Effect of second-generation antipsychotics on cognition: current issues and future challenges

Drug-Induced Cognitive Impairment

Drug-induced cognitive impairment (DICI) is a well-established, yet under-recognised, complication of many types of pharmacological treatment. While there is a large body of scientific literature on DICI, most papers are about drug-induced dementia in the elderly and one specific drug class. However, DICI also comprises subclinical symptoms, domain-specific forms of cognitive impairment as well as mild cognitive impairment (MCI), and delirium. Even mild forms of DICI, if not recognised as such, can have deleterious and life-long consequences. In addition, DICI also occurs in younger adults and in children, and has been reported with many different drug classes. The aim of this review is to raise awareness of DICI by providing an overview on the type(s) and symptoms of observed DICI and the suspected underlying mechanism(s) for various drug classes: antiseizure medications, antidepressants, antiparkinsonian drugs, antipsychotics, lithium, benzodiazepines/Z-drugs, opioids, first-generation antihistamines, drugs for urinary incontinence, proton pump inhibitors, glucocorticoids, NSAIDs, statins, antihypertensives, and chemotherapeutic agents.

Association between white blood cell counts and the efficacy on cognitive function after rTMS intervention in schizophrenia

rTMS has shown some effect in improving cognitive functions in patients with schizophrenia. However, these findings were controversial, and specific mechanisms of action and optimal therapeutic parameters still require further investigation. This study aimed to examine predictive biomarkers of the efficacy of rTMS in cognitive improvement in schizophrenia. A secondary analysis of a previous randomized, controlled trial was performed. Fifty-six patients were allocated to the active rTMS and 28 to the sham group. Patients received 6 weeks of treatment and were followed up for 18 weeks. Cognition was assessed and blood biomarkers were measured in all patients. In patients with schizophrenia, there was a significant interaction between time and group on immediate memory. Furthermore, this study found that after controlling for confounders, patients with higher baseline white blood cell (WBC) counts showed less improvement in immediate memory after rTMS than patients with lower WBC counts. Linear regression analysis showed that WBC counts were associated with immediate memory improvement after rTMS treatment. Our results reveal that WBC counts at baseline correlated with the response to rTMS in patients with schizophrenia. Patients with higher baseline WBC counts improved less after rTMS intervention than those with lower WBC counts.

Deviant sound frequency and time stimuli in auditory oddball tasks reveal persistent aberrant brain activity in patients with psychosis and symptomatic remission

The detection of rare or deviant stimuli shares common brain circuits involved in temporal processing and salience, critical for cognitive control. Disruption in these processes may contribute to the mechanisms of the disease and explain cognitive deficits observed in psychosis and related disorders. We designed a neuroimaging study, using oddball task-based functional sequences (fMRI) and diffusion tensor imaging (DTI), comparing healthy controls (HC, n = 14, 7 females) and patients with stable psychosis (PSY, n = 20, 10 females). The PSY individuals had schizophrenia or bipolar disorder diagnosis (ICD-10), meeting symptom remission criteria in the last 6 months. Two variants of the auditory oddball paradigm were employed, focusing on sound frequency (SF) and time discrimination (TD) tasks, adapted for fMRI. We used a general linear model to analyze fMRI data and a random effects model for group analysis, complemented by an exploratory statistical agnostic mapping analysis. DTI data were processed using FSL (FMRIB Software Library) and TBSS (Tract Based Spatial Statistics). Distinct activation patterns between groups were observed, with increased brain activity in PSY in TD and SF oddball tasks. In response to increased task difficulty, HC predominantly activated cerebellar regions, whereas PSY relied more on frontal regions. Reduced fractional anisotropy in PSY correlated with lower performance scores in the MATRICS (Measurement and Treatment Research to Improve Cognition in Schizophrenia) Consensus Cognitive Battery (MCCB). The study underscores aberrant brain activity and white matter deficits in stable psychosis patients, highlighting distinct responses to cognitive challenges compared to HC. These findings may support the hypothesis of cognitive dysmetria as a potential underlying mechanism in psychosis and highlight future therapeutic strategies, including non-invasive brain stimulation techniques.

Biomarkers of cognitive and memory decline in psychotropic drug users

Psychotropic drugs are vital in psychiatry, aiding in the management of mental health disorders. Their use requires an understanding of their pharmacological properties, therapeutic applications, and potential side effects. Ongoing research aims to improve their efficacy and safety. Biomarkers play a crucial role in understanding and predicting memory decline in psychotropic drug users. A comprehensive understanding of biomarkers, including neuroimaging, biochemical, genetic, and cognitive assessments, is essential for developing targeted interventions and preventive strategies. In this narrative review, we performed a comprehensive search on PubMed and Google using review-specific terms. Clinicians should use a multifaceted approach, including neurotransmitter analysis, neurotrophic factors, miRNA profiling, and cognitive tasks for early intervention and personalized treatment. Anxiolytics' mechanisms involve various neurotransmitter systems and emerging targets. Research on biomarkers for memory decline in anxiolytic users can lead to early detection and intervention, enhancing clinical practices and aligning with precision medicine. Mood stabilizer users can benefit from early detection of memory decline through RNA, neurophysiological, and inflammatory biomarkers, promoting timely interventions. Performance-enhancing drugs may boost athletic performance in the short term, but their long-term health risks and ethical issues make their use problematic. Long-term use of psychotropic performance enhancers in athletes shows changes in biomarkers of cognitive decline, necessitating ongoing monitoring and intervention strategies. Understanding these genetic influences on memory decline helps pave the way for personalized approaches to prevent or mitigate cognitive deterioration, emphasizing the importance of genetic screening and early interventions based on an individual's genetic profile. Future research should focus on refining these biomarkers and protective measures against cognitive deterioration. Overall, a comprehensive understanding of biomarkers in psychotropic drug users is essential for developing targeted interventions and preventive strategies.

Effectiveness of a social cognition remediation intervention for patients with schizophrenia: a randomized-controlled study

This randomized-controlled study evaluates the effectiveness of a newly developed social cognition rehabilitation intervention, the modified Social Cognition Individualized Activity Lab (mSoCIAL), in improving social cognition and clinical and functional outcomes of persons with schizophrenia recruited in two Italian sites: University of Campania "Luigi Vanvitelli" in Naples and ASST Fatebenefratelli-Sacco in Milan. mSoCIAL consists of a social cognitive training module focusing on different domains of social cognition and of a narrative enhancement module. We assessed changes in social cognition, clinical characteristics and functional variables in patients with schizophrenia who participated in 10 weekly sessions of mSoCIAL or received treatment as usual (TAU). A paired-sample t test and a repeated-measures MANOVA were used to investigate respectively within and between-group differences. Twenty people with schizophrenia were blindly assigned to mSoCIAL and 20 to TAU. After 10 weeks, mSoCIAL significantly improved disorganization, emotion recognition, functional capacity and real-life functioning. As compared to TAU, the mSoCIAL group showed a significant improvement in minimal and enriched social inference domain of theory of mind, and in key domains of real-life functioning (interpersonal relationships, everyday life skills, and work skills). mSoCIAL improved social cognition and real-life functioning of people with schizophrenia. These results highlight the importance of social cognition deficit treatment in schizophrenia and the necessity for these interventions to be multifaced and personalized. Such an approach ensures that improvements in social cognition translate into enhanced functional outcomes.Trial registration NCT05130853, registered on 24 November 2021.

Knowledge domain and trends in treatment-resistant schizophrenia (TRS) research based on CiteSpace bibliometrics analysis

Background

Although the number of studies on treatment-resistant schizophrenia (TRS) has been increasing, the global research hotspots and future research trends have not yet been established.

Objective

This study identify the hotspots of TRS research and predict future research trends using a bibliometric analysis.

Methods

The Web of Science Core Collection was searched using the keyword "TRS", econometric and co-occurrence analyses were conducted using CiteSpace and VOSviewer software, and the results were visualised. PRISMA reporting guidelines were used for this study.

Results

In total, 912 publications were included in the analysis. The number of publications on TRS has shown an increasing trend over the past 20 years. The United States and University of London were the countries and institutions with the highest total number of publications, respectively. Schizophrenia Research was the journal with the highest number of articles. American Journal of Psychiatry was the most cited journal. Based on the results of this analysis, cognitive impairment, clozapine-resistant schizophrenia, early-onset schizophrenia, and early recognition of TRS will be hotspots for future research in this field.

Conclusion

There has been an upward trend in the number of publications on TRS each year. However, issues such as how to use antipsychotics more efficiently to treat TRS and how to predict the emergence of TRS as early as possible are still in urgent need of research and are current challenges for clinicians. The results of this study not only predict and analyse future research hotspots but also help researchers identify appropriate research directions and partners.

