Treatment-Resistant Schizophrenia: Treatment Response and Resistance in Psychosis (TRRIP) Working Group Consensus Guidelines on Diagnosis and Terminology

White blood cell counts, ratios, and C-reactive protein among individuals with schizophrenia spectrum disorder and associations with long-term outcomes: a population-based study

BACKGROUND

Immune mechanisms are associated with adverse outcomes in schizophrenia; however, the predictive value of various peripheral immune biomarkers has not been collectively investigated in a large cohort before.

OBJECTIVE

To investigate how white blood cell (WBC) counts, ratios, and C-Reactive Protein (CRP) levels influence the long-term outcomes of individuals with schizophrenia spectrum disorder (SSD).

METHODS

We identified all adults in the Central Denmark Region during 1994-2013 with a measurement of WBC counts and/or CRP at first diagnosis of SSD. WBC ratios were calculated, and both WBC counts and ratios were quartile-categorized (Q4 upper quartile). We followed these individuals from first diagnosis until outcome of interest (death, treatment resistance and psychiatric readmissions), emigration or December 31, 2016, using Cox regression analysis to estimate adjusted hazard ratios (aHRs).

RESULTS

Among 6,845 participants, 375 (5.5 %) died, 477 (6.9 %) exhibited treatment resistance, and 1470 (21.5 %) were readmitted during follow-up. Elevated baseline levels of leukocytes, neutrophils, monocytes, LLR, NLR, MLR, and CRP increased the risk of death, whereas higher levels of lymphocytes, platelets, and PLR were associated with lower risk. ROC analysis identified CRP as the strongest predictor for mortality (AUC=0.84). Moreover, elevated levels of leukocytes, neutrophils, monocytes, LLR, NLR and MLR were associated with treatment resistance. Lastly, higher platelet counts decreased the risk of psychiatric readmissions, while elevated LLR increased this risk.

CONCLUSIONS

Elevated levels of WBC counts, ratios, and CRP at the initial diagnosis of SSD are associated with mortality, with CRP demonstrating the highest predictive value. Additionally, certain WBC counts and ratios are associated with treatment resistance and psychiatric readmissions.

Introducing S.C.O.P.E.™ (Schizophrenia Clinical Outcome Scenarios and Patient-Provider Engagement), an Interactive Digital Platform to Educate Healthcare Professionals on Schizophrenia Care

Despite evidence of benefits beyond those of oral antipsychotics, long-acting injectable antipsychotics (LAIs) are underused in schizophrenia treatment. Underuse may be partially a result of misconceptions held by some healthcare professionals (HCPs) pertaining to LAIs. A panel of four experts convened between January 2022 and May 2022 to identify these misconceptions, and example cases or scenarios were created to illustrate common clinical situations relevant to these beliefs. Ultimately, an online platform and heuristic tool, Schizophrenia Clinical Outcome Scenarios and Patient-Provider Engagement (S.C.O.P.E.™), was developed to help prescribing clinicians and other HCPs better understand common clinical dilemmas, as well as the place for LAIs in schizophrenia treatment. Three main misconceptions related to the use of LAIs to treat schizophrenia were identified and included "physicians/providers know when patients are nonadherent", "patients do not accept/want LAI treatment", and "LAIs are only appropriate for patients who have demonstrated nonadherence". All misconceptions are refuted by current evidence and were used to develop clinical scenarios with questions to consider when patients present to various sites of care for treatment. These cases are presented on the S.C.O.P.E. educational platform. The platform also includes videos designed to help non-prescribing HCPs and mental health professionals address patient/caregiver concerns and to communicate LAI benefits. In addition, S.C.O.P.E. provides a section with information about each LAI that is currently FDA approved in the United States for the treatment of schizophrenia, to help familiarize HCPs with characteristics of LAIs. S.C.O.P.E. is an educational tool designed for HCPs to help improve their understanding of how to manage common clinical dilemmas in the treatment of people with schizophrenia, to clarify the role of LAIs in medication management, and to increase understanding of the characteristics of available LAIs. S.C.O.P.E. also aims to improve care in schizophrenia by facilitating increased awareness to patients and caregivers.

New Drug Treatments for Schizophrenia: A Review of Approaches to Target Circuit Dysfunction

Schizophrenia is a leading cause of global disease burden. Current drug treatments are associated with significant side effects and have limited efficacy for many patients, highlighting the need to develop new approaches that target other aspects of the neurobiology of schizophrenia. Preclinical, in vivo imaging, postmortem, genetic, and pharmacological studies have highlighted the key role of cortical GABAergic (gamma-aminobutyric acidergic)-glutamatergic microcircuits and their projections to subcortical dopaminergic circuits in the pathoetiology of negative, cognitive, and psychotic symptoms. Antipsychotics primarily act downstream of the dopaminergic component of this circuit. However, multiple drugs are currently in development that could target other elements of this circuit to treat schizophrenia. These include drugs for GABAergic or glutamatergic targets, including glycine transporters, D-amino acid oxidase, sodium channels, or potassium channels. Other drugs in development are likely to primarily act on pathways that regulate the dopaminergic system, such as muscarinic or trace amine receptors or 5-HT2A receptors, while PDE10A inhibitors are being developed to modulate the downstream consequences of dopaminergic dysfunction. Our review considers where new drugs may act on this circuit and their latest clinical trial evidence in terms of indication, efficacy, and side effects. Limitations of the circuit model, including whether there are neurobiologically distinct subgroups of patients, and future directions are also considered. Several drugs based on the mechanisms reviewed have promising clinical data, with the muscarinic agonist KarXT most advanced. If these drugs are approved for clinical use, they have the potential to revolutionize understanding of the pathophysiology and treatment of schizophrenia.

Immunophenotyping schizophrenia subtypes stratified by antipsychotic response

Immune dysfunction has been proposed to play a role in the pathophysiology behind the development and persistence of psychosis. Current immunophenotyping studies are limited by small sample sizes and the number of immune markers investigated. Pharmacological subtypes in schizophrenia based on antipsychotic response have been proposed, but few studies have investigated immunophenotypes in treatment-resistant schizophrenia. In this study, we perform comprehensive immunophenotyping on 196 subjects comprising 147 schizophrenia patients stratified by antipsychotic response (49 antipsychotic-responsive, 70 clozapine-responsive, 28 clozapine-resistant) and 49 healthy controls. We aim to identify significant immune cell populations associated with schizophrenia and increasing treatment resistance, as potential modulators of underlying psychosis and/or treatment response. Patients with schizophrenia were recruited and assessed on the Clinical Global Impression - Schizophrenia (CGI-SCH). Treatment response was defined as a rating of three (mild severity) or less on the CGI-SCH positive symptom item after at least 8 weeks of adequate antipsychotic or clozapine treatment. Peripheral blood mononuclear cells were collected and flow cytometry was performed to identify 66 immune cell populations. Differences in cell population proportions were compared between schizophrenia cases and controls, and across all 4 groups, with post-hoc pairwise comparisons. Mucosal-associated invariant T (MAIT) cells (specifically CD8 + and DN double-negative subsets), total, exhausted and memory CD8 + T cells, VD1 + ϒδ T cells, plasmablasts, IgG + B cells and conventional dendritic cells 2 (cDC2) were among the top cell populations downregulated in schizophrenia. We observed increased downregulation with increasing treatment resistance. Conversely, naïve and exhausted CD4 + T cells, CD4/CD8 ratio and CCR5 + CCR2 + HLA DR + Myeloid cells were found to be upregulated in schizophrenia - we observed increased upregulation with increasing treatment resistance. We show significant immunophenotypic differences between schizophrenia cases and healthy controls, and consistent trend differences across varying degrees of antipsychotic resistance. We also examined immune cell populations not previously reported in schizophrenia. Future studies may explore immune markers identified as potential biomarkers of treatment resistance, and clarify on the relationship between immunological changes and pharmacological subtypes in schizophrenia.

Multi-level barriers and facilitators to implementing evidence-based antipsychotics in the treatment of early-phase schizophrenia

Introduction

Long-acting injectable (LAI) antipsychotic medications and clozapine are effective yet underutilized medical therapies in early intervention services. The purpose of this study was to conduct a pre-implementation evaluation of contextual determinants of early intervention programs to implement innovations optimizing LAI antipsychotic and clozapine use within a shared decision-making model.

Methods

Semi-structured interviews explored barriers and facilitators to implementing LAI antipsychotics and clozapine in early intervention services. Participants were: prescribers (n = 2), non-prescribing clinicians (n = 5), administrators (n = 3), clients (n = 3), and caregivers (n = 3). Interviews were structured and analyzed using the Consolidated Framework for Implementation Research (CFIR 2.0).

Results

Participants were supportive of using LAI antipsychotics, despite barriers (e.g., transportation, insurance coverage), while most were unfamiliar with clozapine (Innovation). Critical incidents (e.g., COVID-19) did not interfere with implementation, while barriers included lack of performance measures; stigma affecting willingness to take medication; and clozapine considered to be a "last resort" (Outer Setting). Treatment culture was described as client-centered and collaborative, and most participants indicated LAI antipsychotic use was compatible with clinic workflows, but some were in need of resources (e.g., individuals trained to administer LAI antipsychotics; Inner Setting). Participants on the healthcare team expressed confidence in their roles. Family education and collaborative decision-making were recommended to improve client/family engagement (Individuals). Participants related the importance of tracking medication compliance, addressing client concerns, and providing prescribers with updated guidelines on evidence-based treatment (Implementation Process).

Discussion

Results may guide implementation strategy selection for future programs seeking to optimize the use of LAI antipsychotics and clozapine for early-phase schizophrenia, when appropriate.

Elevated extracellular free water in the brain predicts clinical improvement in first-episode psychosis

BACKGROUND

Despite the diverse nature of clinical trajectories after a first-episode of psychosis, few baseline characteristics have been predictive of clinical improvement, and the neurobiological underpinnings of this heterogeneity remain largely unknown. Elevated extracellular free water (FW) in the brain is a diffusion imaging measure that has been consistently reported in different phases of psychosis that may indicate a neuroinflammatory state. Its predictive capacity in terms of clinical outcomes, however, is unknown.

