Sustained Treatment Response and Global Improvements With Long-term Valbenazine in Patients With Tardive Dyskinesia.

PURPOSE/BACKGROUND: Using data from KINECT® 4, a phase 3, 48-week study of valbenazine, post hoc analyses were conducted to assess long-term outcomes that are relevant to the real-world management of tardive dyskinesia (TD). METHODS/PROCEDURES: Post hoc analyses of the participants of the KINECT 4 study who completed 48 weeks of open-label valbenazine (40 or 80 mg) treatment were conducted. Valbenazine effects on TD were evaluated using the Abnormal Involuntary Movement Scale (AIMS), Clinical Global Impression of Change-TD (CGI-TD), and Patient Global Impression of Change (PGIC). FINDINGS/RESULTS: Of 103 participants completing 48 weeks of treatment, 55% experienced clinically meaningful improvement (defined as ≥2-point reduction in AIMS total score [sum of items 1-7, evaluated by site raters]) by week 4; at week 48, 97% met this threshold. The percentage of completers who achieved AIMS total score response thresholds of ≥10% to ≥90% increased over time, with 86% of completers reaching ≥50% improvement. Of the 40 (39%) completers with AIMS ≥50% response at week 8, 38 (95%) sustained this response at week 48; 81% of those who did not meet this threshold at week 8 had achieved it by week 48. At week 48, more than 85% of completers achieved CGI-TD and PGIC ratings of "much improved" or "very much improved." IMPLICATIONS/CONCLUSIONS: The majority of participants who completed 48 weeks of treatment with once-daily valbenazine experienced substantial clinically meaningful and sustained TD improvements. These findings indicate that valbenazine can be a highly effective long-term treatment in patients with TD.

Implementation of Cognitive Behavioral Therapy for psychosis via telehealth: An expert consultation and clinical service model.

Individuals living with psychosis are often underserved in the United States, partly due to the dearth of providers trained in evidence-based practices for this population. One such practice is Cognitive Behavioral Therapy for psychosis, which the Substance Abuse and Mental Health Services Administration has identified as a standard of care for this population. The explosion of telehealth, in large part due to the COVID-19 pandemic, has led to increased opportunities for virtual psychotherapy. Telehealth offers a number of benefits, such as the ability to address service inequities, including lack of access to a local provider well-trained in the modality of therapy needed. The current article describes the National Psychosis Telehealth Program within the National Expert Consultation and Specialized Services (formerly VA National Telemental Health Center) program, U.S. Department of Veterans Affairs. The goal of this telehealth program is to utilize an expert consultation model and offer a remote individual, time-limited Cognitive Behavioral Therapy for psychosis protocol to Veterans across the nation in order to decrease access disparities to this relatively scarce service. We share our initiation activities and lessons learned as we developed this program in hopes of encouraging others to consider similar efforts at their sites. We also include a typical, complex case that serves to illustrate the challenges and benefits of this approach. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Relapse in clinically stable adult patients with schizophrenia or schizoaffective disorder: evidence-based criteria derived by equipercentile linking and diagnostic test accuracy meta-analysis.

BACKGROUND: There is no consensus on defining relapse in schizophrenia, and scale-derived criteria with unclear clinical relevance are widely used. We aimed to develop an evidence-based scale-derived set of criteria to define relapse in patients with schizophrenia or schizoaffective disorder. METHODS: We searched the Yale University Open Data Access (YODA) for randomised controlled trials (RCTs) in clinically stable adults with schizophrenia or schizoaffective disorder, and obtained individual participant data on Positive and Negative Syndrome Scale (PANSS), Clinical Global Impression Severity (CGI-S), Personal and Social Performance (PSP), and Social and Occupational Functioning Assessment Scale (SOFAS). Our main outcomes were PANSS-derived criteria based on worsening in PANSS total score. We examined their relevance using equipercentile linking with CGI-S and functioning scales, and their test-performance in defining relapse with diagnostic test accuracy meta-analysis against CGI-S worsening (≥1-point increase together with a score ≥4 points) and psychiatric hospitalisation. FINDINGS: Based on data from seven RCTs (2354 participants; 1348 men [57·3%] and 1006 women [42·7%], mean age of 39·5 years [SD 12·0, range 17-89]; 303 Asian [12.9%], 255 Black [10.8%], 1665 White [70.7%], and other or unspecified 131 [5.6%]), an increase of 12 points or more in PANSS total (range 30-210 points) corresponded to clinically important deterioration in global severity of illness (≥1 point increase in CGI-S, range 1-7) and functioning (≥10 points decline in PSP or SOFAS, range 1-100). The interpretation of percentage changes varied importantly across different baseline scores. An increase of 12 points or more in PANSS total had good sensitivity and specificity using CGI-S as reference standard (sensitivity 82·1% [95% CI 77·1-86·4], specificity 86·9% [82·9-90·3]), as well as good sensitivity but lower specificity compared to hospitalisation (sensitivity 81·7% [74·1-87·7], specificity 69·2% [60·5-76·9]). Requiring either an increase in PANSS total or in specific items for positive and disorganization symptoms further improved test-performance. Cutoffs for situations where high sensitivity or specificity is needed are presented. INTERPRETATION: An increase of either 12 points or more in the PANSS total score, or worsening of specific positive and disorganisation symptom items could be a reasonable evidence-based definition of relapse in schizophrenia, potentially linking symptoms used to define remission and relapse. Percentage changes should not be used to define relapse because their interpretation depends on baseline scores. FUNDING: German Research Foundation (grant number: 428509362).

