Is cognitive impairment associated with antipsychotic dose and anticholinergic equivalent loads in first-episode psychosis?

Comparative analysis of anticholinergic burden scales to explain iatrogenic cognitive impairment in schizophrenia: results from the multicenter FACE-SZ cohort

Aim

The anticholinergic properties of medications are associated with poorer cognitive performance in schizophrenia. Numerous scales have been developed to assess anticholinergic burden and yet, there is no consensus indicating which anticholinergic burden scale is more relevant for patients with schizophrenia. We aimed to identify valid scales for estimating the risk of iatrogenic cognitive impairment in schizophrenia.

Methods

We identified 27 scales in a literature review. The responses to neuropsychological tests of 839 individuals with schizophrenia or schizoaffective disorder in the FACE-SZ database were collected between 2010 and 2021. We estimated the association between objective global cognitive performance and the 27 scales, the number of psychotropic drugs, and chlorpromazine and lorazepam equivalents in bivariable regressions in a cross-sectional design. We then adjusted the bivariable models with covariates: the predictors significantly associated with cognitive performance in multiple linear regressions were considered to have good concurrent validity to assess cognitive performance.

Results

Eight scales, the number of psychotropic drugs, and drug equivalents were significantly associated with cognitive impairment. The number of psychotropic drugs, the most convenient predictor to compute, was associated with worse executive function (Standardized β = -0.12, p = .004) and reasoning (Standardized β = -0.08, p = .037).

Conclusion

Anticholinergic burden, the number of psychotropic drugs, and drug equivalents were weakly associated with cognition, thus suggesting that cognitive impairment in schizophrenia and schizoaffective disorder is explained by factors other than medication. The number of psychotropic drugs was the most parsimonious method to assess the risk of iatrogenic cognitive impairment.

Modeling the effects of treatment resistance and anticholinergic burden on cognitive function domains in patients with schizophrenia

The contribution of anticholinergic burden to cognitive function in patients with treatment resistant schizophrenia (TRS) is uncertain. This case-control study aims to comprehensively examine the association between treatment resistance and cognitive functions and the contribution of anticholinergic burden in patients with schizophrenia. Anticholinergic burden of all patients was calculated using the Anticholinergic Cognitive Burden scale. Exploratory Factor Analysis of 11 cognitive assessments identified four cognitive domains: verbal memory, attention and general cognitive functions, visual memory and processing speed, and executive function. Two structural equation models (SEM) examined the relationship of TRS and these cognitive functions with, and without considering anticholinergic burden. A total of 288 participants were included (TRS N=111, non-TRS N=177). Patients with TRS performed poorer than the non-TRS group only in the executive function domain. Anticholinergic burden contributed significantly to the attention and general cognitive functions, visual memory and processing speed, and executive function. The impact of TRS on executive function was no longer significant after adding anticholinergic burden to the SEM. Results suggested that anticholinergic burden contributes to a wide range of cognitive function impairment in patients with schizophrenia and is likely to be part of the apparent differences of cognitive function between TRS and non-TRS.

Neurobiology-based Cognitive Biotypes Using Multi-scale Intrinsic Connectivity Networks in Psychotic Disorders

Objective

Understanding the neurobiology of cognitive dysfunction in psychotic disorders remains elusive, as does developing effective interventions. Limited knowledge about the biological heterogeneity of cognitive dysfunction hinders progress. This study aimed to identify subgroups of patients with psychosis with distinct patterns of functional brain alterations related to cognition (cognitive biotypes).

Methods

B-SNIP consortium data (2,270 participants including participants with psychotic disorders, relatives, and controls) was analyzed. Researchers used reference-informed independent component analysis and the NeuroMark 100k multi-scale intrinsic connectivity networks (ICN) template to obtain subject-specific ICNs and whole-brain functional network connectivity (FNC). FNC features associated with cognitive performance were identified through multivariate joint analysis. K-means clustering identified subgroups of patients based on these features in a discovery set. Subgroups were further evaluated in a replication set and in relatives.

Results

Two biotypes with different functional brain alteration patterns were identified. Biotype 1 exhibited brain-wide alterations, involving hypoconnectivity in cerebellar-subcortical and somatomotor-visual networks and worse cognitive performance. Biotype 2 exhibited hyperconnectivity in somatomotor-subcortical networks and hypoconnectivity in somatomotor-high cognitive processing networks, and better preserved cognitive performance. Demographic, clinical, cognitive, and FNC characteristics of biotypes were consistent in discovery and replication sets, and in relatives. 70.12% of relatives belonged to the same biotype as their affected family members.

Conclusions

These findings suggest two distinctive psychosis-related cognitive biotypes with differing functional brain patterns shared with their relatives. Patient stratification based on these biotypes instead of traditional diagnosis may help to optimize future research and clinical trials addressing cognitive dysfunction in psychotic disorders.

Cognitive Effects of Reducing First-Generation Antipsychotic Dose Compared to Switching to Ziprasidone in Long-Stay Patients with Schizophrenia

Background: Cognitive impairment is a core symptom of schizophrenia and is associated with functional outcomes. Improving cognitive function is an important treatment goal. Studies have reported beneficial cognitive effects of the second-generation antipsychotic (SGA) ziprasidone. Reducing the dose of first-generation antipsychotics (FGA) might also improve cognitive function. This study compared the cognitive effects in long-stay patients who were randomized to groups who underwent FGA dose reduction or switched to ziprasidone. Methods: High-dose FGA was reduced to an equivalent of 5 mg of haloperidol in 10 patients (FGA-DR-condition), and 13 patients switched to ziprasidone 80 mg b.i.d. (ZIPRA condition). Five domains of cognitive function were assessed before dose reduction or switching (T0) and after 1 year (T1). This study was approved by the ethics committee of the Open Ankh (CCMO number 338) and registered at the Netherlands Trial Register (code 5864). Results: Non-significant deterioration was seen in all cognitive domains studied in the FGA-DR condition, whereas there was a non-significant improvement in all cognitive domains in the ZIPRA condition. The most robust difference between conditions, in favor of ziprasidone, was in executive function. Conclusions: In patients with severe chronic schizophrenia, ziprasidone had a non-significant and very modest beneficial effect on cognitive function compared with FGA dose reduction. Larger trials are needed to further investigate this effect.

Long-term trajectories of clinical staging in first-episode psychosis and their associated cognitive outcome: A 21-year follow-up study

Cognitive deficits are already present before psychosis onset but are a key feature of first-episode psychosis (FEP). The objective of this study was to investigate the cognitive outcomes of a cohort of FEP patients who were diagnosed using the clinical staging approach and were followed for up to 21 years. We analyzed data from 173 participants with first-admission psychosis who were followed-up for a mean of 20.9 years. The clinical staging assessment was adapted from the clinical staging framework developed by McGorry et al.1 Cognitive assessment was performed using the MATRICS Consensus Cognitive Battery (MMCB) at the end of follow-up. FEP patients who were longitudinally diagnosed in the lowest clinical stages (stages 2A and 2B) showed better performance in attention, processing speed, and MCCB overall composite score than those in the highest clinical stages (stages 4A and 4B). There was a significant linear trend association between worsening of all MCCB cognitive functions and MCCB overall composite score and progression in clinical staging. Furthermore, the interval between two and five years of follow-up appears to be associated with deficits in processing speed as a cognitive marker. Our results support the validation of the clinical staging model over a long-term course of FEP based on neuropsychological performance. A decline in some cognitive functions, such as processing speed, may facilitate the transition of patients to an advanced stage during the critical period of first-episode psychosis.

