers used standard Cochrane methods to extract data, assess risk of bias, and resolve disagreements. We analysed continuous outcomes with mean difference (MD) or standardised mean difference (SMD) and 95% confidence interval (CI). For dichotomous outcomes, we calculated a relative risk (RR) and 95% CI. Where sufficient data existed, we conducted meta-analyses using random-effects models.

MAIN RESULTS

We included 10 RCTs (2731 participants). Nine were conducted in outpatient settings and one in both in- and outpatients. Mean age of participants ranged from 42 - 50.2 years, and most were female. One study investigated switching to, or augmenting current antidepressant treatment with, another antidepressant (mianserin). Another augmented current antidepressant treatment with the antidepressant mirtazapine. Eight studies augmented current antidepressant treatment with a non-antidepressant (either an anxiolytic (buspirone) or an antipsychotic (cariprazine; olanzapine; quetiapine (3 studies); or ziprasidone (2 studies)). We judged most studies to be at a low or unclear risk of bias. Only one of the included studies was not industry-sponsored. There was no evidence of a difference in depression severity when current treatment was switched to mianserin (MD on Hamilton Rating Scale for Depression (HAM-D) = -1.8, 95% CI -5.22 to 1.62, low-quality evidence)) compared with continuing on antidepressant monotherapy. Nor was there evidence of a difference in numbers dropping out of treatment (RR 2.08, 95% CI 0.94 to 4.59, low-quality evidence; dropouts 38% in the mianserin switch group; 18% in the control). Augmenting current antidepressant treatment with mianserin was associated with an improvement in depression symptoms severity scores from baseline (MD on HAM-D -4.8, 95% CI -8.18 to -1.42; moderate-quality evidence). There was no evidence of a difference in numbers dropping out (RR 1.02, 95% CI 0.38 to 2.72; low-quality evidence; 19% dropouts in the mianserin-augmented group; 38% in the control). When current antidepressant treatment was augmented with mirtazapine, there was little difference in depressive symptoms (MD on Beck Depression Inventory (BDI-II) -1.7, 95% CI -4.03 to 0.63; high-quality evidence) and no evidence of a difference in dropout numbers (RR 0.50, 95% CI 0.15 to 1.62; dropouts 2% in mirtazapine-augmented group; 3% in the control). Augmentation with buspirone provided no evidence of a benefit in terms of a reduction in depressive symptoms (MD on Montgomery and Asberg Depression Rating Scale (MADRS) -0.30, 95% CI -9.48 to 8.88; low-quality evidence) or numbers of drop-outs (RR 0.60, 95% CI 0.23 to 1.53; low-quality evidence; dropouts 11% in buspirone-augmented group; 19% in the control). Severity of depressive symptoms reduced when current treatment was augmented with cariprazine (MD on MADRS -1.50, 95% CI -2.74 to -0.25; high-quality evidence), olanzapine (MD on HAM-D -7.9, 95% CI -16.76 to 0.96; low-quality evidence; MD on MADRS -12.4, 95% CI -22.44 to -2.36; low-quality evidence), quetiapine (SMD -0.32, 95% CI -0.46 to -0.18; I2 = 6%, high-quality evidence), or ziprasidone (MD on HAM-D -2.73, 95% CI -4.53 to -0.93; I2 = 0, moderate-quality evidence) compared with continuing on antidepressant monotherapy. However, a greater number of participants dropped out when antidepressant monotherapy was augmented with an antipsychotic (cariprazine RR 1.68, 95% CI 1.16 to 2.41; quetiapine RR 1.57, 95% CI: 1.14 to 2.17; ziprasidone RR 1.60, 95% CI 1.01 to 2.55) compared with antidepressant monotherapy, although estimates for olanzapine augmentation were imprecise (RR 0.33, 95% CI 0.04 to 2.69). Dropout rates ranged from 10% to 39% in the groups augmented with an antipsychotic, and from 12% to 23% in the comparison groups. The most common reasons for dropping out were side effects or adverse events. We also summarised data about response and remission rates (based on changes in depressive symptoms) for included studies, along with data on social adjustment and social functioning, quality of life, economic outcomes and adverse events.