Negative symptoms in schizophrenia: Newly emerging measurements, pathways, and treatments.

The negative symptoms of schizophrenia, which often appear earlier than any other symptom, are prominent and clinically relevant in the majority of patients. As a result, interest in their treatment has increased. Patients who exhibit significant negative symptoms have worse functional outcomes than those without, resulting in impairments in occupational, household, and recreational functioning, as well as difficulties in relationships. Yet treatment with currently available medications does not lead to any significant improvements in this core component of schizophrenia. An increased understanding of the pathophysiology underlying negative symptoms and the discovery of novel treatments that do not directly target dopamine offer the potential to develop therapies that may reduce negative symptoms and increase quality of life for patients. The current article will discuss the impact of negative symptoms, outline current measurement tools for the assessment of negative symptoms, and examine how these measures may be improved. Insights into the neural circuitry underlying negative symptoms will be discussed, and promising targets for the development of effective treatments for these symptoms will be identified. As more prospective, large-scale, randomized studies focus on the effects of treatments on negative symptoms, progress in this area is foreseeable. However, improvements in clinical assessment instruments, a better understanding of the underlying neural mechanisms, development of novel treatments with varied targets, and a greater focus on personalized treatment are all important to produce significant benefits for patients with negative symptoms of schizophrenia.

Psychosis among individuals with methamphetamine use disorder is associated with elevated rates of hospitalizations and emergency department visits across an academic health care system.

INTRODUCTION: Methamphetamine (MA) is increasingly available in the United States and manufactured with increasing potency. Although psychosis is a known harm related to MA use, we know little about the clinical outcomes and prognosis of individuals who use MA and experience psychosis. Some evidence exists that psychosis among people who use methamphetamine leads to a high utilization of emergency and acute inpatient services, but the extent of this use is unclear. METHODS: Using an electronic health record (EHR) database, this study assessed acute care visits of individuals receiving diagnostic codes of the following disorders: methamphetamine use disorder with undifferentiated psychosis (MUDp), schizophrenia (MUDs) and no history of psychosis (MUD) in addition to individuals without MUD diagnosis but with diagnoses of either undifferentiated psychosis (Psy) or schizophrenia (Scz) from 2006 to 2019. The study explored potential clinical risk factors associated with rate of acute care visits. RESULTS: Receiving diagnoses of psychotic disorders and MUD were both associated with high rates of acute care utilization. The incidence rate ratio (IRR) was highest in the MUDp group 6.30 (95% CI: 5.73, 6.93) followed by the MUDs group 4.03 (95% CI: 3.87, 4.20), the Psy group 3.77 (95% CI: 3.45, 4.11), the Scz group 3.11 (95% CI: 2.99, 3.23), and the MUD group 2.17 (95% CI: 2.09, 2.25). Receiving another SUD diagnosis was identified as a risk factor for acute care visits in the MUDp group, and mood and anxiety disorder diagnoses were a risk factor in the MUDs group. CONCLUSIONS: In a general health care system, individuals receiving diagnoses of MUD and co-occurring psychotic disorders were observed to have particularly high rates of acute care service utilization, suggesting a high degree of disease burden and the need for development of targeted treatment interventions with both MUD and psychosis.

N-Acetylcysteine effects on glutathione and glutamate in schizophrenia: A preliminary MRS study.