Effects of Anticholinergic Burden on Verbal Memory Performance in First-Episode Psychosis

OBJECTIVES

Antipsychotics are widely used to treat first-episode psychosis but may have an anticholinergic burden, that is, a cumulative effect of medications that block the cholinergic system. Studies suggest that a high anticholinergic burden negatively affects memory in psychosis, where cognitive deficits, particularly those in verbal memory, are a core feature of the disease. The present study sought to replicate this in a large cohort of well-characterized first-episode psychosis patients. We expected that patients in the highest anticholinergic burden group would exhibit the poorest verbal memory compared to those with low anticholinergic burden and healthy controls at baseline (3 months following admission). We further hypothesized that over time, at month 12, patients' verbal memory performance would improve but would remain inferior to controls.

METHODS

Patients (n  =  311; low anticholinergic burden [n  =  241] and high anticholinergic burden [n  =  70], defined by a Drug Burden Index cut-off of 1) and healthy controls (n  =  128) completed a clinical and neurocognitive battery including parts of the Wechsler Memory Scale at months 3 and 12.

RESULTS

Cross-sectionally, using an analysis of variance, patients in the highest anticholinergic burden group had the poorest performance in verbal memory when compared to the other groups at month 3, F(2,430)  =  52.33, P < 0.001. Longitudinally, using a Generalized Estimating Equation model, the verbal memory performance of all groups improved over time. However, patients' performance overall remained poorer than the controls.

CONCLUSION

These findings highlight the importance of considering the anticholinergic burden when prescribing medications in the early stages of the disease.

Let's lower the floor: Clinical utility of the D-KEFS TMT with a forensic psychiatric inpatient population

Trail-making tests are widely used as part of neuropsychological assessments, although the prevalence of processing speed deficits in schizophrenia spectrum disorders may limit their utility when administered to this population. In response, our study sought to explore D-KEFS TMT performance among a forensic-oriented schizophrenia spectrum sample, with the goal of generating normative data to enhance the utility of the TMT with this population. Archival data was collected from a sample of patients admitted to a forensic maximum-security psychiatric facility. Analyses revealed a large percentage of individuals achieved an "impaired" result across D-KEFS TMT trials, ranging from 20% to more than 60%. The most noteworthy finding was for Number-Letter Switching, in which approximately 48% of participants performed at the floor level. Following reclassification of performance, 36% of our sample were identified as "below average," while greater than 60% of individuals were captured as average to above average. The current analyses revealed a problematic skew in TMT performance among schizophrenia spectrum patients, in turn complicating interpretation of cognitive status as well as the ability to compare performance between patients and over time. The present adjustments account for this skew and yield more variability in standardized scoring.

Prevalence, correlates and explanatory models of cognitive deficits in patients with schizophrenia-A cross sectional study

Background

Schizophrenia may cause significant impairment in social and economic aspects of a patient's life. Current evidence suggests that cognitive deficits may affect the functioning of a person with schizophrenia more than positive or negative symptoms. There is a lack of literature on explanatory models of cognitive deficits in schizophrenia that can influence help-seeking behavior.

Objectives

This study aimed to estimate the prevalence of cognitive deficits and assess their relationship with socio-demographic and clinical characteristics among patients with schizophrenia. We also planned to explore the explanatory models of cognitive deficits in these patients.

Methods

Consecutive outpatients with schizophrenia who met eligibility criteria were recruited after obtaining informed consent. The Addenbrooke's Cognitive Examination Tamil version (ACE III) and Observable Social Cognition - A Rating Scale (OSCARS) and Positive and Negative Symptom Scale (PANSS) were used to assess cognitive functioning and symptom profile, respectively. Beliefs about illness were recorded using the modified Short Explanatory Model Interview (SEMI). Socio-demographic and treatment-related details were collected with a structured proforma. Statistical analysis was done using SPSS for Windows (version 16.0.1).

Results

One hundred and forty patients participated in the study. The prevalence of cognitive deficits was 75.7% using ACE-III scores, 19.3% on OSCARS, and 40% based on subjective reports. Though the majority (81.4%) of patients reported a medical explanatory model for cognitive impairment, a significant number of them (70.7%) also held non-medical models simultaneously.

Conclusion

Cognitive deficits are prevalent in the majority of patients with schizophrenia. Poor test performance on cognitive testing was observed in those with a significant family history. Multiple contradictory explanatory models for the causation of cognitive deficits were reported.

Link between cognitive polygenic risk scores and clinical progression after a first-psychotic episode

BACKGROUND

Clinical intervention in early stages of psychotic disorders is crucial for the prevention of severe symptomatology trajectories and poor outcomes. Genetic variability is studied as a promising modulator of prognosis, thus novel approaches considering the polygenic nature of these complex phenotypes are required to unravel the mechanisms underlying the early progression of the disorder.

METHODS

The sample comprised of 233 first-episode psychosis (FEP) subjects with clinical and cognitive data assessed periodically for a 2-year period and 150 matched controls. Polygenic risk scores (PRSs) for schizophrenia, bipolar disorder, depression, education attainment and cognitive performance were used to assess the genetic risk of FEP and to characterize their association with premorbid, baseline and progression of clinical and cognitive status.

RESULTS

Schizophrenia, bipolar disorder and cognitive performance PRSs were associated with an increased risk of FEP [false discovery rate (FDR) ⩽ 0.027]. In FEP patients, increased cognitive PRSs were found for FEP patients with more cognitive reserve (FDR ⩽ 0.037). PRSs reflecting a genetic liability for improved cognition were associated with a better course of symptoms, functionality and working memory (FDR ⩽ 0.039). Moreover, the PRS of depression was associated with a worse trajectory of the executive function and the general cognitive status (FDR ⩽ 0.001).

CONCLUSIONS

Our study provides novel evidence of the polygenic bases of psychosis and its clinical manifestation in its first stage. The consistent effect of cognitive PRSs on the early clinical progression suggests that the mechanisms underlying the psychotic episode and its severity could be partially independent.

Effects of risperidone/paliperidone versus placebo on cognitive functioning over the first 6 months of treatment for psychotic disorder: secondary analysis of a triple-blind randomised clinical trial

The drivers of cognitive change following first-episode psychosis remain poorly understood. Evidence regarding the role of antipsychotic medication is primarily based on naturalistic studies or clinical trials without a placebo arm, making it difficult to disentangle illness from medication effects. A secondary analysis of a randomised, triple-blind, placebo-controlled trial, where antipsychotic-naive patients with first-episode psychotic disorder were allocated to receive risperidone/paliperidone or matched placebo plus intensive psychosocial therapy for 6 months was conducted. A healthy control group was also recruited. A cognitive battery was administered at baseline and 6 months. Intention-to-treat analysis involved 76 patients (antipsychotic medication group: 37; 18.6_Mage [2.9] years; 21 women; placebo group: 39; 18.3_Mage [2.7]; 22 women); and 42 healthy controls (19.2_Mage [3.0] years; 28 women). Cognitive performance predominantly remained stable (working memory, verbal fluency) or improved (attention, processing speed, cognitive control), with no group-by-time interaction evident. However, a significant group-by-time interaction was observed for immediate recall (p = 0.023), verbal learning (p = 0.024) and delayed recall (p = 0.005). The medication group declined whereas the placebo group improved on each measure (immediate recall: p = 0.024; η_p² = 0.062; verbal learning: p = 0.015; η_p² = 0.072 both medium effects; delayed recall: p = 0.001; η_p² = 0.123 large effect). The rate of change for the placebo and healthy control groups was similar. Per protocol analysis (placebo n = 16, medication n = 11) produced similar findings. Risperidone/paliperidone may worsen verbal learning and memory in the early months of psychosis treatment. Replication of this finding and examination of various antipsychotic agents are needed in confirmatory trials. Antipsychotic effects should be considered in longitudinal studies of cognition in psychosis.Trial registration: Australian New Zealand Clinical Trials Registry ( http://www.anzctr.org.au/ ; ACTRN12607000608460).

