Cariprazine versus risperidone monotherapy for treatment of predominant negative symptoms in patients with schizophrenia: a randomised, double-blind, controlled trial

The real-world impact of cariprazine on short- and long-term disability outcomes among commercially insured patients in the United States

AIM

To compare all-cause and mental health (MH)-related short-term and long-term disability leaves and associated costs among patients in the United States with bipolar disorder (BP), major depressive disorder (MDD), or schizophrenia spectrum disorders (SCZ) before versus after cariprazine initiation.

METHODS

Merative MarketScan Commercial and Health and Productivity Management (HPM) databases (January 2016 to December 2021) were utilized to identify adults diagnosed with BP, MDD, or SCZ with ≥2 pharmacy cariprazine claims (first claim = index), ≥3 months of cariprazine use (adjunctively for MDD), and continuous commercial insurance coverage and HPM eligibility during baseline (12 months pre-index) and ≥3 months post-index. Observation continued until cariprazine discontinuation, insurance or HPM eligibility end, 1 year post-index, or HPM data availability end. All-cause and MH-related disability claims, days, and costs were evaluated. Baseline versus post-index rates of disability claims (events) and days were compared using rate ratios (RR); costs were compared using mean cost differences. Comparisons were calculated from generalized estimating equation models. Analyses were replicated separately across indications.

RESULTS

There were 489 patients overall (BP = 238, MDD = 233, SCZ = 18; mean age = 43.3 years; 60.7% female; mean follow-up = 7.6 months). All-cause rates of disability events and days following cariprazine initiation were 29% (RR = 0.71 [95% CI = 0.57, 0.86]) and 28% (0.72 [0.53, 0.94]) lower than baseline, respectively (both p < .05). MH-related rates of disability events and days were 40% (0.60 [0.43, 0.80]) and 43% (0.57 [0.34, 0.84]) lower, respectively (both p < .01). All-cause disability costs were $2,917 lower and MH-related disability costs were $2,482 lower than baseline (40% and 51% decrease, respectively; both p < .01). Results were similar for indication-specific analyses.

LIMITATIONS

Limited generalizability to patients who are unemployed, uninsured, or have public insurance.

CONCLUSIONS

Rates of disability events, days, and mean costs were significantly lower after versus before cariprazine initiation. These results can help contextualize cariprazine's role in managing disability for these patients.

A nanoluciferase complementation-based assay for monitoring β-arrestin2 recruitment to the dopamine D3 receptor

Luciferase complementation assays have emerged as a simple means of monitoring receptor-effector interactions in living cells in a time-resolved manner. Here, we describe a nanoluciferase complementation assay capable of reporting on β-arrestin2 recruitment to the human dopamine D3 receptor (D3R) upon its activation in intact HEK293T cells. Using this assay in time-resolved experiments, we detect differences in arrestin response termination rates between the endogenous agonist dopamine and the synthetic D3R agonist FAUC-73. We also investigate the influence of exogenous GRK2 on β-arrestin2 recruitment to the D3R. We find that, in contrast to the D2R and D4R, the potency of dopamine to induce arrestin recruitment to D3R is not significantly influenced by GRK2 overexpression. In further agreement with a lack of GRK2 regulation of D3R signalling and again contrary to the D2R and D4R, we do not observe dopamine-induced recruitment of GRK2 to D3R. Conversely, dopamine concentration-dependently decreases the interaction between GRK2 and D3R. Additionally, we examine both the Ser-9 and Gly-9 variants of the human D3R, which, according to some earlier reports, differ in terms of dopamine affinity and functional potency. However, we find no difference in the concentration-response relationships between these two variants, neither when arrestin recruitment nor GRK2 interactions are studied. In summary, the present report demonstrates the utility of nanoluciferase complementation for studying D3R pharmacology in living cells.

Effect of ponatinib on the metabolism of cariprazine in vitro and in vivo and the underlying mechanism

Cariprazine is an antipsychotic medication that has been approved for the treatment of schizophrenia and manic or mixed episodes. Patients with tumors frequently develop psychiatric disorders, necessitating the combination of antitumor and antipsychotic drugs. The objective of the present study was to examine the inhibitory impacts of three antitumor drugs (olmutinib, napabucasin and ponatinib) on the metabolism of cariprazine, and the molecular docking of cariprazine and ponatinib in relation to CYP3A4 was also evaluated. As the results, the half-maximal inhibitory concentration (IC50) values of ponatinib and olmutinib in vitro were < 10 μM, whereas napabucasin was >20 μM. Among these, ponatinib exhibited the smallest IC50 value. The metabolic stability of cariprazine was observed in the presence or absence of ponatinib in rat liver microsomes (RLM). The IC50 shift experiments demonstrated that the inhibition of cariprazine by ponatinib was non-time-dependent. In addition, ponatinib was shown to inhibit cariprazine in a mixed manner (RLM) and a competitive manner (HLM), respectively. In the in vivo study, the co-administration of ponatinib resulted in a significant 0.35-fold increase in both AUC(0-t) and AUC(0-∞) for cariprazine, accompanied by a significant 0.25-fold decrease in the CLz/F. Furthermore, the metabolites desmethyl-cariprazine (DCAR) and didesmethyl-cariprazine (DDCAR) exhibited disparate increases in both AUC(0-t) and AUC(0-∞). Molecular docking studies had demonstrated that both cariprazine and ponatinib could engage in hydrophobic interactions with residue PHE-304 on CYP3A4. Consequently, when ponatinib is employed in conjunction with cariprazine in a clinical setting, it is imperative to assess the efficacy and adverse effects, and adjust the dosage to attain the optimal efficacy.

The effect of adjunctive cariprazine on symptoms of anhedonia in patients with major depressive disorder

BACKGROUND

Anhedonia is a core diagnostic symptom of major depressive disorder (MDD). Post hoc analyses evaluated cariprazine plus antidepressant treatment (ADT) in patients with MDD and moderate-to-severe anhedonia.

METHODS

Data were analyzed from a positive phase 3, randomized, fixed-dose (1.5 or 3 mg/d), double-blind, placebo-controlled, parallel-group cariprazine study (NCT03738215). Post hoc outcomes (e.g., change from baseline to week 6 in MADRS total score, MADRS anhedonia subscale score, MADRS anhedonia subscale item scores including item 8 [inability to feel]) were assessed in 2 anhedonia patient subgroups (baseline MADRS anhedonia subscale score ≥ 18; baseline MADRS anhedonia item 8 score ≥ 4) using a mixed-effects model for repeated measures.

RESULTS

Most patients met subgroup inclusion criteria (anhedonia subscale score ≥ 18 = 584 [77.8 %]; anhedonia item 8 score ≥ 4 = 508 [67.6 %]). LSMDs in change from baseline were statistically significant in favor of adjunctive cariprazine versus adjunctive placebo in the MADRS anhedonia subscale score ≥ 18 subgroup (MADRS total score: 1.5 mg/d = -3.4, p = .0006; 3 mg/d = -2.1, p = .0358; anhedonia subscale score: 1.5 mg/d = -2.1, p = .0010; 3 mg/d = -1.26, p = .0399) and in the anhedonia item 8 score ≥ 4 subgroup for adjunctive cariprazine 1.5 mg/d (MADRS total score: -3.2, p = .0037; anhedonia subscale score: -1.9, p = .0066). Significant differences were seen for adjunctive cariprazine versus adjunctive placebo on several anhedonia subscale single items, including anhedonia item 8 for the 1.5 mg/d dose.

LIMITATION

Post hoc analysis.

CONCLUSION

In patients with MDD and moderate-to-severe anhedonia, adjunctive cariprazine improved symptoms of general depression and anhedonia, suggesting a potential benefit for patients with this clinically significant symptom.

INTEGRATE: international guidelines for the algorithmic treatment of schizophrenia

Schizophrenia is a mental illness involving multiple symptom domains and is often associated with substantial physical health comorbidities. Guidelines exist, but these tend to be country-specific and are often missing a concise yet comprehensive algorithmic approach. From May 1, 2023, to Jan 1, 2025, International Guidelines for Algorithmic Treatment (INTEGRATE) authors from all UN regions collaborated to develop a consensus guideline focused on the pharmacological treatment of schizophrenia. Following an umbrella review of the literature, input from expert workshops, a consensus survey, and lived experience focus groups, a consensus algorithmic guideline and associated digital tool were developed. Key recommendations include a focus on metabolic health from treatment initiation, timely assessment and management of non-response, symptom domain-specific interventions, mitigation of side-effects, and the prompt use of clozapine in cases of treatment resistance.