AUTHORS' CONCLUSIONS

A small body of evidence shows that augmenting current antidepressant therapy with mianserin or with an antipsychotic (cariprazine, olanzapine, quetiapine or ziprasidone) improves depressive symptoms over the short-term (8 to 12 weeks). However, this evidence is mostly of low or moderate quality due to imprecision of the estimates of effects. Improvements with antipsychotics need to be balanced against the increased likelihood of dropping out of treatment or experiencing an adverse event. Augmentation of current antidepressant therapy with a second antidepressant, mirtazapine, does not produce a clinically important benefit in reduction of depressive symptoms (high-quality evidence). The evidence regarding the effects of augmenting current antidepressant therapy with buspirone or switching current antidepressant treatment to mianserin is currently insufficient. Further trials are needed to increase the certainty of these findings and to examine long-term effects of treatment, as well as the effectiveness of other pharmacological treatment strategies.

Longer-term open-label study of adjunctive riluzole in treatment-resistant depression

BACKGROUND

While riluzole has been investigated for the treatment of depression, little is known about its longer-term efficacy and optimal treatment duration in treatment-resistant depression (TRD). The objective of this study is to characterize the longer-term outcome of adjunctive riluzole therapy for TRD in an open-label extension of an 8-week acute treatment trial.

METHODS

The data from 66 patients with TRD who received adjunctive riluzole in a 12-week open-label extension phase were analyzed. Response rates (⩾50% reduction in the Mongomery-Asberg Depression Rating Scale [MADRS] score), relapse rates (a MADRS score of ⩾22 in patients who had previously achieved response), and adverse events were examined in patients who had achieved response at the end of the acute phase and those who had not.

RESULTS

Among acute phase responders, the maintained response rate was 66.7% (8/12) and the relapse rate was 8.3% (1/12). In acute phase non-responders, the response rate was 24.1% (13/54). The most commonly reported adverse event was fatigue (9.1%). Three cases were considered serious adverse events; vomiting (n = 1), shortness of breath (n = 1), and aborted suicide attempt (n = 1).

LIMITATIONS

This longer-term study was open-label and uncontrolled. The sample size was relatively small.

CONCLUSIONS

Longer-term adjunctive riluzole appears relatively well tolerated and beneficial for maintaining previous response. Additionally, approximately one fourth of patients who did not respond to 8-week antidepressant treatment might respond if treated with riluzole for 12 weeks. Those findings warrant further investigation because adjunctive riluzole could represent an option for treatment of depression when standard antidepressants have failed.

Decreased Striatal Vesicular Monoamine Transporter Type 2 Correlates With the Nonmotor Symptoms in Parkinson Disease

OBJECTIVE

Nonmotor symptoms (NMS) are critical players in the patients' quality of life in Parkinson disease (PD). Vesicular monoamine transporter type 2 (VMAT2) has been reported owing to a role in affecting dopamine neurons in the striatum. Therefore, this study set out to characterize the relationship between VMAT2 distribution in the striatum in relation to the NMS in PD.

METHODS

Totally, 21 age-matched normal controls and 37 patients with PD in the moderate stages were included, followed by examination using F-DTBZ (F-AV133) PET/CT. The specific uptake ratio (SUR) of each striatal subregion was then determined with the occipital cortex as the reference background region. The overall NMSs of each individual patient were evaluated. Finally, the role of the striatal SURs in the clinical symptom scores were evaluated through the application of a Spearman correlation analysis as well as a multivariable stepwise regression analysis.

RESULTS

Patients with PD, particularly those at a more advanced stage, exhibited a more pronounced reduction in SURs in the bilateral putamen and caudate nucleus (P < 0.05, vs healthy controls). Meanwhile, patients at more advanced PD stages were found to have significantly worse scores in NMS except cognitive function. The Spearman correlation analysis demonstrated that NMS scores, with the exception of cognition scores, were correlated with striatal SURs (P < 0.05).

CONCLUSION

The key findings of the study identified a correlation between decreased striatal VMAT2 with a broad spectrum of NMS in patients with PD, highlighting the association between diminished dopamine supply and the development of NMS in PD.

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.