N-acetylcysteine (NAC) is a commonly used antioxidant that may have beneficial effects for schizophrenia. In this double-blind, randomized, placebo-controlled preliminary study, 40 patients with schizophrenia or schizoaffective disorder were randomized to receive 2400 mg NAC daily or placebo over eight weeks to examine the effects of NAC on prefrontal magnetic resonance spectroscopy levels of glutathione and glutamate. Secondary outcomes included negative symptoms, cognition, and plasma glutathione levels. We found that NAC treatment was associated with increased glutathione (statistically significant) and decreased glutamate (trend-level) compared with placebo in medial prefrontal cortex but not dorsolateral prefrontal cortex. We also observed a baseline association between medial prefrontal cortex levels of glutathione and plasma reduced / oxidized glutathione ratios. No treatment effects on symptoms or cognition were observed. Taken together, these findings indicate that treatment with N-acetylcysteine may increase medial prefrontal cortical levels of glutathione after eight weeks of treatment. These changes in cortical levels of glutathione may serve as an early biomarker of later clinical change and may underlie the cognitive and symptomatic improvements reported in longer-term treatment studies.

Comparative risks of all-cause mortality for Veterans with schizophrenia with ongoing receipt of clozapine and other antipsychotic medications.

To guide care for patients with schizophrenia, the Veterans Health Administration (VHA) evaluated the associations between current or recent use of clozapine and all-cause mortality and explored associations for other antipsychotic medications. Using a case-control design, patients with schizophrenia who died in fiscal years 2014-2018 were matched on age, sex, race, and VHA facility to up to 10 controls who were alive on the case's date of death (index date). Medication coverage during the 91 days before the index date was classified as none, partial (1-44 days), and consistent (45-91 days). Medication coverage patterns during the index period were compared to coverage patterns during the period of 92-182 days prior to index date with each medication coverage classified as no change, no coverage, increased, or decreased. Conditional logistic regression analyses controlling for patient characteristics identified no associations of consistent or increasing clozapine coverage with mortality; partial and decreasing coverage were associated with greater mortality and these effects did not differ from those of other the medications considered. Exploratory analyses considering non-clozapine antipsychotic agents suggest that consistent coverage by olanzapine may be associated with increased mortality, that mortality associated with olanzapine may be greater than aripiprazole, and that this effect can be attributed primarily to patients with diabetes. Further study of this topic is needed.

Examining racial differences in community integration between black and white homeless veterans.

Black Americans are overrepresented in Veteran and non-Veteran homeless populations. Community integration remains a problem for many Veterans after they obtain housing, and Black Veterans may encounter additional difficulties due to systemic racism. However, no prior study has specifically examined whether there are racial differences in community integration; similarly, no study has considered racial differences in psychosocial correlates of community integration in homeless Veterans. Knowledge of these factors could inform the development of culturally congruent rehabilitative interventions for Black Veterans. Semi-structured clinical interviews were administered to Black (N = 99) and White (N = 49) homeless Veterans to examine relations among psychiatric symptoms, motivation, and community integration domains (e.g., social integration, work productivity, and independent living). There were no significant racial differences in independent living or work productivity. Black Veterans had better social integration with family compared to White Veterans. In addition, psychiatric symptoms were more strongly correlated with social integration for Black than White Veterans. The association between motivation and work productivity was also stronger for Black Veterans. Recovery-oriented interventions could harness family connections and better target psychiatric symptoms to improve community integration for Black Veterans. Work productivity may improve from interventions aimed at enhancing motivation for Black Veterans.

Motivational and cognitive factors linked to community integration in homeless veterans: study 1 - individuals with psychotic disorders.

BACKGROUND: Little is known about the determinants of community integration (i.e. recovery) for individuals with a history of homelessness, yet such information is essential to develop targeted interventions. METHODS: We recruited homeless Veterans with a history of psychotic disorders and evaluated four domains of correlates of community integration: perception, non-social cognition, social cognition, and motivation. Baseline assessments occurred after participants were engaged in supported housing services but before they received housing, and again after 12 months. Ninety-five homeless Veterans with a history of psychosis were assessed at baseline and 53 returned after 12 months. We examined both cross-sectional and longitudinal relationships with 12-month community integration. RESULTS: The strongest longitudinal association was between a baseline motivational measure and social integration at 12 months. We also observed cross-sectional associations at baseline between motivational measures and community integration, including social, work, and independent living. Cross-lagged panel analyses did not suggest causal associations for the motivational measures. Correlations with perception and non-social cognition were weak. One social cognition measure showed a significant longitudinal correlation with independent living at 12 months that was significant for cross-lagged analysis, consistent with a causal relationship and potential treatment target. CONCLUSIONS: The relatively selective associations for motivational measures differ from what is typically seen in psychosis, in which all domains are associated with community integration. These findings are presented along with a partner paper (Study 2) to compare findings from this study to an independent sample without a history of psychotic disorders to evaluate the consistency in findings regarding community integration across projects.

