Neurocognition as a predictor of transition to psychotic disorder and functional outcomes in ultra-high risk participants: Findings from the NEURAPRO randomized clinical trial

Drug-targeted Mendelian randomization analysis combined with transcriptome sequencing to explore the molecular mechanisms associated with cognitive impairment

BackgroundCurrent therapies for cognitive impairment, including Alzheimer's disease (AD) and mild cognitive impairment, are limited by a lack of universal treatment and adverse effects associated with polypharmacy. Investigating genetic and molecular mechanisms underlying cognitive decline is critical for the development of targeted therapeutics.ObjectiveTo identify causal genes and potential therapeutic targets for cognitive impairment through integrative genomic analyses.MethodsGenome-wide association study data on cognitive impairment were combined with the expression quantitative trait loci (eQTL) data from the eQTLGen consortium. Mendelian randomization (MR) and colocalization analyses were employed to infer causal relationships. Gene Set Enrichment Analysis and Gene Set Variation Analysis evaluated the pathway and functional differences. Immune cell infiltration patterns and the immunometabolic pathways were assessed, followed by drug target prediction.ResultsMR analysis identified seven gene-eQTL pairs significantly associated with cognitive impairment. SMR colocalization prioritized three key genes: HNMT (histamine metabolism), TNFSF8 (inflammatory signaling), and S1PR5 (sphingolipid signaling). HNMT, TNFSF8, and S1PR5 had 39, 24, and 30 predicted targeted drugs, respectively, including arsenic trioxide, aspirin, and immunomodulators.ConclusionsThis study implicates HNMT, TNFSF8, and S1PR5 as potential therapeutic targets for cognitive impairment. Further validation is required to confirm their clinical relevance.

Abnormalities in cognitive-related functional connectivity can be used to identify patients with schizophrenia and individuals in clinical high-risk

BACKGROUND

Clinical high-risk (CHR) refers to prodromal phase before schizophrenia onset, characterized by attenuated psychotic symptoms and functional decline. They exhibit similar but milder cognitive impairments, brain abnormalities and eye movement change compared with first-episode schizophrenia (FSZ). These alterations may increase vulnerability to transitioning to the disease. This study explores cognitive-related functional connectivity (FC) and eye movement abnormalities to examine differences in the progression of schizophrenia.

METHODS

Thirty drug-naive FSZ, 28 CHR, and 30 healthy controls (HCs) were recruited to undergo resting-state functional magnetic resonance imaging (rs-fMRI). Connectome-based predictive modeling (CPM) was employed to extract cognitive-related brain regions, which were then selected as seeds to form FC networks. Support vector machine (SVM) was used to distinguish FSZ from CHR. Smooth pursuit eye-tracking tasks were conducted to assess eye movement features.

RESULTS

FSZ displayed decreased cognitive-related FC between right posterior cingulate cortex and right superior frontal gyrus compared with HCs and between right amygdala and left inferior parietal gyrus (IPG) compared with CHR. SVM analysis indicated a combination of BACS-SC and CFT-A scores, and FC between right amygdala and left IPG could serve as a potential biomarker for distinguishing FSZ from CHR with high sensitivity. FSZ also exhibited a wide range of eye movement abnormalities compared with HCs, which were associated with alterations in cognitive-related FC.

CONCLUSIONS

FSZ and CHR exhibited different patterns of cognitive-related FC and eye movement alteration. Our findings illustrate potential neuroimaging and cognitive markers for early identification of psychosis that could help in the intervention of schizophrenia in high-risk groups.

Cognitive assessment in the Accelerating Medicines Partnership® Schizophrenia Program: harmonization priorities and strategies in a diverse international sample

Cognitive impairment occurs at higher rates in individuals at clinical high risk (CHR) for psychosis relative to healthy peers, and it contributes unique variance to multivariate prediction models of transition to psychosis. Such impairment is considered a core biomarker of schizophrenia. Thus, cognition is a key domain measured in the Accelerating Medicines Partnership® program for Schizophrenia (AMP SCZ initiative). The aim of this paper is to describe the rationale, processes, considerations, and final harmonization of the cognitive battery used in AMP SCZ across the two data collection networks. This battery comprises tests of general intellect and specific cognitive domains. We estimate premorbid intelligence at baseline and measure current intelligence at baseline and 2 years. Eight tests from the Penn Computerized Neurocognitive Battery (PennCNB), which measure verbal learning and memory, sensorimotor ability, attention, emotion recognition, working memory, processing speed, verbal memory, visual memory, and motor speed are administered repeatedly at baseline, and four follow-up timepoints over 2 years.

Tunisian Adolescents at CHR for Psychosis: A Pilot Study of Cognitive Remediation in a LMIC

BACKGROUND

Clinical high risk (CHR) youth are known to exhibit cognitive deficits at similar levels to their more severally ill counter parts. Cognitive training (CT) programs offer a promising method for early intervention and the prevention of further cognitive decline in this vulnerable population. However, there are few structured CT intervention programs addressing the needs of CHR youth in LMICs of the Middle East.