Scientific Issues Relevant to Improving the Diagnosis, Risk Assessment, and Treatment of Major Depression

Over the past two decades, research in the biology and treatment of major depression has led to advances in our understanding of the biology of the disorder and to the development of novel treatments. While progress has been made, a number of key issues have emerged regarding diagnosis of the disorder and how we develop and test new therapies. Among these are the potential need to include new dimensions in the diagnostic criteria, the limited utility of clinical predictors of response, the moving away from traditional blinded trials in major depression, and whether preclinical models tell us much about novel drug development. These issues need to be addressed to avoid the field's embarking on trails of research and treatment development that could actually mislead or misdirect our efforts to develop better diagnostic tools and more effective treatments. Possible solutions to these problems are proposed.

Treating depression with adjunctive antipsychotics

OBJECTIVES

To evaluate the efficacy and safety of using adjunctive antipsychotics in patients with major depressive disorder.

METHOD

Studies published since the last Cochrane review conducted in 2010 were identified via a literature search of recognised databases, using the keywords "adjunct*", "augment*", "antipsychotic" and "depression", and systematically evaluated. A targeted review of relevant guidelines was undertaken.

RESULTS

Adjunctive antipsychotics produce a small but significant improvement in depressive symptoms in most studies. Most of the studies focussed on patients with an inadequate response to antidepressants rather than patients with treatment resistant depression. Treatment guidelines were variable but generally supported the use of adjunctive antipsychotics while cautioning about the risk of side effects. Most were non-specific about the length of time adjunctive antipsychotics should be prescribed.

CONCLUSIONS

The studies do not support the routine use of adjunctive antipsychotics in patients with an inadequate response to antidepressants. They may be beneficial when used short-term in patients with treatment resistant depression who have specific symptoms (severe ruminations, melancholia, major sleep disturbance) that appear to respond well to adjunctive antipsychotics. There is no support for long-term use. Research should focus on specifying which symptom profiles are responsive and how adjunctive antipsychotics compare to other strategies in treatment resistant depression.

[Consequences of the monoaminergic systems cross-talk in the antidepressant activity]

Selective serotonin reuptake inhibitors (SSRIs) are the most prescribed antidepressant treatment for treat major depressive disorders. Despite their effectiveness, only 30% of SSRI-treated patients reach remission of depressive symptoms. SSRIs by inhibiting the serotonin transporter present some limits with residual symptoms. Increasing not only serotonin but also norepinephrine and dopamine levels in limbic areas seems to improve remission. Anatomical relationships across serotoninergic, dopaminergic and noradrenergic systems suggest tight reciprocal regulations among them. This review attempts to present, from acute to chronic administration the consequences of SSRI administration on monoaminergic neurotransmission. The serotonin neurons located in the raphe nucleus (RN) are connected to the locus coeruleus (locus coeruleus), the key structure of norepinephrine synthesis, through GABAergic-inhibiting interneurons. Activation of the 5-HT_2A receptors expressed on GABAergic interneurons following SERT-inhibition induces an increase in serotonin leading to inhibitory effect on NE release. Similarly, the serotonin neurons exert negative regulation on dopaminergic neurons from the ventral tegmental area (VTA) through a GABAergic interneuron. These interneurons express the 5-HT_2C and 5-HT₃ receptors inducing an inhibitory effect of 5-HT on DA release. Positive reciprocal connections are also observed through direct projections from the locus coeruleus to the RN and from the VTA to the RN through α₁ and D₂ receptors respectively, both stimulating the serotoninergic activity. Acute SSRI treatment induces only a slight increase in 5-HT levels in limbic areas due to the activation of presynaptic 5-HT_1A and 5-HT_1B autoreceptors counteracting the effects of the transporter blockade. No change in NE levels and a small decrease in the dopaminergic neurotransmission is also observed. These weak changes in monoamine in the limbic areas after acute SSRI treatment seems to be one of key point involved in the onset of action. Following desensitization of the 5-HT_1A and 5-HT_1B autoreceptors, chronic SSRI treatment induces a large increase in the 5-HT neurotransmission. Changes in 5-HT levels at the limbic areas results in a decrease in NE transmission and an increase in DA transmission through an increase in the post-synaptic D₂ receptors sensitivity and not from a change in DA levels, which is mainly due to a desensitization of the 5-HT_2A receptor. The observed decrease of NE neurotransmission could explain some limits of the SSRI therapy and the interest to activate NE system for producing more robust effects. On the other hand, the D₂ sensitization, especially in the nucleus accumbens, stimulates the motivation behavior as well as remission of anhedonia considering the major role of DA release in this structure. Finally, we need to take into account the key role of each monoaminergic neurotransmission to reach remission. Targeting only one system will limit the therapeutic effectiveness. Clinical evidences, including the STAR*D studies, confirmed this by an increase of the remission rate following the mobilization of several monoaminergic transmissions. However, these combinations cannot constitute first line of treatment considering the observed increase of side effects. Such an approach should be adapted to each patient in regard to its particular symptoms as well as clinical history. The next generation of antidepressant therapy will need to take into consideration the interconnections and the interrelation between the monoaminergic systems.