Effect of HD-tDCS on white matter integrity and associated cognitive function in chronic schizophrenia: A double-blind, sham-controlled randomized trial

Schizophrenia is a disabling major mental disorder, which includes critical deficits in cognitive function, for which no effective intervention currently exists. The aim of our double-blind, randomized, sham-controlled trial was to evaluate the effects of high-definition transcranial direct current stimulation (HD-tDCS) on the cognitive deficits in schizophrenia. This study sample consisted of 56 individuals with chronic schizophrenia, randomly allocated to either the active stimulation or sham group. The treatment consisted of ten consecutive days of HD-tDCS, 20 min/day, applied over the left dorsolateral prefrontal lobe. Changes in clinical outcomes, cognitive assessments, and diffusion tensor imaging were evaluated pre- to post-intervention. Matched-healthy controls (HCs) were included to identify white matter changes in patients with schizophrenia before treatment. Compared to HCs, schizophrenia was associated with reduced integrity of the white matter tracts of the corpus callosum and corona radiata. HD-tDCS enhanced integrity in the corpus callosum and anterior and superior corona radiata, which was associated with the change in cognitive performance. HD-tDCS offers a potential approach to improve cognition deficits in schizophrenia through a modulatory effect on white matter tracts. Given the lack of approved treatments for cognitive deficits, these findings are clinically relevant.

Cross-diagnostic determinants of cognitive functioning: the muscarinic cholinergic receptor as a model system

Cognitive impairment is a predictor of disability across different neuropsychiatric conditions, and cognitive abilities are also strongly related to educational attainment and indices of life success in the general population. Previous attempts at drug development for cognitive enhancement have commonly attempted to remedy defects in transmitters systems putatively associated with the conditions of interest such as the glutamate system in schizophrenia. Recent studies of the genomics of cognitive performance have suggested influences that are common in the general population and in different neuropsychiatric conditions. Thus, it seems possible that transmitter systems that are implicated for cognition across neuropsychiatric conditions and the general population would be a viable treatment target. We review the scientific data on cognition and the muscarinic cholinergic receptor system (M1 and M4) across different diagnoses, in aging, and in the general population. We suggest that there is evidence suggesting potential beneficial impacts of stimulation of critical muscarinic receptors for the enhancement of cognition in a broad manner, as well as the treatment of psychotic symptoms. Recent developments make stimulation of the M1 receptor more tolerable, and we identify the potential benefits of M1 and M4 receptor stimulation as a trans-diagnostic treatment model.

Examining the repeatable battery for the assessment of neuropsychological status validity indices in people with schizophrenia spectrum disorders

Objective: We examined the frequency of possible invalid test scores on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) in patients with schizophrenia spectrum disorders, and whether there was an association between scores on the embedded RBANS performance validity tests (PVTs) and self-reported symptoms of apathy as measured by the Initiate Scale of the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A). Methods: Participants included 250 patients (M = 24.4 years-old, SD = 5.7) with schizophrenia spectrum disorders. Base rates of RBANS Effort Index (EI), Effort Scale (ES), and Performance Validity Index (PVI) test scores were computed. Spearman correlations were used to examine the associations between the RBANS PVTs, the RBANS Index scores, and the BRIEF-A Initiate Scale. Regression analyses were used to investigate how well the RBANS PVTs predicted scores on the BRIEF-A Initiate Scale. Results: The frequency of invalid scores on the EI (>3) and the PVI (<42) in participants with schizophrenia spectrum disorders was 6%. The frequency of invalid ES scores (<12) was 28% in the patients compared to 15% in the U.S. standardization sample. There was a small significant correlation between the EI and the BRIEF-A Initiate Scale (rho=.158, p<.05). Conclusions: The rates of invalid scores were similar to previously published studies. Invalid scores on the BRIEF-A were uncommon. Apathy measured with the BRIEF-A Initiate Scale was not associated with performance on the RBANS validity measures or with measures of cognition.

Neurocognitive correlates of the varied domains of outcomes at 20 year follow-up of first-episode psychosis

Little is known about long-term outcomes of the first episode of psychosis (FEP) other than in the symptomatic domain. We hypothesised that cognitive impairment is associated with poorer multi-domain outcomes at a long-term follow-up of FEP patients. We followed-up 172 FEP patients for a mean of 20.3 years. Ten outcome dimensions were assessed (symptomatic, functional and personal recovery, social disadvantage, physical health, suicide attempts, number of episodes, current drug use, chlorpromazine equivalent doses (CPZ), and schizophrenia/schizoaffective disorder final diagnosis). Cognition was assessed at follow-up. Processing speed and verbal memory deficits showed significant associations with poor outcomes on symptomatic, social functioning, social disadvantage, higher number of episodes, and higher CPZ. Significant associations were found between visual memory impairments were significantly associated with low symptomatic and functional recovery, between attentional deficits and a final diagnosis of schizophrenia/schizoaffective disorder, and between social cognition deficits and poor personal recovery.Lower cognitive global scores were significantly associated with all outcome dimensions except for drug abuse and physical status. Using multiple outcome dimensions allowed for the inclusion of the patients' perspective and other commonly neglected outcome measures. Taken together, cognitive impairment in FEP patients is strongly related to poor performance on several outcome dimensions beyond symptomatic remission.

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.

Prevalence and correlates of cognitive impairment in schizophrenia: a cross-sectional study from a teaching hospital southern Sri Lanka

INTRODUCTIONS

This study assessed the prevalence of cognitive impairment, the degree of impairment in individual cognitive domains and sociodemographic and clinical correlates among patients attending to psychiatry clinics at Teaching Hospital, Karapitiya, Sri Lanka.

METHODS

A cross-sectional study was carried out at the psychiatry outpatient clinics of Teaching Hospital, Karapitiya, Sri Lanka. Their cognitive functions were assessed using the culturally validated Sinhala version of Addenbrooke's Cognitive Examination - III (ACE-III-S). ACE-III-S score below 85.5 was considered as significant cognitive impairment. Linear regression analysis was used to assess the factors associated with cognitive impairment. A P value of 0.05 is considered significant.

RESULTS

One hundred forty patients with schizophrenia were assessed. Of this, 125 patients had significant cognitive impairment with a prevalence of 89.3% (95% CI:84.1-94.5). Impairment in each cognitive domain was as follows: 60% in attention, 65.7% in memory, 55% in fluency, 61.4% in language, and 63.6% in visuospatial skills. Impairment was not different between cognitive domains. Advancing age (P < 0.001), shorter duration of formal education (P = < 0.001), longer duration of illness (P = < 0.001) and not having a full-time employment (P = 0.020) showed a positive association with cognitive impairment.