METHODS

We conducted a study in the Child and Adolescent Psychiatry Department of Razi University Hospital. Patients were assessed by trained raters with the "Comprehensive Assessment of At-Risk Mental States" to confirm their CHR status. Cognitive Training (CT) was combined with the Neuropsychological Educational Approach to Remediation (CT-NEAR) as part of a social rehabilitation program. We enrolled 25 CHR patients and examined several domains of cognitive functioning and evaluated daily functioning prior to starting the intervention and after completion.

RESULTS

There were 20 patients who completed the study. The CT-NEAR group (n = 10) completed an average number 28.33 sessions over 12 weeks, which were matched for therapist time with the TAU group (n = 10). We found statistically significant improvements in CT-NEAR versus TAU in several cognitive domains; such as cognitive flexibility, memory-short and long-term, and verbal fluency. Also, CT-NEAR versus TAU patients improved in global functioning.

CONCLUSIONS

Our findings indicate that cognitive remediation versus TAU for Tunisian CHR youth is feasible and effective especially in improving cognitive functioning when delivered in a social rehabilitation context (Bridging Group) and extends to global level of functioning.

Psychometric properties of the Spanish version of the measure of insight into cognition-self-report in psychosis-risk and non-clinical Mexican young adults

AIM

Cognitive disturbances typically precede the onset of overt psychotic symptoms and represent a neurobiological marker for psychosis risk that is also associated with poor functional outcomes. The Measure of Insight into Cognition-Self Report (MIC-SR) is a widely used 12-item questionnaire that assesses the perceived frequency of cognitive impairment in the domains of executing functioning, attention, and memory. However, the MIC-SR is not available in Spanish, one of the most widely spoken languages worldwide. The present study aimed to provide a Spanish version of the MIC-SR and examine its psychometric properties in psychosis-risk and non-clinical Mexican young adults.

METHODS

The sample comprised 621 participants who completed a battery of self-report measures via an online survey. Of the participants, 478 were non-clinical, and 143 met the screening criteria for a clinical high-risk for psychosis (CHR-positive).

RESULTS

Confirmatory Factor Analyses supported a one-factor model, consistent with the findings for the original MIC-SR. The results showed adequate fit indices for the general model and the independent models for both groups, with high Cronbach's alpha coefficients. Furthermore, the CHR-positive group showed more frequent subjective cognitive problems on each of the 12 items, higher total scores, and higher average frequency than the non-clinical group.

CONCLUSION

To our knowledge, this is the first translation of the MIC-SR into Spanish. Using the MIC-SR at the CHR stage may contribute to our understanding of cognitive processes associated with the onset of a psychotic disorder and provide valuable information in the context of detection and early intervention efforts.

Biomarker discovery using machine learning in the psychosis spectrum

The past decade witnessed substantial discoveries related to the psychosis spectrum. Many of these discoveries resulted from pursuits of objective and quantifiable biomarkers in tandem with the application of analytical tools such as machine learning. These approaches provided exciting new insights that significantly helped improve precision in diagnosis, prognosis, and treatment. This article provides an overview of how machine learning has been employed in recent biomarker discovery research in the psychosis spectrum, which includes schizophrenia, schizoaffective disorders, bipolar disorder with psychosis, first episode psychosis, and clinical high risk for psychosis. It highlights both human and animal model studies and explores a varying range of the most impactful biomarkers including cognition, neuroimaging, electrophysiology, and digital markers. We specifically highlight new applications and opportunities for machine learning to impact noninvasive symptom monitoring, prediction of future diagnosis and treatment outcomes, integration of new methods with traditional clinical research and practice, and personalized medicine approaches.

Cognitive complaint inversely associated to UHR transition

The aim of this study was to identify the impact of staging on a six-months transition in Ultra-High Risk (UHR) youth. Subjects were enrolled at assessment; evolution was monitored for six months. Clinical determinants (unusual thought content, perceptual abnormalities, cognitive complaint, etc.) were collected. 37 non-psychotic and 39 UHR subjects were included. 13 UHR (35.2 %) experienced psychotic transition, while none of non-psychotic subjects did log-rank p < 0.001. Self-reported cognitive complaint was inversely associated to transition OR 0.13 95 % IC [0.03-0.64]. Unusual Thought Content was associated to psychotic transition 0R 8.57 95 % IC [1.17-63]. Self-reported cognitive complaint could be a protective transition marker in UHR.