METHODS

We used diffusion imaging to determine FW and tissue-specific fractional anisotropy (FA-t) in first-episode psychosis. Forty-seven participants were categorized as clinical "Improvers" (n=26) if they achieved a 20% decrease in total Brief Psychiatric Rating Scale (BPRS) score at 12 months. To determine the predictive capacity of FW and FA-t, these measures were introduced in a stepwise logistic regression model to predict clinical improvement. For those measures surviving the model, regional between-group differences were also investigated in cortical surface or white matter tracts as applicable.

RESULTS

Higher gray matter (GM) FW (OR-CI 1.134 - 2.543) and FA-t (OR-CI: 0.905 - 2.038) both predicted Improver status. FW in GM also linearly correlated with BPRS total score at 12 months follow-up. Examining regional specificity, Improvers showed greater FW predominantly in temporal regions and higher FA-t values in several white matter tracts, including bilateral longitudinal superior fasciculus.

CONCLUSIONS

Our results show that elevated FW in GM and FA-t predict further clinical improvement during the initial phases of psychosis. The potential roles of brain inflammatory processes in predicting clinical improvement are discussed.

Association of clozapine with structural and resting-state functional abnormalities of the hippocampus in chronic schizophrenia

Introduction

Abnormalities in the hippocampus have been extensively reported in schizophrenia research. However, inconsistent findings exist, and how structural and functional abnormalities of the hippocampus are associated with clinical symptoms in schizophrenia, especially concerning clozapine treatment, remains uncertain.

Methods

We recruited 52 patients with schizophrenia, each with an illness duration of at least 5 years, and categorized them based on clozapine treatment. T1-weighted images and resting-state functional magnetic resonance imaging scans were obtained and analyzed to perform group comparisons of the structural and functional changes in the hippocampus. Volumes of the hippocampal subregions, as well as resting-state functional connectivity maps from these areas were compared between the groups. Associations with clinical symptoms, including the severity of psychiatric symptoms and cognitive functions, were investigated.

Results

The clozapine group (n=23) exhibited smaller volumes in several hippocampal subregions, including the CA1, CA4, granule cell and molecular layers of the dentate gyrus, compared to the non-clozapine group (n=29). Seven clusters with significant group differences in functional connectivity with these hippocampal subregions were identified, with six of these clusters showing increased functional connectivity in the clozapine group. The reduced volumes of the hippocampal subregions were moderately associated with the severity of negative symptoms, general intelligence, and executive function.

Discussion

Patients with schizophrenia undergoing clozapine treatment exhibited smaller volumes in the hippocampal subregions, which were moderately associated with negative symptoms and cognitive functions, compared to those without clozapine treatment.

Protocol for Cancloz: multicentre randomised, placebo-controlled, double-blind, parallel-group adaptive trial of cannabidiol for clozapine-resistant schizophrenia

BACKGROUND

Although clozapine is the most effective antipsychotic for people with treatment-resistant schizophrenia (TRS), only 40% of people with TRS respond, and there is limited evidence for augmentation agents. Cannabidiol (CBD) reduces positive symptoms in individuals with schizophrenia, but no trials have specifically examined its efficacy in those with clozapine-resistant schizophrenia.

AIMS

To examine the clinical efficacy of CBD augmentation in people with clozapine-resistant schizophrenia.

METHOD

This is a 12-week randomised, placebo-controlled, double-blind, parallel-group trial (registration number: ACTRN12622001112752). We will recruit 88 individuals with clozapine-resistant schizophrenia, randomised (1:1) to 1000 mg daily CBD versus placebo. Eligible individuals will be aged between 18 and 64 years, fulfil DSM-IV criteria for schizophrenia or schizoaffective disorder, have a total PANSS (Positive and Negative Syndrome Scale) score ≥60, have received oral clozapine for at least 18 weeks and have a clozapine level of >350 ng/mL. Interim analyses will be conducted at 25, 50 and 75% recruitment; these will also provide an opportunity to reallocate participants dependent on conditional power. The primary endpoint will be the difference in PANSS positive scores at the end of week 12. Secondary endpoints include depression, anxiety, sleep, quality of life, alcohol consumption, change in weight and metabolic syndrome components, and neurocognitive measures, as well as safety and tolerability.

DISCUSSION

Novel treatments for clozapine-resistant schizophrenia are urgently needed. If found to be effective, CBD may have a role as a novel and safe adjunct to clozapine.

Risk factors, prevention and treatment of weight gain associated with the use of antidepressants and antipsychotics: a state-of-the-art clinical review

INTRODUCTION

People with severe mental illness have poor cardiometabolic health. Commonly used antidepressants and antipsychotics frequently lead to weight gain, which may further contribute to adverse cardiovascular outcomes.

AREAS COVERED

We searched MEDLINE up to April 2023 for umbrella reviews, (network-)meta-analyses, trials and cohort studies on risk factors, prevention and treatment strategies of weight gain associated with antidepressants/antipsychotics. We developed 10 clinical recommendations.

EXPERT OPINION

To prevent, manage, and treat antidepressant/antipsychotic-related weight gain, we recommend i) assessing risk factors for obesity before treatment, ii) monitoring metabolic health at baseline and regularly during follow-up, iii) offering lifestyle interventions including regular exercise and healthy diet based on patient preference to optimize motivation, iv) considering first-line psychotherapy for mild-moderate depression and anxiety disorders, v)choosing medications based on medications' and patient's weight gain risk, vi) choosing medications based on acute vs long-term treatment, vii) using effective, tolerated medications, viii) switching to less weight-inducing antipsychotics/antidepressants where possible, ix) using early weight gain as a predictor of further weight gain to inform the timing of intervention/switch options, and x) considering adding metformin or glucagon-like peptide-1 receptor agonists, or topiramate(second-line due to potential adverse cognitive effects) to antipsychotics, or aripiprazole to clozapine or olanzapine.

Second Opinions for Diagnoses of Psychotic Disorders: Delivering Stage-Specific Recommendations

OBJECTIVE

The impact of obtaining second-opinion consultations on diagnoses of schizophrenia spectrum disorders was evaluated.

METHODS

A retrospective chart review was conducted for 177 patients referred to a psychosis consultation service at an academic medical center from January 1, 2017, to October 1, 2023; these consultations aimed to clarify a diagnosis of psychosis. Diagnoses made before and after consultations were compared, and treatment recommendations resulting from the consultation visit were summarized.

RESULTS

Among patients without a preconsultation diagnosis of schizophrenia, 28% (N=28 of 100) received a postconsultation diagnosis of schizophrenia. Among 62 patients with a postconsultation diagnosis of treatment-resistant schizophrenia (TRS), 56% (N=35) received this diagnosis only after consultation. Nearly all of these patients were advised to begin taking clozapine, and electroconvulsive therapy was less commonly recommended.

CONCLUSIONS

Expert consultation facilitates timely identification and optimal treatment of schizophrenia and its more severe subtype, TRS.

Elevated serum IGFBP-1 levels correlate with cognitive deficits in treatment-resistant and chronic medicated schizophrenia patients

BACKGROUND

Schizophrenia is a debilitating psychiatric disorder with diverse cognitive impairments. Insulin-like growth factor binding protein 1 (IGFBP-1), a ubiquitous negative regulator of IGF signaling, crosses the blood-brain barrier after peripheral synthesis. Given the crucial role of IGF signaling in cognitive function, we reasoned that altered serum IGFBP-1 concentrations might be associated with cognitive impairments in schizophrenia. To test this hypothesis, we examined the relationship between serum IGFBP-1 levels and cognitive performance in both medicated and treatment-resistant schizophrenia (TRS) patients.

METHODS

Serum IGFBP-1 was measured in 31 TRS patients, 49 chronic medicated schizophrenia (CMS) patients, and 53 healthy controls. Clinical symptom severity was evaluated using the Positive and Negative Syndrome Scale (PANSS) and cognitive functions using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

RESULTS

Both TRS and CMS patients exhibited cognitive deficits compared to healthy controls (p < 0.05). Serum IGFBP-1 concentration differed significantly among groups (F=36.805, p < 0.001) and post hoc tests demonstrated significantly higher concentrations in both schizophrenia groups compared to controls (p < 0.001). Further, serum IGFBP-1 concentration was higher in the TRS group than the CMS group (p = 0.048). Correlation analysis identified a significant relationship between serum IGFBP-1 and attention in the TRS group (r = 0.411, p = 0.021), immediate memory in the CMS group (r = -0.417, p = 0.003), and RBANS total score in the CMS group (r = -0.368, p = 0.009). Multiple regression analysis adjusting for confounding factors revealed that serum IGFBP-1 was independently associated with attention in TRS patients (p = 0.016, 95 %CI. 0.002-0.015) and immediate memory in CMS patients (p = 0.022, 95 %CI-0.012 to -0.001).

CONCLUSIONS

Elevated serum IGFBP-1 concentration may serve as a predictive biomarker for distinct cognitive deficits in TRS and CMS patients. Further investigations are warranted.

Longitudinal changes in DNA methylation associated with clozapine use in treatment-resistant schizophrenia from two international cohorts

The second-generation antipsychotic clozapine is used as a medication for treatment-resistant schizophrenia. It has previously been associated with epigenetic changes in pre-clinical rodent models and cross-sectional studies of treatment-resistant schizophrenia. Cross-sectional studies are susceptible to confounding, however, and cannot disentangle the effects of diagnosis and medication. We therefore profiled DNA methylation in sequential blood samples (n = 126) from two independent cohorts of patients (n = 38) with treatment-resistant schizophrenia spectrum disorders who commenced clozapine after study enrolment and were followed up for up to six months. We identified significant non-linear changes in cell-type proportion estimates derived from DNA methylation data - specifically B-cells - associated with time on clozapine. Mixed effects regression models were used to identify changes in DNA methylation at specific sites associated with time on clozapine, identifying 37 differentially methylated positions (DMPs) (p < 5 × 10-5) in a linear model and 90 DMPs in a non-linear quadratic model. We compared these results to data from our previous epigenome-wide association study (EWAS) meta-analysis of psychosis, finding evidence that many previously identified DMPs associated with schizophrenia and treatment-resistant schizophrenia might reflect exposure to clozapine. In conclusion, our results indicate that clozapine exposure is associated with changes in DNA methylation and cellular composition. Our study shows that medication effects might confound many case-control studies of neuropsychiatric disorders performed in blood.