Cariprazine as a maintenance treatment in dual schizophrenia: a 6-month observational study in patients with schizophrenia and cannabis use disorder

Schizophrenia is often associated with substance use disorders, particularly cannabis use disorder (CUD). However, treatments frequently fail to address both conditions simultaneously. This study aimed to evaluate the antipsychotic effectiveness of cariprazine in patients with both schizophrenia and CUD in a real-world setting. A 6-month observational study was conducted on 58 patients diagnosed with schizophrenia and CUD, treated with cariprazine. Antipsychotic effectiveness was measured using the Positive and Negative Syndrome Scale and the Clinical Global Impression-Schizophrenia Scale, along with the Improvement and Severity scales. Cannabis consumption and addiction severity were assessed using the Cannabis Abuse Screening Test and the Severity of Dependence Scale, while functioning was evaluated with the Sheehan Disability Inventory. Cariprazine treatment resulted in significant improvements in schizophrenia symptoms (Positive and Negative Syndrome Scale change: -47.88 points, P  < 0.0001; Clinical Global Impression-Schizophrenia Scale change: -8.26 points, P  < 0.0001). Cannabis use and dependence also decreased (Cannabis Abuse Screening Test change: -7.0 points, P  < 0.0001; Severity of Dependence Scale change: -7.88 points, P  < 0.0001), alongside improvements in functioning (Sheehan Disability Inventory change: -9.48 points, P  < 0.0001). These results suggest that cariprazine is effective for both schizophrenia and CUD, though further research is needed to confirm these findings.

A Phase 3, Randomized, Double-Blind, Placebo-Controlled Study to Evaluate the Efficacy and Safety of Pimavanserin as an Adjunctive Treatment for the Negative Symptoms of Schizophrenia (ADVANCE-2) in Patients With Predominant Negative Symptoms

BACKGROUND AND HYPOTHESES

Negative symptoms of schizophrenia (NSS) carry a substantial burden, and there are no treatments currently approved for NSS. The efficacy of pimavanserin, a selective 5-HT2A inverse agonist and antagonist, in treating NSS was assessed.

STUDY DESIGN

ADVANCE-2 was a phase 3, randomized, double-blind, placebo-controlled study of pimavanserin in patients with schizophrenia and predominantly negative symptoms. Patients were randomized (1:1) to receive pimavanserin (34 mg/day) or placebo alongside ongoing background antipsychotic medication. Eligible adults were aged 18-55 years and had access to a caregiver. The primary and key secondary endpoints were the change from baseline to week 26 in the Negative Symptom Assessment-16 (NSA-16) total score and Clinical Global Impression-Schizophrenia Scale-Severity (CGI-SCH-S) negative symptom score, respectively.

STUDY RESULTS

Of the 454 randomized patients, 71 (39 placebo; 32 pimavanserin) discontinued and 383 (188 placebo; 195 pimavanserin) completed the study. The safety and full analysis sets comprised 453 and 446 patients, respectively. The NSA-16 change from baseline to week 26 was not significantly different between groups (least squares mean difference: -0.67; SE, 0.95; [95% CI: -2.54, 1.20]; P = .48; Cohen's d effect size: 0.07). Treatment-emergent adverse events occurred in 30.4% with pimavanserin and 40.3% with placebo.

CONCLUSIONS

In this study, pimavanserin was well tolerated, and although it demonstrated a similar treatment effect as in the prior phase 2 study favoring pimavanserin, treatment with pimavanserin vs placebo did not result in significant differences for primary or other endpoints.

COSMIN systematic review and meta-analysis of the measurement properties of the Positive and Negative Syndrome Scale (PANSS)

Background

The Positive and Negative Syndrome Scale (PANSS) is the most widely used tool for assessing the symptoms of schizophrenia. Despite its widespread use, the psychometric properties of the PANSS have not been systematically reviewed. This study fills that gap in the scientific literature.

Methods

We utilized the COnsensus-based Standards for the selection of health Measurement INstruments (COSMIN) guideline for systematic reviews and meta-analytical procedures to assess the psychometric properties of the PANSS in its original three-subscale form as well as the quality level of the evidence available. On this basis we formulated recommendations for future research and use. A study protocol was registered under 10.17605/OSF.IO/5EGMD. The search period was until February 21, 2024.

Findings

We included 119 publications. According to COSMIN, the PANSS demonstrated sufficient reliability, construct validity, and responsiveness; but had significant shortcomings in content validity and structural validity. The original three-factor model showed poor structural validity, leading to its COSMIN classification as "not recommendable". The subscales showed overall acceptable measurement properties. However, the lack of structural validity of the three-subscale model renders its subscales less useful. Moreover, the PANSS negative subscale does not cover all domains of the National Institute of Mental Health consensus. Due to the length of the instrument (30-50 min), it is barely useable in clinical practice.

Interpretation

Although the PANSS is the standard scale for schizophrenia symptom severity, its shortcomings regarding fundamental psychometric domains and practical applicability warrant the development of new scales for which appropriate methods should be applied from the start.

Funding

There was no specific funding source for this research.

IUPHAR review - Novel therapeutic targets for schizophrenia treatment: A translational perspective

Schizophrenia is a severe and debilitating psychiatric disorder that profoundly impacts cognitive, emotional, and social functioning. Despite its devastating personal and societal toll, current treatments often provide only partial relief, underscoring the urgent need for innovative therapeutic strategies. This review explores emerging approaches that target the complex neurobiological underpinnings of schizophrenia, moving beyond traditional dopamine-centric models. Among these, some novel drugs still employ multimodal mechanisms, simultaneously targeting dopaminergic and serotonergic systems to enhance efficacy and tolerability. Given the well-documented excitatory/inhibitory imbalance in schizophrenia, significant efforts have been directed toward addressing NMDA receptor hypofunctionality. However, strategies targeting this pathway have yet to demonstrate consistent clinical efficacy. In contrast, therapies targeting the cholinergic system have shown greater promise. For instance, the xanomeline-trospium combination, which modulates muscarinic receptors, has recently gained approval, and other molecules with similar mechanisms are currently under development. Beyond these approaches, novel strategies are being explored to target innovative pathways, including neuroplasticity, neuroinflammation, and mitochondrial dysfunction. These efforts are often designed as part of a combinatorial strategy to enhance the efficacy of currently available antipsychotic drugs. Despite significant progress, challenges remain in translating experimental discoveries into effective clinical applications. Future research should prioritize biomarker-driven approaches and precision medicine to optimize individualized treatment outcomes. By integrating these emerging therapeutic targets, schizophrenia treatment may evolve toward a more comprehensive and personalized approach, addressing the disorder's full spectrum of symptoms and improving patient quality of life.

Physical illness in schizophrenia and the role of tolerability in antipsychotic selection: an expert consensus with a focus on cariprazine

BACKGROUND

Schizophrenia is a highly heterogeneous disease, and a high percentage of patients are at high risk of developing somatic comorbidities, which must be taken into account in disease management and treatment selection.

MAIN BODY

Antipsychotics are often associated with side effects that worsen the somatic comorbidities. Among the different options, cariprazine is generally safe and usually well tolerated in both acute and long-term treatment and is often a good choice when balancing clinical benefits and side effects. Given the lack of consensus on the priority of symptoms to treat and the reasons for switching therapy based on the balance between side effects and symptom resolution, twelve psychiatrists met for an expert meeting to discuss the most common and worrisome antipsychotic side effects leading to switching, the most important somatic comorbidities, and the best way to address specific symptoms in both the acute and maintenance phases of treatment in schizophrenia. Special attention was given to metabolic comorbidities, sexual dysfunction, and cardiovascular disease. This paper aims to examine the relationship between schizophrenia and specific somatic comorbidities, to discuss how the balance between efficacy and tolerability influences treatment choice in the acute and maintenance treatment of schizophrenia, and how these two variables may have different priorities at different stages of treatment.

CONCLUSION

The choice of treatment is based primarily on efficacy and tolerability. Cariprazine is beneficial in patients with positive and negative symptoms, and it has a side-effect profile with low rates of metabolic side effects, sedation, and sexual dysfunction.

Negative Symptoms in Schizophrenia: An Update on Research Assessment and the Current and Upcoming Treatment Landscape

The negative symptoms of schizophrenia include diminished emotional expression, avolition, alogia, anhedonia, and asociality, and due to their low responsiveness to available treatments, are a primary driver of functional disability in schizophrenia. This narrative review has the aim of providing a comprehensive overview of the current research developments in the treatment of negative symptoms in schizophrenia, and begins by introducing the concepts of primary, secondary, prominent, predominant, and broadly defined negative symptoms. We then compare and contrast commonly used research assessment scales for negative symptoms and review the evidence for the specific utility of widely available off-label and investigational treatments that have been studied for negative symptoms. Mechanism of action/putative treatments included are antipsychotics (D2R antagonists), N-methyl-D-aspartate receptor (NMDAR) and other glutamatergic modulators, serotonin receptor (5-HTR) modulators, anti-inflammatory agents, antidepressants, pro-dopaminergic modulators (non-D2R antagonists), acetylcholine modulators, oxytocin, and phosphodiesterase (PDE) inhibitors. With the caveat that no compounds are definitively proven as gold-standard treatments for broadly defined negative symptoms, the evidence base supports several potentially beneficial off-label and investigational medications for treating negative symptoms in schizophrenia, such as monotherapy with cariprazine, olanzapine, clozapine, and amisulpride, or adjunctive use of memantine, setrons such as ondansetron, minocycline, and antidepressants. These medications are widely available worldwide, generally tolerable and could be considered for an off-label, time-limited trial for a predesignated period of time, after which a decision to switch or stay can be made based on clinical response. Among investigational medications, NMDAR agonists, muscarinic agonists, and LB-102 remain under study. Suggestions for future research include reducing placebo effects by designing studies with a smaller number of high-quality study sites, potentially increasing the use of more precise rating scales for negative symptoms, and focused studies in people with predominant negative symptoms.