Human stem cell-based models to study synaptic dysfunction and cognition in schizophrenia: A narrative review

Cognitive impairment is the strongest predictor of functional outcomes in schizophrenia and is hypothesized to result from synaptic dysfunction. However, targeting synaptic plasticity and cognitive deficits in patients remains a significant clinical challenge. A comprehensive understanding of synaptic plasticity and the molecular basis of learning and memory in a disease context can provide specific targets for the development of novel therapeutics targeting cognitive impairments in schizophrenia. Here, we describe the role of synaptic plasticity in cognition, summarize evidence for synaptic dysfunction in schizophrenia and demonstrate the use of patient derived induced-pluripotent stem cells for studying synaptic plasticity in vitro. Lastly, we discuss current advances and future technologies for bridging basic science research of synaptic dysfunction with clinical and translational research that can be used to predict treatment response and develop novel therapeutics.

The potential of muscarinic M1 and M4 receptor activators for the treatment of cognitive impairment associated with schizophrenia

Cognitive impairment is a core symptom of schizophrenia and a major determinant of poor long-term functional outcomes. Despite considerable efforts, we do not yet have any approved pharmacological treatments for cognitive impairment associated with schizophrenia (CIAS). A combination of advances in pre-clinical research and recent clinical trial findings have led to a resurgence of interest in the cognition-enhancing potential of novel muscarinic acetylcholine receptor (mAChR) agonists in schizophrenia. This article provides an overview of the scientific rationale for targeting M1 and M4 mAChRs. We describe the evolution of neuroscience research on these receptors since early drug discovery efforts focused on the mAChR agonist xanomeline. This work has revealed that M1 and M4 mAChRs are highly expressed in brain regions that are implicated in cognition. The functional significance of M1 and M4 mAChRs has been extensively characterized in animal models via use of selective receptor subtype compounds through neuronal and non-neuronal mechanisms. Recent clinical trials of a dual M1/M4 mAChR agonist show promising, replicable evidence of potential pro-cognitive effects in schizophrenia, with several other mAChR agonists in clinical development.

Adjunctive methylphenidate extended release in patients with schizophrenia: Protocol of a single-centre fixed dose cross-over open-label trial to improve functional and cognitive outcomes

Background

Cognitive symptoms, among the core symptoms of schizophrenia, are associated with poor functional outcome and burden of illness. To date, there is no effective pharmacological treatment for these symptom clusters. Augmentation with psychostimulants has been proposed as a potential treatment option.

Objectives

The present study aims to assess off-label use of adjunctive methylphenidate extended release (ER) in patients with schizophrenia who are stable on antipsychotic medications, and to assess its efficacy on functioning and cognitive outcome.

Methods

This is a single centre study at the Royal Ottawa Mental Health Centre. An open-label fixed dose controlled cross-over trial is planned. Eligible participants will be randomized into one of two arms of the study: 1) four weeks of add-on methylphenidate ER 36 mg, or 2) four weeks of treatment as usual. At 4 weeks, participants will switch arms. The duration of the study includes 8 weeks of treatment and a follow-up visit at 12 weeks. Primary outcome measures include tablet-based tests of functioning and cognition (VRFCAT and BAC) and will be administered at baseline and every 4 weeks. We are aiming to recruit a total of 24 participants.

Expected outcomes

The proposed project intends to assess a potential treatment option for cognitive deficits of schizophrenia, for which there are no recommendations by current treatment guidelines. The novelty and significance of the current study is that it investigates this intervention and assess applicability of it in a "real world setting" in a tertiary care hospital.

Enhanced Recognition Memory through Dual Modulation of Brain Carbonic Anhydrases and Cholinesterases

This study introduces a novel multitargeting strategy that combines carbonic anhydrase (CA) activators and cholinesterase (ChE) inhibitors to enhance cognitive functions. A series of tacrine-based derivatives with amine/amino acid moieties were synthesized and evaluated for their dual activity on brain CA isoforms and ChEs (AChE and BChE). Several derivatives, notably compounds 26, 30, 34, and 40, demonstrated potent CA activation, particularly of hCA II and VII, and strong ChE inhibition with subnanomolar to low nanomolar IC50 values. In vivo studies using a mouse model of social recognition memory showed that these derivatives significantly improved memory consolidation at doses 10-100 times lower than the reference compounds (either alone or in combination). Molecular modeling and ADMET predictions elucidated the compound binding modes and confirmed favorable pharmacokinetic and safety profiles. The findings suggest that dual modulation of CA and ChE activities is a promising strategy for treating cognitive deficits associated with neurodegenerative and psychiatric disorders.

The dynamic strategy shifting task: Optimisation of an operant task for assessing cognitive flexibility in rats

Introduction

Although schizophrenia is associated with a broad range of symptoms including hallucinations, delusions, and reduced motivation, measures of cognitive dysfunction, including cognitive flexibility and executive function, are the strongest predictors of functional outcomes. Antipsychotic medications are useful for reducing psychotic symptoms, but they are ineffective at improving cognitive deficits. Despite extensive investment by industry, the transition from preclinical to clinical trials has not been successful for developing precognitive medications for individuals with schizophrenia. Here, we describe the optimisation of a novel dynamic strategy shifting task (DSST) using standard operant chambers to investigate the optimal stimuli required to limit the extensive training times required in previous tasks.

Methods

We determined that optimal learning by male and female Sprague Dawley rats for the flexibility task incorporated dynamic strategy shifts between spatial rules, such as following a visual cue or responding at one location, and non-spatial rules, such as responding to a central visual or auditory cue. A minimum of 6 correct consecutive responses were required to make a within-session change in the behavioural strategies. As a proof of concept, we trained and tested 84 Sprague Dawley rats on the DSST, and then assessed their cognitive flexibility using a within-subject design after an acute dose of ketamine (0, 3, 10 mg/kg). Rats made fewer premature and more perseverant responses to initiate a trial following ketamine. The effects of ketamine on trials to criterion was dependent on the rule.

Results

Ketamine induced a significant improvement on the reversal of a non-spatial visual discrimination rule. There was no significant effect of ketamine on the spatial visual or response discrimination rules.

Discussion

The DSST is a novel assay for studying distinct forms of cognitive flexibility and offers a rapid and adaptable means of assessing the ability to shift between increasingly challenging rule conditions. The DSST has potential utility in advancing our understanding of cognitive processes and the underlying neurobiological mechanisms related to flexibility in neuropsychiatric and neurological conditions where executive dysfunctions occur.>.

Associations between antipsychotics exposure and dementia risk: A prospective cohort study of 415,100 participants

BACKGROUND

Antipsychotics (APs) are among the most widely prescribed medications, and have been shown to cause cognitive decline. But previous studies on their effects on dementia risk are controversial and scarce. We aimed to examine the relationships of APs exposure with the risk of dementia.

METHODS

Data were obtained from a prospective cohort of 415,100 UK Biobank (UKB) participants. We investigated the effects of APs exposure and their various classes on dementia risk by using multivariable Cox proportional hazard models and further the dose-response effects of oral APs.

RESULTS

After a mean follow-up of 8.64 years, 5235 (1.3 %) participants developed all-cause dementia (ACD), among whom 2313 (0.6 %) developed Alzheimer's disease (AD), and 1213 (0.3 %) developed vascular dementia (VaD). Exposure to any APs conferred increased risks of ACD (HR: 1.33, 95 % CI = 1.17-1.51, P < 0.001) and VaD (HR: 1.90, 95 % CI = 1.51-2.40, P < 0.001), but not AD (HR: 1.22, 95 % CI = 1.00-1.48, P = 0.051). Cumulative dose-response relationships of oral APs with the risks of ACD and VaD were observed (P for trend, P < 0.05).

LIMITATIONS

Our study is observational and does not show evidence of causality. Since there are relatively few cases of dementia in the UKB, APs exposure may be higher than estimated in our study.

CONCLUSIONS

APs exposure increased the risk of developing dementia. Dose-response relationships were found between oral APs and dementia risk. Efforts to raise awareness of doctors and patients about this potential drug-related risk are critical to reducing APs use.

Association between CNS-active drugs and risk of Alzheimer's and age-related neurodegenerative diseases

Objective

As neuropsychiatric conditions can increase the risk of age-related neurodegenerative diseases (NDDs), the impact of CNS-active drugs on the risk of developing Alzheimer's Disease (AD), non-AD dementia, Multiple Sclerosis (MS), Parkinson's Disease (PD) and Amyotrophic Lateral Sclerosis (ALS) was investigated.

Research design and methods

A retrospective cohort analysis of a medical claims dataset over a 10 year span was conducted in patients aged 60 years or older. Participants were propensity score matched for comorbidity severity and demographic parameters. Relative risk (RR) ratios and 95% confidence intervals (CI) were determined for age-related NDDs. Cumulative hazard ratios and treatment duration were determined to assess the association between CNS-active drugs and NDDs at different ages and treatment duration intervals.

