Unraveling the Influence of Age, IQ, Education, and Negative Symptoms on Neurocognitive Performance in Schizophrenia: A Conditional Inference Tree Analysis.

INTRODUCTION: The complex nature of neurocognitive impairment in schizophrenia has been discussed in light of the mixed effects of antipsychotic drugs, psychotic symptoms, dopamine D2 receptor blockade, and intelligence quotient (IQ). These factors have not been thoroughly examined before. METHODS: This study conducted a comprehensive re-analysis of the CATIE data using machine learning techniques, in particular Conditional Inference Tree (CTREE) analysis, to investigate associations between neurocognitive functions and moderating factors such as estimated trough dopamine D2 receptor blockade with risperidone, olanzapine, or ziprasidone, Positive and Negative Syndrome Scale (PANSS), and baseline IQ in 573 patients with schizophrenia. RESULTS: The study reveals that IQ, age, and education consistently emerge as significant predictors across all neurocognitive domains. Furthermore, higher severity of PANSS-negative symptoms was associated with lower cognitive performance scores in several domains. CTREE analysis, in combination with a genetic algorithm approach, has been identified as particularly insightful for illustrating complex interactions between variables. Lower neurocognitive function was associated with factors such as age>52 years, IQ<94/95,<12/13 education years, and more pronounced negative symptoms (score<26). CONCLUSIONS: These findings emphasize the multifaceted nature of neurocognitive functioning in patients with schizophrenia, with the PANSS-negative score being an important predictor. This gives rise to a role in addressing negative symptoms as a therapeutic objective for enhancing cognitive impairments in these patients. Further research must examine nonlinear relationships among various moderating factors identified in this work, especially the role of D2 occupancy.

Muscarinic M1 and M4 receptor agonists for schizophrenia: promising candidates for the therapeutic arsenal.

INTRODUCTION: Successful phase 3 trials of KarXT in people with schizophrenia herald a new era of treating the disorder with drugs that do not target the dopamine D2 receptor. The active component of KarXT is xanomeline, a muscarinic (CHRM) M1 and M4 agonist, making muscarinic receptors a viable target for treating schizophrenia. AREAS COVERED: This review covers the process of taking drugs that activate the muscarinic M1 and M4 receptors from conceptualization to the clinic and details the mechanisms by which activating the CHRM1 and 4 can affect the broad spectrum of symptoms experienced by people with schizophrenia. EXPERT OPINION: Schizophrenia is a syndrome which means drugs that activate muscarinic M1 and M4 receptors, as was the case for antipsychotic drugs acting on the dopamine D2 receptor, will not give optimal outcomes in everyone within the syndrome. Thus, it would be ideal to identify people who are responsive to drugs activating the CHRM1 and 4. Given knowledge of the actions of these receptors, it is possible treatment non-response could be restricted to sub-groups within the syndrome who have deficits in cortical CHRM1 or those with one of the cognitive endophenotypes that may be identifiable by changes in the blood transcriptome.

Chronic stress accelerates glioblastoma progression via DRD2/ERK/ß-catenin axis and Dopamine/ERK/TH positive feedback loop.

BACKGROUND: After diagnosis, glioblastoma (GBM) patients undertake tremendous psychological problems such as anxiety and depression, which may contribute to GBM progression. However, systematic study about the relationship between depression and GBM progression is still lacking. METHODS: Chronic unpredictable mild stress and chronic restrain stress were used to mimic human depression in mice. Human GBM cells and intracranial GBM model were used to assess the effects of chronic stress on GBM growth. Targeted neurotransmitter sequencing, RNA-seq, immunoblotting and immunohistochemistry were used to detect the related molecular mechanism. RESULTS: Chronic stress promoted GBM progression and up-regulated the level of dopamine (DA) and its receptor type 2 (DRD2) in tumor tissues. Down-regulation or inhibition of DRD2 abolished the promoting effect of chronic stress on GBM progression. Mechanistically, the elevated DA and DRD2 activated ERK1/2 and consequently inhibited GSK3ß activity, leading to ß-catenin activation. Meanwhile, the activated ERK1/2 up-regulated tyrosine hydroxylase (TH) level in GBM cells and then promoted DA secretion, forming an autocrine positive feedback loop. Remarkably, patients with high-depression exhibited high DRD2 and ß-catenin levels, which showed poor prognosis. Additionally, DRD2 specific inhibitor pimozide combined with temozolomide synergistically inhibited GBM growth. CONCLUSIONS: Our study revealed that chronic stress accelerates GBM progression via DRD2/ERK/ß-catenin axis and Dopamine/ERK/TH positive feedback loop. DRD2 together with ß-catenin may serve as a potential predictive biomarker for worse prognosis as well as therapeutic target of GBM patients with depression.