Neurocognition in adolescents and young adults at clinical high risk for psychosis: Predictive stability for social and role functioning

The prodromal phase of schizophrenia provides an optimal opportunity to mitigate the profound functional disability that is often associated with fully expressed psychosis. Considerable evidence supports the importance of neurocognition in the development of interpersonal (social) and academic (role) skills. Further findings from adolescents and young adults at clinical high risk for developing psychosis (CHRP) suggest that treatment for functioning might be most effective when targeting early and specific neurocognitive deficits. The current study addresses this critical intervention issue by examining the potential of neurocognitive deficits at intake for predicting social and role functioning over time in CHR-P youth. The study included 345 CHR-P participants from the second phase of the North American Prodrome Longitudinal Study (NAPLS2) with baseline neurocognition and 2-year follow-up data on social and role functioning. Slower baseline processing speed consistently predicted poor social functioning over time, while attention deficits predicted poor role functioning at baseline and follow-up. In addition, the impact of processing speed and attention impairments on social and role functioning, respectively, persisted even when adjusting the regression models for attenuated positive, negative, and disorganized symptoms, and transition status. The current study demonstrates for, arguably the first time, that processing speed and attention are strongly predictive of social and role functioning over time, respectively, above and beyond the impact of symptoms and those CHR-P individuals that develop psychosis over the course of the study. These findings imply that early neurocognition is a critical treatment target linked to the developmental trajectory of social and role functioning.

Cognitive subtypes in youth at clinical high risk for psychosis

Introduction

Schizophrenia is a mental health condition that severely impacts well-being. Cognitive impairment is among its core features, often presenting well before the onset of overt psychosis, underscoring a critical need to study it in the psychosis proneness (clinical high risk; CHR) stage, to maximize the benefits of interventions and to improve clinical outcomes. However, given the heterogeneity of cognitive impairment in this population, a one-size-fits-all approach to therapeutic interventions would likely be insufficient. Thus, identifying cognitive subtypes in this population is crucial for tailored and successful therapeutic interventions. Here we identify, validate, and characterize cognitive subtypes in large CHR samples and delineate their baseline and longitudinal cognitive and functional trajectories.

Methods

Using machine learning, we performed cluster analysis on cognitive measures in a large sample of CHR youth (n = 764), and demographically comparable controls (HC; n = 280) from the North American Prodrome Longitudinal Study (NAPLS) 2, and independently validated our findings with an equally large sample (NAPLS 3; n = 628 CHR, 84 HC). By utilizing several statistical approaches, we compared the clusters on cognition and functioning at baseline, and over 24 months of followup. We further delineate the conversion status within those clusters.

Results

Two main cognitive clusters were identified, "impaired" and "intact" across all cognitive domains in CHR compared to HC. Baseline differences between the cognitively intact cluster and HC were found in the verbal abilities and attention and working memory domains. Longitudinally, those in the cognitively impaired cluster group demonstrated an overall floor effect and did not deteriorate further over time. However, a "catch up" trajectory was observed in the attention and working memory domain. This group had higher instances of conversion overall, with these converters having significantly more non-affective psychotic disorder diagnosis versus bipolar disorder, than those with intact cognition. In the cognitively intact group, we observed differences in trajectory based on conversion status, where those who start with intact cognition and later convert demonstrate a sharp decline in attention and functioning. Functioning was significantly better in the cognitively intact than in the impaired group at baseline. Most of the cognitive trajectories demonstrate a positive relationship with functional ones.

Conclusion

Our findings provide evidence for intact and impaired cognitive subtypes in youth at CHR, independent of conversion status. They further indicate that attention and working memory are important to distinguish between the CHR with intact cognition and controls. The cognitively intact CHR group becomes less attentive after conversion, while the cognitively impaired one demonstrates a catch up trajectory on both attention and working memory. Overall, early evaluation, covering several cognitive domains, is crucial for identifying trajectories of improvement and deterioration for the purpose of tailoring intervention for improving outcomes in individuals at CHR for psychosis.

Models of mild cognitive deficits in risk assessment in early psychosis

BACKGROUND

Mild cognitive deficits (MCD) emerge before the first episode of psychosis (FEP) and persist in the clinical high-risk (CHR) stage. This study aims to refine risk prediction by developing MCD models optimized for specific early psychosis stages and target populations.

METHODS

A comprehensive neuropsychological battery assessed 1059 individuals with FEP, 794 CHR, and 774 matched healthy controls (HCs). CHR subjects, followed up for 2 years, were categorized into converters (CHR-C) and non-converters (CHR-NC). The MATRICS Consensus Cognitive Battery standardized neurocognitive tests were employed.

RESULTS

Both the CHR and FEP groups exhibited significantly poorer performance compared to the HC group across all neurocognitive tests (all p < 0.001). The CHR-C group demonstrated poorer performance compared to the CHR-NC group on three sub-tests: visuospatial memory (p < 0.001), mazes (p = 0.005), and symbol coding (p = 0.023) tests. Upon adjusting for sex and age, the performance of the MCD model was excellent in differentiating FEP from HC, as evidenced by an Area Under the Receiver Operating Characteristic Curve (AUC) of 0.895 (p < 0.001). However, when applied in the CHR group for predicting CHR-C (AUC = 0.581, p = 0.008), the performance was not satisfactory. To optimize the efficiency of psychotic risk assessment, three distinct MCD models were developed to distinguish FEP from HC, predict CHR-C from CHR-NC, and identify CHR from HC, achieving accuracies of 89.3%, 65.6%, and 80.2%, respectively.