Results

In 309,128 patients who met inclusion criteria, exposure to CNS-active drugs was associated with a decreased risk of AD (0.86% vs 1.73%, RR: 0.50; 95% CI: 0.47-0.53; p <.0001) and all NDDs (3.13% vs 5.76%, RR: 0.54; 95% CI: 0.53-0.56; p <.0001). Analysis of impact of drug class on risk of AD indicated that antidepressant, sedative, anticonvulsant, and stimulant medications were associated with significantly reduced risk of AD whereas atypical antipsychotics were associated with increased AD risk. The greatest risk reduction for AD and NDDs occurred in patients aged 70 years or older with a protective effect only in patients with long-term therapy (>3 years). Furthermore, responders to these therapeutics were characterized by diagnosed obesity and higher prescriptions of anti-inflammatory drugs and menopausal hormonal therapy, compared to patients with a diagnosis of AD (non-responders). Addition of a second CNS-active drug was associated with greater reduction in AD risk compared to monotherapy, with the combination of a Z-drug and an SNRI associated with greatest AD risk reduction.

Conclusion

Collectively, these findings indicate that CNS-active drugs were associated with reduced risk of developing AD and other age-related NDDs. The exception was atypical antipsychotics, which increased risk. Potential use of combination therapy with atypical antipsychotics could mitigate the risk conferred by these drugs. Evidence from these analyses advance precision prevention strategies to reduce the risk of age-related NDDs in persons with neuropsychiatric disorders.

The cognitive improvement in patients with schizophrenia following low-intensity repetitive transcranial magnetic stimulation could last for 6 months: A randomized controlled trial

Cognitive impairments are a core symptom of schizophrenia. Although low-intensity repetitive transcranial magnetic stimulation (rTMS) also has cognitive improving effect like the commonly used high-intensity rTMS, it has not been applied in schizophrenia yet. To fill this gap, inpatients with schizophrenia were randomized to receive 20 sessions of daily adjunctive active low-intensity rTMS in 4 weeks, or sham treatment. At baseline, 4 weeks, and 6 months, the Positive and Negative Syndrome Scale (PANSS) was used to assess psychotic symptom severity, while the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Stroop Color and Word Test (SCWT) were used to assess cognitive functions. Compared to the sixty-nine patients receiving sham treatment, those fifty-nine patients receiving active rTMS performed better in all cognitive domains at post-treatment with small to large effect sizes. This superiority of active rTMS over sham treatment remained significant at 6-month follow-up, with small to large effect sizes, except for visuospatial function and delayed memory. The reduction in PANSS scores were not correlated with cognitive improvements. Our findings provide evidence for using low-intensity rTMS to ameliorate cognitive impairments in schizophrenia. More research are needed to determine the optimal intensity for each domain of cognitive functions.

Associations of resilience, white matter topological organization, and cognitive functions in first-episode, drug-naïve schizophrenia patients: A moderated mediation analysis

BACKGROUND

Cognitive deficits are core symptoms of schizophrenia (SZ) and are associated with impaired resilience to stress. Different cognitive functions appeared to be interrelated, and the mechanism may involve neural alterations. The disrupted topological organization indicated abnormalities in the segregation and integration of brain networks that support various cognitive processes in SZ patients. Therefore, this study aimed to assess the direct and indirect effects of resilience on cognitive functions. We hypothesized that topological properties would moderate these associations.

METHODS

Forty-nine SZ patients and fifty-two healthy controls (HCs) were recruited in this study. The Connor-Davidson Resilience Scale and the MATRICS Consensus Cognitive Battery were used to examine resilience and cognitive functions, respectively, and a graph theory approach was used to assess white matter topological organization.

RESULTS

Compared to HCs, SZ patients showed lower levels of resilience and cognitive functions in multiple domains as well as abnormal global properties and nodal metrics. In addition, shorter characteristic path length was associated with a stronger indirect effect of resilience on working memory through processing speed in SZ patients.

CONCLUSION

Characteristic path length might moderate the mediating effects of processing speed in the relationship between resilience and working memory in schizophrenia patients.

Impact of Different Diagnostic Measures on Drug Class Association with Dementia Progression Risk: A Longitudinal Prospective Cohort Study

Background

The Clinical Dementia Rating Scale Sum of Boxes (CDRSOB) score is known to be highly indicative of cognitive-functional status and is regularly employed for clinical and research purposes.

Objective

Our aim is to determine whether CDRSOB is consistent with clinical diagnosis in evaluating drug class associations with risk of progression to mild cognitive impairment (MCI) and dementia.

Methods

We employed weighted Cox regression analysis on longitudinal NACC data, to identify drug classes associated with disease progression risk, using clinical diagnosis and CDRSOB as the outcome.

Results

Aspirin (antiplatelet/NSAID), angiotensin II inhibitors (antihypertensive), and Parkinson's disease medications were significantly associated with reduced risk of progression to MCI/dementia and Alzheimer's disease medications were associated with increased MCI-to-Dementia progression risk with both clinical diagnosis and CDRSOB as the outcome. However, certain drug classes/subcategories, like anxiolytics, antiadrenergics, calcium (Ca2+) channel blockers, and diuretics (antihypertensives) were associated with reduced risk of disease progression, and SSRIs (antidepressant) were associated with increased progression risk only with CDRSOB. Additionally, metformin (antidiabetic medication) was associated with reduced MCI-to-Dementia progression risk only with clinical diagnosis as the outcome.

Conclusions

Although the magnitude and direction of the effect were primarily similar for both diagnostic outcomes, we demonstrate that choice of diagnostic measure can influence the significance of risk/protection attributed to drug classes and consequently the conclusion of findings. A consensus must be reached within the research community with respect to the most accurate diagnostic outcome to identify risk and improve reproducibility.

Clinical insight among persons with schizophrenia spectrum disorders treated with amisulpride, aripiprazole or olanzapine: a semi-randomised trial

BACKGROUND

Antipsychotic treatment may improve clinical insight. However, previous studies have reported inconclusive findings on whether antipsychotics improve insight over and above the reduction in symptoms of psychosis. These studies assessed homogeneous samples in terms of stage of illness. Randomised studies investigating a mixed population of first- and multiepisode schizophrenia spectrum disorders might clarify this disagreement.

METHODS

Our data were derived from a pragmatic, rater-blinded, semi-randomised trial that compared the effectiveness of amisulpride, aripiprazole and olanzapine. A sample of 144 patients with first- or multiepisode schizophrenia spectrum disorders underwent eight assessments during a 1-year follow-up. Clinical insight was assessed by item General 12 from the Positive and Negative Syndrome Scale (PANSS). We analysed latent growth curve models to test if the medications had a direct effect on insight that was over and above the reduction in total psychosis symptoms. Furthermore, we investigated whether there were differences between the study drugs in terms of insight.

RESULTS

Based on allocation analysis, all three drugs were associated with a reduction in total psychosis symptoms in the initial phase (weeks 0-6). Amisulpride and olanzapine were associated with improved insight over and above what was related to the reduction in total psychosis symptoms in the long-term phase (weeks 6-52). However, these differential effects were lost when only including the participants that chose the first drug in the randomisation sequence. We found no differential effect on insight among those who were antipsychotic-naïve and those who were previously medicated with antipsychotics.

CONCLUSIONS

Our results suggest that antipsychotic treatment improves insight, but whether the effect on insight surpasses the effect of reduced total psychosis symptoms is more uncertain.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01446328, 05.10.2011.

Comparison of gut microbiome profile in patients with schizophrenia and healthy controls - A plausible non-invasive biomarker?

The human gut microbiome regulates brain function through the microbiome-gut-brain axis and is implicated in several neuropsychiatric disorders. However, the relationship between the gut microbiome and the pathogenesis of schizophrenia (SCZ) is poorly defined, and very few studies have examined the effect of antipsychotic treatment response. We aim to study the differences in the gut microbiota among drug-naïve (DN SCZ) and risperidone-treated SCZ patients (RISP SCZ), compared to healthy controls (HCs). We recruited a total of 60 participants, from the clinical services of a large neuropsychiatric hospital, which included DN SCZ, RISP SCZ and HCs (n = 20 each). Fecal samples were analyzed using 16s rRNA sequencing in this cross-sectional study. No significant differences were found in taxa richness (alpha diversity) but microbial composition differed between SCZ patients (both DN and RISP) and HCs (PERMANOVA, p = 0.02). Linear Discriminant Analysis Effect Size (LEfSe) and Random Forest model identified the top six genera, which significantly differed in abundance between the study groups. A specific genus-level microbial panel of Ruminococcus, UCG005, Clostridium_sensu_stricto_1 and Bifidobacterium could discriminate SCZ patients from HCs with an area under the curve (AUC) of 0.79, HCs vs DN SCZ (AUC: 0.68), HCs vs RISP SCZ (AUC: 0.93) and DN SCZ vs RISP SCZ (AUC: 0.87). Our study identified distinct microbial signatures that could aid in the differentiation of DN SCZ, RISP SCZ, and HCs. Our findings contribute to a better understanding of the role of the gut microbiome in SCZ pathophysiology and suggest potential targeted interventions.