Challenges in the clinical development of non-D2 compounds for schizophrenia.

Schizophrenia is a chronic, heterogeneous, severe psychiatric disorder characterized by a spectrum of symptomology and is associated with substantial morbidity and mortality. For the last 70 years, available treatments have shared blockade of dopamine D2 receptors as their primary mechanism of action (MOA), the efficacy of which has been limited by incomplete resolution of all symptoms as well as treatment non-response in a select subset of patients. In addition, antipsychotics are associated with class-related side effects attributed to this primary MOA, including extrapyramidal symptoms (EPS). The need for non-D2 treatment options for patients which offer a novel risk/benefit profile is therefore apparent. There has been substantial investment in the research and development of non-D2 drug candidates. However, none of these programs have received successful regulatory approval by the FDA (as of Oct 2022). In this article, the scale of industry-sponsored clinical trials for D2-based investigational pharmacological treatments in schizophrenia was quantified and compared with investigational compounds with non-D2 MOAs. In a dataset of 545 clinical trials identified in ClinicalTrials.gov from January 2002 to July 2022, total enrollments in trials of non-D2-based compounds for the treatment of schizophrenia summed to approximately 34,000 patients, compared with 27,144 patients for D2-based compounds. These data indicate that there remains substantial and ongoing investment in the development of novel non-D2 options for schizophrenia, with a success rate measured by regulatory approval that is well-below recent benchmarks for the broader category of CNS drugs. Improved trial design, conduct, endpoints, and analyses/methods may influence signal detection and reliability to support development and registration of non-D2 compounds.

The ANKK1/DRD2 gene TaqIA polymorphism (rs1800497) is associated with the severity of extrapyramidal side effects of haloperidol treatment in CYP2D6 extensive metabolizers with schizophrenia spectrum disorders.

OBJECTIVES: Extrapyramidal symptoms (EPS) are one of the most prominent side effects of haloperidol. Variability of EPS severity may be associated with the genetic factors, affecting both haloperidol pharmacokinetics (e.g., CYP2D6) and pharmacodynamics (e.g., DRD2, ANKK1). We conducted a 3-week prospective study to investigate the associations of ANKK1/DRD2 TaqIA (rs1800497), DRD2 -141C Ins/Del (rs1799732) polymorphisms and CYP2D6 metabolic phenotype on the efficacy of haloperidol treatment and severity of EPS in patients with schizophrenia spectrum disorders. METHODS: In total, 57 inpatients with schizophrenia spectrum disorders (24 (42.1%)) females; age -46.7 (11.8) years (M(SD)) of European ancestry were enrolled. BARS and SAS scales were used to assess EPS. PANSS and CGI scales - to assess the efficacy of haloperidol treatment. Genotyping was performed by real-time PCR. CYP2D6 metabolic phenotype was predicted by the CYP2D6 *3, *4, *5, *6, *9, *10, *41 and xN genotypes. RESULTS: Minor C allele of TaqIA was associated with higher scores of BARS (p=0.029) and SAS (p=0.024) on day 21 and minor Del allele of -141C Ins/Del - with more prominent clinical improvement by CGI scale (p=0.007) but not by PANSS. These differences were observed only in extensive CYP2D6 metabolizers, although no associations with the metabolic type itself were found. General linear model showed that the combination of TaqIA genotype and metabolic type was significantly associated with BARS score on day 21 (p=0.013). CONCLUSIONS: Our results highlight the importance of using both pharmacokinetic and pharmacodynamic genetic markers for predicting haloperidol treatment response to personalize schizophrenia spectrum disorders treatment.