CONCLUSIONS

Nine out of ten patients with schizophrenia experienced significant cognitive impairment. Patients showed more than 50% impairment in all cognitive domains. The cognitive domains did not show disproportionate impairment. This study highlights the importance of introducing routine cognitive assessment protocols in patients with schizophrenia.

Relapse of first-episode schizophrenia patients and neurocognitive impairment: The role of dopaminergic and anticholinergic burden

BACKGROUND

The prevention of relapse may be a key factor to diminish the cognitive impairment of first-episode schizophrenia (FES) patients. We aimed to ascertain the effects of relapse, and dopaminergic and anticholinergic treatment burdens on cognitive functioning in the follow-up.

METHODS

Ninety-nine FES patients participated in this study. Cognitive assessments were performed at baseline and after 3 years of follow-up or, in those patients who relapsed, after &gt;2 months of stabilization of the new acute psychotic episode. The primary outcomes were final cognitive dimensions.

RESULTS

Repeated measures MANOVA analyses showed improvements in the whole sample on the end-point assessments in processing speed and social cognition. However, only impairment in social cognition showed a significant interaction with relapse by time in this sample. Relapse in FES patients was significantly associated with poor performance on end-point assessments of working memory, social cognition and global cognitive score. Anticholinergic burden, but not dopaminergic burden, was associated with verbal memory impairment. These significant associations resulted after controlling for baseline cognitive functioning, relapse and dopaminergic burden.

CONCLUSIONS

The relationship between relapse and cognitive impairment in recovered FES patients seems to be particularly complex at the short-term follow-up of these patients. While relapse was associated with working memory, social cognition impairments and global cognitive score, anticholinergic burden might play an additional worsening effect on verbal memory. Thus, tailoring or changing antipsychotics and other drugs to reduce their anticholinergic burden may be a potential modifiable factor to diminish cognitive impairment at this stage of the illness.

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.

Cognitive dysfunction in schizophrenia: An expert group paper on the current state of the art

Cognitive impairment in schizophrenia represents one of the main obstacles to clinical and functional recovery. This expert group paper brings together experts in schizophrenia treatment to discuss scientific progress in the domain of cognitive impairment to address cognitive impairments and their consequences in the most effective way. We report on the onset and course of cognitive deficits, linking them to the alterations in brain function and structure in schizophrenia and discussing their role in predicting the transition to psychosis in people at risk. We then address the assessment tools with reference to functioning and social cognition, examining the role of subjective measures and addressing new methods for measuring functional outcomes including technology based approaches. Finally, we briefly review treatment options for cognitive deficits, focusing on cognitive remediation programs, highlighting their effects on brain activity and conclude with the potential benefit of individualized integrated interventions combing cognitive remediation with other approaches.

Glutamate levels across deep brain structures in patients with a psychotic disorder and its relation to cognitive functioning

BACKGROUND

Patients with psychotic disorders often show prominent cognitive impairment. Glutamate seems to play a prominent role, but its role in deep gray matter (DGM) regions is unclear.

AIMS

To evaluate glutamate levels within deep gray matter structures in patients with a psychotic disorder in relation to cognitive functioning, using advanced spectroscopic acquisition, reconstruction, and post-processing techniques.

METHODS

A 7-Tesla magnetic resonance imaging scanner combined with a lipid suppression coil and subject-specific water suppression pulses was used to acquire high-resolution magnetic resonance spectroscopic imaging data. Tissue fraction correction and registration to a standard brain were performed for group comparison in specifically delineated DGM regions. The brief assessment of cognition in schizophrenia was used to evaluate cognitive status.

RESULTS

Average glutamate levels across DGM structures (i.e. caudate, pallidum, putamen, and thalamus) in mostly medicated patients with a psychotic disorder (n = 16, age = 33, 4 females) were lower compared to healthy controls (n = 23, age = 24, 7 females; p = 0.005, d = 1.06). Stratified analyses showed lower glutamate levels in the caudate (p = 0.046, d = 0.76) and putamen p = 0.013, d = 0.94). These findings were largely explained by age differences between groups. DGM glutamate levels were positively correlated with psychomotor speed (r(30) = 0.49, p = 0.028), but not with other cognitive domains.

CONCLUSIONS

We find reduced glutamate levels across DGM structures including the caudate and putamen in patients with a psychotic disorder that are linked to psychomotor speed. Despite limitations concerning age differences, these results underscore the potential role of detailed in vivo glutamate assessments to understand cognitive deficits in psychotic disorders.

The relationship between TLR4/NF-κB/IL-1β signaling, cognitive impairment, and white-matter integrity in patients with stable chronic schizophrenia

OBJECTIVE

Previous studies have implicated intricate interactions between innate immunity and the brain in schizophrenia. Monocytic Toll-like receptor (TLR) 4 signaling, a crucial "sensor" of innate immunity, was reported to be over-activated in link with cognitive impairment in schizophrenia. As TLR4 is predominantly expressed on gliocytes prior to expression in neurons, we hypothesized that higher TLR4 levels may contribute to cognitive deterioration by affecting white matter microstructure.

METHODS

Forty-four patients with stable chronic schizophrenia (SCS) and 59 healthy controls (HCs) were recruited in this study. The monocytic function was detected with lipopolysaccharide (LPS) stimulation to simulate bacterial infection. Basal and LPS- stimulated levels of TLR4, nuclear factor-kappa B (NF-κB), and interleukin (IL)-1β were quantified with flow cytometry. Cognitive function was assessed by the MATRICS Consensus Cognitive Battery (MCCB) and psychopathological symptoms were evaluated by the Positive and Negative Syndrome Scale (PANSS). We employed diffusion tensor imaging with a 3-T scanner and evaluated white-matter integrity with fractional anisotropy (FA). Subcortical volume and cortical thickness were also assessed.

RESULTS

The TLR4/NF-κB/IL-1β signaling pathway was activated in patients with SCS, but responded sluggishly to LPS stimulation when compared with HCs. Furthermore, monocytic TLR4 expressions were inversely correlated with cognitive function and white matter FA, but not with cortical thickness or subcortical gray matter volume in schizophrenia.

CONCLUSION

Our findings support altered TLR4 signaling pathway activity in association with deficits in cognition and white matter integrity in schizophrenia.

