Trial of Pimavanserin in Dementia-Related Psychosis

Progress in Pharmacologic Management of Neuropsychiatric Syndromes in Neurodegenerative Disorders: A Review

Importance

Neuropsychiatric syndromes (NPSs) are common in neurodegenerative disorders (NDDs); compromise the quality of life of patients and their care partners; and are associated with faster disease progression, earlier need for nursing home care, and poorer quality of life. Advances in translational pharmacology, clinical trial design and conduct, and understanding of the pathobiology of NDDs are bringing new therapies to clinical care.

Observations

Consensus definitions have evolved for psychosis, agitation, apathy, depression, and disinhibition in NDDs. Psychosocial interventions may reduce mild behavioral symptoms in patients with NDD, and pharmacotherapy is available for NPSs in NDDs. Brexpiprazole is approved for treatment of agitation associated with Alzheimer disease dementia, and pimavanserin is approved for treatment of delusions and hallucinations associated with psychosis of Parkinson disease. Trials are being conducted across several of the NDDs, and a variety of mechanisms of action are being assessed for their effect on NPSs.

Conclusions and Relevance

Detection and characterization of NPSs in patients with NDDs is the foundation for excellent care. New definitions for NPSs in NDDs may inform choices regarding clinical trial populations and translate into clinical practice. Psychosocial and pharmacologic therapies may reduce behavioral symptoms and improve quality of life for patients and caregivers. Approved agents may establish regulatory precedents, demonstrate successful trial strategies, and provide the foundation for further advances in treatment development.

Challenges and proposed solutions to conducting Alzheimer's disease psychosis trials

Alzheimer's disease psychosis (ADP) produces a significant burden for patients and their care partners, but at present there are no approved treatments for ADP. The lack of approved treatments may be due to the challenges of conducting clinical trials for this disease. This perspective article discusses distinct challenges and proposed solutions of conducting ADP trials involving seven key areas: (1) methods to reduce the variable and sometimes high rates of placebo response that occur for treatments of neuropsychiatric symptoms; (2) the use of combined or updated criteria that provide a precise, consensus definition of ADP; (3) the use of eligibility criteria to help recruit individuals representative of the larger ADP population and overcome the difficulty of recruiting patients with moderate-to-severe ADP; (4) consideration of multiple perspectives and implementation of technology to reduce the variability in the administration and scoring of neuropsychiatric symptom assessments; (5) the use of clinically appropriate, a priori-defined severity thresholds and responder cutoffs; (6) the use of statistical approaches that address absolute effect sizes and a three-tier approach to address the fluctuation of neuropsychiatric symptoms; and (7) the implementation of feasible diagnostic and target-engagement biomarkers as they become available. The goal of these proposed solutions is to improve the evaluation of potential ADP therapies, within the context of randomized, placebo-controlled trials with clinically meaningful endpoints and sustained treatment responses.

Psychoplastogenic DYRK1A Inhibitors with Therapeutic Effects Relevant to Alzheimer's Disease

Tauopathy, neuronal atrophy, and psychological impairments are hallmarks of neurodegenerative diseases, such as Alzheimer's disease, that currently lack efficacious clinical treatments capable of rectifying these issues. To address these unmet needs, we used rational drug design to combine the pharmacophores of DYRK1A inhibitors and isoDMTs to develop psychoplastogenic DYRK1A inhibitors. Using this approach, we discovered a nonhallucinogenic compound capable of promoting cortical neuron growth and suppressing tau hyperphosphorylation while also having the potential to mitigate the biological and psychological symptoms of dementia. Together, our results suggest that hybridization of the DYRK1A and psychoplastogen pharmacophores represents a promising strategy for identifying compounds that might address the cognitive as well as the behavioral and psychological symptoms of dementia.

Dementia Prevention and Treatment: A Narrative Review

Importance

Dementia affects 10% of those 65 years or older and 35% of those 90 years or older, often with profound cognitive, behavioral, and functional consequences. As the baby boomers and subsequent generations age, effective preventive and treatment strategies will assume increasing importance.

Observations

Preventive measures are aimed at modifiable risk factors, many of which have been identified. To date, no randomized clinical trial data conclusively confirm that interventions of any kind can prevent dementia. Nevertheless, addressing risk factors may have other health benefits and should be considered. Alzheimer disease can be treated with cholinesterase inhibitors, memantine, and antiamyloid immunomodulators, with the last modestly slowing cognitive and functional decline in people with mild cognitive impairment or mild dementia due to Alzheimer disease. Cholinesterase inhibitors and memantine may benefit persons with other types of dementia, including dementia with Lewy bodies, Parkinson disease dementia, vascular dementia, and dementia due to traumatic brain injury. Behavioral and psychological symptoms of dementia are best treated with nonpharmacologic management, including identifying and mitigating the underlying causes and individually tailored behavioral approaches. Psychotropic medications have minimal evidence of efficacy for treating these symptoms and are associated with increased mortality and clinically meaningful risks of falls and cognitive decline. Several emerging prevention and treatment strategies hold promise to improve dementia care in the future.

Conclusions and Relevance

Although current prevention and treatment approaches to dementia have been less than optimally successful, substantial investments in dementia research will undoubtedly provide new answers to reducing the burden of dementia worldwide.

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.

Parkinson disease psychosis: from phenomenology to neurobiological mechanisms

Parkinson disease (PD) psychosis (PDP) is a spectrum of illusions, hallucinations and delusions that are associated with PD throughout its disease course. Psychotic phenomena can manifest from the earliest stages of PD and might follow a continuum from minor hallucinations to structured hallucinations and delusions. Initially, PDP was considered to be a complication associated with dopaminergic drug use. However, subsequent research has provided evidence that PDP arises from the progression of brain alterations caused by PD itself, coupled with the use of dopaminergic drugs. The combined dysfunction of attentional control systems, sensory processing, limbic structures, the default mode network and thalamocortical connections provides a conceptual framework to explain how new incoming stimuli are incorrectly categorized, and how aberrant hierarchical predictive processing can produce false percepts that intrude into the stream of consciousness. The past decade has seen the publication of new data on the phenomenology and neurobiological basis of PDP from the initial stages of the disease, as well as the neurotransmitter systems involved in PDP initiation and progression. In this Review, we discuss the latest clinical, neuroimaging and neurochemical evidence that could aid early identification of psychotic phenomena in PD and inform the discovery of new therapeutic targets and strategies.

Psychotic Symptoms in Patients With Major Neurological Diseases

Neurological diseases often manifest with neuropsychiatric symptoms such as depression, emotional incontinence, anger, apathy and fatigue. In addition, affected patients may also experience psychotic symptoms such as hallucinations and delusions. Various factors contribute to the development of psychotic symptoms, and the mechanisms of psychosis are similar, but still differ among various neurological diseases. Although psychotic symptoms are uncommon, and have been less well investigated, they may annoy patients and their families as well as impair the patients' quality of life and increase the caregiver burden. Therefore, we need to appropriately identify and treat these psychotic symptoms in patients with neurological diseases.