Effects of Brexpiprazole Across Symptom Domains in Patients With Schizophrenia: Post Hoc Analysis of Short- and Long-Term Studies.

The successful treatment of schizophrenia entails improvement across a spectrum of symptoms. The aim of this post hoc analysis was to characterize the short- and long-term effects of brexpiprazole on Positive and Negative Syndrome Scale (PANSS) 'Marder factors.' Data were included from three 6-week, randomized, double-blind, placebo-controlled studies; a 52-week, randomized, double-blind, placebo-controlled maintenance treatment study; and two 52-week open-label extension (OLEx) studies-all in schizophrenia (DSM-IV-TR criteria). Patients receiving oral brexpiprazole were dosed at 2-4 mg/day (short-term studies) or 1-4 mg/day (long-term studies). At Week 6, least squares mean differences (LSMDs, with 95% confidence limits [CLs]) for brexpiprazole (n = 868) vs placebo (n = 517) were: Positive symptoms: -1.55 (-2.30, -0.80), P < .0001, Cohen's d effect size (ES) = 0.27; Negative symptoms: -1.12 (-1.63, -0.61), P < .0001, ES = 0.29; Disorganized thought: -1.26 (-1.78, -0.74), P < .0001, ES = 0.32; Uncontrolled hostility/excitement: -0.76 (-1.15, -0.37), P = .0002, ES = 0.26; Anxiety/ depression: -0.56 (-0.91, -0.22), P = .0014, ES = 0.22. At last visit of the maintenance study, LSMDs (95% CLs) for brexpiprazole (n = 96) vs placebo (n = 104) were: Positive symptoms: -3.44 (-4.99, -1.89), P < .0001, ES = 0.62; Negative symptoms: -1.23 (-2.52, 0.07), P = .063, ES = 0.27; Disorganized thought: -1.69 (-2.81, -0.56), P = .0035, ES = 0.42; Uncontrolled hostility/excitement: -1.26 (-2.12, -0.39), P = .0046, ES = 0.41; Anxiety/depression: -0.72 (-1.47, 0.03), P = .061, ES = 0.27. In the OLEx studies, improvements were maintained over 58 (6 + 52) weeks of brexpiprazole treatment. In conclusion, these data suggest that brexpiprazole treats the continuum of schizophrenia symptoms, in the short- and long-term. Trial Registration: Data used in this post hoc analysis came from ClinicalTrials.gov identifiers: NCT01396421, NCT01393613, NCT01810380, NCT01668797, NCT01397786, NCT01810783.

PANSS Individual Item and Marder Dimension Analyses From a Pivotal Trial of RBP-7000 (Monthly Extended-Release Risperidone) in Schizophrenia Patients.

Background: Positive and Negative Syndrome Scale (PANSS) data from a pivotal phase 3 study in participants with schizophrenia of RBP-7000, a recently marketed long-acting subcutaneous injectable risperidone formulation, were examined to determine if dose-response relationships existed for different items of the PANSS.Methods: Changes in the 30 PANSS items were analyzed individually and using the 5 factor-analysis-derived dimensions defined by Marder and colleagues. Subgroups of patients who could benefit from the RBP-7000 120 mg dose were investigated.Results: 337 participants were randomized and received study medication (RBP-7000 90 mg n = 111, RBP-7000 120 mg n = 114, placebo n = 112). Dose-dependent responses were observed in items from the study-specified PANSS positive and general psychopathology exploratory subscales. Dose-dependent responses were observed across all 5 Marder dimensions, with the largest effect sizes observed with the 120 mg dose in the uncontrolled hostility/excitement (UHE) and anxiety/depression dimensions. Participants with baseline UHE dimension scores ≥ 9 demonstrated greater improvement in PANSS total score at the 120 mg dose compared to the 90 mg dose.Conclusions: RBP-7000 demonstrated efficacy across both the primary and exploratory PANSS study endpoints and the post hoc Marder dimensions. Schizophrenia patients with higher baseline Marder UHE scores may benefit from initiation of treatment at the 120 mg dose.Trial Registration: ClinicalTrials.gov identifier: NCT02109562.