CONCLUSIONS

The MCD exhibits variations in domains, patterns, and weights across different stages of early psychosis and diverse target populations. Emphasizing precise risk assessment, our findings highlight the importance of tailored MCD models for different stages and risk levels.

Neurocognitive consequences of adolescent sleep disruptions and their relationship to psychosis vulnerability: a longitudinal cohort study

Adolescence is a key period for neurocognitive maturation where deviation from normal developmental trajectories may be tied to adverse mental health outcomes. Cognitive disruptions have been noted in populations at risk for psychosis and are known to accompany periods of sleep deprivation. This study aims to assess the role of cognition as a mediator between sleep disruptions and psychosis risk. A cohort of 3801 high school students (51% female, mean age = 12.8, SD = 0.45 years) was recruited from 31 Montreal high schools. Measures of sleep, psychotic-like experiences, inhibition, working memory, perceptual reasoning, and delayed recall were collected from participants on a yearly basis over the five years of their high school education. A multi-level model mediation analysis was performed controlling for sex and time squared. Response inhibition was shown to be associated with, and to mediate (B = -0.005, SD = 0.003, p = 0.005*) the relationship between sleep disruptions (B = -0.011, SD = 0.004, p < 0.001*) and psychotic-like experiences (B = 0.411, SD = 0.170, p = 0.005*). Spatial working memory deficits on a given year were associated with a higher frequency of psychotic-like experiences that same year (B = -0.046, SD = 0.018, p = 0.005*) and the following year (B = -0.051, SD = 0.023, p = 0.010*), but were not associated with sleep disturbances. No significant associations were found between our variables of interest and either delayed recall or perceptual reasoning at the within person level. Findings from this large longitudinal study provide evidence that the association between sleep disruptions and psychosis risk is specifically mediated by inhibitory rather than general cognitive impairments. The association of spatial working memory, response inhibition, and sleep disruptions with psychotic-like experiences suggests that these factors may represent potential targets for preventative interventions.

Cognitive predictors of transition and remission of psychosis risk syndrome in a child and adolescent sample: longitudinal findings from the CAPRIS study

Cognitive impairments are proposed as predictors in the differentiation between subjects with psychosis risk syndrome (PRS) who will develop a psychotic disorder (PRS-P) and those who will not (PRS-NP). More in-depth study of the PRS-NP group could contribute to defining the role of cognitive alterations in psychosis. This study aims to analyze cognition of children and adolescents with PRS in terms of their clinical outcome at 18-month follow-up (psychosis, remission, and non-remission) and of determinate predictors of transition to psychosis and remission of PRS. The method is two-site, naturalistic, longitudinal study design, with 98 help-seeking adolescents with PRS and 64 healthy controls (HC). PRS-P (n = 24) and PRS-NP (n = 74) participants were clinically and cognitively assessed at baseline, and when full-blown psychotic disorder had developed or at 18-month follow-up. PRS-P subjects showed lower scores at baseline in processing speed, visuospatial memory, attention, and executive function (cognitive flexibility/processing speed) compared to HC. PRS-NP subjects showed lower baseline scores in verbal working memory and verbal fluency compared to HC. This deficit is also observed in the PRS group of participants still presenting attenuated psychotic symptoms at 18-month follow-up, while PRS subjects in remission showed a similar cognitive profile to HC subjects. Baseline score on processing speed, measured with a coding task, appeared to be a predictive variable for the development of a psychotic disorder. Performance in verbal working memory was predictive of remission in the PRS-NP. Post hoc comparisons indicate the need for careful interpretation of cognitive markers as predictors of psychosis. Cognitive impairments are present in both PRS-P and PRS-NP. Those individuals who recover from PRS show baseline cognitive performance comparable to the HC group. Together with sociodemographic variables, this observation could help in the differentiation of a variety of PRS trajectories in children and adolescents.

Brief rapport: Perceptual aberration in patients at ultra-high risk for psychosis

BACKGROUND

Ultra-high risk (UHR) is considered a forerunner of psychosis, but most UHR individuals do not later convert, yet remain symptomatic, disabled and help-seeking. Thus, there is an increased recognition of the UHR phenotype as a syndrome in itself, rather than merely a risk syndrome. It is therefore essential to investigate outcomes other than transition to psychosis. For this purpose, perceptual aberration appears to be a distinct, as well as a stable and less state-specific vulnerability indicator. We aimed to investigate perceptual aberration and associations with functional, neuro and social cognitive risk factors in an UHR sample.