Pimavanserin for psychosis in Parkinson's disease dementia: Subgroup analysis of the HARMONY Trial

INTRODUCTION

Pimavanserin is FDA-approved to treat Parkinson's disease (PD) psychosis. We analyzed the effect of pimavanserin on psychosis in the PD dementia (PDD) subgroup from the phase 3 HARMONY trial.

METHODS

This subgroup analysis included PDD patients enrolled in an international, multicenter, randomized discontinuation study of pimavanserin for dementia-related psychosis. PDD patients with moderate-to-severe psychosis, age 50-90 years, received pimavanserin 34 mg/day for 12 weeks (open-label period). Those with a sustained psychosis response to pimavanserin at weeks 8 and 12 were randomized during the double-blind period to continue pimavanserin or receive placebo. Primary efficacy endpoint was time to psychosis relapse as measured by the SAPS-H + D and CGI-I. Safety was assessed, as were effects on motor symptoms and cognitive abilities using the ESRS-A and MMSE.

RESULTS

392 patients were enrolled in HARMONY (mean age: 72.6 years; 38.8 % female): 59 had PDD; 49/59 remained on pimavanserin during the open-label period (safety analysis set), and 36/49 were randomized to pimavanserin (n = 16) or placebo (n = 20) in the double-blind phase (intent-to-treat analysis set). Risk of psychosis relapse was lower with pimavanserin 34 mg compared with placebo in the double-blind phase (HR = 0.052; 95 % CI 0.016-0.166; 1-sided nominal p < 0.001). During the open-label period, 46.9 % experienced a treatment-emergent adverse event; event incidence was similar across arms in the double-blind period. Pimavanserin did not adversely affect motor or cognitive function in either treatment phase.

CONCLUSIONS

Pimavanserin significantly reduced risk of psychosis relapse in patients with PDD, was well tolerated, and did not worsen motor or cognitive function.

Medical, surgical, and physical treatments for Parkinson's disease

Although dopamine replacement therapy remains a core component of Parkinson's disease treatment, the onset of motor fluctuations and dyskinetic movements might require a range of medical and surgical approaches from a multidisciplinary team, and important new approaches in the delivery of dopamine replacement are becoming available. The more challenging, wide range of non-motor symptoms can also have a major impact on the quality of life of a patient with Parkinson's disease, and requires careful multidisciplinary management using evidence-based knowledge, as well as appropriately tailored strategies according to the individual patient's needs. Disease-modifying therapies are urgently needed to prevent the development of the most disabling refractory symptoms, including gait and balance difficulties, cognitive impairment and dementia, and speech and swallowing impairments. In the third paper in this Series, we present the latest evidence supporting the optimal treatment of Parkinson's disease, and describe an expert approach to many aspects of treatment choice where an evidence base is insufficient.

Aripiprazole Attenuates Cognitive Impairments Induced by Lipopolysaccharide in Rats through the Regulation of Neuronal Inflammation, Oxidative Stress, and Apoptosis

Background and Objectives: Aripiprazole (APZ), an atypical antipsychotic, is mainly prescribed for conditions such as schizophrenia and bipolar disorder, while ongoing research indicates promising neuroprotective qualities. APZ's mechanism of action, involving the regulation of neurotransmitter levels, appears to contribute to its potential to shield neural tissues from specific forms of harm and degeneration. Materials and Methods: To investigate its neuroprotective mechanisms, groups of rats were orally administered APZ at 1 or 2 mg/kg once daily for a 30-day period. In addition, neuronal toxicity was induced through intraperitoneal injection of four doses of lipopolysaccharide (LPS) at a concentration of 1 mg/kg. To evaluate cognitive function, particularly, short-term recognition memory, the procedure implemented the novel object recognition (NOR) task. Subsequently, brain tissues were gathered to examine markers linked with neuroinflammation, oxidative stress, and apoptosis. Results: The administration of LPS led to a decline in memory performance during the NOR tasks. Simultaneously, this LPS treatment raised inflammatory markers like cyclooxygenase (COX)-2, tumor necrosis factor (TNF)-α, and nuclear factor kappa B (NF-κB), increased oxidative markers such as malondialdehyde (MDA), and triggered apoptosis markers like Caspase-3 and Bcl2 associated X protein (Bax) within the brain. Furthermore, it decreased levels of antioxidants like reduced glutathione (GSH) and catalase, as well as the anti-apoptotic marker B-cell lymphoma (Bcl)-2 in brain tissue. The use of APZ resulted in enhanced recognition memory performance, as indicated by improved exploration and discrimination abilities of the objects in the NOR task. Moreover, APZ lowered the markers associated with neuronal vulnerability, such as COX-2, NF-κB, MDA, Caspase-3, and Bax. Additionally, it increased the levels of protective markers, including GSH, catalase, and Bcl-2 in LPS-challenged brains. Conclusions: In summary, the findings suggest that APZ exhibits protective properties against neuronal inflammation, oxidative stress, and apoptosis markers in the context of inflammatory-related neurodegeneration. Additional in-depth investigations are needed to further explore potential applications.

Behavioral or neuropsychiatric symptoms of Alzheimer's disease: from psychopathology to pharmacological management

Neuropsychiatric or behavioral symptoms of dementia encompass a series of disorders, such as anxiety, depression, apathy, psychosis, and agitation, all commonly present in individuals living with dementia. While they are not required for the diagnosis of Alzheimer's disease (AD), they are ubiquitously present in all stages of the disease, contributing to negative clinical outcomes, including cognitive decline, functional disability, and caregiver burden. Neuropsychiatric symptoms have been conceptualized not only as risk factors but as clinical markers of decline along the AD spectrum. The concept of "mild behavioral impairment", the behavioral correlate of mild cognitive impairment, has been proposed within this framework. The first steps in the management of behavioral symptoms in AD involve defining the target and investigating potential causes and/or aggravating factors. Once these factors are addressed, non-pharmacological approaches are preferred as first-line interventions. Following the optimization of anticholinesterase treatments, specific pharmacological approaches (e.g., antidepressants, antipsychotics) can be considered weighing potential side effects.