Alterations in amino acid levels in mouse brain regions after adjunctive treatment of brexpiprazole with fluoxetine: comparison with (R)-ketamine

RATIONALE

Brexpiprazole, a serotonin-dopamine activity modulator, is approved in the USA as an adjunctive therapy to antidepressants for treating major depressive disorders. Similar to the N-methyl-D-aspartate receptor (NMDAR) antagonist ketamine, the combination of brexpiprazole and fluoxetine has demonstrated antidepressant-like effects in animal models of depression.

OBJECTIVES

The present study was conducted to examine whether the combination of brexpiprazole and fluoxetine could affect the tissue levels of amino acids [glutamate, glutamine, γ-aminobutyric acid (GABA), D-serine, L-serine, and glycine] that are associated with NMDAR neurotransmission.

METHODS

The tissue levels of amino acids in the frontal cortex, striatum, hippocampus, and cerebellum were measured after a single [or repeated (14 days)] oral administration of vehicle, fluoxetine (10 mg/kg), brexpiprazole (0.1 mg/kg), or a combination of the two drugs. Furthermore, we measured the tissue levels of amino acids after a single administration of the NMDAR antagonist (R)-ketamine.

RESULTS

A single injection of the combination of fluoxetine and brexpiprazole significantly increased GABA levels in the striatum, the D-serine/L-serine ratio in the frontal cortex, and the glycine/L-serine ratio in the hippocampus. A repeated administration of the combination significantly altered the tissue levels of amino acids in all regions. Interestingly, a repeated administration of the combination significantly decreased the D-serine/L-serine ratio in the frontal cortex, striatum, and hippocampus. In contrast, a single administration of (R)-ketamine significantly increased the D-serine/L-serine ratio in the frontal cortex.

CONCLUSIONS

These results suggested that alterations in the tissue levels of these amino acids may be involved in the antidepressant-like effects of the combination of brexpiprazole and fluoxetine.

Investigational drugs in recent clinical trials for treatment-resistant depression

INTRODUCTION

The authors describe the medications for treatment-resistant depression (TRD) in phase II/III of clinical development in the EU and USA and provide an opinion on how current treatment can be improved in the near future. Areas covered: Sixty-two trials were identified in US and EU clinical trial registries that included six investigational compounds in recent phase III development and 12 others in recent phase II clinical trials. Glutamatergic agents have been the focus of many studies. A single intravenous dose of the glutamatergic modulator ketamine produces a robust and rapid antidepressant effect in persons with TRD; this effect continues to remain significant for 1 week. This observation was a turning point that opened the way for other, more selective glutamatergic modulators (intranasal esketamine, AVP-786, AVP-923, AV-101, and rapastinel). Of the remaining compounds, monoclonal antibodies open highly innovative therapeutic options, based on new pathophysiological approaches to depression. Expert commentary: Promising new agents are emerging for TRD treatment. Glutamatergic modulators likely represent a very promising alternative to monoaminergic antidepressant monotherapy. We could see the arrival of the first robust and rapid acting antidepressant drug in the near future, which would strongly facilitate the ultimate goal of recovery in persons with TRD.