Pharmacological Interventions for Negative Symptoms in Schizophrenia: A Systematic Review of Randomised Control Trials

Background/Objectives: While positive symptoms of schizophrenia are often satisfactorily controlled, negative symptoms are difficult to treat, persisting despite treatment. Different strategies have been devised to deal with this problem. We aimed to review drug treatment for negative symptoms of schizophrenia in controlled trials of marketed drugs. Methods: We searched the PubMed database and the resulting records' reference lists to identify eligible trials using schizophrenia[ti] AND "negative symptom*"[ti] as a search strategy. We determined eligibility through Delphi rounds among all authors. Results: On 11 February 2025, we identified 1485 records on PubMed and 3 more from reference lists. Eligible were 95 records. Most studies were double-blind, randomized controlled trials, carried-out in add-on in patients stabilized with antipsychotics. Other antipsychotics were the most frequent comparators, followed by antidepressants, and recently, antioxidants are gaining importance in trials. Many trials, especially those conducted in the Western world, found no significant effects compared to placebo, while most Iranian studies were positive, although not with a strong effect size. Conclusions: Current research has contributed little to progress in the treatment of the negative symptoms of schizophrenia. The reason might reside in the absence of knowledge of the mechanisms whereby these symptoms are generated, which prevents us from designing possibly effective treatment strategies, and/or to the chronicity of negative symptoms, as they are the first to be established even when they do not become fully apparent.

The immediate alteration of cerebellar Glx/GABA and cerebello-thalamo-cortical connectivity in patients with schizophrenia after cerebellar TMS

Cerebellar dysfunction is a key aspect of schizophrenia, with the cerebello-thalamo-cortical (CTC) hyperconnectivity serving as a neural signature. Abnormalities in gamma-aminobutyric acid (GABA) and glutamate + glutamine (Glx) levels also contribute to this pathology. Transcranial magnetic stimulation (TMS) applied to the cerebellum shows potential in alleviating schizophrenia symptoms, possibly by modulating functional connectivity or neurotransmitter levels. This study aims to explore the immediate effects of cerebellar TMS on CTC circuitry and neurotransmitter levels to elucidate its therapeutic mechanisms in schizophrenia.The study involved 19 stable schizophrenia patients and 26 healthy controls, diagnosed according to DSM-V criteria and assessed for symptom severity using the Positive and Negative Syndrome Scale (PANSS). MRI scans were conducted pre- and post-TMS to detect changes in CTC functional connectivity, GABA, Glx, and Glx/GABA. Linear Mixed-Effects Model (LMEM) and two-sample tests were employed to analyze changes in these variables from baseline to post-TMS. Pearson's correlation analysis was conducted to examine the relationships among these variables and their association with PANSS scores. Mediation analyses were employed to investigate whether GABA and/or Glx serve as potential mediators of CTC hyperconnectivity in patients with schizophrenia. Schizophrenia patients exhibit CTC hyperconnectivity, which remains at a relatively stable level after cerebellar TMS. Compared to healthy controls, schizophrenia patients have significantly higher cerebellar GABA levels, and cerebellar GABA has a significant mediation effect on CTC hyperconnectivity in patients. The Glx/GABA ratio was associated with the severity of clinical symptoms in patients, and cerebellar TMS partially normalized this ratio. Our findings demonstrate that aberrant cerebellar GABA levels contribute to CTC hyperconnectivity in schizophrenia. Additionally, our study shows that cerebellar TMS can increase Glx levels in schizophrenia patients, leading to the normalization of the Glx/GABA ratio, which may contribute to the therapeutic effects of TMS in schizophrenia.

Enhanced computerized cognitive remediation therapy improved cognitive function, negative symptoms, and GDNF in male long-term inpatients with schizophrenia

Objective

Negative and cognitive symptoms present significant challenges in patients with schizophrenia, and cognitive remediation is a promising approach to alleviate these symptoms. This study aimed to explore the efficacy of computerized cognitive remediation therapy (CCRT) on psychiatric symptoms, cognitive deficits, and serum levels of brain-derived neurotrophic factor (BDNF) and glial cell line-derived neurotrophic factor (GDNF) in patients with schizophrenia.

Materials and methods

Forty male long-term institutionalized inpatients with schizophrenia were assigned to either a CCRT group (n = 20) or a control group (n = 20). The CCRT intervention consisted of 40 individual 40-min sessions over 8 weeks, conducted five times a week. Psychiatric symptoms, cognition, and serum levels of BDNF and GDNF were assessed at baseline, 4 weeks, and 8 weeks.

Results

Compared to the control group, the CCRT group exhibited decreased total Positive and Negative Syndrome Scale and negative subscale scores, as well as increased Montreal Cognitive Assessment and Repeatable Battery for the Assessment of Neuropsychological Status scores. Moreover, improvements in list recall were associated with reduced negative symptoms. Additionally, CCRT ameliorated the decrease in serum GDNF levels in patients with schizophrenia.

Conclusion

The effectiveness of CCRT in alleviating negative symptoms was associated with improvements in list recall, and GDNF may play a role in the observed effects of CCRT in patients with schizophrenia.

Effect of Cariprazine on Anhedonia in Patients with Bipolar I Depression: Post Hoc Analysis of Three Randomized Placebo-Controlled Clinical Trials

INTRODUCTION

Anhedonic symptoms in bipolar I (BP-I) depression are associated with decreased quality of life and impaired functioning. We evaluated the effects of cariprazine in patients with BP-I depression with lower or higher levels of anhedonia at baseline.

METHODS

Data were pooled from three clinical trials (NCT01396447, NCT02670538, NCT02670551) analyzing the effects of cariprazine 1.5 and 3 mg/day in adults with BP-I depression. During post hoc analysis, patients were stratified by baseline median Montgomery-Åsberg Depression Rating Scale (MADRS) anhedonia factor score into a lower (score < median) or higher (score ≥ median) anhedonia subgroup. Outcomes included change from baseline to week 6 in MADRS total and anhedonia factor score, with the latter also evaluated after adjusting for other depressive symptoms. Between-group differences in change from baseline to week 6 were compared using least-squares mean differences (LSMD) analyzed via a mixed-effect model for repeated measures.

RESULTS

Median baseline anhedonia factor score was 19, defining the lower (placebo = 211; cariprazine 1.5 mg/day = 200, 3 mg/day = 212) and higher (placebo = 249; cariprazine 1.5 mg/day = 261, 3 mg/day = 250) anhedonia subgroups. In the lower subgroup, cariprazine 1.5 mg/day but not 3 mg/day was superior to placebo in reducing MADRS total (LSMD [95% CI] 1.5 mg/day = - 2.61 [- 4.28, - 0.93], P = .0024) and anhedonia factor scores (- 1.70 [- 2.77, - 0.62], P = .0021) at week 6. In the higher subgroup, both cariprazine doses were associated with significantly greater reductions than placebo in MADRS total (1.5 mg/day = - 3.01 [- 4.84, - 1.19], P = .0012; 3 mg/day = - 3.26 [- 5.12, - 1.40], P = .0006) and anhedonia factor scores (1.5 mg/day = - 1.97 [- 3.13, - 0.81], P = .0009; 3 mg/day = - 2.07 [- 3.26, - 0.89], P = .0006). Anti-anhedonic effects were preserved after adjusting for other depressive symptoms, suggesting the effect was not pseudospecific. Patients in the higher subgroup had higher baseline depression and therefore the lower subgroup may have had a floor effect.

CONCLUSION

Cariprazine demonstrated antidepressant and specific anti-anhedonic effects regardless of baseline anhedonia symptoms in patients with BP-I depression.

TRIAL REGISTRATION

ClinicalTrials.gov identifiers, NCT02670538, NCT02670551, NCT01396447.

How antipsychotics work in schizophrenia: a primer on mechanisms

Antipsychotics effective for schizophrenia approved prior to 2024 shared the common mechanism of postsynaptic dopamine D2 receptor antagonism or partial agonism. Positive psychosis symptoms correlate with excessive presynaptic dopamine turnover and release, yet this postsynaptic mechanism improved positive symptoms only in some patients, and with concomitant risk for off-target motor and endocrine adverse effects; moreover, these agents showed no benefit for negative symptoms and cognitive dysfunction. The sole exception was data supporting cariprazine's superiority to risperidone for negative symptoms. The muscarinic M1/M4 agonist xanomeline was approved in September 2024 and represents the first of a new antipsychotic class. This novel mechanism improves positive symptoms by reducing presynaptic dopamine release. Xanomeline also lacks any D2 receptor affinity and is not associated with motor or endocrine side effects. Of importance, xanomeline treated patients with higher baseline levels of cognitive dysfunction in clinical trials data saw cognitive improvement, a finding likely related to stimulation of muscarinic M1 receptors. Treatment resistance is seen in one-third of schizophrenia patients. These individuals do not have dopamine dysfunction underlying their positive symptoms, and therefore show limited response to antipsychotics that target dopamine neurotransmission. Clozapine remains the only medication with proven efficacy for resistant schizophrenia, and with unique benefits for persistent impulsive aggression and suicidality. New molecules are being studied to address the array of positive, negative and cognitive symptoms of schizophrenia; however, until their approval, clinicians must be familiar with currently available agents and be adept at prescribing clozapine.