Population Pharmacokinetic Modeling and Stochastic Simulations to Support Pediatric Dose Selection of Pimavanserin

Pimavanserin is a selective serotonin-modulating agent with inverse agonist/antagonist activity at the 5-hydroxytryptamine2A (5-HT2A ) receptor. The safety and efficacy of pimavanserin 34 mg once daily were studied in adults with hallucinations and delusions associated with Parkinson's disease psychosis and other neuropsychiatric conditions. This analysis used model-based simulations of pimavanserin steady-state exposures to identify a dose that generated pediatric exposures comparable with adult exposures achieved with 34 mg pimavanserin. A population pharmacokinetics model was developed using pooled plasma drug concentration (ie, actual) data from 13 clinical studies, including a phase 1 study of adolescent pediatric patients (aged 13-17 years) with various psychiatric conditions. Stochastic simulations were performed to predict exposures in a virtual (ie, simulated) group of pediatric patients (aged 5-17 years). Steady-state measures of the area under the plasma concentration-time curve (AUC) and maximum drug concentration (Cmax ) were simulated for relevant age and weight stratifications and compared with simulated exposures in adults (aged 18-49 years). The simulated mean AUC ranged from 47.41 to 54.73 ng d/mL and the mean Cmax ranged from 41.13 to 50.07 ng/mL in adults receiving pimavanserin 34 mg. The simulated mean (SD) Cmax of 56.54 (24.58) ng/mL with pimavanserin 34 mg in patients aged 10-17 years was similar to that in adults. Pimavanserin 20 mg yielded a mean (SD) Cmax of 45.30 (21.31) ng/mL in patients aged 5-9 years and 49.18 (22.91) ng/mL in the pediatric patient weight group of 14-25 kg, which are values close to the Cmax in adults treated with 34 mg. Pimavanserin 20 and 34 mg in pediatric patients aged 5-9 and 10-17 years, respectively, yielded exposures similar to daily pimavanserin 34 mg in adults aged 18-49 years.

Advances in the Diagnosis and Management of Psychotic Symptoms in Neurodegenerative Diseases: A Narrative Review

Background: Approximately 15% of older adults may experience psychotic phenomena. Primary psychiatric disorders that manifest with psychosis (delusions, hallucinations, and disorganized thought or behavior) account for less than half. Up to 60% of late-life psychotic symptoms are due to systemic medical or neurological conditions, particularly neurodegenerative diseases. A thorough medical workup including laboratory tests, additional procedures if indicated, and neuroimaging studies is recommended. This narrative review summarizes current evidence regarding the epidemiology and phenomenology of psychotic symptoms encountered as part of the neurodegenerative disease continuum (including prodromal and manifest stages). Results: Prodromes are constellations of symptoms that precede the onset of overt neurodegenerative syndromes. Prodromal psychotic features, particularly delusions, have been associated with an increased likelihood of receiving a neurodegenerative disease diagnosis within several years. Prompt prodrome recognition is crucial for early intervention. The management of psychosis associated with neurodegenerative diseases includes behavioral and somatic strategies, although evidence is scarce and mostly limited to case reports, case series, or expert consensus guidelines, with few randomized controlled trials. Conclusion: The complexity of psychotic manifestations warrants management by interprofessional teams that provide coordinated, integrated care.

Pimavanserin Use in Lewy Body Dementia: A Case Report Demonstrating the Medication's Efficacy

Pimavanserin is an antipsychotic that is approved for use in Parkinson's disease psychosis. Working as a serotonin 2A inverse agonist, pimavanserin allows patients to improve their psychotic symptoms without worsening the motor symptoms of Parkinson's. This mechanism is mediated via serotonin receptors and may allow for pimavanserin to be considered for use in other disease processes that present with psychosis. Here, the authors describe the case of a 75-year-old man with Lewy Body Dementia (LBD) who was started on pimavanserin. The response of the patient to the medication was measured over a six-week time course using the Scales for the Assessment of Positive Symptoms of Schizophrenia (SAPS). Overall, pimavanserin was shown to be effective in this patient with LBD. The authors also provide a review of the sparse literature attesting to other off-label uses for this unique antipsychotic.

Management of neuropsychiatric symptoms in dementia

PURPOSE OF REVIEW

The purpose is to review the results and clinical implications of recent studies of neuropathology in relation to neuropsychiatric symptoms (NPS) in Alzheimer's disease and related dementias, and discuss new therapeutic approaches based on evidence from clinical trials.

RECENT FINDINGS

In a large autopsy series from a national consortium, multiple neuropathologies of dementia subtypes were common and increased severity of specific NPS during life was associated with greater severity of neuropathology across diagnoses. Based on three clinical trials, brexpiprazole, which is an antipsychotic with dopamine and serotonin receptor partial agonism properties, was recently approved for the treatment of agitation in Alzheimer's dementia by the U.S. Food and Drug Administration (FDA). Its therapeutic profile indicates modest efficacy with high safety. Brexpiprazole has not been compared to other antipsychotics that are commonly prescribed to treat agitation in dementia, though none of them have been approved for this indication. Other drugs that showed positive results in Phase 2 trials are being tested in Phase 3 trials. These include cannabinoids and drug combinations that inhibit dextromethorphan metabolism peripherally, thereby increasing its bioavailability in the brain. Apathy is common in several types of dementia, and there is initial evidence that treatment with methylphenidate, a psychostimulant, may be efficacious with good tolerability.

SUMMARY

Greater understanding of the associations between NPS and dementia subtypes can improve clinical management of these disorders. In addition to the approval of brexpiprazole to treat agitation in Alzheimer's dementia, there is optimism about other medications based on ongoing clinical trials. Along with short-term improvement, altering the adverse impact on NPS on long-term prognosis remains an important challenge for the field.

Lewy Body Dementia: An Overview of Promising Therapeutics

PURPOSE OF REVIEW

Lewy body dementia (LBD) encompasses dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). This article will emphasize potential disease-modifying therapies as well as investigative symptomatic treatments for non-motor symptoms including cognitive impairment and psychosis that can present a tremendous burden to patients with LBD and their caregivers.

RECENT FINDINGS

We review 11 prospective disease-modifying therapies (DMT) including four with phase 2 data (neflamapimod, nilotinib, bosutinib, and E2027); four with some limited data in symptomatic populations including phase 1, open-label, registry, or cohort data (vodabatinib, ambroxol, clenbuterol, and terazosin); and three with phase 1 data in healthy populations (Anle138b, fosgonimeton, and CT1812). We also appraise four symptomatic therapies for cognitive impairment, but due to safety and efficacy concerns, only NYX-458 remains under active investigation. Of symptomatic therapies for psychosis recently investigated, pimavanserin shows promise in LBD, but studies of nelotanserin have been suspended. Although the discovery of novel symptomatic and disease-modifying therapeutics remains a significant challenge, recently published and upcoming trials signify promising strides toward that aim.