METHOD

One hundred and twenty UHR and 64 healthy controls were compared on levels of perceptual aberration using the perceptual aberration scale. We further investigated cross-sectional associations between perceptual aberration and CAARMS (as a measure of subthreshold psychotic symptoms) and functional, neuro and social cognitive risk factors within the UHR using Spearmans ρ.

RESULTS

Perceptual aberration was significantly higher in UHR than in healthy controls and was associated with social functioning, executive functioning, and emotion recognition.

CONCLUSION

Our findings are consistent with a view of perceptual aberration as a stable vulnerability indicator that varies little with clinical state.

The potential of digital behavioural tests as a diagnostic aid for psychosis

Timely interventions have a proven benefit for people experiencing psychotic illness. One bottleneck to accessing timely interventions is the referral process to the specialist team for early psychosis (STEP). Many general practitioners lack awareness or confidence in recognising psychotic symptoms or state. Additionally, referrals for people without apparent psychotic symptoms, although beneficial at a population level, lead to excessive workload for STEPs. There is a clear unmet need for accurate stratification of STEPs users and healthy cohorts. Here we propose a new approach to addressing this need via the application of digital behavioural tests. To demonstrate that digital behavioural tests can be used to discriminate between the STEPs users (SU; n = 32) and controls (n = 32, age and sex matched), we compared performance of five different classifiers applied to objective, quantitative and interpretable features derived from the 'mirror game' (MG) and trail making task (TMT). The MG is a movement coordination task shown to be a potential socio-motor biomarker of schizophrenia, while TMT is a neuropsychiatric test of cognitive function. All classifiers had AUC in the range of 0.84-0.92. The best of the five classifiers (linear discriminant classifier) achieved an outstanding performance, AUC = 0.92 (95%CI 0.75-1), Sensitivity = 0.75 (95%CI 0.5-1), Specificity = 1 (95%CI 0.75-1), evaluated on 25% hold-out and 1000 folds. Performance of all analysed classifiers is underpinned by the large effect sizes of the differences between the cohorts in terms of the features used for classification what ensures generalisability of the results. We also found that MG and TMT are unsuitable in isolation to successfully differentiate between SU with and without at-risk-mental-state or first episode psychosis with sufficient level of performance. Our findings show that standardised batteries of digital behavioural tests could benefit both clinical and research practice. Including digital behavioural tests into healthcare practice could allow precise phenotyping and stratification of the highly heterogenous population of people referred to STEPs resulting in quicker and more personalised diagnosis. Moreover, the high specificity of digital behavioural tests could facilitate the identification of more homogeneous clinical high-risk populations, benefiting research on prognostic instruments for psychosis. In summary, our study demonstrates that cheap off-the-shelf equipment (laptop computer and a leap motion sensor) can be used to record clinically relevant behavioural data that could be utilised in digital mental health applications.

Associations between age and neurocognition in individuals at clinical high risk and first-episode psychosis

Neurocognitive deficits differ with age during the early stages of psychosis. This study aimed to explore age-related differences (9-35 years old) in the neurocognitive performance of a large clinical population. In total, 1059 individuals with first-episode psychosis (FEP), 794 individuals with a clinical high risk of psychosis (CHR), and 774 well-matched healthy controls (HC) were recruited between 2016 and 2021. Neurocognitive assessments were performed using the Chinese version of the Measurement and Treatment Research to Improve Cognition in Schizophrenia Battery(MCCB). The MCCB subtest scores differed significantly among the groups across the age span. The mean scores of subtests in CHR individuals were approximately one standard deviation(SD) lower than that of HC, while that of FEP patients was approximately two SDs. The adolescents performed better than the adults in the HC, CHR, and FEP groups. In the HC group, a stronger correlation was found between age and cognitive function, and more neurocognitive domains were affected by age than in the CHR and FEP groups. These results emphasize that neurocognitive deficits in psychosis are present at the pre-onset stage and deteriorate at the first-episode stage across the age span, implicating the development of specific strategies that could monitor the cognitive trajectory in early psychosis.

Executively-mediated language skills are related to performance-based social functioning in the early psychosis spectrum

Social impairment is a core deficit in psychotic spectrum disorders (PSDs). Prior work shows that language abnormalities can predict psychosis onset and are related to social outcomes in PSDs. Few studies have investigated nuanced relationships between language/verbal abilities and social functioning in the early psychosis spectrum, including at-risk (schizotypy) and first episode of psychosis (FEP) individuals. This study aimed to examine the relationship to between language/verbal performance and performance-based and examiner-rated social functioning. We also aimed to replicate prior models that demonstrate neurocognition is related to social functioning through negative symptoms and social cognition. Low schizotypy (n = 42), high schizotypy (n = 44), and FEP (n = 15) participants completed a battery of language/verbal, social cognition, and social functioning measures. Regression analyses revealed that Proverb Test performance was uniquely and significantly associated with performance-based but not examiner-rated social functioning. Other language/verbal measures were not significantly related to social functioning. In mediational analyses, language/verbal performance was indirectly related to social functioning through negative traits, and also through social cognition. Findings extend support for negative symptom and social cognitive intervention in the early psychosis spectrum, and uniquely suggest that executively-mediated language skills may be an additional target to improve social functioning.