[Anticholinergic scales: Use in psychiatry and update of the anticholinergic impregnation scale]

Anticholinergic properties are well known to prescribers, notably in mental health, as a therapeutic strategy for i.e. extrapyramidal syndrome but also as a source of numerous adverse side effects. Herein, we propose a narrative literature review describing: (i) cholinergic pharmacology and anticholinergic properties; (ii) the importance of anticholinergic therapeutic properties in psychiatry; (iii) the existing anticholinergic drug scales and their usage limitations in Psychiatry and; last (iv) an update to the anticholinergic drug impregnation scale, designed for the French psychiatry practice. The anticholinergic side effects can appear both in the peripheral level (dry mouth, constipation, etc.) and in the central level (especially as cognitive deficits). Many of the so called « anticholinergic » drugs are in fact entirely or mostly antimuscarinic and act essentially as parasympathetic system antagonists. Overall, anticholinergic/antimuscarinic side effects are usually attributed to psychotropic medications: to certain antipsychotics, notably classical neuroleptics such as phenothiazine and also to tricyclic antidepressants. In practice, the impact of anticholinergic toxicity treatments is often highlighted due to their excessively prolonged use in patients on antipsychotics. Interestingly, these antipsychotic treatments are better known for their anticholinergic side effects, especially cognitive ones, with an early onset specially in elder patients and/or in the case of polymedication. In order to evaluate anticholinergic side effects, metrics known as anticholinergic burden scales were created in the last few decades. Nowadays, 13 different scales are documented and accepted by the international academic community, but only three of them are commonly used: the Anticholinergic Drug Scale (ADS), the Anticholinergic Risk Scale (ARS) and the Anticholinergic Burden Scale (ACB). All of them are based on a similar principle, consisting of grading treatments individually, and they are normally scored from 0 - no presence of side effects - to 3 - anticholinergic effects considered to be strong or very strong. Using these scales enables the calculation of the so-called "anticholinergic burden", which corresponds to the cumulative effect of using multiple medications with anticholinergic properties simultaneously. The application of anticholinergic scales to patients with psychiatric disorders has revealed that schizophrenic patients seem to be especially sensitive to anticholinergic cognitive side effects, while elder and depressed patients were more likely to show symptoms of dementia when exposed to higher anticholinergic burden. Unfortunately, these tools appear to have a low parallel reliability, and so they might induce large differences when assessing side effects predictability. In addition, the capacity of these scales to predict central adverse effects is limited due to the fact they poorly or do not differentiate, the ability of treatments to cross the blood-brain barrier. Finally, one last limitation on the validity of these scales is prescription posology is not accounted for side effects considered to be dose dependent. Recently, the MARANTE (Muscarinic Acetylcholine Receptor ANTagonist Exposure) scale has incorporated an anticholinergic burden weighting by posology. Nevertheless, this new model can be criticized, due to the limited number of medications included and due to testing a limited number of potency ranges and dosages for each treatment. Herein, we propose an update to the Anticholinergic Impregnation Scale, developed specifically for the French Psychiatry practice. The scale validation was based on an evaluation of the prescriptions correcting anticholinergic peripheral side effects (constipation, xerostomia and xeropthalmia). This indirect evaluation allowed us to show patients with an anticholinergic impregnation score higher than 5 received significantly more treatments for constipation and xerostomia. This strategy bypasses the bias of a cognitive evaluation in patients with severe mental health disorders. Moreover, the relevance of a tool developed specifically for French psychiatry is justified by the fact that some highly prescribed treatments for mental illness in France (cyamemazine and tropatemine) are strong anticholinergics, and also by the fact they are rarely included in the existing anticholinergic scales. This update of the original scale, published in 2017, includes information whether prescribed drugs cross the blood-brain barrier and thus makes possible a more accurate assessment when evaluating anticholinergic central side effects. Finally, the anticholinergic impregnation scale will soon be integrated into a prescription help software, which is currently being developed to take into consideration dose dependent adverse effects.

Impact of anticholinergic load on functioning and cognitive performances of persons with psychosis referred to psychosocial rehabilitation centers

BACKGROUND

Few studies have explored whether high-anticholinergic load may hamper rehabilitation in persons with schizophrenia. We aim to explore the associations between anticholinergic load of psychotropic treatment and functioning or cognitive performances of persons with psychosis engaged in psychosocial rehabilitation.

METHODS

The study was performed using data collected at baseline assessment in the REHABase cohort including persons referred to a French network of psychosocial rehabilitation centers. The composite-rating scale developed by Salahudeen et al. was used to rate the anticholinergic load of psychotropic drugs prescribed at baseline assessment. The associations between total anticholinergic load score (categorized as 'low' <3 v. 'high' ⩾3) and functioning or cognitive characteristics were explored using multivariate analyses.

RESULTS

Of the 1012 participants with schizophrenia spectrum disorders identified in the REHABase, half used at least two psychotropic drugs with anticholinergic activity and one out of three was prescribed at least one psychotropic drug with high-anticholinergic activity. High-anticholinergic load was significantly associated with lower stage of recovery [odds ratio (OR) = 1.70, 95% confidence interval (CI) 1.05-2.76, p = 0.03], poor mental well-being (OR = 1.55, 95% CI 1.02-2.33, p = 0.04) and poor self-rated medication adherence (OR = 2.14, 95% CI 1.29-3.53, p = 0.003). Regarding cognition, a high-anticholinergic score was associated with poorer delayed-episodic memory (OR = 1.69, 95% CI 1.01-2.85, p = 0.05) and at the trend level with faster completion time on the test exploring executive performance (OR = 0.67, 95% CI 0.43-1.04, p = 0.07).

CONCLUSIONS

The psychosocial rehabilitation plan of persons with psychosis should integrate optimization of psychotropic treatment in order to lessen the functional and cognitive impact of high-anticholinergic load.

Cognitive functioning in first episode psychosis. Gender differences and relation with clinical variables

AIMS

to study the differences in cognitive functioning in patients and controls. In addition, study the influence of symptoms, cannabis consumption, chlorpromazine doses, DUP and IQ in cognitive performance in patients, both in the total sample and divided by gender.

METHODS

70 first episode psychosis patients and 63 healthy controls (HC) participated in the study and were assessed with the MATRICS battery and the Vocabulary subtest of WAIS-IV. Symptoms in FEP patients were evaluated with the Emsley factors of the PANSS scale.

RESULTS

patients showed lower scores than controls in all cognitive domains studied. There were no significant differences between FEP men and FEP women, but we found gender differences in favour of women in processing speed, working memory and composite total scored domains in the HC group. Finally, symptoms and Chlorpromazine doses showed an influence on cognitive performance in the total FEP sample. When splitting the sample by gender, positive symptoms may be more detrimental to women's cognitive functioning, while disorganized symptoms may play the most important role in cognitive performance in men.

CONCLUSIONS

patients showed worse cognitive performance in all cognitive domains compared to healthy controls. In our FEP sample, gender does not seem to influence cognitive performance measured with the MATRICS. Severity of symptoms influences positively in cognitive performance. The dose of Chlorpromazine and symptoms are influential variables to be taken into account in cognition rehabilitation programs.

Association of negative symptoms with cognitive impairment in Chinese Han patients with chronic schizophrenia

OBJECTIVE

Cognitive impairment is an essential feature of schizophrenia; however, the relationship between clinical psychiatric symptoms with cognitive impairment is still unclear. Therefore, we aimed to assess cognitive deficits and the relationship between clinical symptoms and cognitive function in patients with chronic schizophrenia, which provide a reference guide for psychiatrists.

METHODS

We compared the cognitive function in 312 schizophrenia inpatients and 397 healthy controls by using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The positive and negative symptom scale (PANSS) was used to assess the clinical symptoms of the patients.

RESULTS

Analysis of covariance showed that the RBANS total and four index scores (all p < 0.001) were significantly lower in patients than healthy controls. After Bonferroni correction, Pearson correlation analysis showed that there was a significant negative association between PANSS negative symptom subscale and RBANS total score and all 5 domain scores (all p < 0.01). Further regression analysis showed that negative symptoms, age, age of onset, and antipsychotic dose were important independent predictors of cognitive deficits.