Frontotemporal lobar degeneration

Frontotemporal lobar degeneration (FTLD) is one of the most common causes of early-onset dementia and presents with early social-emotional-behavioural and/or language changes that can be accompanied by a pyramidal or extrapyramidal motor disorder. About 20-25% of individuals with FTLD are estimated to carry a mutation associated with a specific FTLD pathology. The discovery of these mutations has led to important advances in potentially disease-modifying treatments that aim to slow progression or delay disease onset and has improved understanding of brain functioning. In both mutation carriers and those with sporadic disease, the most common underlying diagnoses are linked to neuronal and glial inclusions containing tau (FTLD-tau) or TDP-43 (FTLD-TDP), although 5-10% of patients may have inclusions containing proteins from the FUS-Ewing sarcoma-TAF15 family (FTLD-FET). Biomarkers definitively identifying specific pathological entities in sporadic disease have been elusive, which has impeded development of disease-modifying treatments. Nevertheless, disease-monitoring biofluid and imaging biomarkers are becoming increasingly sophisticated and are likely to serve as useful measures of treatment response during trials of disease-modifying treatments. Symptomatic trials using novel approaches such as transcranial direct current stimulation are also beginning to show promise.

BPSD Patterns in Patients With Severe Neuropsychiatric Disturbances: Insight From the RECAGE Study

OBJECTIVE

Behavioral and psychological symptoms of dementia (BPSD) profiles vary depending on etiology in patients with mild-to-moderate BPSD. It is not known if similar differences exist in patients with severe BPSD.

METHODS

We analyzed data collected at baseline in 398 patients with severe BPSD (NPI ≥ 32) and defined diagnosis of dementia (Alzheimer's disease [AD] 297; frontotemporal dementia [FTD] 39; Lewy body disease/Parkinsonian dementia [LBD/PD] 31; and vascular dementia [VD] 31) included in the European multicenter cohort RECAGE.

RESULTS

Mean total NPI was 52.11 (18.55). LBD/PD patients demonstrated more hallucinations, more anxiety and more delusions than patients with other dementia. FTD patients had less delusions and more disinhibition than patients with other neurodegenerative disorders. These profiles overlapped partially with those reported in the literature in patients with less severe symptoms.

CONCLUSION

Patients with severe BPSD display different and specific profiles of neuropsychiatric symptoms depending on dementia etiology.

Advances in the treatment and management of frontotemporal dementia

INTRODUCTION

Frontotemporal dementia (FTD) is a complex neurodegenerative disorder, characterized by a wide range of pathological conditions associated with the buildup of proteins such as tau and TDP-43. With a strong hereditary component, FTD often results from genetic variants in three genes - MAPT, GRN, and C9orf72.

AREAS COVERED

In this review, the authors explore abnormal protein accumulation in FTD and forthcoming treatments, providing a detailed analysis of new diagnostic advancements, including innovative markers. They analyze how these discoveries have influenced therapeutic strategies, particularly disease-modifying treatments, which could potentially transform FTD management. This comprehensive exploration of FTD from its molecular underpinnings to its therapeutic prospects offers a compelling overview of the current state of FTD research.

EXPERT OPINION

Notable challenges in FTD management involve identifying reliable biomarkers for early diagnosis and response monitoring. Genetic forms of FTD, particularly those linked to C9orf72 and GRN, show promise, with targeted therapies resulting in substantial progress in disease-modifying strategies. The potential of neuromodulation techniques, like tDCS and rTMS, is being explored, requiring further study. Ongoing trials and multi-disciplinary care highlight the continued push toward effective FTD treatments. With increasing understanding of FTD's molecular and clinical intricacies, the hope for developing effective interventions grows.

Parkinson's disease therapy: what lies ahead?

The worldwide prevalence of Parkinson's disease (PD) has been constantly increasing in the last decades. With rising life expectancy, a longer disease duration in PD patients is observed, further increasing the need and socioeconomic importance of adequate PD treatment. Today, PD is exclusively treated symptomatically, mainly by dopaminergic stimulation, while efforts to modify disease progression could not yet be translated to the clinics. New formulations of approved drugs and treatment options of motor fluctuations in advanced stages accompanied by telehealth monitoring have improved PD patients care. In addition, continuous improvement in the understanding of PD disease mechanisms resulted in the identification of new pharmacological targets. Applying novel trial designs, targeting of pre-symptomatic disease stages, and the acknowledgment of PD heterogeneity raise hopes to overcome past failures in the development of drugs for disease modification. In this review, we address these recent developments and venture a glimpse into the future of PD therapy in the years to come.

Pimavanserin: A Truly Effective Treatment for Parkinson's Disease Psychosis? A Review of Interventions

Parkinson's disease (PD) is the second-most common neurodegenerative disorder with a long-term 60% cumulative prevalence of PD psychosis. Medical treatment is limited to few atypical antipsychotic drugs with low affinity to dopamine D2 receptors. In 2016, pimavanserin, a selective 5-HT2A inverse agonist/antagonist, was approved by the US Food and Drug Administration (FDA) as the only treatment for PD psychosis (PDP). This article provides an overview of the epidemiology, pathophysiology, and treatment options for PDP and illuminates the mode of action and therapy options with pimavanserin and the current study data.

High-throughput drug screening identifies fluoxetine as a potential therapeutic agent for neuroendocrine prostate cancer

Introduction

Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer with poor prognosis and resistance to hormone therapy, which has limited therapeutic approaches. Therefore, this study aimed to identify a novel treatment for NEPC and provide evidence of its inhibitory effects.

Methods

We performed a high-throughput drug screening and identified fluoxetine, originally an FDA-approved antidepressant, as candidate therapeutic agent for NEPC. We carried out both in vitro and in vivo experiments to demonstrate the inhibitory effects of fluoxetine on NEPC models and its mechanism in detail.

Results

Our results demonstrated that fluoxetine effectively curbed the neuroendocrine differentiation and inhibited cell viability by targeting the AKT pathway. Preclinical test in NEPC mice model (PBCre4: Ptenf/f; Trp53f/f; Rb1f/f) showed that fluoxetine effectively prolonged the overall survival and reduced the risk of tumor distant metastases.

Discussion

This work repurposed fluoxetine for antitumor application, and supported its clinical development for NEPC therapy, which may provide a promising therapeutic strategy.

Serotonin in synucleinopathies

Dysfunction of the serotonergic system represents an important feature in synucleinopathies like Parkinson disease (PD), dementia with Lewy bodies (DLB) and Multiple system atrophy (MSA). Serotonergic fibers from the raphe nuclei (RN) extend broadly throughout the central nervous system, innervating several brain areas affected in synucleinopathies. Alterations of the serotonergic system are associated with non-motor symptoms or motor complications in PD as well as with autonomic features of MSA. Postmortem studies, data from transgenic animal models and imaging techniques greatly contributed to the understanding of this serotonergic pathophysiology in the past, even leading to preclinical and clinical candidate drug tests targeting different parts of the serotonergic system. In this article, we review most recent work extending the knowledge of the serotonergic system and highlighting its relevance for the pathophysiology of synucleinopathies.