Clinical benefits of modifying the evening light environment in an acute psychiatric unit: A single-centre, two-arm, parallel-group, pragmatic effectiveness randomised controlled trial

BACKGROUND

The impact of light exposure on mental health is increasingly recognised. Modifying inpatient evening light exposure may be a low-intensity intervention for mental disorders, but few randomised controlled trials (RCTs) exist. We report a large-scale pragmatic effectiveness RCT exploring whether individuals with acute psychiatric illnesses experience additional benefits from admission to an inpatient ward where changes in the evening light exposure are integrated into the therapeutic environment.

METHODS AND FINDINGS

From 10/25/2018 to 03/29/2019, and 10/01/2019 to 11/15/2019, all adults (≥18 years of age) admitted for acute inpatient psychiatric care in Trondheim, Norway, were randomly allocated to a ward with a blue-depleted evening light environment or a ward with a standard light environment. Baseline and outcome data for individuals who provided deferred informed consent were used. The primary outcome measure was the mean duration of admission in days per individual. Secondary outcomes were estimated mean differences in key clinical outcomes: Improvement during admission (The Clinical Global Impressions Scale-Improvement, CGI-I) and illness severity at discharge (CGI-S), aggressive behaviour during admission (Broset Violence Checklist, BVC), violent incidents (Staff Observation Aggression Scale-Revised, SOAS-R), side effects and patient satisfaction, probabilities of suicidality, need for supervision due to suicidality, and change from involuntary to voluntary admission. The Intent to Treat sample comprised 476 individuals (mean age 37 (standard deviation (SD) 13.3); 193 (41%) were male, 283 (59%) were female). There were no differences in the mean duration of admission (7.1 days for inpatients exposed to the blue-depleted evening light environment versus 6.7 days for patients exposed to the standard evening light environment; estimated mean difference: 0.4 days (95% confidence interval (CI) [-0.9, 1.9]; p = 0.523). Inpatients exposed to the blue-depleted evening light showed higher improvement during admission (CGI-I difference 0.28 (95% CI [0.02, 0.54]; p = 0.035), Number Needed to Treat for clinically meaningful improvement (NNT): 12); lower illness severity at discharge (CGI-S difference -0.18 (95% CI [-0.34, -0.02]; p = 0.029), NNT for mild severity at discharge: 7); and lower levels of aggressive behaviour (difference in BVC predicted serious events per 100 days: -2.98 (95% CI [-4.98, -0.99]; p = 0.003), NNT: 9). There were no differences in other secondary outcomes. The nature of this study meant it was impossible to blind patients or clinical staff to the lighting condition.

CONCLUSIONS

Modifying the evening light environment in acute psychiatric hospitals according to chronobiological principles does not change duration of admissions but can have clinically significant benefits without increasing side effects, reducing patient satisfaction or requiring additional clinical staff.

TRIAL REGISTRATION

Clinicaltrials.gov NCT03788993; 2018 (CRISTIN ID 602154).

Antipsychotic dopamine D2 affinity and negative symptoms in remitted first episode psychosis patients

Negative symptoms can be an integral part of schizophrenia spectrum pathology and can be secondary to other psychotic symptoms or caused by antipsychotic medication. As antipsychotic drugs differ in their affinity to dopamine receptors and some antipsychotics have partial agonistic effects, antipsychotic drugs are expected to vary in their ability to cause negative symptoms. The association between negative symptoms and antipsychotic medication divided into partial agonists, or antagonists with high or low D2 affinity was assessed in 310 remitted first episode psychosis (FEP) patients. Severity of negative symptoms was assessed with the Comprehensive Assessment of Symptoms and History, and the Positive and Negative Syndrome Scale. Linear regression analyses were performed while controlling for differences in clinical and sociodemographic characteristics between the groups using inverse probability of treatment weighting. Patients using partial agonists (n = 78) showed fewer negative symptoms compared to those using high affinity antagonists (n = 84). Patients using partial agonists displayed less severe negative symptoms compared to those using low affinity antagonists (n = 148) at a trend level (p = 0.051). Negative symptom severity was higher in patients who had higher antipsychotic doses. In remitted FEP patients, we observed that the use of antipsychotic medication classified as partial agonists was associated with lower severity of negative symptoms, while the use of antagonists with high D2 affinity was associated with more severe negative symptoms.

Association between treatment response and dose of blonanserin transdermal patch in patients with acute schizophrenia: A post hoc cluster analysis based on baseline psychiatric symptoms

AIM

To explore the optimal dose of blonanserin transdermal patch (BNS-P) based on baseline psychiatric symptomatic characteristics during acute schizophrenia.

METHODS

A post hoc cluster analysis was conducted using data from a 6-week randomized, double-blind, placebo-controlled study of BNS-P (40 or 80 mg/day) in acute schizophrenia. We classified patients into three clusters based on baseline psychiatric symptoms. Efficacy was assessed using the change from baseline to week 6 in the PANSS total score. Safety was assessed by the incidence of adverse events.

RESULTS

Among 577 patients, three clusters were identified, characterized by severe psychiatric (Cluster-S; n = 122), predominant negative (Cluster-N; n = 191), and predominant positive (Cluster-P; n = 264) symptoms. In Cluster-P, both BNS-P 40 and 80 mg/day reduced PANSS total score significantly more than placebo (p = 0.036, effect size = 0.342; p < 0.001, effect size = 0.687, respectively). In Cluster-S and -N, only BNS-P 80 mg/day reduced PANSS total score significantly more than placebo (p = 0.045, effect size = 0.497; p = 0.034, effect size = 0.393, respectively). The effect size was greater at 80 mg/day than at 40 mg/day across all clusters. The most common treatment-emergent adverse events were akathisia and skin-related adverse events in all clusters.

CONCLUSION

BNS-P exhibited a dose-dependent antipsychotic effect in all clusters, particularly highlighting its efficacy in patients with predominant positive symptoms, even at lower doses. These findings provide novel and valuable insights for determining BNS-P dose tailoring to individual symptomatic characteristics in real-world practice.

Efficacy of KarXT on negative symptoms in acute schizophrenia: A post hoc analysis of pooled data from 3 trials

BACKGROUND

Currently approved antipsychotics do not adequately treat negative symptoms (NS), which are a major determinant of functional disability in schizophrenia. KarXT, an M1 /M4 preferring muscarinic receptor agonist, has shown efficacy as a broad-spectrum monotherapy for the treatment of schizophrenia in participants with acute psychosis. Post hoc analyses evaluated the possibility that NS improve independently of positive symptoms with KarXT in a subgroup of participants with moderate-to-severe NS and no predominance of positive symptoms.

METHODS

Data were pooled from the three pivotal trials of KarXT monotherapy in people with schizophrenia with an acute exacerbation of psychosis. All 3 studies used similar 5-week randomized, double-blind, placebo-controlled designs (modified intention-to-treat sample N = 640). PANSS criteria proposed in the literature identified a subset of study participants (n = 64) with prominent NS.

RESULTS

KarXT was significantly better than placebo on PANSS Marder Negative Factor Scores in the full sample (p < .001; Cohen's d = 0.42) and more so in the prominent NS subgroup (p < .001; Cohen's d = 1.18). Further, the KarXT effect in the NS subgroup remained significant after accounting for changes in positive symptoms, depression/anxiety, disorganization, and hostility.

CONCLUSIONS

Participants with prominent NS revealed greater improvement of NS following KarXT therapy than the full sample that persisted after accounting for positive and other symptoms. While these findings must be interpreted with caution, they are consistent with the possibility that NS improvements associated with KarXT are not secondary to improvements in other symptom domains and support further investigation in larger, stable outpatient studies.

Pharmacological Treatments of Negative Symptoms in Schizophrenia-An Update

Schizophrenia is a chronic psychotic disorder comprising positive symptoms, negative symptoms, and cognitive deficits. Negative symptoms are associated with stigma, worse functional outcomes, and a significant deterioration in quality of life. Clinical diagnosis is challenging despite its significance, and current treatments offer little improvement in the burden of negative symptoms. This article reviews current pharmacological strategies for treating negative symptoms. Dopaminergic, glutamatergic, serotonergic, noradrenergic, cholinergic, anti-inflammatory compounds, hormones, and psychostimulants are explored. Finally, we review pharmacological global treatment guidelines for negative symptoms. In general, switching to a second-generation antipsychotic seems to be most often recommended for patients with schizophrenia on first-generation antipsychotics, and an add-on antidepressant is considered when depression is also present. However, the treatment of negative symptoms remains an unmet need. Future, larger clinical studies and meta-analyses are needed to establish effective pharmacological agents for the effective treatment of negative symptoms.