CONCLUSIONS

Our findings suggest that patients with chronic schizophrenia exhibit cognitive deficits compared with healthy people. Negative symptoms and some clinical variables are associated with cognitive impairment in patients with schizophrenia.KEYPOINTSThis study indicates that patients with chronic schizophrenia have extensive cognitive impairment shown on RBANS except for the visuospatial/constructional domain.Cognitive impairment in patients is associated with age, negative symptoms, age of onset, and antipsychotic dose.There is a significant negative association between cognitive deficits and negative symptoms in patients with chronic schizophrenia.The results of this study need to be confirmed in future studies with longitudinal designs with a large and sex-balanced sample in first-episode drug naïve patients with schizophrenia.

Longitudinal course of cognition in schizophrenia: Does treatment resistance play a role?

Treatment-resistant schizophrenia (TRS) represents a main clinical issue, associated with worse functional outcome and higher healthcare costs. Clozapine is the most effective antipsychotic for TRS, although 40% of resistant patients, defined as ultra-treatment resistant (UTR), are clozapine-refractory. Previous literature suggests that TRS is characterized by worse cognitive functioning and a more disrupted neurobiological substrate, but only few studies focused on UTR schizophrenia. Moreover, despite this evidence and the central role of cognition, to date no study has investigated long-term cognitive outcome in TRS. Based on these premises, this study aims to analyze cross-sectional and long-term cognitive functioning of patients with schizophrenia, stratified according to antipsychotic response: first-line responders (FLRs), clozapine responders (CRs) and UTRs. We analyzed cross-sectional and retrospective cognitive evaluations of 93 patients with schizophrenia (32 FLRs, 42 CRs, 19 UTRs) over a mean follow-up period of 9 years, also taking into account possible influencing factors such as clinical severity and antipsychotic load. Analyses showed that UTR is associated with overall impaired cognitive functioning and represents the main predictor of long-term cognitive decline. We observed no significant differences between FLR and CR patients, which showed moderate cognitive improvement over time. This is the first study to report an association of treatment resistance with longitudinal cognitive course in schizophrenia, indicating that UTR is correlated with cognitive decline over time. This decline may either be a consequence of the persistence of psychotic symptoms or depend on a distinct and more disrupted neurobiological substrate affecting both cognition and antipsychotic response.

The longitudinal effect of antipsychotic burden on psychosocial functioning in first-episode psychosis patients: the role of verbal memory

BACKGROUND

Previous literature supports antipsychotics' (AP) efficacy in acute first-episode psychosis (FEP) in terms of symptomatology and functioning but also a cognitive detrimental effect. However, regarding functional recovery in stabilised patients, these effects are not clear. Therefore, the main aim of this study is to investigate dopaminergic/anticholinergic burden of (AP) on psychosocial functioning in FEP. We also examined whether cognitive impairment may mediate these effects on functioning.

METHODS

A total of 157 FEP participants were assessed at study entry, and at 2 months and 2 years after remission of the acute episode. The primary outcomes were social functioning as measured by the functioning assessment short test (FAST). Cognitive domains were assessed as potential mediators. Dopaminergic and anticholinergic AP burden on 2-year psychosocial functioning [measured with chlorpromazine (CPZ) and drug burden index] were independent variables. Secondary outcomes were clinical and socio-demographic variables.

RESULTS

Mediation analysis found a statistical but not meaningful contribution of dopaminergic receptor blockade burden to worse functioning mediated by cognition (for every 600 CPZ equivalent points, 2-year FAST score increased 1.38 points). Regarding verbal memory and attention, there was an indirect effect of CPZ burden on FAST (b = 0.0045, 95% CI 0.0011-0.0091) and (b = 0.0026, 95% CI 0.0001-0.0006) respectively. However, only verbal memory post hoc analyses showed a significant indirect effect (b = 0.009, 95% CI 0.033-0.0151) adding premorbid IQ as covariate. We did not find significant results for anticholinergic burden.

CONCLUSION

CPZ dose effect over functioning is mediated by verbal memory but this association appears barely relevant.

Cytomegalovirus infection and IQ in patients with severe mental illness and healthy individuals

Cytomegalovirus (CMV) infection in immunocompetent adults is usually asymptomatic, but results in lifelong latency. Infection occurring congenitally or in immunodeficiency can lead to cognitive impairment. We aimed to investigate the associations between CMV exposure and intelligence quotient (IQ) in patients with schizophrenia spectrum disorders (SZS), bipolar spectrum disorders (BDS) and healthy controls (HC). CMV immunoglobulin G antibody concentrations were measured by immunoassay and expressed as dichotomous measures (seropositive/CMV+ vs. seronegative/CMV-). Based on a significant CMV-by-diagnosis-by-sex interaction on IQ, we investigated main and interaction effects of CMV and sex on IQ in each diagnostic category. Significant CMV-by-sex interactions were found in patient groups. In SZS, CMV+ female patients (n = 50) had significantly lower IQ than CMV- female patients (n = 33), whereas CMV+ (n = 48) and CMV- (n = 45) male patients did not differ in IQ. In BDS, CMV+ (n = 49) and CMV- (n = 37) female patients did not differ in IQ, whereas CMV+ male patients (n = 33) had significantly higher IQ than CMV- male patients (n = 32). Among HC, CMV+ (n = 138) and CMV- (n = 118) male participants as well as CMV+ (n = 125) and CMV- (n = 93) female participants did not differ in IQ. Our findings suggest that CMV exposure may affect IQ in patients with severe mental illness but not HC.

Cognitive ability and metabolic physical health in first-episode psychosis

Cognitive impairments are a core feature of first-episode psychosis (FEP), arising before illness onset and antipsychotic exposure. Individuals with chronic psychosis experience poorer physical health while taking antipsychotic medication, but health disparities may be evident at FEP onset, prior to antipsychotic exposure. Given the links between cognition and physical health in healthy populations, the aim was to explore whether cognition and physical health are associated in FEP, which could inform early physical health interventions for cognition in FEP. Participants were aged 15 to 25 and included 86 individuals experiencing FEP with limited antipsychotic exposure and duration of untreated psychosis of ≤six months, and 43 age- and sex-matched controls. Individuals with FEP performed significantly poorer than controls in most cognitive domains (Cohen's d = 0.38 to 1.59). Groups were similar in metabolic health measures, excluding a significantly faster heart rate in FEP (d = 0.68). Through hierarchical regression analyses, we found that in the overall sample, BMI was negatively related to current IQ after controlling for education and group (FEP/control). Relationships between BMI and cognition were consistent across the FEP and healthy control groups. In FEP, current IQ and working memory were negatively correlated with lipid profiles. Findings suggest that in FEP, impaired cognition is exhibited earlier than physical health problems, and that compared to controls, similar relationships with cognition are demonstrated. Causal pathways and trajectories of relationships between health and cognition in FEP require investigation, especially as antipsychotic medications are introduced. The findings have implications for cognitive and health interventions.