The future of psychopharmacology: a critical appraisal of ongoing phase 2/3 trials, and of some current trends aiming to de-risk trial programmes of novel agents

Despite considerable progress in pharmacotherapy over the past seven decades, many mental disorders remain insufficiently treated. This situation is in part due to the limited knowledge of the pathophysiology of these disorders and the lack of biological markers to stratify and individualize patient selection, but also to a still restricted number of mechanisms of action being targeted in monotherapy or combination/augmentation treatment, as well as to a variety of challenges threatening the successful development and testing of new drugs. In this paper, we first provide an overview of the most promising drugs with innovative mechanisms of action that are undergoing phase 2 or 3 testing for schizophrenia, bipolar disorder, major depressive disorder, anxiety and trauma-related disorders, substance use disorders, and dementia. Promising repurposing of established medications for new psychiatric indications, as well as variations in the modulation of dopamine, noradrenaline and serotonin receptor functioning, are also considered. We then critically discuss the clinical trial parameters that need to be considered in depth when developing and testing new pharmacological agents for the treatment of mental disorders. Hurdles and perils threatening success of new drug development and testing include inadequacy and imprecision of inclusion/exclusion criteria and ratings, sub-optimally suited clinical trial participants, multiple factors contributing to a large/increasing placebo effect, and problems with statistical analyses. This information should be considered in order to de-risk trial programmes of novel agents or known agents for novel psychiatric indications, increasing their chances of success.

Implications of Adverse Outcomes Associated with Antipsychotics in Older Patients with Dementia: A 2011-2022 Update

Neuropsychiatric symptoms affect most patients with dementia over the course of the disease. They include a wide variety of symptoms from apathy and depression to psychosis, irritability, impulsivity and agitation. These symptoms are associated with significant distress to the patient and caregivers, as well as more rapid progression of dementia, institutionalisation and higher mortality. The first-line management of the neuropsychiatric symptoms of dementia should be non-pharmacological. If medications are required, antipsychotics are commonly chosen. Second-generation antipsychotics such as risperidone, olanzapine, quetiapine and aripiprazole are prescribed more often than first-generation antipsychotics, such as haloperidol. The aim of this review is to provide an update on findings on adverse outcomes and clinical implications of antipsychotic use in dementia. These medications may increase mortality and can be associated with adverse events including pneumonia, cerebrovascular events, parkinsonian symptoms or higher rates of venous thromboembolism. Risks related to antipsychotic use in dementia are moderated by a number of modifiable and non-modifiable factors such as co-prescribing of other medications, medical and psychiatric co-morbidities, and demographics such as age and sex, making individualised treatment decisions challenging. Antipsychotics have further been associated with an increased risk of reliance on long-term care and institutionalisation, and they might not be cost-effective for healthcare systems. Many of these risks can potentially be mitigated by close physical health monitoring of antipsychotic treatment, as well as early withdrawal of pharmacotherapy when clinically possible.

Schizophrenia: One Name, Many Different Manifestations

Schizophrenia is a disabling condition impacting approximately 1% of the worldwide population. Symptoms include positive symptoms (eg, hallucinations, delusions), negative symptoms (eg, avolition, anhedonia), and cognitive impairment. There are likely many different environmental and pathophysiologic etiologies involving distinct neurotransmitters and neurocircuits. Pharmacologic treatment at present consists of dopamine receptor antagonists, which are reasonably effective at treating positive symptoms, but less effective at treating cognitive and negative symptoms. Nondopaminergic medications targeting alternative receptors are under investigation. Supportive psychosocial treatments can work in tandem with antipsychotic medications and optimize patient care.

Synucleinopathies

The α-synucleinopathies include pure autonomic failure, multiple system atrophy, dementia with Lewy bodies, and Parkinson disease. The past two decades have witnessed significant advances in the diagnostic strategies and symptomatic treatment of motor and nonmotor symptoms of the synucleinopathies. This chapter provides an in-depth review of the pathophysiology, pathology, genetic, epidemiology, and clinical and laboratory autonomic features that distinguish the different synucleinopathies with an emphasis on autonomic failure as a common feature. The treatment of the different synucleinopathies is discussed along with the proposal for multidisciplinary, individualized care models that optimally address the various symptoms. There is an urgent need for clinical scientific studies addressing patients at risk of developing synucleinopathies and the investigation of disease mechanisms, biomarkers, potential disease-modifying therapies, and further advancement of symptomatic treatments for motor and nonmotor symptoms.

Antipsychotics in Alzheimer's Disease: Current Status and Therapeutic Alternatives

Psychosis and hyperactive behaviors, such as agitation and wandering, affect a significant proportion of patients with Alzheimer's disease (AD). These symptoms are often treated with antipsychotics, usually in an off-label approach. This mini-review provides an updated perspective on the pharmacological approach for the neuropsychiatric symptoms (NPS) in AD. The results of new studies have provided a better understanding of AD-related NPS management, but high-quality evidence still needs to be obtained. Herein, we argue for a more cautious approach to the use of antipsychotics in AD and highlight the importance of exploring alternative treatments for NPS. By doing so, we can ensure that patients with AD receive optimal care that is both effective and safe.

A New Hope in Alzheimer's Disease Psychosis: Pimavanserin

Alzheimer's disease (AD) ranks first among the causes of dementia worldwide. AD can develop a psychotic manifest at a significant rate. AD prognosis worsens by added psychosis clinic. There is no treatment approved by the United States Food and Drug Administration (FDA) among antipsychotics for Alzheimer's disease Psychosis (ADP). However, pimavanserine, an atypical antipsychotic, has been approved by the FDA for Parkinson's psychosis. It is predicted that pimavanserin, a new antipsychotic, will fill an important gap in this area. In clinical trials, it appears to be effective in the treatment of delusions and hallucinations at psychosis in both Parkinson's and AD. In this systematic review, we evaluated the analysis of current literature data on pimavanserin used in ADP. We searched the existing literature on clinical studies on pimavanserin therapy used in ADP. Data were determined by systematically searching PubMed, MEDLINE, EMBASE, and Google Scholar until December 2022. A total of 35 citations were found and uploaded on the Mendeley program. Abstracts and full texts of literature data were examined. Pimavanserin was observed, and satisfactory results were obtained in treating ADP. Pimavanserin has a unique mechanism of action. Pimavanserin, an atypical antipsychotic drug, has a low affinity for 5-HT2C receptors and has selective 5-HT2A reverse agonist/antagonist action. Pimavanserin has no clinically significant affinity for dopaminergic, histaminergic, muscarinic or adrenergic receptors. This agent may also achieve significant positive results in resistant psychosis treatments.