Effects of online high-definition transcranial direct current stimulation over left dorsolateral prefrontal cortex on predominant negative symptoms and EEG functional connectivity in patients with schizophrenia: a randomized, double-blind, controlled trial

AIMS

Schizophrenia, a debilitating mental disorder, is characterized by persistent negative symptoms such as avolition and anhedonia. Currently, there are no effective treatments available for these symptoms. Thus, our study aims to assess the efficacy of online high-definition transcranial direct current stimulation (online HD-tDCS) in addressing the negative symptoms of schizophrenia, utilizing a double-blind, randomized, sham-controlled trial design.

METHODS

Fifty-nine patients with schizophrenia were randomized to receive either active HD-tDCS or sham stimulation, targeting the left dorsolateral prefrontal cortex. Outcomes were measured by changes in the Positive and Negative Syndrome Scale Factor Score for Negative Symptom (PANSS-FSNS). Exact low-resolution electromagnetic tomography was used to assess the functional connectivity.

RESULTS

All 59 participants, including 50.84% females with an average age of 43.36 years, completed the trial. In the intention-to-treat analysis, patients receiving active HD-tDCS showed greater improvement in PANSS-FSNS scores compared to those receiving the sham procedure. The differences were 2.34 (95% confidence interval [CI], 1.28-3.40), 4.28 (95% CI, 2.93-5.62), and 4.91 (95% CI, 3.29-6.52) after the intervention, as well as at 1-week and 1-month follow-ups, respectively. A tingling sensation on the scalp was more common in the active group (63.3%) compared to the sham group (10.3%). Additionally, HD-tDCS was associated with a decrease in delta-band connectivity within the default mode network.

CONCLUSIONS

High-definition transcranial direct current stimulation was effective and safe in ameliorating negative symptoms in patients with schizophrenia when combined with online functional targeting.

Sex-dependent association study of complement C4 gene with treatment-resistant schizophrenia and hospitalization frequency

The complement component 4 (C4) gene, codes for two isotypes, C4A and C4B, and can exist in long or short forms (C4L and C4S). The C4AL variant has been associated with elevated schizophrenia (SCZ) risk. Here, we investigated the relationship between C4 variation and clinical outcomes in SCZ. N = 434 adults with SCZ or schizoaffective disorder were included in this retrospective study. A three-step genotyping workflow was performed to determine C4 copy number variants. These variants were tested for association with clinical outcome measures, including treatment-resistant SCZ (TRS), number of hospitalizations (NOH), and symptom severity (PANSS). Sex and ancestry stratified analyses were performed. We observed a marginally significant association between C4S and TRS in males only, and a negative association between C4S and NOH in the total sample. C4AS had negative association with NOH in males and non-Europeans. Lastly, C4A copy numbers and C4A predicted brain expression showed negative association with NOH in males only. Our study provides further support for sex-specific effect of C4 on SCZ clinical outcomes, and also suggests that C4S and C4AS might have a protective effect against increased severity. C4 could potentially serve as a genetic biomarker in the future, however, more research is required.

Investigating Cannabidiol's potential as a supplementary treatment for schizophrenia: A narrative review

Schizophrenia presents a complex mental health challenge, often inadequately addressed by existing antipsychotic treatments, leading to persistent symptoms and adverse effects. Hence, developing alternative therapeutic approaches is crucial. Cannabidiol (CBD), a nonpsychoactive compound in Cannabis sativa, has been extensively explored for its therapeutic potential in treating psychiatric disorders, including schizophrenia. CBD exhibits antipsychotic, anxiolytic, and neuroprotective effects. However, distinguishing the individual effects of CBD and THC remains challenging. Therefore, this review aims to critically analyze the potential role of CBD as an adjunctive therapy in schizophrenia treatment. The therapeutic action of CBD may involve activating the 5-hydroxytryptamine 1A receptors and suppressing the G-protein-coupled receptor 55, thereby affecting various neurotransmitter systems. Additionally, the anti-inflammatory and antioxidative effects of CBD may contribute to alleviating neuroinflammation linked to schizophrenia. Compared to typical antipsychotics, CBD demonstrates a lower incidence of side effects and it exhibited favorable tolerability in clinical trials. A 2012 clinical trial demonstrated the efficacy of CBD in reducing both positive and negative symptoms of schizophrenia, presenting a safer profile than that of traditional antipsychotics. However, further research is needed to fully establish the safety and efficacy of CBD as an adjunctive treatment. Future research directions encompass exploring detailed antipsychotic mechanisms, long-term safety profiles, interactions with current antipsychotics, optimal dosing, and patient-specific factors such as genetic predispositions. Despite these research needs, the potential of CBD to enhance the quality of life and symptom management positions it as a promising candidate for innovative schizophrenia treatment approaches.

Predicting treatment resistance in positive and negative symptom domains from first episode psychosis: Development of a clinical prediction model

BACKGROUND

Treatment resistance (TR) in schizophrenia may be defined by the persistence of positive and/or negative symptoms despite adequate treatment. Whilst previous investigations have focused on positive symptoms, negative symptoms are highly prevalent, impactful, and difficult to treat. In the current study we aimed to develop easily employable prediction models to predict TR in positive and negative symptom domains from first episode psychosis (FEP).

METHODS

Longitudinal cohort data from 1027 individuals with FEP was utilised. Using a robust definition of TR, n = 51 (4.97 %) participants were treatment resistant in the positive domain and n = 56 (5.46 %) treatment resistant in the negative domain 12 months after first presentation. 20 predictor variables, selected by existing evidence and availability in clinical practice, were entered into two LASSO regression models. We estimated the models using repeated nested cross-validation (NCV) and assessed performance using discrimination and calibration measures.

RESULTS

The prediction model for TR in the positive domain showed good discrimination (AUC = 0.72). Twelve predictor variables (male gender, cannabis use, age, positive symptom severity, depression and academic and social functioning) were retained by each outer fold of the NCV procedure, indicating importance in prediction of the outcome. However, our negative domain model failed to discriminate those with and without TR, with results only just over chance (AUC = 0.56).

CONCLUSIONS

Treatment resistance of positive symptoms can be accurately predicted from FEP using routinely collected baseline data, however prediction of negative domain-TR remains a challenge. Detailed negative symptom domains, clinical data, and biomarkers should be considered in future longitudinal studies.

Dysfunction of the NMDA Receptor in the Pathophysiology of Schizophrenia and/or the Pathomechanisms of Treatment-Resistant Schizophrenia

For several decades, the dopamine hypothesis contributed to the discovery of numerous typical and atypical antipsychotics and was the sole hypothesis for the pathophysiology of schizophrenia. However, neither typical nor atypical antipsychotics, other than clozapine, have been effective in addressing negative symptoms and cognitive impairments, which are indices for the prognostic and disability outcomes of schizophrenia. Following the development of atypical antipsychotics, the therapeutic targets for antipsychotics expanded beyond the blockade of dopamine D2 and serotonin 5-HT2A receptors to explore the partial agonism of the D2 receptor and the modulation of new targets, such as D3, 5-HT1A, 5-HT7, and metabotropic glutamate receptors. Despite these efforts, to date, psychiatry has not successfully developed antipsychotics with antipsychotic properties proven to be superior to those of clozapine. The glutamate hypothesis, another hypothesis regarding the pathophysiology/pathomechanism of schizophrenia, was proposed based on clinical findings that N-methyl-D-aspartate glutamate receptor (NMDAR) antagonists, such as phencyclidine and ketamine, induce schizophrenia-like psychotic episodes. Large-scale genome-wide association studies (GWASs) revealed that approximately 30% of the risk genes for schizophrenia (the total number was over one hundred) encode proteins associated with glutamatergic transmission. These findings supported the validation of the glutamate hypothesis, which was inspired by the clinical findings regarding NMDAR antagonists. Additionally, these clinical and genetic findings suggest that schizophrenia is possibly a syndrome with complicated pathomechanisms that are affected by multiple biological and genetic vulnerabilities. The glutamate hypothesis has been the most extensively investigated pathophysiology/pathomechanism hypothesis, other than the dopamine hypothesis. Studies have revealed the possibility that functional abnormalities of the NMDAR play important roles in the pathophysiology/pathomechanism of schizophrenia. However, no antipsychotics derived from the glutamatergic hypothesis have yet been approved for the treatment of schizophrenia or treatment-resistant schizophrenia. Considering the increasing evidence supporting the potential pro-cognitive effects of glutamatergic agents and the lack of sufficient medications to treat the cognitive impairments associated with schizophrenia, these previous setbacks cannot preclude research into potential novel glutamate modulators. Given this background, to emphasize the importance of the dysfunction of the NMDAR in the pathomechanism and/or pathophysiology of schizophrenia, this review introduces the increasing findings on the functional abnormalities in glutamatergic transmission associated with the NMDAR.

DNA methylation and histone modifications associated with antipsychotic treatment: a systematic review

Antipsychotic medications are essential when treating schizophrenia spectrum and other psychotic disorders, but the efficacy and tolerability of these medications vary from person to person. This interindividual variation is likely mediated, at least in part, by epigenomic processes that have yet to be fully elucidated. Herein, we systematically identified and evaluated 65 studies that examine the influence of antipsychotic drugs on epigenomic changes, including global methylation (9 studies), genome-wide methylation (22 studies), candidate gene methylation (16 studies), and histone modification (18 studies). Our evaluation revealed that haloperidol was consistently associated with increased global hypermethylation, which corroborates with genome-wide analyses, mostly performed by methylation arrays. In contrast, clozapine seems to promote hypomethylation across the epigenome. Candidate-gene methylation studies reveal varying effects post-antipsychotic therapy. Some genes like Glra1 and Drd2 are frequently found to undergo hypermethylation, whereas other genes such as SLC6A4, DUSP6, and DTNBP1 are more likely to exhibit hypomethylation in promoter regions. In examining histone modifications, the literature suggests that clozapine changes histone methylation patterns in the prefrontal cortex, particularly elevating H3K4me3 at the Gad1 gene and affecting the transcription of genes like mGlu2 by modifying histone acetylation and interacting with HDAC2 enzymes. Risperidone and quetiapine, however, exhibit distinct impacts on histone marks across different brain regions and cell types, with risperidone reducing H3K27ac in the striatum and quetiapine modifying global H3K9me2 levels in the prefrontal cortex, suggesting antipsychotics demonstrate selective influence on histone modifications, which demonstrates a complex and targeted mode of action. While this review summarizes current knowledge, the intricate dynamics between antipsychotics and epigenetics clearly warrant more exhaustive exploration with the potential to redefine our understanding and treatment of psychiatric conditions. By deciphering the epigenetic changes associated with drug treatment and therapeutic outcomes, we can move closer to personalized medicine in psychiatry.