Association between inflammation and cognition: Triangulation of evidence using a population-based cohort and Mendelian randomization analyses

BACKGROUND

Inflammation is associated with cognitive functioning and dementia in older adults, but whether inflammation is related to cognitive functioning in youth and whether these associations are causal remains unclear.

METHODS

In a population-based cohort (Avon Longitudinal Study of Parents and Children; ALSPAC), we investigated cross-sectional associations of inflammatory markers (C-reactive protein [CRP], Interleukin-6 [IL-6] and Glycoprotein acetyls [GlycA]) with measures of cold (working memory, response inhibition) and hot (emotion recognition) cognition at age 24 (N = 3,305 in multiple imputation models). Furthermore, we conducted one-sample and two-sample bidirectional Mendelian randomization (MR) analyses to examine potential causal effects of genetically-proxied inflammatory markers (CRP, GlycA, IL-6, IL-6 receptor, soluble IL-6 receptor) on cognitive measures (above) and on general cognitive ability.

RESULTS

In the ALSPAC cohort, there was limited evidence of an association between standardised inflammatory markers and standardised cognitive measures at age 24 after adjusting for potential confounders (N = 3,305; beta range, -0.02 [95 % confidence interval (CI) -0.06 to 0.02, p = 0.27] to 0.02 [95 % CI -0.02 to 0.05, p = 0.33]). Similarly, we found limited evidence of potential effects of 1-unit increase in genetically-proxied inflammatory markers on standardised working memory, emotion recognition or response inhibition in one-sample MR using ALSPAC data (beta range, -0.73 [95 % CI -2.47 to 1.01, p = 0.41] to 0.21 [95 % CI -1.42 to 1.84, p = 0.80]; or on standardised general cognitive ability in two-sample MR using the latest Genome-Wide Association Study (GWAS) datasets (inverse-variance weighted beta range, -0.02 [95 % CI -0.05 to 0.01, p = 0.12] to 0.03 [95 % CI -0.01 to 0.07, p = 0.19]).

CONCLUSIONS

Our MR findings do not provide strong evidence of a potential causal effect of inflammatory markers (CRP, IL-6, IL-6 receptor, GlycA) on the cognitive functions examined here. Given the large confidence intervals in the one-sample MR, larger GWAS of specific cognitive measures are needed to enable well-powered MR analyses to investigate whether inflammation causally influences specific cognitive domains.

Cross-sectional and longitudinal assessment of the association between DDR1 variants and processing speed in patients with early psychosis and healthy controls

Recent evidence indicates that DDR1 participates in myelination and that variants of DDR1 are associated with decreased cognitive processing speed (PS) in schizophrenia (SZ). Here, we explored whether DDR1 variants were associated with PS in subjects diagnosed with an early psychosis (EP), a condition often preceding SZ. Data from two Spanish independent samples (from Reus and Santander) including patients with EP (n = 75 and n = 312, respectively) and healthy controls (HCs; n = 57 and n = 160) were analyzed. The Trail Making Test part A was used to evaluate PS. Participants underwent genotyping to identify DDR1 variants rs1264323 and rs2267641. Cross-sectional data were analyzed with general linear models and longitudinal data were analyzed using mixed models. We examined the combined rs1264323AA-rs2267641AC/CC genotypes (an SZ-risk combination) on PS. The SZ-risk combined genotypes were associated with increased PS in EP patients but not in HCs in the cross-sectional analysis. In the longitudinal analysis, the SZ-risk combined genotypes were significantly associated with increased PS in both HCs and EP patients throughout the 10-year follow-up but no genotype × time interaction was observed. These results provide further evidence that DDR1 is involved in cognition and should be replicated with other samples.

Prospects for Neurotrophic Factor-Based Early Intervention in Schizophrenia: Lessons Learned from the Effects of Antipsychotic Drugs on Cognition, Neurogenesis, and Neurotrophic Factors

Although reducing psychotic symptoms in schizophrenia has been a major focus of therapeutic interventions for decades, improving cognition is considered a better predictor of functional outcomes. However, the most commonly prescribed antipsychotic drugs (APDs) show only marginal beneficial effects on cognition in patients with schizophrenia. The neural mechanisms underlying cognitive disturbances in schizophrenia remain unknown that making drug development efforts very challenging. Since neurotrophic factors are the primary architects of neurogenesis, synaptic plasticity, learning, and memory, the findings from preclinical and clinical studies that assess changes in neurogenesis and neurotrophic factors and their relationship to cognitive performance in schizophrenia, and how these mechanisms might be impacted by APD treatment, may provide valuable clues in developing therapies to combat cognitive deficit in schizophrenia. Numerous evidence produced over the years suggests a deficit in a wide spectrum of neurotrophic factors in schizophrenia. Since schizophrenia is considered a neurodevelopmental disorder, early intervention with neurotrophic factors may be more effective in ameliorating the cognitive deficits and psychopathological symptoms associated with this pathology. In this context, results from initial clinical trials with neurotrophic factors and their future potential to improve cognition and psychosocial functioning in schizophrenia are discussed.