Extracellular Matrix in Synthetic Hydrogel-Based Prostate Cancer Organoids Regulate Therapeutic Response to EZH2 and DRD2 Inhibitors.

Following treatment with androgen receptor (AR) pathway inhibitors, ≈20% of prostate cancer patients progress by shedding their AR-dependence. These tumors undergo epigenetic reprogramming turning castration-resistant prostate cancer adenocarcinoma (CRPC-Adeno) into neuroendocrine prostate cancer (CRPC-NEPC). No targeted therapies are available for CRPC-NEPCs, and there are minimal organoid models to discover new therapeutic targets against these aggressive tumors. Here, using a combination of patient tumor proteomics, RNA sequencing, spatial-omics, and a synthetic hydrogel-based organoid, putative extracellular matrix (ECM) cues that regulate the phenotypic, transcriptomic, and epigenetic underpinnings of CRPC-NEPCs are defined. Short-term culture in tumor-expressed ECM differentially regulated DNA methylation and mobilized genes in CRPC-NEPCs. The ECM type distinctly regulates the response to small-molecule inhibitors of epigenetic targets and Dopamine Receptor D2 (DRD2), the latter being an understudied target in neuroendocrine tumors. In vivo patient-derived xenograft in immunocompromised mice showed strong anti-tumor response when treated with a DRD2 inhibitor. Finally, we demonstrate that therapeutic response in CRPC-NEPCs under drug-resistant ECM conditions can be overcome by first cellular reprogramming with epigenetic inhibitors, followed by DRD2 treatment. The synthetic organoids suggest the regulatory role of ECM in therapeutic response to targeted therapies in CRPC-NEPCs and enable the discovery of therapies to overcome resistance.

Treatment Response and GWAS Risk Allele rs2514218 (C) of the Dopamine D2 Receptor Gene in Inpatients with Schizophrenia.

INTRODUCTION: The pathophysiological mechanisms of acute schizophrenia are largely unknown, but it is widely accepted that dopamine D2 receptors (DRD2s) are involved in psychosis treatments for schizophrenic patients. We suggest that genetic variation in these receptors may play a role in patients' responses to commonly used antipsychotics, particularly D2-blockers. METHODS: This study included adult patients with ICD-10 diagnoses of schizophrenia and current acute psychosis who were treated with antipsychotics. All patients underwent genotyping for DRD2 rs2514218 polymorphism. The definition of overall treatment response was based on changes in treatment scheme: no changes indicated a good response, and changes indicated a limited response. RESULTS: There were 275 inpatients (38.1% of whom were female; mean age = 32.7 years, SD = 11.1 years) who met the inclusion criteria. Of the participants, 99 were good responders (34% of whom were female), and 176 were limited responders (40% of whom were female). No differences in demographic, premorbid, or disease characteristics were found. The number of patients that were homozygous for the risk allele was significantly greater in the limited response group than in the good response group. CONCLUSION: Our findings suggest that the risk variant at the DRD2 locus can be used as an indicator for patients' responses to antipsychotics without direct DRD2-blocking, thereby shortening the time needed for drug selection.

Antipsychotic-induced supersensitivity - A reappraisal.

OBJECTIVES: Tardive dyskinesia, psychotic relapse and treatment-refractory psychosis have long been associated. A common underlying mechanism involving antipsychotic-induced 'supersensitivity', albeit in different brain pathways, was proposed as early as 1978. This piece seeks to reappraise the concept and potential implications of antipsychotic-induced supersensitivity. CONCLUSIONS: Evidence increasingly suggests that chronic antipsychotic exposure induces neuroadaptive physiological changes in dopaminergic, and other, neurotransmitter systems that may render some individuals more vulnerable to psychotic relapse - including those receiving continuous antipsychotic treatment. It is possible that in treating every episode of psychosis with prolonged or indefinite antipsychotic therapy, we paradoxically increase the risk of psychotic relapse in a significant proportion of people. A greater appreciation of supersensitivity may allow us to optimise any potential benefits of antipsychotics while minimising the risk of inadvertent iatrogenic harms. More research is needed to improve our understanding of the underlying neurophysiology of supersensitivity and to better identify which individuals are most vulnerable to its development. It is time we paid more attention to the concept, emerging evidence and potential implications of antipsychotic-induced supersensitivity and, where appropriate, adjusted our practice accordingly.