The role of control groups in non-pharmacological randomised controlled trials of treatment-resistant schizophrenia: A systematic review and meta-analysis

Control groups used in randomised controlled trials investigating psychological interventions for depression and anxiety disorders have effects of their own. This has never been investigated for schizophrenia, in particular treatment-resistant schizophrenia. This systematic review and meta-analysis aimed to examine how control groups in randomised controlled trials on psychological interventions for treatment-resistant schizophrenia behave in their effects on general symptomatology. In a search of various databases until July 2023, 31 eligible studies with 3125 participants were found whose control groups were assigned to four categories: active, inactive, treatment as usual and waitlist. The analyses showed that psychological interventions had a greater effect on symptom reduction to all control groups combined. When separating the control groups, only compared to TAU and waitlist controls the psychological interventions were superior. The difference was larger when less active control groups (e.g. waitlist - or treatment as usual control groups) were used. All control groups were associated with an improvement in symptoms from pre- to post-measurement point, with the greatest improvement observed in the inactive control group. The results are preliminary, but they suggest that the choice of the control group has a considerable impact on study effects as it has been shown in other psychiatric diagnoses.

When, Why and How to Re-challenge Clozapine in Schizophrenia Following Myocarditis

Clozapine-induced myocarditis (CIM) is among the most important adverse events limiting the use of clozapine as the most effective treatment for schizophrenia. CIM necessitates the immediate termination of clozapine, often resulting in its permanent discontinuation with considerable detrimental effects on patients' psychopathology and long-term outcome. Consequently, a clozapine re-challenge after CIM is increasingly regarded as a viable alternative, with published reports indicating a success rate of approximately 60%. However, published cases of re-challenges after CIM remain limited. Here, we provide a narrative review of the current state of research regarding the epidemiology, pathophysiology, risk factors, diagnosis and clinical management of CIM as well as a synthesis of current recommendations for re-challenging patients after CIM. This includes a step-by-step guide for this crucial procedure based on the current evidence regarding the pathophysiology and risk factors for CIM. Slow dose titration regimes and addressing risk factors including concomitant valproate and olanzapine are crucial both to prevent CIM and to ensure a safe and successful re-challenge. Furthermore, we discuss the utility of C-reactive protein, troponin, N-terminal-pro hormone and brain natriuretic peptide, therapeutic drug-monitoring and cardiac magnetic resonance imaging for CIM screening and diagnosis as well as for post-CIM re-challenges.

Improving outcome of treatment-resistant schizophrenia: effects of cognitive remediation therapy

Treatment-Resistant Schizophrenia (TRS) represents a main clinical issue, associated with worse psychopathological outcomes, a more disrupted neurobiological substrate, and poorer neurocognitive performance across several domains, especially in verbal abilities. If cognitive impairment is a major determinant of patients' functional outcomes and quality of life, targeting cognitive dysfunction becomes even more crucial in TRS patients in order to minimize cognitive and functional deterioration. However, although Cognitive Remediation Therapy (CRT) represents the best available tool to treat cognitive dysfunction in schizophrenia, specific evidence of its efficacy in TRS is lacking. Based on these premises, our study aimed at investigating possible differences in CRT outcomes in a sample of 150 patients with schizophrenia, stratified according to antipsychotic response (TRS vs. non-TRS). Subjects were assessed for neurocognition through Brief Assessment of Cognition in Schizophrenia (BACS) and the Wisconsin Card Sorting Test (WCST) at baseline and after CRT. As expected, we observed greater baseline impairment among TRS patients in BACS-Verbal Memory and WCST-Executive Functions. Repeated measures ANCOVAs showed significant within-group pre-/post-CRT differences in the above-mentioned domains, both among non-TRS and TRS subjects. However, after CRT, no differences were observed between groups. This is the first study to indicate that CRT represents a highly valuable resource for TRS patients, since it may be able to fill the cognitive gap between treatment response groups. Our finding further highlights the importance of early implementation of CRT in addition to pharmacotherapy to reduce the cognitive and functional burden associated with the disease, especially for TRS patients.

NMDAR dysfunction and the regulation of dopaminergic transmission in schizophrenia

A substantial body of evidence implicates dysfunction in N-methyl-d-aspartate receptors (NMDARs) in the pathophysiology of schizophrenia. This article illustrates how NMDAR dysfunction may give rise to many of the neurobiological phenomena frequently associated with schizophrenia with a particular focus on how NMDAR dysfunction affects the thalamic reticular nucleus (nRT) and pedunculopontine tegmental nucleus (PPTg). Furthermore, this article presents a model for schizophrenia illustrating how dysfunction in the nRT may interrupt prefrontal regulation of midbrain dopaminergic neurons, and how dysfunction in the PPTg may drive increased, irregular burst firing.

Immunoinflammatory features and cognitive function in treatment-resistant schizophrenia: unraveling distinct patterns in clozapine-resistant patients

Patients with treatment-resistant schizophrenia (TRS), particularly those resistant to clozapine (CTRS), pose a clinical challenge due to limited response to standard antipsychotic treatments. Inflammatory factors like tumor necrosis factor-alpha (TNF-α), interleukin 2 (IL-2), and interleukin 6 (IL-6) are implicated in schizophrenia's pathophysiology. Our study examines cognitive function, psychopathological symptoms and inflammatory factors in TRS patients, focusing on differences between CTRS and non-CTRS individuals, as well as healthy controls. A cohort of 115 TRS patients and 84 healthy controls were recruited, assessing IL-2, IL-6 and TNF-α. The Positive and Negative Syndrome Scale (PANSS) was applied to assess psychopathological symptoms, while the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was applied to assess cognitive functioning. CTRS patients showed lower visuospatial constructional score (p = 0.015), higher PANSS scores, higher levels of IL-2 and reduced TNF-α than non-CTRS patients (p < 0.05). Notably, IL-2 was independently associated with psychopathology symptoms in CTRS patients (Beta = 0.268, t = 2.075, p = 0.042), while IL-6 was associated with psychopathology symptoms in non-CTRS patients (Beta = - 0.327, t = - 2.109, p = 0.042). Sex-specific analysis in CTRS patients revealed IL-2 associations with PANSS total and positive symptoms in females, and TNF-α associations with PANSS positive symptoms in males. Furthermore, IL-2, IL-6, and TNF-α displayed potential diagnostic value in TRS patients and CTRS patients (p < 0.05). Clozapine‑resistant symptoms represent an independent endophenotype in schizophrenia with distinctive immunoinflammatory characteristics, potentially influenced by sex.

Prevalence of treatment-resistant schizophrenia among people with early psychosis and its clinical and demographic correlates

OBJECTIVE

The prevalence of treatment-resistant schizophrenia (TRS) among people with first-episode schizophrenia (FES) has been sub-optimally researched in Australia and internationally. We evaluated the prevalence of TRS among a cohort of FES patients and compared their sociodemographic and clinical characteristics to those with FES who were treatment responsive.

METHODS

Over 2 years, we collated demographic, clinical and treatment-related data of all patients with ICD-10 (International Classification of Diseases, Tenth revision) diagnosis of schizophrenia who were active in October 2020 at four early psychosis intervention services (EPIS) in Western Australia. We used a modified version of Suzuki et al. criteria to diagnose TRS. The data were analysed utilising descriptive statistics, the Mann-Whitney U test, Student's t-test and the False-Discovery Rate method.

RESULTS

The prevalence of TRS among the 167 patients diagnosed with FES was 41.3%, and the rates did not differ significantly between the services (p = 0.955). Those in the TRS group were less independent (p = 0.011), had more prolonged unemployment (p = 0.014) and were more likely to be on disability pension (p = 0.011) compared to the treatment responsive group. Furthermore, they had greater severity of symptoms (p = 0.002), longer duration of psychiatric symptoms (p = 0.019), more hospitalisations (p = 0.002) and longer cumulative admission durations (p = 0.002).

CONCLUSIONS

Our study revealed that treatment resistance to antipsychotics is prevalent among people with FES managed at EPIS. Notably, it establishes an association between TRS and heightened clinical severity and psychosocial and treatment burden. These findings highlight the imperative for early detection of treatment resistance and timely and specialised interventions for this condition in mental health services.

Treatment-resistant schizophrenia with 22q11.2 deletion and additional genetic defects

We report a case of a 61-year-old female with 22q11.2 deletion syndrome (22q11.2DS) and a novel heterozygous nonsense variant in MAP1A, identified through whole-genome sequencing (WGS). The patient presented with intellectual developmental disorder, treatment-resistant schizophrenia (SCZ), and multiple congenital anomalies. Despite aggressive pharmacotherapy, she experienced persistent auditory hallucinations and negative symptoms. WGS revealed a 3 Mb deletion at 22q11.2 and a nonsense variant in MAP1A (c.4652T>G, p.Leu1551*). MAP1A, encoding microtubule-associated protein 1A, is crucial for axon and dendrite development and has been implicated in autism spectrum disorder and SCZ. The MAP1A variant may contribute to the severe psychiatric phenotype, as it is thought to influence synaptic plasticity, a process also affected by 22q11.2 deletion. This case highlights the importance of WGS in identifying additional pathogenic variants that may explain phenotypic variability in 22q11.2DS. Thus, WGS can lead to a better understanding of the genetic architecture of 22q11.2DS. However, further studies are needed to elucidate the role of secondary genetic contributors in the diverse clinical presentations of 22q11.2DS.