Prevalence of prominent and predominant negative symptoms across different criteria for negative symptom severity and minimal positive symptoms: A comparison of different criteria

Negative symptoms are a source of disability in schizophrenia, but criteria for identifying patients for clinical trials are in flux. Minimum severity for negative symptoms is paired with a definition of minimal psychosis to identify predominant negative symptoms. Two previous successful negative symptoms treatment studies used very different severity and selection criteria. We compared the prevalence of participants meeting those two criteria in a large outpatient sample of participants with schizophrenia. Data from 867 outpatients with schizophrenia who participated in one of four NIMH-funded studies were analyzed. Common data elements included diagnoses, the PANSS, and an assessment of everyday functioning. We compared previous criterion for premoninant negative symptoms based on low levels of agitation and psychosis and different cut-offs for negative symptoms severity. 57 % of the participants met the agitation-based criteria for low scores and 33 % met the psychosis-based criteria. 18 % met total PANSS score ≥ 20 and 8 % met ≥24 prominent negative symptoms criteria. 14 % met low agitation and PANSS≥20 and 2 % met the low psychosis and negative symptoms ≥24 criteria. Participants who met all predominant criteria had more impairments in social functioning (all p < .001, all d > 0.37). Criteria for predominant negative symptoms from previous clinical trials identify widely different numbers of cases, with criteria for negative symptom severity and low symptoms both impacting. All criteria yield the expected profile of relatively specific social deficits. Even in unselected populations who participated in complex research protocols, 14 % meet low- agitation based criteria for predominant negative symptoms and many more participants would be expected to meet criteria with enrichment for the presence of negative symptoms.

Clinical challenges in the dosing and titration of cariprazine

The introduction of a new psychopharmaceutical medication instead of the previous one always poses a certain challenge. In the case of antipsychotics (AP), these problems are considerably more complicated and are mainly caused by the question of dose equivalents, but also by the pharmacokinetic properties of the drug. In the case of partial dopamine D2 agonists, an additional issue is the possibility of deterioration when switching from the previous D2 antagonists to these drugs. Cross-titration is therefore generally recommended. Finally, due to the capsule form, it is not possible to increase the dose of cariprazine by less than 1.5 mg during titration. In this paper, we have presented our proposal to replace the most commonly used second-generation APs with the third-generation AP cariprazine. We have taken into account the dose equivalents, the pharmacological forms of the drugs and their pharmacokinetic and pharmacodynamic properties.

Intestinal mycobiota dysbiosis associated inflammation activation in chronic schizophrenia

The microbiome-gut-brain axis is related to schizophrenia (SCZ). The role of intestinal mycobiota in SCZ has been under investigated. We present a half-year follow-up study involving 109 chronic SCZ patients and 77 healthy controls. Intestinal mycobiota was tested by internal transcribed spacer (ITS). Untargeted liquid chromatography-mass spectrometry (LC-MS) was used to measure fecal metabolites. Symptom severity was assessed using the Positive and Negative Syndrome Scale. Enterotype analysis showed that Candida-type patients exhibited severer positive symptoms and depression factors than Saccharomyces-type patients. Candida and its top species and operational taxonomic units (OTUs) were positively correlated with depression factors (all p=0.001). Fecal metabolites analysis showed that upregulated metabolites were associated with chronic inflammation (NF-κB pathway and T helper cell differentiation), downregulated metabolites were associated with glutamate metabolism, serotonergic and dopaminergic synapse. Procrustes analysis revealed significant correlation between intestinal mycobiota and fecal metabolites (M2=0.937, p<0.001). Metabolic module analysis showed that the top module, MEturquoise (associated with Th1 and Th2 cell differentiation), was negatively correlated with SCZ (r=-0.783, p<0.0001), positively correlated with Candida, Aspergillus, Trichosporon and Talaromyces (decreased in SCZ) and negatively correlated with Saccharomyces (increased in SCZ). We also found impairments of intestinal barrier in SCZ, characterized by increased in blood D-lactate (mucosa impairment marker) and decreased in blood mucin 2 (mucosal barrier protective protein). Serum levels of TNF-α was increased and showed stable high levels during treatment. This study suggests that mycobiota dysbiosis-related chronic inflammation and an impaired intestinal mucosal barrier are associated with chronic SCZ.

Cariprazine in the management of emotionally unstable personality disorder in female patients: a case series

Background

Emotionally unstable personality disorder (EUPD) is debilitating psychiatric disorder, particularly common in female and forensic populations. However, appropriate pharmacological treatment to effectively manage symptoms of EUPD remains an unmet clinical need. Dopamine receptor partial agonists (DRPAs), such as aripiprazole, have a favourable tolerability profile and have demonstrated some benefits in targeting symptoms of emotional dysregulation, although, evidence regarding the effects of novel D2/D3 DRPA cariprazine in EUPD patients has been limited.

Objectives

To evaluate the efficacy and tolerability of cariprazine for EUPD in a case series of female forensic inpatients where the diagnosis is more prevalent.

Methods

Demographic and clinical information of the patients were collected from patient electronic records during their admission in a specialized NHS forensic service. Treatment response was measured using the Positive and Negative Syndrome Scale (PANSS) at baseline, 3 and 6 months and Global Clinical Impression Scale (CGI-scores) at baseline and 6 months. Tolerability and BMI, ECG QTc interval and prolactin levels were recorded prior to initiation and at 6 months.

Results

Eight female patients with EUPD (mean age 29.8 years, SD 5.3) were treated with cariprazine (range 3-6mg). Total CGI-scores modestly improved from 5.6 baseline to 5.0 at 6 months. There was a reduction in mean total PANSS scores from baseline to 6 months (92.5, SD 8.1 to 72.4, SD 15.8), general psychopathology (56.1 SD 6.7 to 42.5, SD9.7), positive (21.9 SD 4.6 to 17.1, SD4.8) and negative PANSS scores (14.5 SD 6.3 to 12.8, SD4.6), corresponding to a 21%, 23%, 20% and 3% mean score reduction, respectively. Cariprazine demonstrated a favourable metabolic and hormonal side effect profile with no treatment discontinuation at 6 months follow up.

Conclusion

This is the first case series to evaluate the effectiveness of cariprazine in EUPD. Its efficacy in improving PANSS and CGI-S scores was overall modest and highly variable, reflective of an inherently heterogenous and comorbid patient sample but the benefits on treatment perseverance and tolerability were considerable. Cariprazine may be of particular benefit in EUPD where psychotic symptoms are co-morbid, as an augmentation strategy to clozapine, or where previous antipsychotics have caused metabolic or hormonal side effects.

Intermittent Theta Burst Stimulation Combined with Cognitive Training to Improve Negative Symptoms and Cognitive Impairment in Schizophrenia: A Pilot Study

Schizophrenia is a chronic psychiatric disorder severely affecting patients' functioning and quality of life. Unlike positive symptoms, cognitive impairment and negative symptoms cannot be treated pharmacologically and represent consistent predictors of the illness's prognosis. Cognitive remediation (CR) interventions have been applied to target these symptoms. Brain stimulation also provides promising yet preliminary results in reducing negative symptoms, whereas its effect on cognitive impairment remains heterogeneous. Here, we combined intermittent theta burst stimulation (iTBS) with CR to improve negative symptoms and cognitive impairment in schizophrenia spectrum patients. One hundred eligible patients were invited, and twenty-one participated. We randomized them into four groups, manipulating the stimulation condition (real vs. sham) and CR (no training vs. training). We delivered fifteen iTBS sessions over the left dorsolateral prefrontal cortex for three weeks, followed (or not) by 50 min of training. Consensus-based clinical and cognitive assessment was administered at baseline and after the treatment, plus at three follow-ups occurring one, three, and six months after the intervention. Mixed-model analyses were run on cognitive and negative symptom scores. The preliminary findings highlighted a marginal modulation of iTBS on negative symptoms, whereas CR improved isolated cognitive functions. We herein discuss the limitations and strengths of the methodological approach.

Cariprazine Orodispersible Tablet: A New Formulation for Cariprazine

INTRODUCTION

Cariprazine is an atypical dopamine receptor partial agonist antipsychotic available in the form of capsules. Although capsules are one of the most desirable routes of administration, there are certain situations (e. g., in an acute psychiatric setting, or when swallowing difficulties, or liquid shortages are present) when they cannot be administered. Therefore, alternative solutions like orodispersible tablets are needed. This study aimed to investigate the bioequivalence of a newly developed orodispersible tablet to the commercially available hard gelatine capsule of cariprazine 1.5 mg.

METHODS

This was a phase I, open-label, randomized, single-dose bioequivalence study. It had a 2-period, 2-sequence, cross-over design, where each subject received one test and one reference product in a randomized sequence, separated by a wash-out period of 55 days. Blood sampling was performed over 72 h after dosing. Cariprazine concentrations were analyzed by a validated HPLC-MS/MS method. Standard bioequivalence statistics was applied to PK parameters calculated by non-compartmental analysis. Safety measures were analyzed descriptively.

RESULT

Pharmacokinetic data of 43 healthy volunteers and safety data of 54 subjects was analyzed. Cariprazine AUC0-72h and Cmax geometric mean ratios were 117.76% and 100.88%, respectively. The 90% confidence intervals were within the pre-defined bioequivalence acceptance limits of 80.00% - 125.00%. Safety data was in line with the Summary of Product Characteristics of Cariprazine.

DISCUSSION

The result of this clinical trial proved the bioequivalence of the new orodispersible tablet formulation when compared to hard gelatine capsules, enabling an alternative option for treatment of those suffering from schizophrenia.