White Matter Alterations Between Brain Network Hubs Underlie Processing Speed Impairment in Patients With Schizophrenia

Processing speed (PS) impairment is one of the most severe and common cognitive deficits in schizophrenia. Previous studies have reported correlations between PS and white matter diffusion properties, including fractional anisotropy (FA), in several fiber bundles in schizophrenia, suggesting that white matter alterations could underpin decreased PS. In schizophrenia, white matter alterations are most prevalent within inter-hub connections of the rich club. However, the spatial and topological characteristics of this association between PS and FA have not been investigated in patients. In this context, we tested whether structural connections comprising the rich club network would underlie PS impairment in 298 patients with schizophrenia or schizoaffective disorder and 190 healthy controls from the Australian Schizophrenia Research Bank. PS, measured using the digit symbol coding task, was largely (Cohen’s d = 1.33) and significantly (P < .001) reduced in the patient group when compared with healthy controls. Significant associations between PS and FA were widespread in the patient group, involving all cerebral lobes. FA was not associated with other cognitive measures of phonological fluency and verbal working memory in patients, suggesting specificity to PS. A topological analysis revealed that despite being spatially widespread, associations between PS and FA were over-represented among connections forming the rich club network. These findings highlight the need to consider brain network topology when investigating high-order cognitive functions that may be spatially distributed among several brain regions. They also reinforce the evidence that brain hubs and their interconnections may be particularly vulnerable parts of the brain in schizophrenia.

"Cool" and "Hot" Executive Functions in Patients With a Predominance of Negative Schizophrenic Symptoms

Background

Patients with psychosis often present significant neurocognitive deficits, with executive function deficits (EEFF) being one of the most relevant cognitive impairments with the greatest impact on the functioning of their daily lives. However, although various findings of executive involvement were reported, it is not entirely clear whether there is a differential pattern of involvement according to the clinical symptoms or the deficits occur in all or only in some subcomponents of EEFF.

Objective

The present study had a double objective: to study the specific deficits in the cool and hot EEFF in a group of psychotic patients with a predominance of negative symptoms; and determine the possible associations between the performance of the patients in the cool an hot EEFF tasks with the negative symptoms, and with the behavioral alterations associated with the dysexecutive syndrome.

Method

66 participants, 33 psychotic patients with a predominance of negative symptoms and 33 healthy control subjects matched in gender, age and educational level participated. Both groups were administered 4 cool EEFF tasks (coding/maintenance and updating of information in working memory, ability to change the mental set and planning), and 3 hot EEFF tasks (decision making in situations of uncertainty, recognition of emotions through facial expressions and theory of mind). In the group of patients, the Negative symptoms were evaluated through the Scale for the Evaluation of Negative Symptoms (SANS), and the behavioral alterations associated with dysexecutive syndrome through the subscale of "Executive Dysfunction" of the Frontal Systems Behavior Scale.

Results

Patients performed worse on three cool EEFF tasks and on two of the hot EEFF tasks. Additionally, we found a correlation between the SANS score and the "executive dysfunction" subscale, with the cold EEFF task that measures planning.

Conclusion

Our findings showed that in psychotic patients with a predominance of negative symptoms, both, the cognitive (cool) and emotional (hot) components of executive functions are affected. The results reinforce the need for a cognitive rehabilitation treatment of the executive components of the working memory and of those more socio-emotional aspects.

Cognitive impairment and C-reactive protein in clinically stable schizophrenia outpatients: a focus on sex differences

Although previous findings identified an association between C-reactive protein (CRP) levels, and impaired cognitive functions in patients with schizophrenia (SZ), little is currently known about the relationship between inflammation, cognition, and sex in SZ. The current study aimed to explore the association between peripheral inflammation and cognitive impairment in SZ as a function of sex. The sample included 132 clinically stable patients with SZ, of whom 82 were males (62.1%) and 50 females (37.9%). Sociodemographic data were collected, an accurate assessment was performed using the Positive and Negative Syndrome (PANSS), Clinical Assessment Interview for Negative Symptoms (CAINS), and Calgary Depression (CDS) scales, and the MATRICS Consensus Cognitive Battery (MCCB), and CRP levels were tested. A Pearson correlation and multiple regression analyses, including potential confounding factors, were performed. We found an inverse association between CRP levels and performance on visual learning (r = − 0.386, p = 0.006) domain in female patients only, whereas no correlations were found in males. The regression model for women retained age (β = − 0.319, p = 0.017), the CAINS-MAP score (β = − 0.247, p = 0.070), and the CRP (β = − 0.321, p = 0.013) as predictors of visual learning. Our results suggest the possible existence of sex-specific modulation of the association between systemic inflammation and the cognitive features of the illness.

Verbal memory measurement towards digital perspectives in first-episode psychosis: A review

BACKGROUND

Even in the early phases of psychotic spectrum illnesses such as schizophrenia, patients can experience cognitive decline or deficits prior to the onset of psychotic symptoms such as delusions and hallucinations. In this systematic review, we assessed which verbal memory assessments are most widely used in first-episode psychosis and may be applied via digital technologies (smartphone applications, etc.) for use in early detection.

METHODS

In November 2019, we searched for studies measuring verbal memory in first episode psychosis or schizophrenia over the past 10 years on PubMed and PsycINFO. We screened abstracts of these studies and excluded review studies. Full-texts of included studies were used to identify the verbal memory measurement tests, follow-up frequencies, and sample sizes.

RESULTS

We screened 233 reports and found that 120 original research studies measured verbal memory in first episode psychosis over the past 10 years. Four of these studies specified using a computer, 24 (20%) used a paper-pen format, 1(1%) used both, and 91 (76%) studies did not specify their administration tools or suggest there were offered in digital formats. Thirty-five (30%) studies had follow-up measurements of verbal memory, while 85 (70%) had only a single verbal memory measurement.

DISCUSSION

While many scales are commonly used to measure verbal memory in first episode psychosis, they are not often administered via digital technology. There is an emerging opportunity to administer these and other tests via digital technologies for expanding access to early detection of cognitive decline in clinical high risk and first-episode psychosis.

Sex difference in cognitive impairment in drug-free schizophrenia: Association with miR-195 levels

OBJECTIVE

There is evidence that microRNA-195 (miR-195) is associated with schizophrenia (SZ) and cognition, but the relationship between miR-195 and cognitive impairment in SZ is still unknown. Sex differences in both microRNA (miRNA) expression and cognition were found in SZ. We aim to investigate whether sex moderates the relationship between miR-195 levels and cognition in SZ.

METHODS

We recruited 121 drug-free SZ patients and 129 healthy controls. miR-195 expression levels in peripheral blood mononuclear cells (PBMCs) were measured using qRT-PCR. The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was performed to assess cognitive function. MANCOVA, ANCOVA, correlation analysis and hierarchical linear regression analysis were used to test the effect of sex on the aforementioned variables.

RESULTS

All RBANS scores significantly decreased in patients compared to healthy controls (all p < 0.001); ANCOVA analysis demonstrated female SZ patients had lower delayed memory score (F = 15.36, p < 0.001) and total score (F = 5.26, p = 0.024) than male patients. There was no diagnosis, sex or sex by diagnosis interaction effect on miR-195 levels (all p > 0.05). Interestingly, correlation analysis showed significant negative association between miR-195 and attention score (r = -0.389, p = 0.019), delayed memory score (r= -0.351, p = 0.036), and total score (r = -0.386, p = 0.020) only in female patients. Hierarchical regression analysis showed sex by miR-195 interaction was a significant predictor of the RBANS total score (ΔR2 = 0.042, F(1, 67) = 4.71, p = 0.033).

CONCLUSION

Our data indicate that miR-195 is associated with cognitive impairment in female SZ patients, and it may be involved in the underlying mechanism of sex differences in cognitive impairment in SZ.