Long-term clinical recovery and treatment resistance in first-episode psychosis: a 10-year follow-up study

Illness trajectories in people with first-episode psychosis (FEP) vary significantly over time. Identifying early-course parameters predicting outcomes is essential, but long-term data still needs to be provided. We conducted a 10-year follow-up study of a comprehensive first-episode psychosis (FEP) cohort investigating the prevalence of clinical recovery (CR) and treatment resistance (TR) after ten years, as well as clinical, demographic, and pre-illness predictors of long-term outcomes. 102 participants with FEP DSM-IV Schizophrenia spectrum disorders were recruited within their first year of treatment. The Treatment Response and Resistance in Psychosis Working Group (TRRIP) and the Remission in Schizophrenia Working Group (RSWG) criteria were used to define TR and CR, respectively. At 10-year follow-up, 29 (29%) of the participants were classified as in CR, while 32 (31%) were classified as TR. We also identified a larger middle group (n = 41, 40%) consisting of participants in partial recovery. 7% of all participants had tried Clozapine at the 10-year follow-up. Logistic regression analyses identified insidious onset (OR = 4.16) and baseline disorganized symptoms (OR = 2.96) as significantly associated with an increased risk of developing TR. Good premorbid academic adjustment (OR = 1.60) and acute onset (OR = 3.40) were associated with an increased chance of CR. We identified three long-term outcome groups by using recent consensus definitions. We also identified the potential importance of assessing baseline disorganized symptoms and monitoring patients with insidious onset more closely. Further, the findings suggest that clinicians should pay close attention to early-course parameters and provide adequate treatment to improve long-term outcomes of FEP.

Identifying clinically relevant agranulocytosis in people registered on the UK clozapine Central Non-Rechallenge Database: retrospective cohort study

BACKGROUND

Clozapine is the most effective antipsychotic for treatment-resistant psychosis. However, clozapine is underutilised in part because of potential agranulocytosis. Accumulating evidence indicates that below-threshold haematological readings in isolation are not diagnostic of life-threatening clozapine-induced agranulocytosis (CIA).

AIMS

To examine the prevalence and timing of CIA using different diagnostic criteria and to explore demographic differences of CIA in patients registered on the UK Central Non-Rechallenge Database (CNRD).

METHOD

We analysed data of all patients registered on the UK Clozaril® Patient Monitoring Service Central Non-Rechallenge Database (at least one absolute neutrophil count (ANC) < 1.5 × 109/L and/or white blood cell count < 3.0 × 109/L) between May 2000 and February 2021. We calculated prevalence rates of agranulocytosis using threshold-based and pattern-based criteria, stratified by demographic factors (gender, age and ethnicity). Differences in epidemiology based on rechallenge status and clozapine indication were explored. The proportion of patients who recorded agranulocytosis from a normal ANC was explored.

RESULTS

Of the 3029 patients registered on the CNRD with 283 726 blood measurements, 593 (19.6%) were determined to have threshold-based agranulocytosis and 348 (11.4%) pattern-based agranulocytosis. In the total sample (75 533), the prevalence of threshold-based agranulocytosis and pattern-based agranulocytosis was 0.8% and 0.5%, respectively. The median time to threshold-based agranulocytosis was 32 weeks (IQR 184) and 15 (IQR 170) weeks for pattern-based agranulocytosis. Among age groups, the prevalence of pattern-based agranulocytosis and threshold-based agranulocytosis was highest in the >48 age group. Prevalence rates were greatest for White (18%) and male individuals (13%), and lowest for Black individuals (0.1%). The proportion of people who were determined to have pattern-based agranulocytosis without passing through neutropenia was 70%.

CONCLUSIONS

Threshold-based definition of agranulocytosis may over-diagnose CIA. Monitoring schemes should take into consideration neutrophil patterns to correctly identify clinically relevant CIA. In marked contrast to previous studies, CIA occurred least in Black individuals and most in White individuals.

Development and initial evaluation of a clinical prediction model for risk of treatment resistance in first-episode psychosis: Schizophrenia Prediction of Resistance to Treatment (SPIRIT)

BACKGROUND

A clinical tool to estimate the risk of treatment-resistant schizophrenia (TRS) in people with first-episode psychosis (FEP) would inform early detection of TRS and overcome the delay of up to 5 years in starting TRS medication.

AIMS

To develop and evaluate a model that could predict the risk of TRS in routine clinical practice.

METHOD

We used data from two UK-based FEP cohorts (GAP and AESOP-10) to develop and internally validate a prognostic model that supports identification of patients at high-risk of TRS soon after FEP diagnosis. Using sociodemographic and clinical predictors, a model for predicting risk of TRS was developed based on penalised logistic regression, with missing data handled using multiple imputation. Internal validation was undertaken via bootstrapping, obtaining optimism-adjusted estimates of the model's performance. Interviews and focus groups with clinicians were conducted to establish clinically relevant risk thresholds and understand the acceptability and perceived utility of the model.

RESULTS

We included seven factors in the prediction model that are predominantly assessed in clinical practice in patients with FEP. The model predicted treatment resistance among the 1081 patients with reasonable accuracy; the model's C-statistic was 0.727 (95% CI 0.723-0.732) prior to shrinkage and 0.687 after adjustment for optimism. Calibration was good (expected/observed ratio: 0.999; calibration-in-the-large: 0.000584) after adjustment for optimism.

CONCLUSIONS

We developed and internally validated a prediction model with reasonably good predictive metrics. Clinicians, patients and carers were involved in the development process. External validation of the tool is needed followed by co-design methodology to support implementation in early intervention services.

Predictors of continuation for asenapine from real-world data in patients with schizophrenia

BACKGROUND

The continuation rates of pharmacotherapy in schizophrenia exhibit variability, a phenomenon influenced by the specific antipsychotic agent prescribed and patient-related factors such as age and duration of illness. In this context, our study aims to elucidate the predictors of medication continuation for asenapine sublingual tablets, characterized by unique formulation properties.

METHODS

Our investigation leveraged real-world data collected through post-marketing surveillance in Japan, comprising 3236 cases. Utilizing multivariate logistic regression analysis, we identified patient-related factors associated with medication continuation as the primary outcome measure, subsequently employing survival analysis for further evaluation. Additionally, adverse event occurrence was assessed as a secondary outcome measure.

RESULTS

Multivariate logistic regression analysis unveiled significant predictors of asenapine continuation, notably including patient-related factors such as a chlorpromazine equivalent dose exceeding 600 mg/day and an illness duration of 25 years or more. While the overall continuation rate stood at 40.6%, patients exhibiting factors such as a chlorpromazine equivalent dose surpassing 600 mg/day or an illness duration exceeding 25 years demonstrated continuation rates of 46.3% and 47.9%, respectively. Remarkably, patients presenting both factors showcased the highest continuation rate at 52.5%.

CONCLUSIONS

Our findings shed light on distinct patient-related predictors of asenapine continuation, deviating from those observed with other antipsychotic medications. This underscores the necessity of recognizing that predictive factors for antipsychotic medication continuation vary across different agents. Moving forward, elucidating these predictive factors for various antipsychotic medications holds paramount importance in schizophrenia treatment, facilitating the delivery of tailored therapeutic interventions for individual patients.

Evaluation of the pharmacodynamic interaction effect of augmentation agents with clozapine in patients with treatment-resistant schizophrenia: A simulation study of clinical data

INTRODUCTION

The aim of the study was to evaluate interaction effect of various augmentation strategies with clozapine in patients with Treatment-resistant schizophrenia.

METHODS

Data was extracted for change in positive and negative syndrome scale (PANSS) or brief psychiatric rating scale (BPRS) scores for monotherapy with various antipsychotic agents alone and their combination with clozapine. Individual patient data was generated using simulation of data (factorial trial framework) from published clinical trials for sample sizes from eight to 400 to evaluate interaction effect through linear modeling. Dose equivalents were calculated, and best fit models were determined for simulated data.

RESULTS

The polynomial model was found to be the best fit for the simulated data to determine interaction effect of combination. The clozapine augmentation with risperidone and ziprasidone was found to be antagonistic, whereas it was additive for haloperidol, aripiprazole, and quetiapine. A synergistic effect was observed for ECT combined with clozapine (Interaction effect: -7.62; p <0.001). A sample size of 250-300 may be sufficient to demonstrate a clinically significant interaction in future trials.

CONCLUSION

Clozapine may be augmented with electroconvulsive therapy, leading to the enhancement of antipsychotic effect. Though some antipsychotics like aripiprazole demonstrate additive effects, they may also add to the adverse effects.

Childhood trauma and treatment resistance in first-episode psychosis: Investigating the role of premorbid adjustment and duration of untreated psychosis

BACKGROUND

Early identification of treatment non-response in first-episode psychosis (FEP) is essential to outcome. Despite indications that exposure to childhood trauma (CT) can have adverse effects on illness severity, its impact on treatment non-response and the interplay with other pre-treatment characteristics is sparsely investigated. We use a lack of clinical recovery as an early indicator of treatment resistance to investigate the relationship between CT and treatment resistance status at one-year follow-up and the potential mediation of this effect by other pre-treatment characteristics.

METHODS

This prospective one-year follow-up study involved 141 participants recruited in their first year of treatment for a schizophrenia-spectrum disorder. We investigated clinical status, childhood trauma (CT), premorbid adjustment (PA), and duration of untreated psychosis (DUP) at baseline and clinical status at one-year follow-up. Ordinal regression analyses were conducted to investigate how PA and DUP affected the relationship between CT and one-year outcome in FEP.

RESULTS

45 % of the FEP sample reported moderate to severe CT, with significantly higher levels of CT in the early treatment resistant group compared to participants with full or partial early recovery. Ordinal regression analysis showed that CT was a significant predictor of being in a more severe outcome group (OR = 4.59). There was a partial mediation effect of PA and a full mediation effect of DUP on the effect of CT on outcome group membership.