Association between mitochondria-related genes and cognitive performance in the PsyCourse Study

BACKGROUND

Mitochondria generate energy through oxidative phosphorylation (OXPHOS). The function of key OXPHOS proteins can be altered by variation in mitochondria-related genes, which may increase the risk of mental illness. We investigated the association of mitochondria-related genes and their genetic risk burden with cognitive performance.

METHODS

We leveraged cross-sectional data from 1320 individuals with a severe psychiatric disorder and 466 neurotypical individuals from the PsyCourse Study. The cognitive tests analyzed were the Trail-Making Test, Verbal Digit Span Test, Digit-Symbol Test, and Multiple Choice Vocabulary Intelligence Test. Association analyses between the cognitive tests, and single-nucleotide polymorphisms (SNPs) mapped to mitochondria-related genes, and their polygenic risk score (PRS) for schizophrenia (SCZ) were performed with PLINK 1.9 and R program.

RESULTS

We found a significant association (FDR-adjusted p < 0.05) in the Cytochrome C Oxidase Assembly Factor 8 (COA8) gene locus of the OXPHOS pathway with the Verbal Digit Span (forward) test. Mitochondrial PRS was not significantly associated with any of the cognitive tests.

LIMITATIONS

Moderate statistical power due to relatively small sample size.

CONCLUSIONS

COA8 encodes a poorly characterized mitochondrial protein involved in apoptosis. Here, this gene was associated with the Verbal Digit Span (forward) test, which evaluates short-term memory. Our results warrant replication and may lead to better understanding of cognitive impairment in mental disorders.

The relationship between inflammatory biomarkers and cognitive dysfunction in patients with schizophrenia: A systematic review and meta-analysis

BACKGROUND

Schizophrenia is a complex psychiatric disorder that includes positive and negative symptoms but also debilitating cognitive deficits. Current pharmacological interventions do not target these deficits. Recent evidence suggests a connection between some inflammatory markers (including C-reactive protein) and cognitive impairment, but did not address other inflammatory markers. In the current study, we try to fill the gap by focusing on the association of Interleukin-6 (IL-6), IL-1β, Tumor Necrosis Factor-α and CRP with cognitive dysfunction.

METHODS

PUBMED and Web of Science databases were searched for all studies published until July 2022. A total of 25 studies were included in an analysis of the association between cognitive performance and variation in IL-6, IL-1β, TNF-α and CRP.

RESULTS

A total of 2398 patients were included in this study. Meta-analyses results showed a significant inverse relationship between performance in five cognitive domains (attention-processing speed, executive function, working memory, verbal and visual learning and memory) and systemic IL-6, IL-1β, TNF-α and CRP plasma levels in patients with schizophrenia. The meta-analyses results showed a significant decline in the cognitive performances with the evaluated inflammatory markers with effect sizes ranging from -0.136 to -0.181 for IL-6, -0.188 to -0.38 for TNF-α -0.372 to -0.476 for IL-1β and - 0.168 to -0.311 for CRP.

CONCLUSION

Findings from the current study shows that cognitive deficits are reflective of elevated proinflammatory biomarkers (IL-6, IL-1β, TNF-α and CRP) levels. The results obtained indicate relatedness between inflammation and cognitive decline in patients with schizophrenia. Understanding the underlying pathways between them could have a significant impact on the disease progression and quality of life in schizophrenia patients.

Association of serum homocysteine levels with intestinal flora and cognitive function in schizophrenia

Some studies have indicated that elevated homocysteine (Hcy) levels and intestinal flora may be involved in schizophrenia (SZ) cognition pathophysiology. This study was the first to investigate the association among Hcy, intestinal flora and schizophrenia cognition. Here, 140 individuals were divided into two groups: SZ patients (N = 68) and healthy controls (HCs, N = 72). Participant data on serum Hcy levels, intestinal flora and cognitive function evaluation using the MATRICS Consensus Cognitive Battery (MCCB) were collected. Clinical symptoms of patients were evaluated using the Positive and Negative Syndrome Scale. Serum Hcy levels and the incidence of hyperhomocysteinaemia were considerably increased in SZ patients compared with HCs. Hcy levels were significantly negatively associated with verbal learning index scores (r = -0.425, p < 0.001) but positively associated with Eubacterium (r = 0.32, p = 0.007), Lactobacillus (r = 0.32, p = 0.008), Corynebacterium (r = 0.26, p = 0.035), Mogibacterium (r = 0.31, p = 0.01), and Bulleidia (r = 0.31, p = 0.01) in SZ patients. Our findings suggest that serum Hcy levels are associated with cognitive function and intestinal flora in SZ patients. However, the mechanism of the interaction between Hcy and intestinal flora and its effects on cognitive function in SZ patients requires further investigation.

Aberrant memory and delusional ideation: A pernicious partnership?

Delusions can be conceptualized as beliefs that are both at odds with consensus reality and espoused with high conviction. While delusions represent a cardinal symptom of schizophrenia, delusion-like beliefs can be found in the general population. Do similar cognitive mechanisms support delusionality across this spectrum? If so, what are they? Here, we examine evidence for a mechanistic role of the (associative) memory system in the formation and maintenance of delusions and delusion-like beliefs. While general neurocognitive metrics do not tend to associate with delusionality, our scoping review of the clinical and subclinical literature reveals several subdomains of memory function that do. These include a propensity to commit errors of commission (i.e., false alarms and intrusions), source memory biases, and metamemory impairment. We discuss how several of these effects may stem from aberrant associative memory function and offer recommendations for future research. Further, we propose a state/trait interaction model in which underlying traits (i.e., impaired associative and metamemory function) may become coupled with delusionality during states of acute psychosis, when memory function is particularly challenged by aberrant salience attribution and noisy perceptual input. According to this model, delusions may arise as explanations to high-salience (but low-source) mnemonic content that is endorsed with high confidence.

Cognitive function and treatment response trajectories in first-episode schizophrenia: evidence from a prospective cohort study

OBJECTIVES

This prospective cohort study tested for associations between baseline cognitive performance in individuals early within their first episode and antipsychotic treatment of psychosis. We hypothesised that poorer cognitive functioning at the initial assessment would be associated with poorer antipsychotic response following the subsequent 6 weeks.

DESIGN

Prospective cohort .

SETTING

National Health Service users with a first-episode schizophrenia diagnosis, recently starting antipsychotic medication, recruited from two UK sites (King's College London, UK and University of Manchester, UK). Participants attended three study visits following screening.

PARTICIPANTS

Eighty-nine participants were recruited, with 46 included in the main analysis. Participants required to be within the first 2 years of illness onset, had received minimal antipsychotic treatment, have the capacity to provide consent, and be able to read and write in English. Participants were excluded if they met remission criteria or showed mild to no symptoms.

PRIMARY AND SECONDARY OUTCOME MEASURES

Antipsychotic response was determined at 6 weeks using the Positive and Negative Syndrome Scale (PANSS), with cognitive performance assessed at each visit using the Brief Assessment of Cognition in Schizophrenia (BACS). The groups identified (responders and non-responders) from trajectory analyses, as well as from >20% PANSS criteria, were compared on baseline BACS performance.

RESULTS

Trajectory analyses identified 84.78% of the sample as treatment responsive, and the remaining 15.22% as treatment non-responsive. Unadjusted and adjusted logistic regressions observed no significant relationship between baseline BACS on subscale and total performance (BACS t-score: OR=0.98, p=0.620, Cohen's d=0.218) and antipsychotic response at 6 weeks.

CONCLUSIONS

This investigation identified two clear trajectories of treatment response in the first 6 weeks of antipsychotic treatment. Responder and non-responder groups did not significantly differ on performance on the BACS, suggesting that larger samples may be required or that an association between cognitive performance and antipsychotic response is not observable in the first 2 years of illness onset.

TRIAL REGISTRATION NUMBER

REC: 17/NI/0209.

The role of glutamate and GABA in cognitive dysfunction in schizophrenia and mood disorders - A systematic review of magnetic resonance spectroscopy studies

Epidemiologic, genetic, and neurobiological studies suggest considerable overlap between schizophrenia and mood disorders. Importantly, both disorders are associated with a broad range of cognitive deficits as well as altered glutamatergic and GABAergic neurometabolism. We conducted a systematic review of magnetic resonance spectroscopy (MRS) studies investigating the relationship between glutamatergic and GABAergic neurometabolites and cognition in schizophrenia spectrum disorders and mood disorders. A literature search in Pubmed of studies published before April 15, 2019 was conducted and 37 studies were deemed eligible for systematic review. We found that alterations in glutamatergic and GABAergic neurotransmission have been identified relatively consistently in both schizophrenia and mood disorders. However, because of the vast heterogeneity of published studies in terms of illness stage, medication exposure, MRS acquisition parameters and data post-processing strategies, we still do not understand the relationship between those neurotransmitters and cognitive dysfunction in mental illness, which is a critical initial step for rational drug development. Our findings emphasize the need for coordinated multi-center studies that characterize cognitive function and its biological substrates in large and well-defined clinical populations, using harmonized imaging sequences and analytical methods with the goal to elucidate the underlying pathophysiological mechanisms and to inform future clinical trials.