A neuroimaging study of emotion-cognition interaction in schizophrenia: the effect of ziprasidone treatment

Functional and structural brain changes associated with the cognitive processing of emotional visual stimuli were assessed in schizophrenic patients after 16 weeks of antipsychotic treatment with ziprasidone. Forty-five adults aged 18 to 40 were recruited: 15 schizophrenia patients (DSM-IV criteria) treated with ziprasidone (mean daily dose = 120 mg), 15 patients treated with other antipsychotics, and 15 healthy controls who did not receive any medication. Functional and structural neuroimaging data were acquired at baseline and 16 weeks after treatment initiation. In each session, participants selected stimuli, taken from standardized sets, based on their emotional valence. After ziprasidone treatment, several prefrontal regions, typically involved in cognitive control (anterior cingulate and ventrolateral prefrontal cortices), were significantly activated in patients in response to positive versus negative stimuli. This effect was greater whenever they had to select negative compared to positive stimuli, indicating an asymmetric effect of cognitive treatment of emotionally laden information. No such changes were observed for patients under other antipsychotics. In addition, there was an increase in the brain volume commonly recruited by healthy controls and patients under ziprasidone, in response to cognitive processing of emotional information. The structural analysis showed no significant changes in the density of gray and white matter in ziprasidone-treated patients compared to patients receiving other antipsychotic treatments. Our results suggest that functional changes in brain activity after ziprasidone medication precede structural and clinical manifestations, as markers that the treatment is efficient in restoring the functionality of prefrontal circuits involved in processing emotionally laden information in schizophrenia.

Experimental medication treatment approaches for depression

Depression is one of the most common psychiatric conditions. Symptoms can lead to significant disability, which result in impairments in overall quality of life. Though there are many approved antidepressant treatments for depression-including selective serotonin reuptake inhibitors, tricyclic antidepressants and monoamine oxidase inhibitors-about a third of patients do not respond to these medications. Therefore, it is imperative for drug discovery to continue towards the development of novel and rapidly acting compounds, especially for patients with treatment-resistant depression. After a brief review of the efficacy of approved antidepressant therapies, we will discuss experimental medication treatments for depression. Specifically, we examine novel medications that are thought to primarily modulate the glutamatergic, cholinergic and opioid systems to achieve antidepressant efficacy. We also give examples of anti-inflammatories, neurokinin-1 modulators, vasopressin antagonists and neurogenesis enhancers that may have a therapeutic role in treatment-resistant depression. The current pipeline of antidepressant treatments is shifting towards medications with novel mechanisms, which may lead to important, life-changing discoveries for patients with severe disease.

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.

Antidepressant effects of combination of brexpiprazole and fluoxetine on depression-like behavior and dendritic changes in mice after inflammation

RATIONALE

Addition of low doses of atypical antipsychotic drugs with selective serotonin reuptake inhibitors (SSRIs) could promote a rapid antidepressant effect in treatment-resistant patients with major depression. Brexpiprazole, a new atypical antipsychotic drug, has been used as adjunctive therapy for the treatment of major depression.

OBJECTIVES

The present study was undertaken to examine whether brexpiprazole could augment antidepressant effects of the SSRI fluoxetine in an inflammation model of depression.

METHODS

We examined the effects of fluoxetine (10 mg/kg), brexpiprazole (0.1 mg/kg), or the combination of the two drugs on depression-like behavior, alterations in the brain-derived neurotrophic factor (BDNF) - TrkB signaling, and dendritic spine density in selected brain regions after administration of lipopolysaccharide (LPS) (0.5 mg/kg).

RESULTS

Combination of brexpiprazole and fluoxetine promoted a rapid antidepressant effect in inflammation model although brexpipazole or fluoxetine alone did not show antidepressant effect. Furthermore, the combination significantly improved LPS-induced alterations in the BDNF - TrkB signaling and dendritic spine density in the prefrontal cortex, CA3 and dentate gyrus, and nucleus accumbens.

CONCLUSIONS

These results suggest that add-on of brexpiprazole to fluoxetine can produce a rapid antidepressant effect in the LPS inflammation model of depression, indicating that adjunctive therapy of brexpiprazole to SSRIs could produce a rapid antidepressant effect in depressed patients with inflammation.