Synonymous polymorphism rs201256011 in dopamine receptor type 2 gene is associated with schizophrenia and PANSS score in Pakistani population: A first report.

AIM: Variations of dopamine receptor type 2 (DRD2) are among the key factors involved in the pathology of schizophrenia. Presence of certain SNPs in DRD2 gene also amend patients' response to antipsychotics. Keeping in view the genetic diversity among populations and important role of DRD2 polymorphisms in schizophrenia, we aimed to study two of its SNPs rs1801028 and rs6277 in patients with schizophrenia from Pakistan. METHODS: A total of 100 schizophrenia cases and 100 healthy controls were recruited. DNA was extracted from whole blood followed by PCR, Sanger sequencing and genotyping of two SNPs, that is, rs1801028 and rs6277. RESULTS: No association of rs1801028 and rs6277 was found with schizophrenia in Pakistani population (P > .05). Highlight of our study is the association of polymorphism rs201256011 with schizophrenia (P = .001), which is being reported for the first time. Significant association of rs201256011 was also found with Positive and Negative Syndrome Scale negative, cognitive and total score (P < .05). CONCLUSION: In conclusion, genetic variants rs1801028 and rs6277 of DRD2 are not associated with schizophrenia in Pakistani population. While, previously unreported polymorphism rs201256011 have shown significant association with schizophrenia and its severity. A large scale multicentre replication study is required to confirm the association of this SNP with schizophrenia.

Consenso español sobre los riesgos y detección de la hiperprolactinemia iatrogénica por antipsicóticos / Spanish consensus on the risks and detection of antipsychotic drug-related hyperprolactinaemia

Introducción. La hiperprolactinemia iatrogénica (HPRLi) se ha descrito con más frecuencia con algunos antipsicóticos, dependiendo de su capacidad de bloqueo de los receptores de dopamina D2. Existe gran heterogeneidad de la práctica clínica y posiblemente falta de concienciación sobre este problema entre los médicos. Dada la elevada frecuencia con la que los pacientes con enfermedad mental grave reciben antipsicóticos de forma prolongada, se precisa vigilar posibles riesgos en su salud física. La HPRLi y sus síntomas pueden pasar desapercibidos si no se investigan rutinariamente. Metodología. Se realiza una revisión profunda de la literatura para elaborar un consenso multidisciplinario con psiquiatras junto a otros especialistas (de Endocrinología, Medicina Interna y Oncología) con el fin de consensuar los riesgos clínicos y los métodos de detección más adecuados de la HPRLi de acuerdo con los distintos niveles de evidencia científica (I-IV). Resultados. Los síntomas a corto plazo incluyen amenorrea, galactorrea y disfunción sexual (descenso del deseo y disfunción eréctil por hipogonadismo secundario). A medio-largo plazo y relacionado con la disminución de estrógenos, se pueden inducir baja masa ósea (osteopenia y osteoporosis), hipogonadismo, menopausia precoz, incremento del riesgo de algunos tipos de cáncer (mama y endometrio), aumento del riesgo cardiovascular, alteraciones en la inmunidad, dislipidemia y disfunción cognitiva, entre otros. La petición de niveles de PRL debería realizarse al inicio del tratamiento en todos los pacientes que reciben antipsicóticos, aunque no se observen síntomas precoces (amenorrea, galactorrea) por el riesgo de subestimar otros síntomas que pueden aparecen a medio plazo. Se aconseja determinar también niveles de FSL, LH, testosterona y vitamina D. Se recomienda explorar rutinariamente la función sexual, ya que puede ser un síntoma mal tolerado que podría conducir al abandono del tratamiento. Se propone un especial cuidado en niños y adolescentes, así como en pacientes con PRL > 50 ng/ml (intensidad moderada), revisando periódicamente si existe hipogonadismo o disfunción sexual. En los pacientes con PRL > 150 ng/ml debe descartarse siempre un prolactinoma radiológicamente y se debe prestar especial atención a posibles antecedentes de cáncer de mama o endometrio. Se aconseja realizar densitometrías en varones >50 años y en mujeres con amenorrea > 6 meses o menopausia precoz para detectar osteoporosis y evitar riesgo de fracturas por fragilidad (AU)