DISCUSSION

Our findings indicate that reducing treatment delays may mitigate the adverse effects of CT on clinical outcomes and support the inclusion of broad trauma assessment in FEP services.

Association of neurotransmitter pathway polygenic risk with specific symptom profiles in psychosis

A primary goal of psychiatry is to better understand the pathways that link genetic risk to psychiatric symptoms. Here, we tested association of diagnosis and endophenotypes with overall and neurotransmitter pathway-specific polygenic risk in patients with early-stage psychosis. Subjects included 205 demographically diverse cases with a psychotic disorder who underwent comprehensive psychiatric and neurological phenotyping and 115 matched controls. Following genotyping, we calculated polygenic scores (PGSs) for schizophrenia (SZ) and bipolar disorder (BP) using Psychiatric Genomics Consortium GWAS summary statistics. To test if overall genetic risk can be partitioned into affected neurotransmitter pathways, we calculated pathway PGSs (pPGSs) for SZ risk affecting each of four major neurotransmitter systems: glutamate, GABA, dopamine, and serotonin. Psychosis subjects had elevated SZ PGS versus controls; cases with SZ or BP diagnoses had stronger SZ or BP risk, respectively. There was no significant association within psychosis cases between individual symptom measures and overall PGS. However, neurotransmitter-specific pPGSs were moderately associated with specific endophenotypes; notably, glutamate was associated with SZ diagnosis and with deficits in cognitive control during task-based fMRI, while dopamine was associated with global functioning. Finally, unbiased endophenotype-driven clustering identified three diagnostically mixed case groups that separated on primary deficits of positive symptoms, negative symptoms, global functioning, and cognitive control. All clusters showed strong genome-wide risk. Cluster 2, characterized by deficits in cognitive control and negative symptoms, additionally showed specific risk concentrated in glutamatergic and GABAergic pathways. Due to the intensive characterization of our subjects, the present study was limited to a relatively small cohort. As such, results should be followed up with additional research at the population and mechanism level. Our study suggests pathway-based PGS analysis may be a powerful path forward to study genetic mechanisms driving psychiatric endophenotypes.

Negative symptoms in treatment-resistant schizophrenia and its relationship with functioning

BACKGROUND

Recent operational criteria for treatment-resistant schizophrenia (TRS) recognized positive and negative symptoms. TRS patients may have heterogeneity in negative symptoms, but empirical data were lacking. We aimed to characterize TRS patients based on negative symptoms using cluster analysis, and to examine between-cluster differences in social functioning.

METHODS

We administered the Clinical Assessment Interview of Negative symptoms (CAINS), Brief Negative Symptom Scale (BNSS), the Positive and Negative Syndrome Scale (PANSS) and the Social and Occupational Functional Assessment (SOFAS to 126 TRS outpatients. All patients also completed the Temporal Experience of Pleasure Scale (TEPS), the Emotion Expressivity Scale (EES), and the Social Functional Scale (SFS). A two-stage hierarchical cluster analysis was performed with the CAINS, TEPS and EES as clustering variables. We validated the clusters using ANOVAs to compare group differences in the BNSS, PANSS, SOFAS and SFS.

RESULTS

Clustering indices supported a 3-cluster solution. Clusters 1 (n = 46) and 3 (n = 16) exhibited higher CAINS scores than Cluster 2 (n = 64), and were negative-symptom TRS subtypes. Cluster 1 reported lower TEPS than Cluster 3; but Cluster 3 reported lower EES than Cluster 1. Upon validation, Clusters 1 and 3 exhibited higher BNSS scores than Cluster 2, but only Cluster 1 exhibited lower SOFAS and higher PANSS general symptoms than Cluster 2. Both Clusters 1 and 3 had higher self-report functioning than Cluster 2.

CONCLUSION

We provided evidence for heterogeneity of negative symptoms in TRS. Negative symptoms can characterize TRS patients and predict functional outcome.

Clozapine treatment and astrocyte activity in treatment resistant schizophrenia: A proton magnetic resonance spectroscopy study

Clozapine is the only antipsychotic approved for treating treatment-resistant schizophrenia (TRS), characterized by persistent positive symptoms despite adequate antipsychotic treatment. Unfortunately, clozapine demonstrates clinical efficacy in only ~30-60 % of patients with TRS (clozapine-responders; ClzR+), while the remaining ~40-70 % are left with no pharmacological recourse for improvement (clozapine-resistant; ClzR-). Mechanism(s) underlying clozapine's superior efficacy remain unclear. However, in vitro evidence suggests clozapine may mitigate glutamatergic dysregulations observed in TRS, by modulating astrocyte activity in ClzR+, but not ClzR-. A factor that if proven correct, may help the assessment of treatment response and development of more effective antipsychotics. To explore the presence of clozapine-astrocyte interaction and clinical improvement, we used 3 T proton-magnetic resonance spectroscopy to quantify levels of myo-Inositol, surrogate biomarker of astrocyte activity, in regions related to schizophrenia neurobiology: Dorsal-anterior-cingulate-cortex (dACC), left-dorsolateral-prefrontal-cortex (left-DLPFC), and left-striatum (left-striatum) of 157 participants (ClzR- = 30; ClzR+ = 37; responders = 38; controls = 52). Clozapine treatment was assessed using clozapine to norclozapine plasma levels, 11-12 h after last clozapine dose. Measures for symptom severity (i.e., Positive and Negative Symptoms Scale) and cognition (i.e., Mini-Mental State Examination) were also recorded. Higher levels of myo-Inositol were observed in TRS groups versus responders and controls (dACC (p < 0.001); left-striatum (p = 0.036); left-DLPFC (p = 0.023)). In ClzR+, but not ClzR-, clozapine to norclozapine ratios were positively associated with myo-Inositol levels (dACC (p = 0.004); left-DLPFC (p < 0.001)), and lower positive symptom severity (p < 0.001). Our results support growing in vitro evidence of clozapine-astrocyte interaction in clozapine-responders. Further research may determine the viability of clozapine-astrocyte interactions as an early marker of clozapine response.

An overview of the currently available and emerging long-acting formulations of risperidone for schizophrenia and bipolar disorder

INTRODUCTION

Long-acting injectable (LAI) antipsychotic medications can help improve treatment adherence in patients with schizophrenia and bipolar disorder. Despite this, they are underutilized. In 2003, intramuscular risperidone became the first available LAI atypical antipsychotic medication, and since then, a number of competing long-acting risperidone formulations have been brought to market, with additional options under active development. These include intramuscular, subcutaneous, long-acting oral, and implantable formulations.

AREAS COVERED

This review summarizes currently available and emerging long-acting risperidone formulations, including efficacy and safety data, and practical considerations aimed to help prescribers distinguish one formulation from another.

EXPERT OPINION

There is an expanding number of currently available LAI antipsychotic medications giving patients and providers an opportunity to personalize and individualize care. Rates of adherence to treatment in patients with schizophrenia and bipolar disorder are low, and individualizing care can help improve this. The risperidone LAI treatment landscape includes five options approved by the U.S. Food and Drug Administration, with others under clinical development. These options differ in regard to mode of administration, approved indications, available dose strengths, injection intervals, needle size, injection volume, storage, and other variables. Prescribers should be familiar with these differing options to help patients find the best fit for their individual needs.

What Remains to Be Discovered in Schizophrenia Therapeutics: Contributions by Advancing the Molecular Mechanisms of Drugs for Psychosis and Schizophrenia

Schizophrenia is a frequently debilitating and complex mental disorder affecting approximately 1% of the global population, characterized by symptoms such as hallucinations, delusions, disorganized thoughts and behaviors, cognitive dysfunction, and negative symptoms. Traditional treatment has centered on postsynaptic dopamine antagonists, commonly known as antipsychotic drugs, which aim to alleviate symptoms and improve functioning and the quality of life. Despite the availability of these medications, significant challenges remain in schizophrenia therapeutics, including incomplete symptom relief, treatment resistance, and medication side effects. This opinion article explores advancements in schizophrenia treatment, emphasizing molecular mechanisms, novel drug targets, and innovative delivery methods. One promising approach is novel strategies that target neural networks and circuits rather than single neurotransmitters, acknowledging the complexity of brain region interconnections involved in schizophrenia. Another promising approach is the development of biased agonists, which selectively activate specific signaling pathways downstream of receptors, offering potential for more precise pharmacological interventions with fewer side effects. The concept of molecular polypharmacy, where a single drug targets multiple molecular pathways, is exemplified by KarXT, a novel drug combining xanomeline and trospium to address both psychosis and cognitive dysfunction. This approach represents a comprehensive strategy for schizophrenia treatment, potentially improving outcomes for patients. In conclusion, advancing the molecular understanding of schizophrenia and exploring innovative therapeutic strategies hold promise for addressing the unmet needs in schizophrenia treatment, aiming for more effective and tailored interventions. Future research should focus on these novel approaches to achieve better clinical outcomes and improve the functional level and quality of life for individuals with schizophrenia.

Decreased free D-aspartate levels in the blood serum of patients with schizophrenia

Introduction

Schizophrenia (SCZ) and autism spectrum disorder (ASD) are neurodevelopmental diseases characterized by different psychopathological manifestations and divergent clinical trajectories. Various alterations at glutamatergic synapses have been reported in both disorders, including abnormal NMDA and metabotropic receptor signaling.

Methods

We conducted a bicentric study to assess the blood serum levels of NMDA receptors-related glutamatergic amino acids and their precursors, including L-glutamate, L-glutamine, D-aspartate, L-aspartate, L-asparagine, D-serine, L-serine and glycine, in ASD, SCZ patients and their respective control subjects. Specifically, the SCZ patients were subdivided into treatment-resistant and non-treatment-resistant SCZ patients, based on their responsivity to conventional antipsychotics.

Results

D-serine and D-aspartate serum reductions were found in SCZ patients compared to controls. Conversely, no significant differences between cases and controls were found in amino acid concentrations in the two ASD cohorts analyzed.

Discussion

This result further encourages future research to evaluate the predictive role of selected D-amino acids as peripheral markers for SCZ pathophysiology and diagnosis.