The Role of Norepinephrine and Its α-Adrenergic Receptors in the Pathophysiology and Treatment of Major Depressive Disorder and Schizophrenia: A Systematic Review

Norepinephrine (NE) is recognized as having a key role in the pathophysiology of major depressive disorder (MDD) and schizophrenia, although its distinct actions via α-adrenergic receptors (α-ARs) are not well defined. We performed a systematic review examining the roles of NE and α-ARs in MDD and schizophrenia. PubMed and ProQuest database searches were performed to identify English language papers published between 2008 and 2015. In total, 2,427 publications (PubMed, n = 669; ProQuest, n = 1,758) were identified. Duplicates, articles deemed not relevant, case studies, reviews, meta-analyses, preclinical reports, or articles on non-target indications were excluded. To limit the review to the most recent data representative of the literature, the review further focused on publications from 2010 to 2015, which were screened independently by all authors. A total of 16 research reports were identified: six clinical trial reports, six genetic studies, two biomarker studies, and two receptor studies. Overall, the studies provided indirect evidence that α-AR activity may play an important role in aberrant regulation of cognition, arousal, and valence systems associated with MDD and schizophrenia. Characterization of the NE pathway in patients may provide clinicians with information for more personalized therapy of these heterogeneous diseases. Current clinical studies do not provide direct evidence to support the role of NE α-ARs in the pathophysiology of MDD and schizophrenia and in the treatment response of patients with these diseases, in particular with relation to specific valence systems. Clinical studies that attempt to define associations between specific receptor binding profiles of psychotropics and particular clinical outcomes are needed.

Adjunctive treatment of brexpiprazole with fluoxetine shows a rapid antidepressant effect in social defeat stress model: Role of BDNF-TrkB signaling

Addition of low doses of the atypical antipsychotic drug brexpiprazole with selective serotonin reuptake inhibitors (SSRIs) could promote antidepressant effect in patients with major depressive disorder although the precise mechanisms underlying the action of the combination are unknown. Combination of low dose of brexpiprazole (0.1 mg/kg) and SSRI fluoxetine (10 mg/kg) could promote a rapid antidepressant effect in social defeat stress model although brexpiprazole or fluoxetine alone did not show antidepressant effect. Furthermore, the combination significantly improved alterations in the brain-derived neurotrophic factor (BDNF) - TrkB signaling and dendritic spine density in the prefrontal cortex, hippocampus, and nucleus accumbens in the susceptible mice after social defeat stress. Interestingly, TrkB antagonist ANA-12 significantly blocked beneficial effects of combination of brexpiprazole and fluoxetine on depression-like phenotype. These results suggest that BDNF-TrkB signaling plays a role in the rapid antidepressant action of the combination of brexpiprazole and fluoxetine.

Ziprasidone augmentation for anxious depression

Previously, we found an anxiolytic effect of ziprasidone augmentation to escitalopram (compared with placebo augmentation) in patients with depression in an 8-week, randomized, double-blind, parallel-group, placebo-controlled trial. Here, we carried out a post-hoc analysis, comparing changes in the Hamilton Depression and Anxiety Rating Scales between patients with anxious depression versus nonanxious depression, using a moderator analysis. Hamilton Depression Rating Scales total change scores from baseline and endpoint were not significantly different (interaction term P=0.91) in patients with anxious depression on ziprasidone augmentation (n=19; -9.1±4.9) or placebo (n=19; -6.1±8.9) versus patients without anxious depression on ziprasidone (n=52; -5.5±6.7) or placebo (n=49; -2.3±4.5). There was a trend toward statistical significance (interaction term P=0.1) in favor of patients without anxious depression for a difference in Hamilton Anxiety Rating Scale total change scores from baseline to endpoint [patients with anxious depression on ziprasidone augmentation (n=19; -2.7±5.3) or placebo (n=19; -3.3±5.8) versus patients without anxious depression on ziprasidone (n=51; -3.9±6.6) or placebo (n=44; -0.9±4.7)]. Ziprasidone augmentation was equally efficacious in treating depression in patients with versus without anxious depression. However, the observed anxiolytic effect for patients with higher anxiety was not clinically significant.