Emotion Recognition Deficits in Psychiatric Disorders as a Target of Non-invasive Neuromodulation: A Systematic Review

Background. Social cognition deficits are a core feature of psychiatric disorders, such as schizophrenia and mood disorder, and deteriorate the functionality of patients. However, no definite strategy has been established to treat social cognition (eg, emotion recognition) impairments in these illnesses. Here, we provide a systematic review of the literature regarding transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) for the treatment of social cognition deficits in individuals with psychiatric disorders. Methods. A literature search was conducted on English articles identified by PubMed, PsycINFO, and Web of Science databases, according to the guidelines of the PRISMA statement. We defined the inclusion criteria as follows: (1) randomized controlled trials (RCTs), (2) targeting patients with psychiatric disorders (included in F20-F39 of the 10th revision of the International Statistical Classification of Diseases and Related Health Problems [ICD-10]), (3) evaluating the effect of tDCS or rTMS, (4) reporting at least one standardized social cognition test. Results. Five papers (3 articles on tDCS and 2 articles on rTMS) met the inclusion criteria which deal with schizophrenia or depression. The significant effects of tDCS or rTMS targeting the left dorsolateral prefrontal cortex on the emotion recognition domain were reported in patients with schizophrenia or depression. In addition, rTMS on the right inferior parietal lobe was shown to ameliorate social perception impairments of schizophrenia. Conclusions. tDCS and rTMS may enhance some domains of social cognition in patients with psychiatric disorders. Further research is warranted to identify optimal parameters to maximize the cognitive benefits of these neuromodulation methods.

Association between Motor Signs and Cognitive Performance in Cognitively Unimpaired Older Adults: A Cross-Sectional Study Using the NACC Database

Aiming to examine whether specific motor signs are associated with worse performance in specific cognitive domains among cognitively unimpaired (CU) individuals, we performed a cross-sectional analysis of data from the baseline evaluations of older, CU participants from the National Alzheimer's Coordinating Center (NACC) Uniform Data Set. In total, 8149 CU (≥60 years) participants were included. Of these, 905 individuals scored ≥ 2 on at least one of the motor domains of the Unified Parkinson's Disease Rating Scale part III (UPDRSIII). Cognitively impaired individuals, participants with psychiatric disorders and/or under treatment with antipsychotic, anxiolytic, sedative or hypnotic agents were excluded. Nine motor signs were examined: hypophonia, masked facies, resting tremor, action/postural tremor, rigidity, bradykinesia, impaired chair rise, impaired posture/gait and postural instability. Their association with performance on episodic memory, semantic memory, language, attention, processing speed or executive function was assessed using crude and adjusted linear regression models. Individuals with impaired chair rise had worse episodic memory, semantic memory, processing speed and executive function, while those with bradykinesia had worse language, processing speed and executive function. Sensitivity analyses, by excluding participants with cerebrovascular disease or PD, or other Parkinsonism, produced similar results with the exception of the relationship between bradykinesia and language performance.

Cognitive profiles in bipolar I disorder and associated risk factors: Using Wechsler adult intelligence scale—IV

Background

Despite the growing evidence of cognitive impairments in bipolar disorder (BD), little work has evaluated cognitive performances utilizing the latest version of the Wechsler Intelligence Scale-IV (WAIS-IV), which is one of the most widely used neurocognitive assessments in clinical settings. Furthermore, clinical characteristics or demographic features that negatively affect the cognitive functioning of BD were not systematically compared or evaluated. Accordingly, the present study aimed to examine the cognitive profile of bipolar I disorder (BD-I) patients and associated risk factors.

Methods

Participants included 45 patients, diagnosed with BD-I, current or most recent episode manic, and matching 46 healthy controls (HC). Cognitive performance was evaluated via WAIS-IV, and clinical characteristics of the BD-I group were examined via multiple self- and clinician-report questionnaires.

Results

Multivariate analysis of covariance (MANCOVA) results indicated that the BD-I group demonstrated significantly poorer performance compared to the HC group in subtests and indexes that reflect working memory and processing speed abilities. Redundancy analysis revealed that overall symptom severity, manic symptom severity, and anxiety were significant predictors of cognitive performance in BD-I, while age of onset, past mood disorder history, depression severity, and impulsiveness showed comparatively smaller predictive values.

Conclusion

The current study suggests cognitive deterioration in the cognitive proficiency area while generalized ability, including verbal comprehension and most of the perceptual reasoning skills, remain intact in BD-I. The identified risk factors of cognitive performance provide specific clinical recommendations for intervention and clinical decision-making.

Thalamocortical Development: A Neurodevelopmental Framework for Schizophrenia

Adolescence is a period of increased vulnerability for the development of psychiatric disorders, including schizophrenia. The prefrontal cortex (PFC) undergoes substantial maturation during this period, and PFC dysfunction is central to cognitive impairments in schizophrenia. As a result, impaired adolescent maturation of the PFC has been proposed as a mechanism in the etiology of the disorder and its cognitive symptoms. In adulthood, PFC function is tightly linked to its reciprocal connections with the thalamus, and acutely inhibiting thalamic inputs to the PFC produces impairments in PFC function and cognitive deficits. Here, we propose that thalamic activity is equally important during adolescence because it is required for proper PFC circuit development. Because thalamic abnormalities have been observed early in the progression of schizophrenia, we further postulate that adolescent thalamic dysfunction can have long-lasting consequences for PFC function and cognition in patients with schizophrenia.

Considering medication exposure in genomic association studies of cognition in psychotic disorders

Cognitive dysfunction is a core feature of psychosis-spectrum illnesses, and the characterization of related genetic mechanisms may provide insights regarding the disease pathophysiology. Substantial efforts have been made to determine the genetic component of cognitive symptoms, without clear success. Illness-related moderators and environmental factors such as medications hinder the detection of genomic association with cognition. Polypharmacy is common in psychotic disorders, and the cumulative effects of medication regimens can confound gene-cognition associations. A review of the relative contributions of important pharmacological and genetic relationships identifies that the effects of medications on cognition in psychotic disorders may be at least, if not more, impactful than individual genes, thus underscoring the importance of accounting for medication exposure in gene-cognition association studies.

Paliperidone Extended Release Versus Olanzapine in Treatment-Resistant Schizophrenia: A Randomized, Double-Blind, Multicenter Study

PURPOSE

Paliperidone is an atypical antipsychotic as effective as other atypical antipsychotics for schizophrenia. However, few studies have explored the efficacy of paliperidone for treatment-resistant schizophrenia. This study aimed to compare the efficacy and safety of paliperidone extended release (ER) versus olanzapine in schizophrenia patients with either poor treatment response or intolerable adverse effects due to standardized antipsychotic therapy.

METHODS

This 12-week randomized, double-blind, multicenter study compared the treatment efficacy on psychotic symptoms, cognitive functions, and tolerance between paliperidone ER (6-15 mg/d, n = 45) and olanzapine (10-30 mg/d, n = 41) in treatment-resistant or treatment-intolerant patients with schizophrenia. The severity of psychotic symptoms was evaluated by the Positive and Negative Syndrome Scale and the Clinical Global Impression Severity of Illness Scale. The cognitive functions were assessed by the MATRICS Consensus Cognitive Battery. In addition, the metabolic impacts were evaluated by weight gain and waist circumference.

RESULTS

Patients with either paliperidone ER or olanzapine treatment showed apparent improvement in psychotic symptoms, without significant intergroup difference. Twelve-week paliperidone ER or olanzapine treatment did not improve the cognitive functions. Both paliperidone ER and olanzapine treatment caused significant increase in weight and waist circumference, and olanzapine had a greater impact on waist circumference than paliperidone ER. In addition, both drugs were well tolerated.

CONCLUSIONS

Paliperidone ER could be a safe alternative for treatment-resistant schizophrenia.

Correlation between telomere length and efficacy of oral and long-acting injectable antipsychotics on severity and cognitive impairment of schizophrenia

OBJECTIVE

To study the correlation between telomere length (TL) and long-acting injectable (LAI) and oral atypical antipsychotic (OAA) efficacy on schizophrenia (SCZ) severity and cognitive impairment.

METHODS

Sixty Schizophrenia patients of 18-50 years and of either sex were included in a 12-week study. Thirty patients were recruited in each group, LAI and OAA. Positive and Negative Syndrome Scale (PANSS) and National Institute of Mental Health and Neuro-Sciences (NIMHANS) neuropsychological battery tests were evaluated at baseline and 12 weeks. TL was estimated at baseline.