Introduction. Iatrogenic hyperprolactinaemia (IHPRL) has been more frequently related to some antipsychotic drugs that provoke an intense blockade of dopamine D2 receptors. There is a wide variation in clinical practice, and perhaps some more awareness between clinicians is needed. Due to the high frequency of chronic treatment in severe mental patients, careful attention is recommended on the physical risk. IHPRL symptoms could be underestimated without routine examination. Methodology. An intense scientific literature search was performed in order to draw up a multidisciplinary consensus, including different specialists of psychiatry, endocrinology, oncology and internal medicine, and looking for a consensus about clinical risk and detection of IHPRL following evidence-based medicine criteria levels (EBM I- IV). Results. Short-term symptoms include amenorrhea, galactorrhoea, and sexual dysfunction with decrease of libido and erectile difficulties related to hypogonadism. Medium and long-term symptoms related to oestrogens are observed, including a decrease bone mass density, hypogonadism, early menopause, some types of cancer risk increase (breast and endometrial), cardiovascular risk increase, immune system disorders, lipids, and cognitive dysfunction. Prolactin level, gonadal hormones and vitamin D should be checked in all patients receiving antipsychotics at baseline although early symptoms (amenorrhea-galactorrhoea) may not be observed due to the risk of underestimating other delayed symptoms that may appear in the medium term. Routine examination of sexual dysfunction is recommended due to possible poor patient tolerance and low compliance. Special care is required in children and adolescents, as well as patients with PRL levels >50 ng/ml (moderate hyperprolactinaemia). A possible prolactinoma should be investigated in patients with PRL levels >150 ng/ml, with special attention to patients with breast/endometrial cancer history. Densitometry should be prescribed for males >50 years old, amenorrhea > 6 months, or early menopause to avoid fracture risk (AU)

Dopamine receptor D2S gene transfer improves the sensitivity of GH3 rat pituitary adenoma cells to bromocriptine.

Bromocriptine, a dopamine agonist (DA), has been used in the treatment of prolactinomas. Recent studies have indicated that dopamine 2 receptor short isoform (D2S) may play an important role in suppressing PRL synthesis and prolactinoma cell growth under DA treatment. In the current study, we investigated the role of D2S in the therapeutic action of bromocriptine in GH3 using both in vitro and in vivo approaches. Infection of adenovirus-D2S increased D2S expression in GH3 cells (P<0.05). D2S expression significantly decreased the GH3 cell viability subjected to bromocriptine treatment in vitro (P<0.05). In nude mice, adenovirus-D2S transfection sensitized GH3 xenograft to bromocriptine treatment evidenced by the significant inhibition of D2S expressed tumor growth as compared with vector control. Furthermore, decrease of Bcl-2 expression, increase of Bax, and active Caspase-3 were found in D2S expressed GH3 xenograft subjected to bromocriptine treatment. In summary, our study indicates that D2S expression plays a critical role in the therapeutic action of bromocriptine in pituitary adenomas and that adenovirus-mediated D2S gene transfer combined with bromocriptine may provide a novel treatment for DA-resistant prolactinomas.

Utilization of health care services by patients with chronic obstructive pulmonary disease.