Sequential Multiple-Assignment Randomized Trials to Compare Antipsychotic Treatments (SMART-CAT) in first-episode schizophrenia patients: Rationale and trial design.

Accumulated studies have investigated pharmacological interventions for first-episode schizophrenia (FES) patients. However, studies on subsequent treatment steps, which are essential to guide clinicians, are largely missing. This Sequential Multiple-Assignment Randomized Trials comparing Antipsychotic Treatments (SMART-CAT) program intends to evaluate the effectiveness of commonly used antipsychotic drugs in FES patients. The major goals of this study are to examine: 1) what would be the optimal subsequent sequential treatment if the first antipsychotic drug failed; 2) whether clozapine could be used in those first-trial failed and have superior efficacy compared to other atypical antipsychotics. In this article we will report the detail protocol of SMART-CAT. The SMART-CAT is a randomized controlled clinical multicenter trial in which 9 institutions in China will participate. A total of 720 FES patients will be enrolled and followed up for 12 months in this study. The trial includes three treatment phases (each phase lasting for 8 weeks) and a naturalistic follow-up phase; participants who do well on an assigned treatment will remain on that treatment for the duration of the 12-month treatment period, while non-responders will move to the next phase of the study to receive a new treatment. Phase 1 is a randomized controlled trial; patients will be randomly assigned to one of the treatments with oral olanzapine, risperidone, amisulpride, aripiprazole or perphenazine. Subjects who fail to respond after 8 weeks will enter the phase 2 randomization. Phase 2 is an equipoise-stratified randomization trial, and patients will be randomly assigned to oral olanzapine, amisulpride or clozapine for 8 weeks. Subjects who fail to respond after phase 2 will enter an open label trial (phase 3); patients who receive clozapine in phase 2 and fail to respond will be assigned to an extended clozapine treatment or modified electroconvulsive therapy add-on therapy (Phase 3A). Patients who were not assigned to clozapine in phase 2 will be assigned to treatment with clozapine or another SGAs not previously used in phase 1 and 2 (Phase 3B). The primary outcome for the treatment phase is the treatment efficacy rate, which is defined as at least 40% reduction in Positive and Negative Syndrome Scale (PANSS) total score. We hypothesize that clozapine is more therapeutically effective than any other SGAs to patients who failed to meet efficacy criteria in Phase 1, and earlier treatment with clozapine can improve the functional outcomes of schizophrenia patients. As for the naturalistic follow-up phase, time to all-cause treatment failure, marked by its discontinuation is selected as the primary outcome, since it reflects both efficacy and side effects. The all-cause discontinuation is defined as discontinuing for any reasons, including poor efficacy, intolerance of adverse reactions, poor compliance and other reasons. The results of the SMART-CAT trial will provide evidence for the selection of antipsychotics in FES patients who fail to respond to the first trial of an antipsychotic drug. It will also provide evidence for the efficacy and safety of using clozapine in the early phase of schizophrenia treatment by comparing with other SGAs. The study is based on the combination of sequential therapy and dynamic therapy, which can be more suitable to assess the effectiveness of treatment options in the real-world clinical setting. As a result, we hope that this study can provide guidance for an optimal treatment algorithm in first-episode schizophrenia patients. Trial registration: ID NCT03510325 in ClinicalTrials.gov.

Motivational and cognitive factors linked to community integration in homeless veterans: Study 2 - clinically diverse sample.

BACKGROUND: In an initial study (Study 1), we found that motivation predicted community integration (i.e. functional recovery) 12 months after receiving housing in formerly homeless Veterans with a psychotic disorder. The current study examined whether the same pattern would be found in a broader, more clinically diverse, homeless Veteran sample without psychosis. METHODS: We examined four categories of variables as potential predictors of community integration in non-psychotic Veterans: perception, non-social cognition, social cognition, and motivation at baseline (after participants were engaged in a permanent supported housing program but before receiving housing) and a 12-month follow-up. A total of 82 Veterans had a baseline assessment and 41 returned for testing after 12 months. RESULTS: The strongest longitudinal association was between an interview-based measure of motivation (the motivation and pleasure subscale from the Clinical Assessment Interview for Negative Symptoms) at baseline and measures of social integration at 12 months. In addition, cross-lagged panel analyses were consistent with a causal influence of general psychiatric symptoms at baseline driving social integration at 12 months, and reduced expressiveness at baseline driving independent living at 12 months, but there were no significant causal associations with measures of motivation. CONCLUSIONS: The findings from this study complement and reinforce those in Veterans with psychosis. Across these two studies, our findings suggest that motivational factors are associated at baseline and at 12 months and are particularly important for understanding and improving community integration in recently-housed Veterans across psychiatric diagnoses.