RESULTS

Both groups showed a significant improvement in PANSS and NIMHANS battery test scores after treatment (p < 0.001) within the group, though not between the groups. Mean TL at baseline was 407.58 ± 143.93 and 443.40 ± 178.46 in LAI and OAA groups respectively. A significant negative correlation (r = -0.28, p = 0.03) of TL was seen with the mean change in negative PANSS score after treatment.

CONCLUSIONS

LAI antipsychotics are similar to OAA in decreasing the disorder severity and improving the cognitive impairment in schizophrenia. Also, patients who have shorter TL show greater improvement in the negative PANSS score. Hence, TL holds the potential of predicting antipsychotic drug response in schizophrenia patients.KEY POINTSLong-acting injectable antipsychotic was comparable to oral atypical antipsychotics in bringing out improvement in disorder severity, cognitive functions over 12 weeks.Shorter telomere length has been found to be associated with a greater response in negative symptoms of schizophrenia.

Cariprazine's Potential in Improving Social Dysfunction in Patients With Schizophrenia: A Perspective

Social dysfunction is one of the most debilitating aspects of schizophrenia. Treatment of this complex phenomenon, constituted by negative, cognitive, and affective symptoms, has been difficult with the available pharmacological agents, hence it represents an unmet medical need. Cariprazine, a novel, third-generation antipsychotic with a unique mechanism of action has been proven to sufficiently alleviate negative, cognitive, and affective symptoms of schizophrenia. These characteristics make this compound a valid candidate for addressing social dysfunction too. In this perspective, we argue that cariprazine can be viewed as a "socializing drug" that has the ability to improve the patient's functionality and ultimately their quality of life. Data from animal research, clinical trials, an observational study, and patient cases are provided.

Sex Differences in Demographic and Pharmacological Factors in Alzheimer Patients With Dementia and Cognitive Impairments

Objective

The current study investigates sex differences associated with pharmacological and demographic characteristics in Alzheimer patients (AD) with dementia (ADD) or mild cognitive impairment (MCI).

Method

A retrospective analytical approach was used to analyze data from 45,696 AD patients with MCI or ADD. The univariate analysis was used to determine differences in demographic, and pharmacological characteristics for male and female ADD and MCI-AD patients. Multivariate analysis was used to predict specific pharmacological and demographic factors that are associated with male and female MCI and ADD patients.

Result

In the adjusted analysis for male patients, Hispanics [0.166,0.020 – 1.355, P = 0.094] or African Americans [OR = 2.380, 95% CI,2.120 – 2.674, P &lt; 0.001], were more likely to have MCI-AD and be treated with galantamine [OR = 0.559, 95% CI, 0.382 – 0.818, P = 0.003], donepezil [OR = 1.639, 95% CI,1.503 – 1.787, P &lt; 0.001], rivastigmine [OR = 1.394, 95% CI,1.184 – 1.642, P &lt; 0.001], olanzapine [OR = 2.727, 95% CI,2.315 – 3.212, P &lt; 0.001], risperidone [OR = 2.973, 95% CI,2.506 – 3.526, P &lt; 0.001], present with increasing age [1.075,1.071 – 1.079, P &lt; 0.001], and are on tobacco use [OR = 1.150, 95% CI,1.054 – 1.254, P = 0.002]. For female patients, buspirone [OR = 0.767, 95% CI, 0.683 – 0.861, P &lt; 0.001] and a history of alcohol (ETOH) use [OR = 0.484, 95% CI, 0.442 – 0.529, P &lt; 0.001] were associated with MCI-AD. Increasing age [OR = 1.096, 95% CI, 1.093 – 1.100, P &lt; 0.001], donepezil [OR = 2.185, 95% CI, 2.035 – 2.346, P &lt; 0.001], memantine [OR = 2.283, 95% CI, 2.104 – 2.477, P &lt; 0.001] aripiprazole [OR = 1.807, 95% CI, 1.544 – 2.113, P &lt; 0.001] olanzapine [OR = 2.289, 95% CI, 1.986 – 2.640, P &lt; 0.001] risperidone [OR = 2.548, 95% CI, 2.246 – 2.889, P &lt; 0.001] buspirone [OR = 0.767, 95% CI, 0.683 – 0.861, P &lt; 0.001] escitalopram [OR = 1.213, 95% CI,1.119 – 1.315, P &lt; 0.001] African Americans [OR = 1.395, 95% CI, 1.268 – 1.535, P &lt; 0.001] and tobacco use [OR = 1.150, 95% CI, 1.073 – 1.233, P &lt; 0.001] were associated with ADD.

Conclusion

Our findings reveal that MCI-AD patients were more likely to be Hispanics or African American males treated with rivastigmine, olanzapine and citalopram. African American females were associated with ADD and more likely to be treated with buspirone and presented with a history of ETOH. This finding suggests the need for a pharmacological treatment approach encompassing sex-sensitive strategies for MCI-AD and ADD patients.

Impact of polygenic risk for coronary artery disease and cardiovascular medication burden on cognitive impairment in psychotic disorders

BACKGROUND

Cognitive impairment is a core deficit across psychotic disorders, the causes and therapeutics of which remain unclear. Epidemiological observations have suggested associations between cognitive dysfunction in psychotic disorders and cardiovascular risk factors, but an underlying etiology has not been established.

METHODS

Neuropsychological performance using the Brief Assessment of Cognition in Schizophrenia (BACS) was assessed in 616 individuals of European ancestry (403 psychosis, 213 controls). Polygenic risk scores for coronary artery disease (PRSCAD) were quantified for each participant across 13 p-value thresholds (PT 0.5-5e-8). Cardiovascular and psychotropic medications were categorized for association analyses. Each PRSCAD was examined in relation to the BACS and the optimized PT was confirmed with five-fold cross-validation and independent validation. Functional enrichment analyses were used to identify biological mechanisms linked to PRSCAD-cognition associations. Multiple regression analyses examined PRSCAD under the optimal PT and medication burden in relation to the BACS composite and subtest scores.

RESULTS

Higher PRSCAD was associated with lower BACS composite scores (p = 0.001) in the psychosis group, primarily driven by the Verbal Memory subtest (p < 0.001). Genes linked to multiple nervous system related processes and pathways were significantly enriched in PRSCAD. After controlling for PRSCAD, a greater number of cardiovascular medications was also correlated with worse BACS performance in patients with psychotic disorders (p = 0.029).

CONCLUSIONS

Higher PRSCAD and taking more cardiovascular medications were both significantly associated with cognitive impairment in psychosis. These findings indicate that cardiovascular factors may increase the risk for cognitive dysfunction and related functional outcomes among individuals with psychotic disorders.

Antipsychotic Medication Risk of Dementia and Death: A Propensity Matched Cohort Study

OBJECTIVE

This study aimed to compare the incidence of dementia and all-cause mortality up to 20 years post-treatment in an index non-demented cohort between antipsychotic (AP) medication treatment and non-AP treatment groups.

METHOD

All patients in Kaiser Permanente Northern California with a major psychiatric diagnosis between 01/01/1996 and 12/31/2000, age ≥ 50 years, and without dementia diagnosis were included. The study cohort was divided into a "user group", patients treated with AP for ≥ 365 days (n = 1,829), and a "non-user group", propensity score matched on age, sex, and race (n = 9,145). The association between AP exposure and dementia or mortality during the follow-up period (01/01/2001-12/31/2015) was evaluated using Cox proportional hazard models adjusted for psychiatric diagnosis, comorbidities, and other medications. The user group had a hazard ratio (HR) of 2.2 (CI 1.8-2.7) for dementia and 1.3 (CI 1.2-1.5) for death. The onset of dementia in the user group was significantly higher in patients aged ≤ 65 years (p < 0.001). The user group was sub-grouped into atypical, typical, and both; HR for dementia was 1.7 (CI 1.2-2.4), 2.5 (CI 1.9-3.1), and 1.8 (CI 1.4-2.4), respectively.

RESULT

Dementia and mortality were significantly higher in patients concurrently treated with benzodiazepine (HR 1.3; CI 1.2-1.5 and HR 1.4; CI 1.3-1.5) or tricyclic antidepressants (HR 1.2; CI 1.1-1.4 and HR 1.1; CI 1.0-1.2), respectively.

CONCLUSION

Our preliminary results reveal an association between AP treatment and increased rates of both dementia and mortality. Future research is needed to substantiate our current findings.