Psychotic Disorders in the Elderly: Diagnosis, Epidemiology, and Treatment

This review covers the latest advances in our understanding of psychosis in the elderly population with respect to diagnosis, epidemiology, and treatment. Major topics of discussion include late life psychiatric disorders such as schizophrenia, schizoaffective disorder, and delusional disorder as well as dementia-related psychosis. Clinical differences between early-onset and late-onset disorders are reviewed in terms of prevalence, symptomatology, and approach to treatment. Newly revised research and clinical criteria for dementia-related psychosis are referenced. The evidence base for emerging therapies including citalopram and pimavanserin in relation to conventional therapies such as atypical antipsychotics are discussed..

Promising candidates from drug clinical trials: Implications for clinical treatment of Alzheimer's disease in China

Alzheimer's disease is the most common neurodegenerative disease. Prior to 2017, National Medical Products Administration approved only four drugs to treat Alzheimer's disease, including three cholinesterase inhibitors and one N-methyl-D-aspartate receptor antagonist. We queried ClinicalTrials.gov to better understand Alzheimer's drug development over the past 5 years and found 16 promising candidates that have entered late-stage trials and analyzed their impact on clinical treatment of Alzheimer's disease in China. The 16 compounds selected include disease-modifying therapies and symptomatic therapies. The research and development pipeline now focuses on disease-modifying therapies such as gantenerumab, aducanumab, ALZ-801, ALZT-OP1, donanemab, lecanemab, simufilam, NE3107, semaglutide, and GV-971, which could put an end to the situation where Alzheimer's patients in China have no effective treatment alternatives. The reuse of drugs or combinations currently under investigation for the psychiatric treatment of Alzheimer's disease, including AXS-05, AVP-786, nabilone, brexpiprazole, methylphenidate, and pimavanserin, could provide physicians with additional treatment options. Although most of these drugs have not been explored in China yet, due to the current development trend in this field in China, it is expected that China will be involved in research on these drugs in the future.

Adjunctive Pimavanserin in Patients with Major Depressive Disorder: Combined Results from Two Randomized, Double-Blind, Placebo-Controlled Phase 3 Studies

Objective

In a phase 2 study, pimavanserin demonstrated efficacy as adjunctive treatment for major depressive disorder (MDD). Subsequently, two phase 3 studies (NCT03968159 in the US; NCT03999918 in Europe) were initiated to examine the efficacy and safety of adjunctive pimavanserin in subjects with MDD and inadequate response to antidepressant treatment. Studies were combined with a prespecified statistical analysis plan owing to recruitment challenges related to the COVID-19 pandemic.

Experimental design

The randomized, double-blind studies enrolled 298 patients with MDD and inadequate response to current antidepressants. Patients were randomly assigned 1:1 to pimavanserin or placebo added to current antidepressant for 6 weeks. Primary endpoint was change from baseline to week 5 in the Hamilton Rating Scale for Depression, 17-item version (HAM-D-17).

Principal observations

There was no effect of pimavanserin in change from baseline to week 5 in the HAM-D-17 (pimavanserin [n = 138]: least-squares mean [LSM] [standard error {SE}], -9.0 [0.58]; placebo [n = 135]: -8.1 [0.58]; mixed-effects model for repeated measures LSM [SE] difference, -0.9 [0.82], P = 0.2956). Nominal improvement with pimavanserin was observed on 2 secondary endpoints: Clinical Global Impressions-Severity scale, Karolinska Sleepiness Scale. Treatment-emergent adverse events occurred in 58.1% of pimavanserin-treated and 54.7% of placebo-treated patients.

Conclusions

Adjunctive pimavanserin did not significantly improve depressive symptoms, although pimavanserin was well tolerated.

Risks and benefits of current and novel drugs to treat agitation in Alzheimer's disease

INTRODUCTION

At present, no pharmacological interventions have been approved for the treatment of agitation in Alzheimer's disease (AD), an important neuropsychiatric symptom that has been linked to increased mortality and greater caregiver burden. Antipsychotics offer some benefit, but increase the risk of adverse events such as falls, extrapyramidal symptoms, stroke, and mortality. Over the past 10 years, several new and repurposed medications have shown promise for treating AD-associated agitation.

AREAS COVERED

We review the risks and benefits of emerging therapies for agitation in AD, which include newer atypical antipsychotics, selective serotonin reuptake inhibitors, cannabinoids, and dextromethorphan combination products. Other drugs such as mirtazapine, prazosin, and lithium are also discussed. Clinicaltrials.gov, PubMed/MEDLINE, EMBASE and Cochrane Central databases were searched for relevant studies from 1 January 2012 to 1 May 2022.

EXPERT OPINION

At the present time, there are no pharmacological interventions for the treatment of agitation in AD whose benefits clearly outweigh their potential safety concerns. Therefore, management of agitation in AD should primarily be based on non-pharmacological approaches. When medications are considered necessary, they should only be initiated with the caregiver's appreciation of their risks and benefits and with careful and ongoing assessment of their safety.

Motor- and cognition-related safety of pimavanserin in patients with Parkinson's disease psychosis

Background

Pimavanserin, a selective 5-HT_2A inverse agonist/antagonist, is the only treatment approved by the US Food and Drug Administration for hallucinations and delusions associated with Parkinson's disease (PD) psychosis.

Aim

We aimed to evaluate motor- and cognition-related safety in pimavanserin-treated patients with PD psychosis.

Methods

This analysis included patients with PD psychosis treated with pimavanserin 34 mg from a pooled analysis of 3 randomized, double-blind, placebo-controlled, 6-week studies [NCT00477672 (study ACP-103-012), NCT00658567 (study ACP-103-014), and NCT01174004 (study ACP-103-020)] and a subgroup of patients with PD dementia with psychosis from HARMONY (NCT03325556), a randomized discontinuation study that included a 12-week open-label period followed by a randomized double-blind period of up to 26 weeks. Motor- and cognition-related safety were examined.

Results

The pooled analysis included 433 randomized patients (pimavanserin, 202; placebo, 231). Least squares mean (standard error [SE]) change from baseline to week 6 Unified Parkinson's Disease Rating Scale (UPDRS) II + III score was similar for pimavanserin [−2.4 (0.69)] and placebo [−2.3 (0.60)] (95% Confidence Interval [CI]:−1.9, 1.6). The change from baseline to week 6 for UPDRS II and UPDRS III scores was similar between groups. In the HARMONY open-label period, 49 patients with PD dementia with psychosis were treated with pimavanserin 34 mg, 36 of whom were randomized in the double-blind period (pimavanserin, 16; placebo, 20). In the open-label period, the mean (SE) change from baseline to week 12 (n = 39) Extra-Pyramidal Symptom Rating Scale (ESRS-A) score was −1.7 (0.74); in the double-blind period, the results were generally comparable between the pimavanserin and placebo arms. The change from baseline in Mini-Mental State Examination (MMSE) score was also comparable between pimavanserin- and placebo-treated patients in HARMONY [open-label (n = 37): mean (SE) change from baseline to week 12, 0.3 (0.66)]. Rates of motor- and cognition-related adverse events were similar between pimavanserin and placebo in both analyses.