In order to identify healthcare resource use patterns associated with chronic obstructive pulmonary disease (COPD), resource utilization (RU) data collection was integrated into a randomized, double-blind placebo-controlled study of Viozan (sibenadet HCl). This study enrolled patients with symptomatic, smoking-related COPD, randomized to receive sibenadet or placebo for a 52-week treatment period. A questionnaire establishing typical pre-trial, COPD-related RU was completed by each patient. Subsequent data were collected by means of an Interactive Voice Response System (IVRS) at 30-day intervals (14 time points) during the study and in the follow-up period. The IVRS system facilitated data collection and minimized inconvenience to the patient. Compliance with the requirement to record details of the healthcare services during the year-long study was high. No overall trend for lower RU was associated with sibenadet therapy, which correlates with the lack of sustained clinical effect seen in studies conducted concurrently. These data do, however, provide valuable information on RU associated with COPD and insights into adjustments associated with changes in disease course. Physicians were seen to be the most common source of care for patients with COPD and more of the patients with severe COPD (stage III) than mild (stage I) were seen to utilize the most expensive resources (e.g. inpatient hospital care). For those patients who experienced an exacerbation during the trial (irrespective of treatment group), resource use was increased during the periods when an exacerbation was reported when compared with the periods before or after an exacerbation. The proportion of cases attending the physician doubled and with a trip to the Emergency Room (ER) increased approximately ninefold during the reporting period in which the exacerbation occurred compared with the previous month. This study has shown that use of an IVRS, even in elderly patients, is an effective means of gathering RU data over long periods. The study findings suggest that the advent of effective therapeutic interventions, particularly any with the ability to minimize exacerbations and limit disease progression, could impact on the health care services used and potentially reduce associated costs.

Conclusion. Lessons from the novel D2 dopamine receptor, beta2-adrenoceptor agonist, Viozan: chronic obstructive pulmonary disease and drug development implications.

The development of novel drugs for the treatment of chronic obstructive pulmonary disease (COPD) poses significant challenges. The mechanisms through which the chronic symptoms of COPD arise are poorly understood, making identification of potential therapeutic targets and in vivo evaluation of potential therapies extremely difficult. Despite these challenges, a unique approach of combined D2 dopamine, beta2-adrenoceptor agonism was identified as a valid potential target for the treatment of key COPD symptoms, the therapeutic potential of which was investigated in a series of preclinical evaluations. Subsequent clinical assessment has amassed a wealth of data from over 4000 patients, providing valuable insights into COPD, clinical trial design and the value of patient self-assessment tools.

Mmu and D2 receptor antisense oligonucleotides injected in nucleus accumbens suppress high alcohol intake in genetic drinking HEP rats.

Numerous pharmacological and other studies have implicated both Mmu and dopamine receptor subtypes in alcohol consumption. In the genetic drinking rat as well as those chemically induced to drink, evidence has accrued that the abnormal intake of alcohol is underpined by these receptors in the brain. The purpose of this investigation was to demonstrate unequivocally that a biological impairment by antisense oligodeoxynucleotide (ODN) targeted specifically to these two receptor subtypes would disrupt ongoing alcohol drinking. In this project, a new strain of female and male high-ethanol preferring (HEP) rats was used that had free access to preferred concentrations of alcohol over water in a two choice paradigm. A guide cannula for a microinjection needle was first implanted bilaterally above the nucleus accumbens (NAC) of each rat. Following recovery, a dose of either 250 or 500 ng of the Mmu ODN or 500 ng D2ODN was microinjected into the NAC of the rat in a volume of 0.8-1.0 microl. A standard temporal sequence was used in which microinjections were given four times at successive 12-h intervals over a 2-day interval. The control mismatch ODNs corresponding to both the Mmu or D2 receptor antisense were microinjected identically at homologous sites in the NAC. Following the experiments, the brain of each rat was removed and sectioned in the coronal plane for histological analysis so that each microinjection site was identified. The results showed that the Mmu receptor antisense caused a significant dose dependent fall in free access alcohol drinking within 12 to 24 h following the initial microinjection. This decline often persisted for 1 to 2 days in terms of both g/kg intake and proportion of alcohol to water consumed. Similarly, the D2 receptor ODN likewise induced an intense and significant decline in both g/kg and proportion measures of alcohol intake. Since the corresponding mismatch ODN for both Mmu and D2 receptors exerted no effect on either of these measures of alcohol consumption, the specificity of molecular action of the respective antisense molecules on drinking behavior of the HEP rats was confirmed. Thus, these results provide the first unequivocal evidence that the genes for D2 and Mmu receptors are fundamentally involved in abnormal alcohol drinking in the genetically predisposed individual. Finally, important new anatomical evidence is introduced for the critical role of the NAC in the genetic basis of aberrant drinking of alcohol.