Cerebellar correlates of social dysfunction among individuals at clinical high risk for psychosis

Introduction

Social deficits are a significant feature among both individuals with psychosis and those at clinical high-risk (CHR) for developing psychosis. Critically, the psychosis risk syndrome emerges in adolescence and young adulthood, when social skill development is being fine-tuned. Yet, the underlying pathophysiology of social deficits in individuals at CHR for psychosis remains unclear. Literature suggests the cerebellum plays a critical role in social functioning. Cerebellar dysfunction in psychosis and CHR individuals is well-established, yet limited research has examined links between the cerebellum and social functioning deficits in this critical population.

Method

In the current study, 68 individuals at CHR for developing psychosis and 66 healthy controls (HCs) completed social processing measures (examining social interaction, social cognition, and global social functioning) and resting-state MRI scans. Seed-to-voxel resting-state connectivity analyses were employed to examine the relationship between social deficits and lobular cerebellar network connectivity.

Results

Analyses indicated that within the CHR group, each social domain variable was linked to reduced connectivity between social cerebellar subregions (e.g., Crus II, lobules VIIIa and VIIIb) and cortical regions (e.g., frontal pole and frontal gyrus), but a control cerebellar subregion (e.g., lobule X) and was unrelated to these social variables.

Discussion

These results indicate an association between several cerebellar lobules and specific deficits in social processing. The cerebellum, therefore, may be particularly salient to the social domain and future research is need to examine the role of the cerebellum in psychosis.

A narrative review of treatment interventions to improve cognitive performance in schizophrenia, with an emphasis on at-risk and early course stages

Cognitive dysfunction is a core feature of schizophrenia (SCZ), which unfavorably affects SCZ patients' daily functioning and overall clinical outcome. An increasing body of evidence has shown that cognitive deficits are present not only at the beginning of the illness but also several years before the onset of psychosis. Nonetheless, the majority of treatment interventions targeting cognitive dysfunction in SCZ, using both pharmacological and nonpharmacological approaches, have focused on chronic patients rather than individuals at high risk or in the early stages of the disease. In this article, we provide a narrative review of cognitive interventions in SCZ patients, with a particular focus on pre-emptive interventions in at-risk/early course individuals when available. Furthermore, we discuss current challenges for these pre-emptive treatment interventions and provide some suggestions on how future work may ameliorate cognitive dysfunction in these individuals.

Premorbid adjustment associates with cognitive and functional deficits in individuals at ultra-high risk of psychosis

Premorbid social and academic adjustment are important predictors of cognitive and functional performance in schizophrenia. Whether this relationship is also present in individuals at ultra-high risk (UHR) for psychosis is the focus of the present study. Using baseline data from a randomised clinical trial (N = 146) this study investigated associations between premorbid adjustment and neuro- and social cognition and functioning in UHR individuals aged 18–40 years. Patients were evaluated with the Premorbid Adjustment Scale (PAS) comprising a social and an academic domain. Using validated measures neurocognition was assessed in the domains of processing speed, executive function, attention, verbal learning and memory, visual learning and memory, and working memory along with estimated IQ. Social cognitive domains assessed were theory of mind, emotion recognition, and attributional bias. Functional assessment comprised the domains of social- and role functioning, functional capacity, and quality of life. Linear regression analyses revealed poor premorbid academic adjustment to be associated with poorer performance in processing speed, working memory, attention, full scale IQ, and verbal IQ. Poor premorbid social adjustment was associated with theory of mind deficits. Additionally, both premorbid adjustment domains were associated with social- and role functioning and quality of life. Corroborating evidence from schizophrenia samples, our findings indicate poor premorbid adjustment to correlate with deficits in specific cognitive and functional domains in UHR states. Early premorbid adjustment difficulties may therefore indicate a poor cognitive and functional trajectory associated with significant impairments in early and established psychotic disorders suggesting targets for primary intervention.