Conclusions

Pimavanserin 34 mg was well tolerated and did not yield a negative impact on motor- or cognition-related function in patients with PD psychosis.

Dementia Is More Than Memory Loss: Neuropsychiatric Symptoms of Dementia and Their Nonpharmacological and Pharmacological Management

Neuropsychiatric symptoms of dementia (NPS) are a group of noncognitive symptoms that occur in over 90% of individuals with dementia. NPS seem to result from a complex interaction among various biological, psychosocial, and environmental factors, and they are associated with greater morbidity and mortality, higher caregiver burden and burnout, high risk of nursing home placement, and increased cost of care for patients with dementia. Use of standardized assessment tools like the Neuropsychiatric Inventory can assist with qualifying and quantifying NPS. In this review, the authors evaluate the evidence for efficacy and safety of nonpharmacological and pharmacological interventions for treating NPS, mostly based on published meta-analyses. Commonly prescribed medications include atypical antipsychotics, acetylcholinesterase inhibitors, memantine, antidepressants, and mood stabilizers. There are also limited data on cannabinoids, repetitive transcranial magnetic stimulation, and ECT in individuals with NPS. Available evidence indicates that several nonpharmacological interventions are beneficial in the management of NPS and are recommended as first-line treatments. Pharmacotherapy should be reserved for the treatment of more severe or refractory NPS or where nonpharmacological management is not feasible. Atypical antipsychotics have shown mostly modest benefit in reducing NPS, and their use is limited by their adverse effect profiles. Recent investigations suggest potential strategies for preventing or at least reducing the risk of dementia and NPS. The authors conclude with brief guidelines for clinical practice as well as future research.

Current Therapies and Drug Development Pipeline in Lewy Body Dementia: An Update

The term Lewy body dementia refers to either of two related diagnoses: dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD). Clinical management of Lewy body dementia is challenging. The current treatment options focus on relieving symptoms; no disease-modifying therapies are available. There are currently no US Food and Drug Administration (FDA) approved drugs for the treatment of DLB, and there are only a few for PDD. Cholinesterase inhibitors are shown to be beneficial in improving cognitive symptoms in Lewy body dementia. Rivastigmine was approved by the FDA to treat PDD. Donepezil was approved in Japan as a treatment for DLB. Levodopa may provide modest benefit in treating motor symptoms and zonisamide in adjunct to low-dose levodopa helps with parkinsonism. Treatment of autonomic symptoms are based on symptomatic treatment with off-label agents. Our main objective in this article is to present an overview of the current pharmacological options available to treat the clinical features of DLB and PDD. When evaluating the existing management options for Lewy body dementia, it is difficult to fully separate PDD from DLB. However, we have attempted to identify whether the cited studies include patients with PDD and/or DLB. Moreover, we have provided an overview of the current drug pipeline in Lewy body dementia. All currently active trials are in phase I or II and most are focused on disease modification rather than symptomatic treatment. Phase II trial results for neflamapimod show promising results. Due to heterogeneity of symptoms and underlying pathophysiology, there is a need for new biomarker strategies and improved definitions of outcome measures for Lewy body dementia drug trials.

The role of basket trials in drug development for neurodegenerative disorders

Background

Drug development for neurodegenerative disorders (NDDs) is a long, complex, and expensive enterprise. Methods to optimize drug development for NDDs are needed. Basket trials have been widely used in oncology and have been promoted by the Food and Drug Administration as a means of enhancing the efficiency of drug development.

Discussion

We reviewed clinical trials for NDDs registered on clinicaltrials.gov in the past 10 years. We identified 59 basket trials assessing the impact of treatment on more than one NDD in the trial. Forty-one of the trials were for 25 agents addressing symptoms of NDD such as motor impairment, hypotension, or psychosis. Eighteen of the trials assessed 14 disease-modifying therapies; the principal targets were mitochondrial function, tau biology, or alpha-synuclein aggregation. Basket trials are most common in phase 2 but have been conducted in phase 1, phase 3, and phase 4. The duration and size of the basket trials are highly variable depending on their developmental phase and the intent of the trial. Parkinson’s disease was the most common disorder included in basket trials of symptomatic agents, and Alzheimer’s disease was the most common disorder included in basket trials of disease-modifying therapies. Most of the basket trials of symptomatic agents were sponsored by pharmaceutical companies (29 of 41 trials); similarly, most of the basket trials investigating DMTs in basket trials were sponsored by the biopharmaceutical industry (11/17 trials).

Conclusions

Basket trials may increase drug development efficiency by reducing redundancy in trial implementation, enhancing recruitment, sharing placebo groups, and using biomarkers relevant to the mechanism of action of the treatment across NDDs. There have been relatively few basket trials including multiple NDDs in the same trial conducted over the past 10 years. The use of the basket trial strategy may represent an opportunity to increase the efficiency of development programs for agents to treat NDDs.

Behavior of KCNQ Channels in Neural Plasticity and Motor Disorders

The broad distribution of voltage-gated potassium channels (VGKCs) in the human body makes them a critical component for the study of physiological and pathological function. Within the KCNQ family of VGKCs, these aqueous conduits serve an array of critical roles in homeostasis, especially in neural tissue. Moreover, the greater emphasis on genomic identification in the past century has led to a growth in literature on the role of the ion channels in pathological disease as well. Despite this, there is a need to consolidate the updated findings regarding both the pharmacotherapeutic and pathological roles of KCNQ channels, especially regarding neural plasticity and motor disorders which have the largest body of literature on this channel. Specifically, KCNQ channels serve a remarkable role in modulating the synaptic efficiency required to create appropriate plasticity in the brain. This role can serve as a foundation for clinical approaches to chronic pain. Additionally, KCNQ channels in motor disorders have been utilized as a direction for contemporary pharmacotherapeutic developments due to the muscarinic properties of this channel. The aim of this study is to provide a contemporary review of the behavior of these channels in neural plasticity and motor disorders. Upon review, the behavior of these channels is largely dependent on the physiological role that KCNQ modulatory factors (i.e., pharmacotherapeutic options) serve in pathological diseases.

Long-term outcomes with pimavanserin for psychosis in clinical practice

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Psychosis in PD is a common problem, with limited treatment options.