Finding the Right Setting for the Right Treatment During the Acute Treatment of Individuals with Schizophrenia: A Narrative Review and Clinical Practice Guideline

Background

Schizophrenia is most times a chronic and often debilitating illness associated with poor mental health outcomes. Early and effective treatment of schizophrenia in the most appropriate setting can make a significant difference in the long-term recovery. The aim of this narrative review was to provide suggestions and recommendations for effectively managing patients with schizophrenia during acute exacerbations and to enhance awareness and skills related to personalized medicine.

Methods

A panel of academics and clinicians with experience in the field of psychosis met virtually on July 13th 2023 to narratively review and discuss the research evidence and their clinical experience about the most appropriate acute treatments for patients with schizophrenia. This manuscript represents a synthesis of the panel analysis and discussion.

Results

First contact is very important for service users, as is finding the most adequate treatment setting. If patients present to the emergency department, which may be a traumatic setting for service users, a dedicated environment with adequate space and specialized mental health support, including personnel trained in de-escalation techniques, is recommended. A well-connected continuum of care is strongly recommended, possibly with seamless links between inpatient units, day hospital services, outpatient facilities and rehabilitation services. Ideally, this should be structured as part of a coordinated step-down service line. Treatment challenges include suboptimal response, side effects, and nonadherence, which is reduced by the use of long-acting injectable antipsychotics.

Conclusion

Individual circumstances, including age, gender, and presence of hostility/aggression or self-harm, cognitive impairment and negative symptoms, comorbidities (depression, substance use disorders) or associated symptoms (anxiety, insomnia), should be considered when selecting the most appropriate treatment for the acute phase of schizophrenia. Efficacy and feasibility, as well as acceptability and tolerability of treatments, require joint consideration from the early stages of schizophrenia, thereby enhancing the possibility of improved short- and long-term outcomes.

Systematic Literature Review of Studies Reporting Measures of Functional Outcome or Quality of Life in People with Negative Symptoms of Schizophrenia

Aim

Negative symptoms of schizophrenia (NSS) have been linked with poor functional outcomes. A literature review was performed to identify instruments used to assess functional outcomes and quality of life in clinical trials and observational studies conducted in groups of people with NSS.

Methods

Literature search strings were designed using Medical Subject Headings combined with free-text terms and searches were performed using the PubMed, Embase and the Cochrane Library databases. For inclusion, articles were required to be published as full-text articles, in English, over the period 2011-2021, include at least one group or treatment arm of people with NSS and report either functional outcomes or quality of life (QoL).

Results

Literature searches identified a total of 3,268 unique hits. After two rounds of screening, 37 publications (covering 35 individual studies) were included in the review. A total of fourteen different instruments were used to assess functional outcomes and eleven different instruments were used to assess QoL. In studies in people with NSS, the most frequently used functional outcome measures were the Personal and Social Performance scale and the Global Assessment of Functioning. The most frequently used QoL instruments included the Manchester Short Assessment of Quality of Life, the Heinrich Carpenter Quality of Life Scale, the Schizophrenia Quality of Life Scale and the EQ-5D.

Conclusion

A large number of measures have been used to assess functional outcomes and QoL in people with NSS, these include both generic and condition-specific as well as both interviewer-administered and self-reported instruments.

Cariprazine maintenance treatment during pregnancy - a case report

Data on reproductive safety of recently approved newer antipsychotics are limited. Here, we report a case vignette of a patient with schizophrenia treated with cariprazine during pregnancy. The patient became pregnant unexpectedly while taking medication. As a result of shared decision-making, the patient and her psychiatrist decided to continue the treatment, which proved to be protective against relapse and had no adverse effect either on the course of pregnancy or on the health of the newborn. Cariprazine maintenance treatment during pregnancy was found to be safe in our case.

D3 Receptor-Targeted Cariprazine: Insights from Lab to Bedside

Until the late 1800s, drug development was a chance finding based on observations and repeated trials and errors. Today, drug development must go through many iterations and tests to ensure it is safe, potent, and effective. This process is a long and costly endeavor, with many pitfalls and hurdles. The aim of the present review article is to explore what is needed for a molecule to move from the researcher bench to the patients' bedside, presented from an industry perspective through the development program of cariprazine. Cariprazine is a relatively novel antipsychotic medication, approved for the treatment of schizophrenia, bipolar mania, bipolar depression, and major depression as an add-on. It is a D3-preferring D3-D2 partial agonist with the highest binding to the D3 receptors compared to all other antipsychotics. Based on the example of cariprazine, there are several key factors that are needed for a molecule to move from the researcher bench to the patients' bedside, such as targeting an unmet medical need, having a novel mechanism of action, and a smart implementation of development plans.

Psychosis superspectrum II: neurobiology, treatment, and implications

Alternatives to traditional categorical diagnoses have been proposed to improve the validity and utility of psychiatric nosology. This paper continues the companion review of an alternative model, the psychosis superspectrum of the Hierarchical Taxonomy of Psychopathology (HiTOP). The superspectrum model aims to describe psychosis-related psychopathology according to data on distributions and associations among signs and symptoms. The superspectrum includes psychoticism and detachment spectra as well as narrow subdimensions within them. Auxiliary domains of cognitive deficit and functional impairment complete the psychopathology profile. The current paper reviews evidence on this model from neurobiology, treatment response, clinical utility, and measure development. Neurobiology research suggests that psychopathology included in the superspectrum shows similar patterns of neural alterations. Treatment response often mirrors the hierarchy of the superspectrum with some treatments being efficacious for psychoticism, others for detachment, and others for a specific subdimension. Compared to traditional diagnostic systems, the quantitative nosology shows an approximately 2-fold increase in reliability, explanatory power, and prognostic accuracy. Clinicians consistently report that the quantitative nosology has more utility than traditional diagnoses, but studies of patients with frank psychosis are currently lacking. Validated measures are available to implement the superspectrum model in practice. The dimensional conceptualization of psychosis-related psychopathology has implications for research, clinical practice, and public health programs. For example, it encourages use of the cohort study design (rather than case-control), transdiagnostic treatment strategies, and selective prevention based on subclinical symptoms. These approaches are already used in the field, and the superspectrum provides further impetus and guidance for their implementation. Existing knowledge on this model is substantial, but significant gaps remain. We identify outstanding questions and propose testable hypotheses to guide further research. Overall, we predict that the more informative, reliable, and valid characterization of psychopathology offered by the superspectrum model will facilitate progress in research and clinical care.

A review on the pharmacology of cariprazine and its role in the treatment of negative symptoms of schizophrenia

Management of negative symptoms is one of the most challenging and important unmet needs of schizophrenia treatment. Negative symptoms together with positive symptoms result in significant psychosocial impairment and poor quality of life. Existing studies on atypical antipsychotics reported limited treatment adherence due to higher prevalence of treatment-emergent adverse events, such as diabetes, weight gain, hyperlipidemia, hyperprolactinemia and hypertension. A compound with greater affinity for dopamine D2/D3 receptors may improve negative symptoms, mood, and cognitive impairment associated with schizophrenia. In 2015, the US FDA has approved cariprazine, a partial D2/D3 agonist for treatment of schizophrenia, mania or mixed episodes. Midlands and Lancashire Commissioning Support Unit, UK (2019) has particularly suggested cariprazine for the treatment of predominant negative symptoms of schizophrenia. India's Central Drugs Standard Control Organization (CDSCO) has approved cariprazine in 2021 for the treatment of schizophrenia, manic or mixed episodes associated with bipolar I disorder. A ten-fold greater affinity for D3 receptors and partial agonism to serotonin receptors, along with longer half-life make cariprazine distinct when compared with other atypical antipsychotics. Cariprazine is also reported to have fewer incidents of metabolic and hormonal adverse events, and has been shown to provide better relapse prevention. Recent evidence indicates promising effect of cariprazine in ameliorating negative symptoms as well as psychotic symptoms in patients with schizophrenia. In addition, improved adherence to treatment (adjunctive/monotherapy) with cariprazine in patients having inadequate response to an ongoing antipsychotic treatment has also been clinically established. This review presents the evidence-based safety and efficacy of cariprazine for treatment of predominant negative symptoms of schizophrenia.

Statistical analyses of ordinal outcomes in randomised controlled trials: a scoping review

BACKGROUND

Randomised controlled trials (RCTs) aim to estimate the causal effect of one or more interventions relative to a control. One type of outcome that can be of interest in an RCT is an ordinal outcome, which is useful to answer clinical questions regarding complex and evolving patient states. The target parameter of interest for an ordinal outcome depends on the research question and the assumptions the analyst is willing to make. This review aimed to provide an overview of how ordinal outcomes have been used and analysed in RCTs.

METHODS

The review included RCTs with an ordinal primary or secondary outcome published between 2017 and 2022 in four highly ranked medical journals (the British Medical Journal, New England Journal of Medicine, The Lancet, and the Journal of the American Medical Association) identified through PubMed. Details regarding the study setting, design, the target parameter, and statistical methods used to analyse the ordinal outcome were extracted.