Electrophysiological Markers Predicting Antipsychotic Treatment Response in Patients with Schizophrenia: A Retrospective Study

Purpose

This study aimed to provide an objective means of predicting treatment responses in patients with schizophrenia using quantitative electroencephalography (qEEG) as an electrophysiological indicator. We obtained qEEG recordings from patients with schizophrenia and explored them for patterns indicative of treatment responsiveness.

Patients and Methods

The study included 68 patients had been diagnosed with schizophrenia spectrum disorder. After retrospectively gathering demographic information, clinical data such as qEEG, Positive and Negative Syndrome Scale (PANSS), a multiple regression analysis was performed. This analysis employed baseline qEEG findings as independent variables and PANSS score changes as dependent variables to discern causal relationships.

Results

The mean age of the participants was 38.4 years(SD =13.73). The mean PANSS score on admission was 92.97, decreasing to 67.41 at discharge. Multiple regression analysis revealed that delta waves in T4 (β=0.346, t=3.165, p=0.002), and high-beta waves in Fp2 (β=0.231, t=2.361, p=0.021) were associated with PANSS changes in absolute power. In addition, the delta waves of O2 (β=0.250, t=3.288, p=0.002); beta waves of T3 (β=-1.463, t=-5.423, p<0.001) and O2 (β=0.551, t=3.366, p=0.001); high beta waves of Fp1 (β=0.307, t=4.026, p<0.001), T3 (β=0.855, t=4.414, p<0.001) and T6 (β=-0.838, t=-4.559, p<0.001) of absolute power using the Z-score were also related to PANSS changes. Pearson's correlation analysis showed that only delta waves at Cz (r= 0.246, p=0.043) in absolute power correlated with changes in the PANSS.

Conclusion

We found that certain qEEG wave patterns in patients with schizophrenia prior to antipsychotic treatment were linked to PANSS changes before and after treatment. Delta waves and beta waves, primarily in the frontal and temporal regions, were found to be significantly associated with changes in PANSS scores. In the future, the qEEG indicators identified in this study could serve as electrophysiological markers for predicting antipsychotic treatment responses in patients with schizophrenia.

Predicting Clinical Improvement in Early Psychosis Using Circuit-Based Resting-State Functional Magnetic Resonance Imaging

BACKGROUND AND HYPOTHESIS

Identifying biomarkers that predict treatment response in early psychosis (EP) is a priority for psychiatry research. Previous work suggests that resting-state connectivity biomarkers may have promise as predictive measures, although prior results vary considerably in direction and magnitude. Here, we evaluated the relationship between intrinsic functional connectivity of the attention, default mode, and salience resting-state networks and 12-month clinical improvement in EP.

STUDY DESIGN

Fifty-eight individuals with EP (less than 2 years from illness onset, 35 males, average age 20 years) had baseline and follow-up clinical data and were included in the final sample. Of these, 30 EPs showed greater than 20% improvement in Brief Psychiatric Rating Scale (BPRS) total score at follow-up and were classified as "Improvers."

STUDY RESULTS

The overall logistic regression predicting Improver status was significant (χ2 = 23.66, Nagelkerke's R2 = 0.45, P < .001, with 85% concordance). Significant individual predictors of Improver status included higher default mode within-network connectivity, higher attention-default mode between-network connectivity, and higher attention-salience between-network connectivity. Including baseline BPRS as a predictor increased model significance and concordance to 92%, and the model was not significantly influenced by the dose of antipsychotic medication (chlorpromazine equivalents). Linear regression models predicting percent change in BPRS were also significant.

CONCLUSIONS

Overall, these results suggest that resting-state functional magnetic resonance imaging connectivity may serve as a useful biomarker of clinical outcomes in recent-onset psychosis.

Semi-physiological Pharmacokinetic Model of Clozapine and Norclozapine in Healthy, Non-smoking Volunteers: The Impact of Race and Genetics

BACKGROUND AND OBJECTIVES: Clozapine is the medication of choice for treatment-resistant schizophrenia. However, it has a complex metabolism and unexplained interindividual variability. The current work aims to develop a pharmacokinetic model of clozapine and norclozapine in non-smokers and assess the impact of demographic and genetic predictors.

METHODS

Healthy volunteers were recruited in a population pharmacokinetic study. Blood samples were collected at 30 min and 1, 2, 3, 5 and 8 h following a single flat dose of clozapine (12.5 mg). The clozapine and norclozapine concentrations were measured via high-performance liquid chromatography-ultraviolet method. A semi-physiological pharmacokinetic model of clozapine and norclozapine was developed using nonlinear mixed-effects modeling. Clinical and genetic predictors were evaluated, including CYP1A2 (rs762551) and ABCB1 (rs2032582), using restriction fragment length polymorphism.

RESULTS

A total of 270 samples were collected from 33 participants. The data were best described using a two-compartment model for clozapine and a two-compartment model for norclozapine with first-order absorption and elimination and pre-systemic metabolism. The estimated (relative standard error) clearance of clozapine and norclozapine were 27 L h-1 (31.5 %) and 19.6 L h-1 (30%), respectively. Clozapine clearance was lower in sub-Saharan Africans (n = 4) and higher in Caucasians (n = 9) than Asians (n = 20). Participants with CYP1A2 (rs762551) (n = 18) and ABCB1 (rs2032582) (n = 12) mutant alleles had lower clozapine clearance in the univariate analysis.

CONCLUSIONS

This is the first study to develop a semi-physiological pharmacokinetic model of clozapine and norclozapine accounting for the pre-systemic metabolism. Asians required lower doses of clozapine as compared with Caucasians, while clozapine pharmacokinetics in sub-Saharan Africans should be further investigated in larger trials.

Overcoming the barriers to identifying and managing treatment-resistant schizophrenia and to improving access to clozapine: A narrative review and recommendation for clinical practice

Clozapine is the only approved antipsychotic for treatment-resistant schizophrenia (TRS). Although a large body of evidence supports its efficacy and favorable risk-benefit ratio in individuals who have failed two or more antipsychotics, clozapine remains underused. However, variations in clozapine utilization across geographic and clinical settings suggest that it could be possible to improve its use. In this narrative review and expert opinion, we summarized information available in the literature on the mechanisms of action, effectiveness, and potential adverse events of clozapine. We identified barriers leading to discouragement in clozapine prescription internationally, and we proposed practical solutions to overcome each barrier. One of the main obstacles identified to the use of clozapine is the lack of appropriate training for physicians: we highlighted the need to develop specific professional programs to train clinicians, both practicing and in residency, on the relevance and efficacy of clozapine in TRS treatment, initiation, maintenance, and management of potential adverse events. This approach would facilitate physicians to identify eligible patients and offer clozapine as a treatment option in the early stage of the disease. We also noted that increasing awareness of the benefits of clozapine among healthcare professionals, people with TRS, and their caregivers can help promote the use of clozapine. Educational material, such as leaflets or videos, could be developed and distributed to achieve this goal. The information provided in this article may be useful to improve disease burden and support healthcare professionals, patients, and caregivers navigating the complex pathways to TRS management.

Blood Cell Count Ratios at Baseline are Associated with Initial Clinical Response to Clozapine in Treatment-Resistant, Clozapine-Naïve, Schizophrenia-Spectrum Disorder

BACKGROUND

Clozapine is the recommended treatment for managing treatment-resistant schizophrenia (TRS), and immunological mechanisms may be involved in its unique antipsychotic efficacy. This study investigated whether baseline immune abnormalities measured with blood cell count ratios can predict the clinical response after initiating treatment with clozapine in patients with clozapine naïve TRS.

METHODS

A longitudinal design was developed, involving 32 patients diagnosed with treatment-resistant, clozapine-naïve schizophrenia-spectrum disorder. Patients were evaluated at baseline before clozapine starting and 8 weeks of follow-up. Psychopathological status and immune abnormalities (blood cell count ratios: neutrophil-lymphocyte ratio [NLR], monocyte-lymphocyte ratio [MLR], platelet-lymphocyte ratio [PLR] and basophil-lymphocyte ratio [BLR]) were evaluated in each visit.

RESULTS

Baseline NLR (b=- 0.364; p=0.041) and MLR (b =- 0.400; p=0.023) predicted the change in positive symptoms over the 8-week period. Patients who exhibited a clinical response showed higher baseline NLR (2.38±0.96 vs. 1.75±0.83; p=0.040) and MLR (0.21±0.06 vs. 0.17±0.02; p=0.044) compared to non-responders. In the ROC analysis, the threshold points to distinguish between responders and non-responders were approximately 1.62 for NLR and 0.144 for MLR, yielding AUC values of 0.714 and 0.712, respectively. No statistically significant differences were observed in the blood cell count ratios from baseline to the 8-week follow-up.

CONCLUSION

Our study emphasizes the potential clinical significance of baseline NLR and MLR levels as predictors of initial clozapine treatment response in patients with TRS. Future studies with larger sample sizes and longer follow-up periods should replicate our findings.

Association of symptom severity and cerebrospinal fluid alterations in recent onset psychosis in schizophrenia-spectrum disorders - An individual patient data meta-analysis

Neuroinflammation and blood-cerebrospinal fluid barrier (BCB) disruption could be key elements in schizophrenia-spectrum disorderś(SSDs) etiology and symptom modulation. We present the largest two-stage individual patient data (IPD) meta-analysis, investigating the association of BCB disruption and cerebrospinal fluid (CSF) alterations with symptom severity in first-episode psychosis (FEP) and recent onset psychotic disorder (ROP) individuals, with a focus on sex-related differences. Data was collected from PubMed and EMBASE databases. FEP, ROP and high-risk syndromes for psychosis IPD were included if routine basic CSF-diagnostics were reported. Risk of bias of the included studies was evaluated. Random-effects meta-analyses and mixed-effects linear regression models were employed to assess the impact of BCB alterations on symptom severity. Published (6 studies) and unpublished IPD from n = 531 individuals was included in the analyses. CSF was altered in 38.8 % of individuals. No significant differences in symptom severity were found between individuals with and without CSF alterations (SMD = -0.17, 95 %CI -0.55-0.22, p = 0.341). However, males with elevated CSF/serum albumin ratios or any CSF alteration had significantly higher positive symptom scores than those without alterations (SMD = 0.34, 95 %CI 0.05-0.64, p = 0.037 and SMD = 0.29, 95 %CI 0.17-0.41p = 0.005, respectively). Mixed-effects and simple regression models showed no association (p > 0.1) between CSF parameters and symptomatic outcomes. No interaction between sex and CSF parameters was found (p > 0.1). BCB disruption appears highly prevalent in early psychosis and could be involved in positive symptomś severity in males, indicating potential difficult-to-treat states. This work highlights the need for considering BCB breakdownand sex-related differences in SSDs clinical trials and treatment strategies.