Effect of antipsychotic dose reduction on cognitive function in schizophrenia

Cognitive deficits are predictors of social functioning but remain an unmet therapeutic challenge. While lowering the antipsychotics carries a risk of relapse, it possibly has a beneficial effect on cognitive function. However, this has not been examined in a real-world setting. A prospective naturalistic 6-month follow-up study (n = 71) was conducted with patients between 18 and 45 years in their first five years of illness and the maintenance phase of the treatment. Brief Assessment of Cognition in Schizophrenia (BACS) was administered to assess cognitive functions. Patients were divided into three groups based on the change in dose of antipsychotics. The data were analyzed using linear mixed-effects modeling (LMEM) to examine the group differences. At the end of six months, those with decreased antipsychotic dose had significant improvement in BACS total score, token test, and symbol coding compared to those with no change in the dose of antipsychotic. Reducing the dose of antipsychotics during the maintenance phase was associated with improved cognitive functions without an increased risk of relapse. Antipsychotic dose reduction may be better than discontinuation as the relapse risk is higher with the discontinuation strategy. Clinicians must balance the improvements in cognitive functions and relapse risk.

Transcranial Direct Current Stimulation on the Left Superior Temporal Sulcus Improves Social Cognition in Schizophrenia: An Open-Label Study

BACKGROUND

Patients with schizophrenia show impairments of social cognition, which cause poor real-world functional outcomes. Transcranial direct current stimulation (tDCS) delivered to frontal brain areas has been shown to partially alleviate disturbances of social cognition. In this study, we aimed to determine whether multisession tDCS targeting the superior temporal sulcus (STS), a brain region closely related to social cognition, would improve social cognitive performance in patients with schizophrenia.

METHODS

This was an open-label, single-arm trial to investigate the benefits and safety of multisession tDCS over the left STS. Fifteen patients received tDCS (2 mA × 20 min) two times per day for 5 consecutive days. Anodal and cathodal electrodes were placed over the left STS and right supraorbital regions, respectively. Assessments with the Social Cognition Screening Questionnaire (SCSQ), the Hinting Task (HT), the Brief Assessment of Cognition in Schizophrenia (BACS), and the Positive and Negative Syndrome Scale (PANSS) were conducted at baseline and 1 month after the final stimulation.

RESULTS

Significant improvements were found on theory of mind, as measured using the SCSQ (d = 0.53) and the HT (d = 0.49). These changes on social cognition were not correlated with those of neurocognition, as measured using the BACS or psychotic symptoms, as measured using the PANSS. There were no adverse events of serious/moderate levels attributable to tDCS.

CONCLUSION

These results suggest that administration of multisession tDCS with anode stimulation targeting the left STS provides a novel strategy to improve functional outcomes in patients with schizophrenia.

ETHICS STATEMENT

The National Center of Neurology and Psychiatry Clinical Research Review Board (CRB3180006) approved this study.

TRIAL REGISTRATION

This study was registered within the Japan Registry of Clinical Trials (jRCTs032180026).

Social Cognition Individualized Activities Lab for Social Cognition Training and Narrative Enhancement in Patients With Schizophrenia: A Randomized Controlled Study to Assess Efficacy and Generalization to Real-Life Functioning (Prot. n°: NCT05130853)

Subjects affected by schizophrenia present significant deficits in various aspects of social cognition, such as emotion processing, social perception and theory of mind (ToM). These deficits have a greater impact than symptoms on occupational and social functioning. Therefore, social cognition represents an important therapeutic target in people with schizophrenia. Recent meta-analyses showed that social cognition training (SCT) is effective in improving social cognition in subjects with schizophrenia; however, real-life functioning is not always ameliorated. Integration of SCT with an intervention targeting metacognitive abilities might improve the integration of social cognitive skills to daily life functioning. Our research group has implemented a new individualized rehabilitation program: the Social Cognition Individualized Activities Lab, SoCIAL, which integrates SCT with a module for narrative enhancement, an intervention targeting metacognitive abilities. The present multi-center randomized controlled study will compare the efficacy of SoCIAL and treatment as usual (TAU) in subjects diagnosed with a schizophrenia-spectrum disorder. The primary outcome will be the improvement of social cognition and real-life functioning; while the secondary outcome will be the improvement of symptoms, functional capacity and neurocognition. The results of this study will add empirical evidence to the benefits and feasibility of SCT and narrative enhancement in people with schizophrenia-spectrum disorders.

Association between lipid metabolism and cognitive function in patients with schizophrenia

BACKGROUND

The association between blood lipids and cognitive function in schizophrenia is still controversial. Thus, the present study aimed to verify the association between various lipid parameters and cognitive impairment in schizophrenic patients and potential lipid pathways.

METHODS

A total of 447 adult inpatients with schizophrenia were divided into cognitive normal and cognitive impairment groups based on the Mini-Mental State Examination with a cut-off of 26. The blood lipid parameters were defined as abnormal levels based on the guideline. The liquid chromatography-mass spectrometry method was used to preliminarily explore the potential lipid metabolism pathway associated with cognitive impairment.

RESULTS

There were 368 (82.3%) patients who had cognitive impairment. Herein, apolipoprotein B was positively associated with cognitive function in overall patients and age (≥45 and <45 years) and sex subgroups. After excluding patients with hypertension and diabetes, ApoB was still significantly associated with cognitive function in all the patients. The associations between other lipid parameters, including non-high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol and triglyceride, and cognitive impairment were heterogeneous in age and sex subgroups. In contrast, total cholesterol and apolipoprotein A1 were not significantly associated with cognitive impairment. Metabolomics analysis showed that metabolic pathway mainly involved sphingolipid metabolism. Meanwhile, sphinganine and 3-dehydrosphinganine were positively correlated with lipid parameters and decreased in patients with cognitive impairment as compared to those with normal cognition.

CONCLUSIONS

The present study suggests a positive association between lipids and cognitive function in schizophrenic patients and needs to be further verified by a prospective study.

Multi-omics of human plasma reveals molecular features of dysregulated inflammation and accelerated aging in schizophrenia

Schizophrenia is a devastating psychiatric illness that detrimentally affects a significant portion of the worldwide population. Aging of schizophrenia patients is associated with reduced longevity, but the potential biological factors associated with aging in this population have not yet been investigated in a global manner. To address this gap in knowledge, the present study assesses proteomics and metabolomics profiles in the plasma of subjects afflicted with schizophrenia compared to non-psychiatric control patients over six decades of life. Global, unbiased analyses of circulating blood plasma can provide knowledge of prominently dysregulated molecular pathways and their association with schizophrenia, as well as features of aging and gender in this disease. The resulting data compiled in this study represent a compendium of molecular changes associated with schizophrenia over the human lifetime. Supporting the clinical finding of schizophrenia's association with more rapid aging, both schizophrenia diagnosis and age significantly influenced the plasma proteome in subjects assayed. Schizophrenia was broadly associated with prominent dysregulation of inflammatory and metabolic system components. Proteome changes demonstrated increased abundance of biomarkers for risk of physiologic comorbidities of schizophrenia, especially in younger individuals. These findings advance our understanding of the molecular etiology of schizophrenia and its associated comorbidities throughout the aging process.

mGlu1 potentiation enhances prelimbic somatostatin interneuron activity to rescue schizophrenia-like physiological and cognitive deficits

Evidence for prefrontal cortical (PFC) GABAergic dysfunction is one of the most consistent findings in schizophrenia and may contribute to cognitive deficits. Recent studies suggest that the mGlu1 subtype of metabotropic glutamate receptor regulates cortical inhibition; however, understanding the mechanisms through which mGlu1 positive allosteric modulators (PAMs) regulate PFC microcircuit function and cognition is essential for advancing these potential therapeutics toward the clinic. We report a series of electrophysiology, optogenetic, pharmacological magnetic resonance imaging, and animal behavior studies demonstrating that activation of mGlu1 receptors increases inhibitory transmission in the prelimbic PFC by selective excitation of somatostatin-expressing interneurons (SST-INs). An mGlu1 PAM reverses cortical hyperactivity and concomitant cognitive deficits induced by N-methyl-d-aspartate (NMDA) receptor antagonists. Using in vivo optogenetics, we show that prelimbic SST-INs are necessary for mGlu1 PAM efficacy. Collectively, these findings suggest that mGlu1 PAMs could reverse cortical GABAergic deficits and exhibit efficacy in treating cognitive dysfunction in schizophrenia.

Erythropoietin and Non-Erythropoietic Derivatives in Cognition

Cognitive deficits are widespread in psychiatric disorders, including major depression and schizophrenia. These deficits are known to contribute significantly to the accompanying functional impairment. Progress in the development of targeted treatments of cognitive deficits has been limited and there exists a major unmet need to develop more efficacious treatments. Erythropoietin (Epo) has shown promising procognitive effects in psychiatric disorders, providing support for a neurotrophic drug development approach. Several preclinical studies with non-erythropoietic derivatives have demonstrated that the modulation of behavior is independent of erythropoiesis. In this review, we examine the molecular, cellular and cognitive actions of Epo and non-erythropoietic molecular derivatives by focusing on their neurotrophic, synaptic, myelin plasticity, anti-inflammatory and neurogenic mechanisms in the brain. We also discuss the role of receptor signaling in Epo and non-erythropoietic EPO-mimetic molecules in their procognitive effects.