RESULTS

The search identified 309 studies, of which 144 were eligible for inclusion. The most used target parameter was an odds ratio, reported in 78 (54%) studies. The ordinal outcome was dichotomised for analysis in 47 ( 33 % ) studies, and the most common statistical model used to analyse the ordinal outcome on the full ordinal scale was the proportional odds model (64 [ 44 % ] studies). Notably, 86 (60%) studies did not explicitly check or describe the robustness of the assumptions for the statistical method(s) used.

CONCLUSIONS

The results of this review indicate that in RCTs that use an ordinal outcome, there is variation in the target parameter and the analytical approaches used, with many dichotomising the ordinal outcome. Few studies provided assurance regarding the appropriateness of the assumptions and methods used to analyse the ordinal outcome. More guidance is needed to improve the transparent reporting of the analysis of ordinal outcomes in future trials.

Understanding the Therapeutic Action of Antipsychotics: From Molecular to Cellular Targets With Focus on the Islands of Calleja

The understanding of the pathophysiology of schizophrenia as well as the mechanisms of action of antipsychotic drugs remains a challenge for psychiatry. The demonstration of the therapeutic efficacy of several new atypical drugs targeting multiple different receptors, apart from the classical dopamine D2 receptor as initially postulated unique antipsychotic target, complicated even more conceptualization efforts. Here we discuss results suggesting a main role of the islands of Calleja, still poorly studied GABAergic granule cell clusters in the ventral striatum, as cellular targets of several innovative atypical antipsychotics (clozapine, cariprazine, and xanomeline/emraclidine) effective in treating also negative symptoms of schizophrenia. We will emphasize the potential role of dopamine D3 and M4 muscarinic acetylcholine receptor expressed at the highest level by the islands of Calleja, as well as their involvement in schizophrenia-associated neurocircuitries. Finally, we will discuss the implications of new data showing ongoing adult neurogenesis of the islands of Calleja as a very promising antipsychotic target linking long-life neurodevelopment and dopaminergic dysfunction in the striatum.

Third-Generation Antipsychotics and Lurasidone in the Treatment of Substance-Induced Psychoses: A Narrative Review

This narrative review explores the efficacy and tolerability of third-generation antipsychotics (TGAs)-aripiprazole, cariprazine, brexpiprazole, and lurasidone-for the management of substance-induced psychosis (SIP). SIP is a psychiatric condition triggered by substance misuse or withdrawal, characterized by unique features distinct from those of primary psychotic disorders. These distinctive features include a heightened prevalence of positive symptoms, such as hallucinations and delusions, in addition to a spectrum of mood and cognitive disturbances. This review comprehensively investigates various substances, such as cannabinoids, cocaine, amphetamines, and LSD, which exhibit a greater propensity for inducing psychosis. TGAs exhibit substantial promise in addressing both psychotic symptoms and issues related to substance misuse. This review elucidates the distinctive pharmacological properties of each TGA, their intricate interactions with neurotransmitters, and their potential utility in the treatment of SIP. We advocate for further research to delineate the long-term effects of TGAs in this context and underscore the necessity for adopting an integrated approach that combines pharmacological and psychological interventions. Our findings underscore the intricate and multifaceted nature of treating SIP, highlighting the potential role of TGAs within therapeutic strategies.

Prevalence and Cost of Antipsychotic Prescribing, within the Context of Psycholeptic Prescribing, in the Irish Setting

Psycholeptic and specifically antipsychotic prescribing is increasing worldwide each year. This study aims to investigate the prevalence and cost of antipsychotic prescribing, within the wider frame of psycholeptic prescribing, in the Irish context. Quantitative analysis of a dataset from the Primary Care Reimbursement Service relating to cost and prescribing frequency of ATC Class N05 psycholeptic drugs from January 2020-August 2022 inclusive was conducted using Microsoft® Excel® for Microsoft 365 MSO (Version 2311) and STATA 18. Descriptive statistics and time-trend regression analysis were used to investigate the prescribing prevalence of psycholeptics and antipsychotics licensed for use in the Republic of Ireland, and the total cost per funding scheme. The prevalence of psycholeptic prescribing increased yearly from 2020-2022, peaking at 328,572 prescriptions in December 2020 with a total cost of psycholeptic drugs to the State in 2021 of €57,886,250, which was 0.5% of an increase on 2020. Over the 32-month time period, the average monthly cost of psycholeptic drugs was €4,436,469 on the General Medical Services (GMS) scheme and €369,154 on the Drug Payment Scheme (DPS). In 2021, quetiapine, olanzapine, and risperidone were the most prescribed antipsychotics, accounting for 66.58% of antipsychotics prescribed on the GMS scheme. This study identified the large expenditure on psycholeptics and antipsychotics in Ireland, with a higher proportion of the Irish healthcare budget spent on antipsychotics than that of the UK and the USA. The development of Irish antipsychotic prescribing guidelines may allow for structured, cost-effective prescribing.

Multilevel evidence of MECP2-associated mitochondrial dysfunction and its therapeutic implications

We present a male patient carrying a pathogenic MECP2 p. Arg179Trp variant with predominant negative psychiatric features and multilevel evidence of mitochondrial dysfunction who responded to the cariprazine treatment. He had delayed speech development and later experienced severe social anxiety, learning disabilities, cognitive slowing, and predominant negative psychiatric symptoms associated with rigidity. Clinical examinations showed multisystemic involvement. Together with elevated ergometric lactate levels, the clinical picture suggested mitochondrial disease, which was also supported by muscle histopathology. Exploratory transcriptome analysis also revealed the involvement of metabolic and oxidative phosphorylation pathways. Whole-exome sequencing identified a pathogenic MECP2 variant, which can explain both the dopamine imbalance and mitochondrial dysfunction in this patient. Mitochondrial dysfunction was previously suggested in classical Rett syndrome, and we detected related phenotype evidence on multiple consistent levels for the first time in a MECP2 variant carrier male. This study further supports the importance of the MECP2 gene in the mitochondrial pathways, which can open the gate for more personalized therapeutic interventions. Good cariprazine response highlights the role of dopamine dysfunction in the complex psychiatric symptoms of Rett syndrome. This can help identify the optimal treatment strategy from a transdiagnostic perspective instead of a classical diagnostic category.

Cariprazine augmentation of clozapine in schizophrenia-a retrospective chart review

The aim of our study was to evaluate the efficacy of cariprazine augmentation of clozapine in treatment-resistant schizophrenia in a retrospective chart review. Among 916 medical records of schizophrenia patients, we identified 12 individuals treated with a combination of those drugs for a duration of 3-60 weeks [median 32 (10-40)]. Clinical Global Impression-Improvement (CGI-I) scores were used to measure the treatment response between the introduction of cariprazine augmentation of clozapine and the last point of observation. The majority of the patients presented treatment response (9/12 patients, 75%) after 4-16 weeks of therapy [median 6 (4-12)]. Treatment was associated with the decrease in positive, negative, affective, and anxiety symptom severity, as well as improvement of patient global functioning. One patient discontinued the treatment due to side effects (akathisia), and two patients halted the therapy due to the exacerbation of psychotic symptoms. Our study presents a thorough clinical description of the largest number of treatment-resistant schizophrenia patients medicated using cariprazine augmentation of clozapine in a "real-world" setting. Our results suggest that the use of this combination may lead to the improvement in a broad range of symptoms of patients with this condition.

Aripiprazole 2-month ready-to-use 960 mg (Ari 2MRTU): review of its possible role in schizophrenia therapy

Most patients with schizophrenia need life-long treatment. There is therefore a continued need for effective and tolerable treatment options. A 2-monthly LAI formulation of aripiprazole, Aripiprazole 2-Month Ready-to-Use 960 mg (Ari 2MRTU 960) has recently been approved in the US. Here, the possible role in therapy for this new treatment option is discussed in a narrative review. PubMed was searched for literature on long-acting injectables with a focus on patient-reported outcomes and real-world evidence on extended injection intervals (2-3 months). Dopamine D2 partial agonists, one of which is aripiprazole, exhibit favorable tolerability and safety properties. Additionally, there are many advantages in using long-acting injectable formulations such as enhanced treatment persistence and stability of patients as well as reduced rates of relapses, hospitalizations, and death. Some of these advantages become more pronounced with longer injection intervals. Additional advantages of longer injection intervals are more room for non-medication-related communication between healthcare professionals and patients, patient and physician preferences, reduced caregiver burden, and easier transitioning from inpatient to outpatient treatment. Taken together, since aripiprazole may be a good treatment choice for many patients based on its favorable safety and tolerability profile, and given the advantages of LAI treatment over oral treatment and the advantages of reduced dosing frequency, Ari 2MRTU 960 may become an important treatment option for many clinically stable patients with schizophrenia.

Efficacy and Safety Profiles of Antipsychotic Drugs as Viewed by Psychiatrists: A Comparative Analysis of Cariprazine and Risperidone

BACKGROUND

Physicians hold the belief that the treatment outcomes and the treatment strategy they eventually adopt is largely determined by the differences in medications. Despite numerous studies focusing on the decision-making processes of psychiatrists, including the choice of antipsychotics when prescribing pharmacotherapy, the impact of therapeutic drug profiling on physicians' decision-making remains poorly comprehended.