Contribution of copy number variants on antipsychotic treatment response in Han Chinese patients with schizophrenia

BACKGROUND

Response to antipsychotic drugs (APD) varies greatly among individuals and is affected by genetic factors. This study aims to demonstrate genome-wide associations between copy number variants (CNVs) and response to APD in patients with schizophrenia.

METHODS

A total of 3030 patients of Han Chinese ethnicity randomly received APD (aripiprazole, olanzapine, quetiapine, risperidone, ziprasidone, haloperidol and perphenazine) treatment for six weeks. This study is a secondary data analysis. Percentage change on the Positive and Negative Syndrome Scale (PANSS) reduction was used to assess APD efficacy, and more than 50% change was considered as APD response. Associations between CNV burden, gene set, CNV loci and CNV break-point and APD efficacy were analysed.

FINDINGS

Higher CNV losses burden decreased the odds of 6-week APD response (OR = 0.66 [0.44, 0.98]). CNV losses in synaptic pathway involved in neurotransmitters were associated with 2-week PANSS reduction rate. CNV involved in sialylation (1p31.1 losses) and cellular metabolism (19q13.32 gains) associated with 6-week PANSS reduction rate at genome-wide significant level. Additional 36 CNVs associated with PANSS factors improvement. The OR of protective CNVs for 6-week APD response was 3.10 (95% CI: 1.33-7.19) and risk CNVs was 8.47 (95% CI: 1.92-37.43). CNV interacted with genetic risk score on APD efficacy (Beta = -1.53, SE = 0.66, P = 0.021). The area under curve to differ 6-week APD response attained 80.45% (95% CI: 78.07%-82.82%).

INTERPRETATION

Copy number variants contributed to poor APD efficacy and synaptic pathway involved in neurotransmitter was highlighted.

FUNDING

National Natural Science Foundation of China, National Key R&D Program of China, China Postdoctoral Science Foundation.

MicroRNAs as potential biomarkers for diagnosis of schizophrenia and influence of antipsychotic treatment

ABSTRACT

Characterized by positive symptoms (such as changes in behavior or thoughts, including delusions and hallucinations), negative symptoms (such as apathy, anhedonia, and social withdrawal), and cognitive impairments, schizophrenia is a chronic, severe, and disabling mental disorder with late adolescence or early adulthood onset. Antipsychotics are the most commonly used drugs to treat schizophrenia, but those currently in use do not fully reverse all three types of symptoms characterizing this condition. Schizophrenia is frequently misdiagnosed, resulting in a delay of or inappropriate treatment. Abnormal expression of microRNAs is connected to brain development and disease and could provide novel biomarkers for the diagnosis and prognosis of schizophrenia. The recent studies reviewed included microRNA profiling in blood- and urine-based materials and nervous tissue materials. From the studies that had validated the preliminary findings, potential candidate biomarkers for schizophrenia in adults could be miR-22-3p, -30e-5p, -92a-3p, -148b-5p, -181a-3p, -181a-5p, -181b-5p, -199b-5p, -137 in whole blood, and miR-130b, -193a-3p in blood plasma. Antipsychotic treatment of schizophrenia patients was found to modulate the expression of certain microRNAs including miR-130b, -193a-3p, -132, -195, -30e, -432 in blood plasma. Further studies are warranted with adolescents and young adults having schizophrenia and consideration should be given to using animal models of the disorder to investigate the effect of suppressing or overexpressing specific microRNAs.

Polypharmacy to Clozapine Monotherapy in Treatment-Resistant Schizophrenia: A Case Report and Review of the Literature

This case report discusses a 25-year-old Middle Eastern female with a 14-year history of schizophrenia, managed as an inpatient for nearly eight years. Initially referred to a psychiatrist at age 12, with one-year-long concerns about preoccupation with the idea of having a serious illness, depressed mood, decreased appetite, social withdrawal, and aggression, she underwent multiple admissions, various medication combinations, and electroconvulsive therapy but remained resistant to treatment until clozapine monotherapy was initiated in 2023. After starting clozapine, improvements were noted in speech, communication, and eye contact, though negative symptoms and bouts of aggression persisted. This case highlights the efficacy of clozapine monotherapy in managing treatment-resistant schizophrenia after years of ineffective polypharmacy treatment. The importance of clozapine in treating treatment-resistant schizophrenia cannot be understated. Despite its efficacy, clozapine is often underutilised globally due to concerns about adverse effects and the need for blood monitoring, leading to the overuse of antipsychotic polypharmacy. This polypharmacy is associated with higher adverse event rates, increased costs, and uncertain long-term safety. This case report demonstrates the successful management of treatment-resistant schizophrenia with clozapine monotherapy. The patient's significant improvement supports the need to prioritise clozapine, highlighting its benefits over polypharmacy and advocating for its broader use to enhance patient outcomes.

Psychological and psychosocial interventions for treatment-resistant schizophrenia: a systematic review and network meta-analysis

BACKGROUND

Many patients with schizophrenia have symptoms that do not respond to antipsychotics. This condition is called treatment-resistant schizophrenia and has not received specific attention as opposed to general schizophrenia. Psychological and psychosocial interventions as an add-on treatment to pharmacotherapy could be useful, but their role and comparative efficacy to each other and to standard care in this population are not known. We investigated the efficacy, acceptability, and tolerability of psychological and psychosocial interventions for patients with treatment-resistant schizophrenia.

METHODS

In this systematic review and network meta-analysis (NMA), we searched for published and unpublished randomised controlled trials (RCTs) through a systematic database search in BIOSIS, CINAHL, Embase, LILACS, MEDLINE, PsychInfo, ClinicalTrials.gov, and the WHO International Clinical Trials Registry Platform for articles published from inception up to Jan 31, 2020. We also searched the Cochrane Schizophrenia Group registry for studies published from inception up to March 31, 2022, and PubMed and Cochrane CENTRAL for studies published from inception up to July 31, 2023. We included RCTs that included patients with treatment-resistant schizophrenia. The primary outcome was overall symptoms. We did random-effects pairwise meta-analyses and NMAs to calculate standardised mean differences (SMDs) or risk ratios with 95% CIs. No people with lived experience were involved throughout the research process. The study protocol was registered in PROSPERO, CRD42022358696.

FINDINGS

We identified 30 326 records, excluding 24 526 by title and abstract screening. 5762 full-text articles were assessed for eligibility, of which 5540 were excluded for not meeting the eligibility criteria, and 222 reports corresponding to 60 studies were included in the qualitative synthesis. Of these, 52 RCTs with 5034 participants (1654 [33·2%] females and 3325 [66·8%] males with sex indicated) comparing 20 psychological and psychosocial interventions provided data for the NMA. Mean age of participants was 38·05 years (range 23·10-48·50). We aimed to collect ethnicity data, but they were scarcely reported. According to the quality of evidence, cognitive behavioural therapy for psychosis (CBTp; SMD -0·22, 95% CI -0·35 to -0·09, 35 trials), virtual reality intervention (SMD -0·41, -0·79 to -0·02, four trials), integrated intervention (SMD -0·70, -1·18 to -0·22, three trials), and music therapy (SMD -1·27, -1·83 to -0·70, one study) were more efficacious than standard care in reducing overall symptoms. No indication of publication bias was identified.

INTERPRETATION

We provide robust findings that CBTp can reduce the overall symptoms of patients with treatment-resistant schizophrenia, and therefore clinicians can prioritise this intervention in their clinical practice. Other psychological and psychosocial interventions showed promising results but need further investigation.

FUNDING

DAAD-ASFE.

Elevated intrinsic cortical curvature in treatment-resistant schizophrenia: Evidence of structural deformation in functional connectivity areas and comparison with alternate indices of structure

BACKGROUND

Research suggests structural and connectivity abnormalities in patients with treatment-resistant schizophrenia (TRS) compared to first-line responders and healthy-controls. However, measures of these abnormalities are often influenced by external factors like nicotine and antipsychotics, limiting their clinical utility. Intrinsic-cortical-curvature (ICC) presents a millimetre-scale measure of brain gyrification, highly sensitive to schizophrenia differences, and associated with TRS-like traits in early stages of the disorder. Despite this evidence, ICC in TRS remains unexplored. This study investigates ICC as a marker for treatment resistance in TRS, alongside structural indices for comparison.

METHODS

We assessed ICC in anterior cingulate, dorsolateral prefrontal, temporal, and parietal cortices of 38 first-line responders, 30 clozapine-resistant TRS, 37 clozapine-responsive TRS, and 52 healthy-controls. For comparative purposes, Fold and Curvature indices were also analyzed.

RESULTS

Adjusting for age, sex, nicotine-use, and chlorpromazine equivalence, principal findings indicate ICC elevations in the left hemisphere dorsolateral prefrontal (p < 0.001, η2partial = 0.142) and temporal cortices (LH p = 0.007, η2partial = 0.060; RH p = 0.011, η2partial = 0.076) of both TRS groups, and left anterior cingulate cortex of clozapine-resistant TRS (p = 0.026, η2partial = 0.065), compared to healthy-controls. Elevations that correlated with reduced cognition (p = 0.001) and negative symptomology (p < 0.034) in clozapine-resistant TRS. Fold and Curvature indices only detected group differences in the right parietal cortex, showing interactions with age, sex, and nicotine use. ICC showed interactions with age.

CONCLUSION

ICC elevations were found among patients with TRS, and correlated with symptom severity. ICCs relative independence from sex, nicotine-use, and antipsychotics, may support ICC's potential as a viable marker for TRS, though age interactions should be considered.