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Pimavanserin is FDA approved for PDP, but long-term outcomes in clinical practice are lacking.

•

While it has been proven to be effective in short-duration clinical trials, our clinical experiences, however, demonstrate less promising results in the long term.

Introduction

Pimavanserin is the only medication FDA-approved for the treatment of Parkinson disease (PD) psychosis (PDP), but reports of long-term, real-world clinical experience are lacking.

Methods

A retrospective chart review of all patients treated with pimavanserin was conducted at our large Movement Disorders practice in Providence, Rhode Island, USA. Demographic and clinical data for each patient were collected and descriptive analyses were performed.

Results

We identified 54 patients (23 female) who initiated pimavanserin, whose median age was 70 years (range 44–87 years) and the median duration of pimavanserin therapy was 26 weeks. Initial improvement was seen in 47% of the entire group, and 50% of the DLB patients. Additional antipsychotic medication was needed concomitantly with pimavanserin to maintain a positive response for 40% of patients. Only 15% of the entire group had effective treatment of their condition with pimavanserin monotherapy over a median of 52 weeks. Among the initial responders, 32% continued on pimavanserin monotherapy. Among the non-responders, the mean trial period for patients who did not improve was 27 weeks, for patients who worsened was 16 weeks, and for those who experienced adverse effects was 1–2 weeks. Reported sex was similar across responders (60%), non-responders (56%), and the overall cohort (57%).

Conclusion

Our real-world experience shows that pimavanserin is safe and tolerable, with a lower response rate than reported in other publications. While it has been proven to be effective in short-duration clinical trials, our clinical experiences, however, demonstrate less promising results in the long term.

Hallucinations and delusions associated with Parkinson's disease psychosis: safety of current treatments and future directions

INTRODUCTION

: Over half of Parkinson's disease (PD) patients develop psychotic symptoms, and PD psychosis (PDP) is associated with significant distress to patients, caregiver burden, and impairs quality of life. Pharmacological therapy is limited to atypical antipsychotics.

AREAS COVERED

: This review will summarize efficacy but will focus on the safety of antipsychotics for treating PDP, and in particular the off-target safety issues including cognitive impairment, sleep disturbance, cardiovascular effects, and motor function.

EXPERT OPINION

: Pimavanserin is the only medication approved in the US for treating PDP, however clozapine is also considered efficacious. Despite lack of substantial evidence for efficacy, quetiapine is commonly used to treat PDP. Despite the effectiveness of pimavanserin and clozapine for treating PDP, a need exists for additional pharmacological agents that are effective for PDP while providing an acceptable safety and tolerability profile. Medications to treat PDP should avoid worsening motor function, and also minimize sleep disturbances, cognitive impairment, cardiovascular effects, and other non-motor safety concerns. A neutral effect or reduction in mortality risk associated with PD and PDP would be ideal, and low rate of discontinuation due to AEs is desirable. Lastly, medications that can be used safely in combination with other pharmacological agents is essential.

Alzheimer's Disease-Related Psychosis: An Overview of Clinical Manifestations, Pathogenesis, and Current Treatment

Behavioral and psychotic manifestations, including aggression, delusions, and hallucinations, are frequent comorbidities in patients with debilitating nervous illnesses such as Alzheimer's disease (AD), Amyotrophic Lateral Sclerosis, Multiple Sclerosis, and Parkinson's disease. AD-related psychosis may be linked to a poor disease prognosis, highlighting that early detection and management are mandatory. The manifestations are variable and may be very heterogeneous, imposing a real diagnostic issue. Some assessment tools such as BEHAVE-AD, CERAD-BRSD, and the Psycho-Sensory Hallucinations Scale have been designed to facilitate the diagnosis. The mechanisms behind neurodegeneration-related psychosis are complex and are not fully understood, imposing a burden on researchers to find appropriate management modalities. Familial history and some genetic disturbances may have a determinant role in these delusions and hallucinations in cases with AD. The loss of neuronal cells, atrophy in some regions of the central nervous, and synaptic dysfunction may also contribute to these comorbidities. Furthermore, inflammatory disturbances triggered by pro-inflammatory agents such as interleukins and tumor necrosis factors are stratified among the potential risk factors of the onset of numerous psychotic symptoms in Alzheimer's patients. Little is known about the possible management tools; therefore, it is urgent to conduct well-designed trials to investigate pharmacological and non-pharmacological interventions that can improve the care process of these patients. This review summarizes the current findings regarding the AD-related psychosis symptoms, pathological features, assessment, and management.

"Selective" serotonin 5-HT2A receptor antagonists

Blockade of the serotonin 5-HT_2A G protein-coupled receptor (5-HT_2AR) is a fundamental pharmacological characteristic of numerous antipsychotic medications, which are FDA-approved to treat schizophrenia, bipolar disorder, and as adjunctive therapies in major depressive disorder. Meanwhile, activation of the 5-HT_2AR by serotonergic psychedelics may be useful in treating neuropsychiatric indications, including major depressive and substance use disorders. Serotonergic psychedelics and other 5-HT_2AR agonists, however, often bind other receptors, and standard 5-HT_2AR antagonists lack sufficient selectivity to make well-founded mechanistic conclusions about the 5-HT_2AR-dependent effects of these compounds and the general neurobiological function of 5-HT_2ARs. This review discusses the limitations and strengths of currently available "selective" 5-HT_2AR antagonists, the molecular determinants of antagonist selectivity at 5-HT_2ARs, and the utility of molecular pharmacological and computational methods in guiding the discovery of novel unambiguously selective 5-HT_2AR antagonists.

Relapse in Dementia-related Psychosis and Clinical Decisions

Patients with dementia can experience hallucinations and delusions because of their underlying neurodegenerative condition, a syndrome known as dementia-related psychosis. Dementia-related psychosis contributes to morbidity and mortality among patients with dementia and increases the burden on caregivers and the health care system. With no pharmacological treatment currently approved in the United States for this condition, patients are often treated off-label with antipsychotics. Though typical and atypical antipsychotics have demonstrated variable to modest efficacy in dementia-related psychosis, serious safety concerns arise with their use. Accordingly, clinical and Centers for Medicare & Medicaid Services guidelines recommend trying antipsychotics only when other therapies have failed and encourage treatment discontinuation of antipsychotics after 4 months to assess whether ongoing therapy is needed. Discontinuation of effective antipsychotic treatment, however, may increase the risk for relapse of symptoms and the associated morbidities that accompany relapse. A randomized medication withdrawal clinical trial design allows assessment of relapse risk after discontinuation and can provide initial information on longer-term safety of therapy for dementia-related psychosis. Given the substantial unmet need in this condition, new, well-tolerated therapies that offer acute and sustained reduction of symptoms while also preventing recurrence of symptoms of psychosis are critically needed.