AIM

The aim of this study is to assess the quantitative differences in perceptions of antipsychotics by psychiatrists using cariprazine and risperidone as examples.

METHODS

A total of 79 psychiatrists were interviewed anonymously in St. Petersburg, Russia. The physicians documented the clinical advantages they perceived drugs to possess relative to one another, following a predetermined principle: A B, A=B, A B (2-AC protocol). The comparison is based on eleven parameters that assess the effectiveness and safety of cariprazine or risperidone. It has been hypothesized that the pattern of responses (qualitative difference) and the degree of preference for each drug (quantitative difference) may not align with the data in the original meta-analyses.

RESULTS

The perception parameter exhibited a greater difference than anticipated (δ - 0.889), while the threshold for differentiating between the drugs was lower (τ - 1.001). The response pattern only aligned with theory by 44.37%. The dispersion of responses was associated with the length of work experience.

CONCLUSION

The perceived difference between the drugs significantly deviates from the theoretical data, both in terms of strength of perception and pattern (quantitative and qualitative differences).

Hypersexuality during treatment with cariprazine in a patient with schizophrenia? A case report

BACKGROUND

Cariprazine is a third-generation antipsychotic with a unique mechanism of action. It functions as a partial agonist with high affinity for dopamine D2 and D3 and serotonin 5-HT1A receptors, an antagonist for 5-HT2A (moderate affinity) and 5-HT2B (high affinity) receptors. It binds to histamine H1 receptors and has a low affinity for 5-HT2C and alpha 1A-adrenergic receptors and no affinity for muscarinic (cholinergic) receptors. Among the troubling side effects, symptoms related to impulse control, such as hypersexuality, pathological gambling, compulsive shopping, compulsive eating etc., have been reported with the use of antipsychotic medications. However, no reports have been published regarding impulse control symptoms associated with cariprazine. We report a case of cariprazine-induced hypersexuality in a patient with schizophrenia, which was resolved by discontinuation of the medication.

CASE PRESENTATION

A 67-year-old Caucasian woman with schizophrenia was admitted to the hospital inpatient unit after she discontinued olanzapine and psychotic symptoms reappeared. Prior to that, she was in remission, taking olanzapine for approximately one year. After discontinuation, she experienced auditory hallucinations with persecutory delusions and became anergic and withdrawn, with blunted affect. Olanzapine was reintroduced, as it was proven successful in her past treatments. However, since there were no changes, especially in negative symptoms, cariprazine was added. Seven days after the introduction of cariprazine, the patient developed compulsive sexual behaviour. Therefore, cariprazine was discontinued, and the hypersexual behaviour was resolved.

CONCLUSIONS

In this case report, we describe hypersexual behaviour that could potentially be induced by cariprazine. As a single case study, conclusions cannot be drawn. Controlled studies are warranted to better determine causality and the significance of this possible side-effect of cariprazine.

Switching antipsychotics to partial dopamine D2-agonists in individuals affected by schizophrenia: a narrative review

OBJECTIVE

The aim of this review is to analyse the literature regarding studies centred on the clinical outcome of individuals affected by schizophrenia and treated with various antipsychotics, and then switched to orally administered partial D2-dopamine agonists (PD2A): Aripiprazole (ARI), brexpiprazole (BREX) or cariprazine (CARI).

METHOD

A PubMed literature search was performed on 16 February 2021, and updated on Jan 26, 2022 for literature on antipsychotic switching in individuals affected by schizophrenia. Literature was included from 2002 onward. Six strategies were defined: Abrupt, gradual and cross-taper switch, and 3 hybrid strategies. The primary outcome was all-cause discontinuation rate per switch strategy per goal medication.

RESULTS

In 10 reports on switching to ARI, 21 studies with different strategies were described, but there were only 4 reports and 5 strategies on switching to BREX. Only one study about CARI was included, but it was not designed as a switch study. The studies are difficult to compare due to differences in methodology, previous antipsychotic medication, doses of the introduced P2DA and study duration.

CONCLUSION

This analysis did not reveal evidence for a preferable switching strategy. A protocol should be developed which defines optimal duration, instruments to be used, and the timing of the exams.KEY MESSAGESMost switch studies on partial D2-agonists focus on ARI, with only a few on BREX, while little is known about the clinical outcome of switching individuals to CARIThere is a wide variation of possible switch methods: Abrupt switch - gradual switch - cross-tapering switch - hybrid strategies including plateau switchThe protocols used differ considerably between the studies. A strict comparison between the studies is difficult, for which reason the present evidence does not support an unambiguous preference for a particular switch strategy.From a methodological point of view, a standardised clinical protocol should be developed to allow comparisons between studies regarding the clinical outcome of individuals switched from one antipsychotic drug to another.

Single trajectory treatment response for predominant negative symptoms: Post-hoc analysis of a clinical trial with cariprazine and risperidone

Examining the heterogeneity of negative symptoms of schizophrenia contributes to the identification of available treatment targets. Generally, prior evidence classified three to four symptom treatment response trajectory groups over the course of positive symptoms, yet, no evidence exists regarding the heterogeneity of medium-term response to predominant negative symptoms. The current post-hoc analysis aims to identify the heterogeneity in negative symptom treatment response trajectories among patients with predominant negative symptoms who received either cariprazine or risperidone for 26 weeks. Treatment response was analyzed based on the: the Positive and Negative Syndrome Scale Factor Score for Negative Symptoms (PANSS-FSNS), and the Clinical Global Impression Severity (CGIS) and Improvement (CGII) scales. To identify subgroups of patients with a similar course of treatment response, group-based trajectory modelling was utilized. Results demonstrated that in comparison with competing models, a single trajectory best described the treatment response of patients with predominant negative symptoms. The results indicate that patients with predominant negative symptoms with over ten years of schizophrenia respond rapidly to adequate treatment and follow a course of steady improvement.

Design, Synthesis, and Insecticidal Evaluation of N-Pyridylpyrazole Amide Derivatives Containing 4,5-Dihydroisoxazole Amide as Potential Ryanodine Receptor Activators

Using the 4,5-dihydroisoxazol amide structure to expand the aliphatic amide moiety of chlorantraniliprole, a series of 28 novel N-pyridylpyrazolecarboxamide derivatives containing 4,5-dihydroisoxazol amide fragment were designed and synthesized. All target compounds had been properly characterized and confirmed by 1H NMR, 13C NMR, and HRMS, and the effects were evaluated against Mythimna separata (M. separata) and Plutella xylostella (P. xylostella). The bioassay results indicated that most of the target compounds exhibited good insecticidal activities against M. separata and P. xylostella at 50 mg/L; especially, compound A4 showed an LC50 value of 3.27 mg/L against M. separata. Calcium imaging experiments indicated that the target compound A4 had a similar mechanism of action to chlorantraniliprole, causing an increase in the cytoplasmic Ca2+ concentration. The molecular docking revealed the possible binding mode of compound A4 with a ryanodine receptor.

The role of the D3 dopamine receptor and its partial agonist cariprazine in patients with schizophrenia and substance use disorder

INTRODUCTION

Comorbidity of substance use disorder (SUD) with schizophrenia, referred to as dual disorder (DD), significantly increases morbidity and mortality compared to schizophrenia alone. A dopaminergic dysregulation seems to be a common pathophysiological basis of the comorbidity.

AREAS COVERED

This article reports the current evidence on the role of dopamine dysregulations in DD, the pharmacological profile of cariprazine, a partial agonist of D3 and D2 dopamine receptors, and first clinical observations that may support its usefulness in the therapy of DD. PubMed/MEDLINE was searched for the keywords 'cariprazine,' 'schizophrenia,' 'dual disorder,' 'dopamine,' and 'dopamine receptor.' Preclinical and clinical studies, and reviews published in English were retrieved.

EXPERT OPINION

Although the management of DD remains challenging, and the evidence for pharmacologic treatments is still unsatisfactory, cariprazine may be a candidate medication in DD due to its unique mechanism of action. Preliminary clinical experiences suggest that cariprazine has both antipsychotic and anticraving properties and should be considered early in patients with DD.

Dopamine partial agonists: a discrete class of antipsychotics

Worldwide, there are now three marketed dopamine D2 partial agonists: aripiprazole, brexpiprazole and cariprazine. These three drugs share a number of properties other than their action at D2 receptors. Pharmacologically, they are 5HT2 antagonists and D3 and 5HT1A partial agonists but with little or no alpha-adrenergic, anticholinergic or antihistaminic activity. They also share a long duration of action. Clinically, D2 partial agonists are effective antipsychotics and generally have useful antimanic and antidepressant activity. They are usually well tolerated, causing akathisia and insomnia only at the start of treatment, and are non-sedating. These drugs also share a very low risk of increased prolactin and of weight gain and accompanying metabolic effects. They may also have a relatively low risk of tardive dyskinesia. There is some evidence that they are preferred by patients to dopamine antagonists. Individual dopamineD2 partial agonists have much in common and as a group they differ importantly from dopamine D2 antagonists. Dopamine D2 partial agonists should be considered a distinct class of antipsychotics.Key pointsD2 partial agonists share many pharmacological and clinical propertiesD2 partial agonists differ in several important respects from D2 antagonistsD2 partial agonists should be considered a discrete class of antipsychotics.