A long-term, open-label study of valbenazine for tardive dyskinesia.

BACKGROUND: Individuals with tardive dyskinesia (TD) who completed a long-term study (KINECT 3 or KINECT 4) of valbenazine (40 or 80 mg/day, once-daily for up to 48 weeks followed by 4-week washout) were enrolled in a subsequent study (NCT02736955) that was primarily designed to further evaluate the long-term safety of valbenazine. METHODS: Participants were initiated at 40 mg/day (following prior valbenazine washout). At week 4, dosing was escalated to 80 mg/day based on tolerability and clinical assessment of TD; reduction to 40 mg/day was allowed for tolerability. The study was planned for 72 weeks or until termination due to commercial availability of valbenazine. Assessments included the Clinical Global Impression of Severity-TD (CGIS-TD), Patient Satisfaction Questionnaire (PSQ), and treatment-emergent adverse events (TEAEs). RESULTS: At study termination, 85.7% (138/161) of participants were still active. Four participants had reached week 60, and none reached week 72. The percentage of participants with a CGIS-TD score ≤2 (normal/not ill or borderline ill) increased from study baseline (14.5% [23/159]) to week 48 (64.3% [36/56]). At baseline, 98.8% (158/160) of participants rated their prior valbenazine experience with a PSQ score ≤2 (very satisfied or somewhat satisfied). At week 48, 98.2% (55/56) remained satisfied. Before week 4 (dose escalation), 9.4% of participants had ≥1 TEAE. After week 4, the TEAE incidence was 49.0%. No TEAE occurred in ≥5% of participants during treatment (before or after week 4). CONCLUSIONS: Valbenazine was well-tolerated and persistent improvements in TD were found in adults who received once-daily treatment for >1 year.

The Neurobiology of Treatment-Resistant Schizophrenia: Paths to Antipsychotic Resistance and A Roadmap for Future Research.

(Reprinted with permission from NPJ Schizophrenia (2020) 6:1).

Proof of mechanism and target engagement of glutamatergic drugs for the treatment of schizophrenia: RCTs of pomaglumetad and TS-134 on ketamine-induced psychotic symptoms and pharmacoBOLD in healthy volunteers.

Glutamate neurotransmission is a prioritized target for antipsychotic drug development. Two metabotropic glutamate receptor 2/3 (mGluR2/3) agonists (pomaglumetad [POMA] and TS-134) were assessed in two Phase Ib proof of mechanism studies of comparable designs and using identical clinical assessments and pharmacoBOLD methodology. POMA was examined in a randomized controlled trial under double-blind conditions for 10-days at doses of 80 or 320 mg/d POMA versus placebo (1:1:1 ratio). The TS-134 trial was a randomized, single-blind, 6-day study of 20 or 60 mg/d TS-134 versus placebo (5:5:2 ratio). Primary outcomes were ketamine-induced changes in pharmacoBOLD in the dorsal anterior cingulate cortex (dACC) and symptoms reflected on the Brief Psychiatric Rating Scale (BPRS). Both trials were conducted contemporaneously. 95 healthy volunteers were randomized to POMA and 63 to TS-134. High-dose POMA significantly reduced ketamine-induced BPRS total symptoms within and between-groups (p < 0.01, d = -0.41; p = 0.04, d = -0.44, respectively), but neither POMA dose significantly suppressed ketamine-induced dACC pharmacoBOLD. In contrast, low-dose TS-134 led to moderate to large within and between group reductions in both BPRS positive symptoms (p = 0.02, d = -0.36; p = 0.008, d = -0.82, respectively) and dACC pharmacoBOLD (p = 0.004, d = -0.56; p = 0.079, d = -0.50, respectively) using pooled across-study placebo data. High-dose POMA exerted significant effects on clinical symptoms, but not on target engagement, suggesting a higher dose may yet be needed, while the low dose of TS-134 showed evidence of symptom reduction and target engagement. These results support further investigation of mGluR2/3 and other glutamate-targeted treatments for schizophrenia.