Second Generation Antipsychotics in the Treatment of Major Depressive Disorder: An Update

Less than one third of patients who suffer from major depressive disorder (MDD) report remission following antidepressant treatments requiring more diverse treatment approaches. Augmentation of second generation antipsychotics (SGAs) has been increasingly recognized as an important treatment option. The authors have previously provided a comprehensive review of SGAs for the treatment of MDD in 2013. Since then, numerous additional clinical trials have been conducted to investigate diverse issues regarding the utility of SGAs in MDD. Moreover, a new SGA, brexpiprazole, was recently approved by the Food and Drug Administration in July 2015 for the treatment of MDD as an augmentation agent to antidepressants. Thus, the aim of this study was to provide a concise update of all the available SGAs for the treatment of MDD, in particular on the additional clinical trials which have been published since 2013.

Canadian Network for Mood and Anxiety Treatments (CANMAT) 2016 Clinical Guidelines for the Management of Adults with Major Depressive Disorder: Section 3. Pharmacological Treatments

BACKGROUND

The Canadian Network for Mood and Anxiety Treatments (CANMAT) conducted a revision of the 2009 guidelines by updating the evidence and recommendations. The scope of the 2016 guidelines remains the management of major depressive disorder (MDD) in adults, with a target audience of psychiatrists and other mental health professionals.

METHODS

Using the question-answer format, we conducted a systematic literature search focusing on systematic reviews and meta-analyses. Evidence was graded using CANMAT-defined criteria for level of evidence. Recommendations for lines of treatment were based on the quality of evidence and clinical expert consensus. "Pharmacological Treatments" is the third of six sections of the 2016 guidelines. With little new information on older medications, treatment recommendations focus on second-generation antidepressants.

RESULTS

Evidence-informed responses are given for 21 questions under 4 broad categories: 1) principles of pharmacological management, including individualized assessment of patient and medication factors for antidepressant selection, regular and frequent monitoring, and assessing clinical and functional outcomes with measurement-based care; 2) comparative aspects of antidepressant medications based on efficacy, tolerability, and safety, including summaries of newly approved drugs since 2009; 3) practical approaches to pharmacological management, including drug-drug interactions and maintenance recommendations; and 4) managing inadequate response and treatment resistance, with a focus on switching antidepressants, applying adjunctive treatments, and new and emerging agents.

CONCLUSIONS

Evidence-based pharmacological treatments are available for first-line treatment of MDD and for management of inadequate response. However, given the limitations of the evidence base, pharmacological management of MDD still depends on tailoring treatments to the patient.

Adverse Effects of Second-Generation Antipsychotics as Adjuncts to Antidepressants: Are the Risks Worth the Benefits?

Over the past decades, several adjunctive therapies have been introduced for treatment-resistant depression (TRD), and these strategies have ebbed and flowed in popularity. Currently, adjunctive therapy with the second-generation antipsychotics (SGAs) is most commonly used by psychiatrists. Four SGAs are FDA approved for indications related to TRD (aripiprazole, brexpiprazole, olanzapine, and quetiapine extended release); some evidence also supports use of risperidone and ziprasidone as adjunctive therapies. This article briefly reviews the role of adjunctive therapy with SGAs in contemporary algorithms for TRD, considering both the evidence of benefit and the adverse effects.

Optimizing the Use of Aripiprazole Augmentation in the Treatment of Major Depressive Disorder: From Clinical Trials to Clinical Practice

Major depressive disorder (MDD) is a recurrent, chronic, and devastating disorder leading to serious impairment in functional capacity as well as increasing public health care costs. In the previous decade, switching therapy and dose adjustment of ongoing antidepressants was the most frequently chosen subsequent treatment option for MDD. However, such recommendations were not based on firmly proven efficacy data from well-designed, placebo-controlled, randomized clinical trials (RCTs) but on practical grounds and clinical reasoning. Aripiprazole augmentation has been dramatically increasing in clinical practice owing to its unique action mechanisms as well as proven efficacy and safety from adequately powered and well-controlled RCTs. Despite the increased use of aripiprazole in depression, limited clinical information and knowledge interfere with proper and efficient use of aripiprazole augmentation for MDD. The objective of the present review was to enhance clinicians' current understanding of aripiprazole augmentation and how to optimize the use of this therapy in the treatment of MDD.