Psychiatric symptoms and quality of life in older adults with schizophrenia spectrum disorder: results from a multicenter study

The severity of psychopathology has a strong negative impact on quality of life (QoL) among older adults with schizophrenia spectrum disorder. However, because these subjects generally experience multiple psychiatric symptoms, it remains unclear whether decreased QoL in this population is due to specific symptoms (e.g., hallucinations), specific dimensions of psychopathology (e.g., negative symptoms), a general psychopathology dimension representing the shared effect across all psychiatric symptoms, or a combination of these explanations. Data were derived from the Cohort of individuals with Schizophrenia Aged 55 years or more (CSA) study, a large (N = 353) multicenter sample of older adults with schizophrenia spectrum disorder recruited from French public-sector psychiatric departments. We used structural equation modeling to examine the shared and specific effects of psychiatric symptoms on QoL, while adjusting for sociodemographic characteristics, general medical conditions, global cognitive functioning and psychotropic medications. Psychiatric symptoms and QoL were assessed face-to-face by psychiatrists using the Brief Psychiatric Rating Scale (BPRS) and the Quality of Life Scale (QLS). Among older adults with schizophrenia spectrum disorder, effects of psychiatric symptoms on QoL were exerted mostly through a general psychopathology dimension (β = - 0.43, p < 0.01). Negative symptom dimension had an additional negative effect on QoL beyond the effect of that factor (β = - 0.28, p < 0.01). Because psychiatric symptoms affect QoL mainly through two dimensions of psychopathology, i.e., a general psychopathology dimension and a negative symptom dimension, mechanisms underlying those dimensions should be considered as promising targets for therapeutic interventions to substantially improve quality of life of this vulnerable population.

Targeting cognition in schizophrenia through transcranial direct current stimulation: A systematic review and perspective

Cognitive deficits are a fundamental feature of schizophrenia for which currently no effective treatments exist. This paper examines the possibility to use transcranial direct current stimulation (tDCS) to target cognitive deficits in schizophrenia as evidence from studies in healthy participants suggests that tDCS may improve cognitive functions and associated neural processes. We carried out a systematic review with the following search terms: 'tDCS', 'electric brain stimulation', 'schizophrenia', 'cognitive', 'cognition' until March 2019. 659 records were identified initially, 612 of which were excluded after abstract screening. The remaining 47 articles were assessed for eligibility based on our criteria and 26 studies were excluded. In addition, we compared several variables, such as online vs. offline-stimulation protocols, stimulation type and intensity on mediating positive vs. negative study outcomes. The majority of studies (n = 21) identified significant behavioural and neural effects on a range of cognitive functions (versus n = 11 with null results), including working memory, attention and social cognition. However, we could not identify tDCS parameters (electrode montage, stimulation protocol, type and intensity) that clearly mediated effects on cognitive deficits. There is preliminary evidence for the possibility that tDCS may improve cognitive deficits in schizophrenia. We discuss the rationale and strength of evidence for using tDCS for targeting cognitive deficits in schizophrenia as well as methodological issues and potential mechanisms of action.

Longitudinal effects of clozapine concentration and clozapine to N-desmethylclozapine ratio on cognition: A mediation model

Previous cross-sectional studies have found clozapine to N-desmethylclozapine (CLZ:NDMC) ratio to be negatively correlated with cognition in clozapine-treated patients with schizophrenia. However, no work has examined the association between CLZ:NDMC ratio and cognition using a within-subjects design. Here, we investigate the longitudinal effects of changes in the clozapine load and the CLZ:NDMC ratio on cognition whilst controlling for a range of independent factors. We analyzed data from a cohort of seventeen clozapine-treated patients who have been repeatedly assessed with the Brief Assessment of Cognition for Schizophrenia (BACS). The Positive symptoms sub-score of the Clinical Global Impression for Schizophrenia (CGI-P) was used to assess severity of psychosis. Blood samples were collected to measure the plasmatic levels of clozapine (CLZ) and of N-desmethylclozapine, allowing calculation of the CLZ:NDMC ratio. Our analyses included bivariate and partial correlations, along with a mediation model analysis. We found that both plasmatic levels of CLZ and the CLZ:NDMC ratio were negatively correlated with cognitive performance, and that these associations were independent of changes in both daily clozapine dose and severity of psychotic symptoms. Mediation analyses further revealed the association between CLZ concentration and cognition to be partially mediated by changes in the CLZ:NDMC ratio. This is the first longitudinal analysis of the influence of CLZ concentration and CLZ:NDMC ratio on cognition. Our findings suggest that reduction of CLZ concentration and the CLZ:NDMC ratio might favorably affect cognition. Thus, the CLZ:NDMC ratio may represent a promising target for novel therapeutic strategies aiming to ameliorate cognitive impairment in clozapine-treated patients.

Virtual screening-driven discovery of dual 5-HT6/5-HT2A receptor ligands with pro-cognitive properties

A virtual screening campaign aimed at finding structurally new compounds active at 5-HT₆R provided a set of candidates. Among those, one structure, 4-(5-{[(2-{5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl}ethyl)amino]methyl}furan-2-yl)phenol (1, 5-HT₆R K_i = 91 nM), was selected as a hit for further optimization. As expected, the chemical scaffold of selected compound was significantly different from all the serotonin receptor ligands published to date. Synthetic efforts, supported by molecular modelling, provided 43 compounds representing different substitution patterns. The derivative 42, 4-(5-{[(2-{5-fluoro-1H-pyrrolo[2,3-b]pyridin-3-yl}ethyl)amino]methyl}furan-2-yl)phenol (5-HT₆R K_i = 25, 5-HT_2AR K_i = 32 nM), was selected as a lead and showed a good brain/plasma concentration profile, and it reversed phencyclidine-induced memory impairment. Considering the unique activity profile, the obtained series might be a good starting point for the development of a novel antipsychotic or antidepressant with pro-cognitive properties.

Psychotic experiences and subjective cognitive complaints among 224 842 people in 48 low- and middle-income countries

AIMS

Cognitive deficits are an important factor in the pathogenesis of psychosis. Subjective cognitive complaints (SCCs) are often considered to be a precursor of objective cognitive deficits, but there are no studies specifically on SCC and psychotic experiences (PE). Thus, we assessed the association between SCC and PE using data from 48 low- and middle-income countries.

METHODS

Community-based cross-sectional data of the World Health Survey were analysed. Two questions on subjective memory and learning complaints in the past 30 days were used to create a SCC scale ranging from 0 to 10 with higher scores representing more severe SCC. The Composite International Diagnostic Interview was used to identify past 12-month PE. Multivariable logistic regression and mediation analyses were performed.

RESULTS

The final sample consisted of 224 842 adults aged ⩾18 years [mean (SD) age 38.3 (16.0) years; 49.3% males]. After adjustment for sociodemographic factors, a one-unit increase in the SCC scale was associated with a 1.17 (95% CI 1.16-1.18) times higher odds for PE in the overall sample, with this association being more pronounced in younger individuals: age 18-44 years OR = 1.19 (95% CI 1.17-1.20); 45-64 years OR = 1.15 (95% CI 1.12-1.17); ⩾65 years OR = 1.14 (95% CI 1.09-1.19). Collectively, other mental health conditions (perceived stress, depression, anxiety, sleep problems) explained 43.4% of this association, and chronic physical conditions partially explained the association but to a lesser extent (11.8%).

CONCLUSIONS

SCC were associated with PE. Future longitudinal studies are needed to understand temporal associations and causal inferences, while the utility of SCC as a risk marker for psychosis especially for young adults should be scrutinised.