Different neurocognitive profiles of risperidone and aripiprazole in the FIRST episode of psychosis: A 3-year follow-up comparison

Cognitive deficits have been recognized as a central feature of schizophrenia spectrum disorders. These deficits are often related to more severe negative symptoms, as well as a poorer adjustment in social functioning. Therefore, it is important to improve cognitive performance from the onset of the disease. In this study, we compared the effects of two atypical antipsychotics, risperidone and aripiprazole, on cognition. The data used in the present investigation were obtained from a large epidemiological cohort of patients with a first episode of psychosis who were treated in a longitudinal intervention programme. The patients included in the program were randomized to treatment with risperidone or aripiprazole and were assessed for cognitive function at baseline and 3 years later. The final sample consisted of 115 patients, 55 of whom were initially assigned to risperidone and 60 to aripiprazole. The groups did not show significant differences in their sociodemographic or clinical characteristics at intake. Longitudinal analyses showed that risperidone-treated patients improved in the processing speed domain at the 3-year follow-up, while the aripiprazole group showed better scores for the executive function domain. Our study shows slight differences between the effects of risperidone and aripiprazole on cognition, suggesting different patterns of efficacy on cognitive function that may warrant more thorough research to determine the beneficial effects of these drugs on cognition. Future studies should evaluate the effects of these treatments over longer follow-up periods using standardized tools for the assessment of cognitive function.

Sex differences between serum total bilirubin levels and cognition in patients with schizophrenia

BACKGROUND

Cognitive deficits are common in patients with schizophrenia (SCZ). Abnormal serum total bilirubin (TBIL) levels have been involved in cognitive deficits associated with neuropsychiatric diseases such as mild cognitive impairment and subcortical ischemic vascular disease. However, this relationship has not yet been fully investigated in patients with SCZ. Therefore, the aim of this study was to investigate the association between the serum TBIL concentration and cognitive deficits in SCZ patients and to determine whether a sex difference exists in the association.

METHODS

A total of 455 participants were eligible and included in this cross-sectional study. Cognition was evaluated using the Montreal Cognitive Assessment. Serum TBIL concentration was measured with an automatic biochemistry analyzer according to the routine protocol in the hospital medical laboratory.

RESULTS

Serum TBIL levels were lower in the cognition impairment group than in the cognition normal group in male patients. In contrast, serum TBIL levels tended to be increased in the cognition impairment group in female patients, although the difference was not significant. Further stepwise multiple regression analysis stratified by sex showed that serum TBIL was independently and positively associated with cognitive function in male patients but not in female patients. Moreover, the association between serum TBIL level and cognitive function was also identified by the propensity score matching (PSM) method in male patients, but not in female patients.

CONCLUSION

These findings suggest that lower serum TBIL levels may be associated with cognitive impairment in male SCZ patients.

Treating cognitive impairment in schizophrenia with GLP-1RAs: an overview of their therapeutic potential

INTRODUCTION

Schizophrenia is a neuropsychiatric disorder that affects approximately 1% of individuals worldwide. There are no available medications to treat cognitive impairment in this patient population currently. Preclinical evidence suggests that glucagon-like peptide-1 receptor agonists (GLP-1 RAs) improve cognitive function. There is a need to evaluate how GLP-1 RAs alter specific domains of cognition and whether they will be of therapeutic benefit in individuals with schizophrenia.

AREAS COVERED

This paper summarizes the effects of GLP-1 RAs on metabolic processes in the brain and how these mechanisms relate to improved cognitive function. We provide an overview of preclinical studies that demonstrate GLP-1 RAs improve cognition and comment on their potential therapeutic benefit in individuals with schizophrenia.

EXPERT OPINION

To understand the benefits of GLP-1 RAs in individuals with schizophrenia, further preclinical research with rodent models relevant to schizophrenia symptomology are needed. Moreover, preclinical studies must focus on using a wider range of behavioral assays to understand whether important aspects of cognition such as executive function, attention, and goal-directed behavior are improved using GLP-1 RAs. Further research into the specific mechanisms of how GLP-1 RAs affect cognitive function and their interactions with antipsychotic medication commonly prescribed is necessary.

Experiences of Hospitalization of Patients With Psychotic Disorders on Medical-Surgical Units: A Thematic Analysis

BACKGROUND:Individuals with psychotic disorders are more likely to have nonpsychiatric hospitalizations than the general population. Moreover, they experience worse outcomes in terms of rehospitalization, adverse events, in-hospital mortality, and longer length of stay. AIM: A patient-centered understanding of inpatient medical-surgical hospitalization experiences could shed light on disparities in hospital outcomes among individuals with psychotic disorders. METHOD: This article reports findings from Phase 1 (Qualitative) of a mixed methods, exploratory sequential study of nonpsychiatric hospitalizations of patients with psychotic disorders. Patients on medical-surgical units with diagnosed psychotic disorders (n = 20) were interviewed about their experiences of hospitalization, and a thematic analysis was conducted of transcripts, case notes, and setting notes. RESULTS: Five themes emerged from analysis: (1) managing through hard times (subthemes: intense emotions, medically complex with many symptoms, strategies for self-management), (2) ignored and treated unfairly, (3) actively involved in health (subthemes: seeking health education, suggesting changes), (4) appreciation of caring providers, and (5) violence: expected and enacted. Participants connected the difficult nature of their hospitalization experiences with a variety of sources and outcomes, including strong emotions, variable relationships with providers and a struggle to receive health education. CONCLUSIONS: Nurses who care for patients with psychotic disorders in medical-surgical settings can better meet patients' needs by concentrating on relationship building, especially during initial interactions, and helping patients better manage their medical and psychiatric symptoms through both pharmaceutical and nursing interventions.

Repurposing of Anti-Diabetic Agents as a New Opportunity to Alleviate Cognitive Impairment in Neurodegenerative and Neuropsychiatric Disorders

Cognitive impairment is a shared abnormality between type 2 diabetes mellitus (T2DM) and many neurodegenerative and neuropsychiatric disorders, such as Alzheimer’s disease (AD) and schizophrenia. Emerging evidence suggests that brain insulin resistance plays a significant role in cognitive deficits, which provides the possibility of anti-diabetic agents repositioning to alleviate cognitive deficits. Both preclinical and clinical studies have evaluated the potential cognitive enhancement effects of anti-diabetic agents targeting the insulin pathway. Repurposing of anti-diabetic agents is considered to be promising for cognitive deficits prevention or control in these neurodegenerative and neuropsychiatric disorders. This article reviewed the possible relationship between brain insulin resistance and cognitive deficits. In addition, promising therapeutic interventions, especially current advances in anti-diabetic agents targeting the insulin pathway to alleviate cognitive impairment in AD and schizophrenia were also summarized.

Improving cognition in severe mental illness by combining cognitive remediation and transcranial direct current stimulation: study protocol for a pragmatic randomized controlled pilot trial (HEADDSET)

Background

A fundamental challenge for many people with severe mental illness (SMI) is how to deal with cognitive impairments. Cognitive impairments are common in this population and limit daily functioning. Moreover, neural plasticity in people with SMI appears to be reduced, a factor that might hinder newly learned cognitive skills to sustain. The objective of this pilot trial is to investigate the effects of cognitive remediation (CR) on cognitive and daily functioning in people dependent on residential settings. In addition, transcranial direct current stimulation (tDCS) is used to promote neural plasticity. It is expected that the addition of tDCS can enhance learning and will result in longer-lasting improvements in cognitive and daily functioning.

Methods

This is a pragmatic, triple-blinded, randomized, sham-controlled, pilot trial following a non-concurrent multiple baseline design with the participants serving as their own control. We will compare (1) CR to treatment as usual, (2) active/sham tDCS+CR to treatment as usual, and (3) active tDCS+CR to sham tDCS+CR. Clinical relevance, feasibility, and acceptability of the use of CR and tDCS will be evaluated. We will recruit 26 service users aged 18 years or older, with a SMI and dependent on residential facilities. After a 16-week waiting period (treatment as usual), which will serve as a within-subject control condition, participants will be randomized to 16 weeks of twice weekly CR combined with active (N = 13) or sham tDCS (N = 13). Cognitive, functional, and clinical outcome assessments will be performed at baseline, after the control (waiting) period, directly after treatment, and 6-months post-treatment.

Discussion

The addition of cognitive interventions to treatment as usual may lead to long-lasting improvements in the cognitive and daily functioning of service users dependent on residential facilities. This pilot trial will evaluate whether CR on its own or in combination with tDCS can be a clinically relevant addition to further enhance recovery. In case the results indicate that cognitive performance can be improved with CR, and whether or not tDCS will lead to additional improvement, this pilot trial will be extended to a large randomized multicenter study.

Trial registration

Dutch Trial Registry NL7954. Prospectively registered on August 12, 2019.