Cognitive Dysfunction as a Risk Factor for Psychosis

The current chapter summarizes recent evidence for cognition as a risk factor for the development of psychosis, including the range of cognitive impairments that exist across the spectrum of psychosis risk symptoms. The chapter examines several possible theories linking cognitive deficits with the development of psychotic symptoms, including evidence that cognitive deficits may be an intermediate risk factor linking genetic and/or neural metrics to psychosis spectrum symptoms. Although there is not strong evidence for unique cognitive markers associated specifically with psychosis compared to other forms of psychopathology, psychotic disorders are generally associated with the greatest severity of cognitive deficits. Cognitive deficits precede the development of psychotic symptoms and may be detectable as early as childhood. Across the psychosis spectrum, both the presence and severity of psychotic symptoms are associated with mild to moderate impairments across cognitive domains, perhaps most consistently for language, cognitive control, and working memory domains. Research generally indicates the size of these cognitive impairments worsens as psychosis symptom severity increases. The chapter points out areas of unclarity and unanswered questions in each of these areas, including regarding the mechanisms contributing to the association between cognition and psychosis, the timing of deficits, and whether any cognitive systems can be identified that function as specific predictors of psychosis risk symptoms.

Positive symptoms of schizophrenia and their relationship with cognitive and emotional executive functions

BACKGROUND

Positive symptoms of schizophrenia are associated with significant difficulties in daily functioning, and these difficulties have been associated with impaired executive functions (EEFF). However, specific cognitive and socio-emotional executive deficits have not been fully established.

OBJECTIVE

The present study has several objectives. First, we aimed to examine the specific deficits in cognitive and socio-emotional EEFF in a group of patients with schizophrenia with a predominance of positive symptoms, as well as to determine if these patients present clinically significant scores in any of the three fronto-subcortical behavioral syndromes: Dorsolateral, Orbitofrontal, or Anterior Cingulate.

METHOD

The sample consisted of 54 patients, 27 with a predominance of positive symptoms, and 27 healthy controls matched for gender, age, and education. The two groups completed four cognitive and three socio-emotional EEFF tasks. In the group of patients, positive symptoms were evaluated using the scale for the Evaluation of Positive Symptoms (SANS), while the behavioral alterations associated with the three fronto-subcortical syndromes were evaluated using the Frontal System Behavior Scale (FrSBe).

RESULTS

The patients, in comparison with a control group, presented specific deficits in cognitive and socio-emotional EEFF. In addition, a high percentage of patients presented clinically significant scores on the three fronto-subcortical syndromes.

CONCLUSION

The affectation that these patients present, in terms of both cognitive and emotional components, highlights the importance of developing a neuropsychological EEFF intervention that promotes the recovery of the affected cognitive capacities and improves the social and emotional functioning of the affected patients.

Comparison of two cognitive screening measures in a longitudinal sample of youth at-risk for psychosis

BACKGROUND

Validated screening tools are needed to detect subtle cognitive impairment in individuals at-risk for developing psychosis. Here, the utility of the Mini-Mental Status Examination (MMSE) and Penn Computerized Neurocognitive Battery (CNB) were evaluated for detecting cognitive impairment in individuals with psychosis spectrum (PS) symptoms.

METHODS

Participants (n = 229; 54 % female) completed the MMSE and CNB at baseline and two-year follow-up. PS (n = 91) and typically developing (TD; n = 138) participants were enrolled at baseline based on the presence or absence of PS symptoms. After two years, 65 participants remained PS, 104 participants remained TD, 23 participants had Emergent (EP) subthreshold PS symptoms, and 37 participants were experiencing Other Psychopathology (OP).

RESULTS

Generally, those with PS had lower scores than TD on both the MMSE (p < 0.0001) and CNB (p < 0.0001). Additionally, OP participants performed lower on the MMSE than TD (p = 0.02). Receiver operating characteristic (ROC) analyses indicated similar area under the curve (AUCs) for the two instruments (0.67); the MMSE showed higher specificity (0.71 vs. 0.62), while the CNB showed higher sensitivity (0.66 vs 0.52). Use of the MMSE and CNB in combination provided the highest diagnostic classification.

CONCLUSION

The MMSE and CNB can be used to screen for cognitive impairment in PS. The MMSE is better at ruling out PS-related cognitive impairment while the CNB is better at ruling in PS-related cognitive impairment. Overall, our results indicate that both tests are useful in screening for cognitive impairment, particularly in combination, in a PS population.

A systematic review of premorbid cognitive functioning and its timing of onset in schizophrenia spectrum disorders

Cognitive impairments are core features of established schizophrenia spectrum disorders (SSD). However, it remains unclear whether specific cognitive functions are differentially impaired pre-onset and at what age these impairments can be detected. The purpose of this review was to elucidate these issues through a systematic summary of results from longitudinal studies investigating impairment in specific cognitive domains as antecedents of SSD. Relevant studies were identified by electronic and manual literature searches and included any original study of cognitive domains any time pre-onset of SSDs that included a control group. Effect sizes were calculated by domain for studies comparing high-risk participants who developed SSD with those who did not. The strongest evidence for impairment pre-onset was for mental processing speed, verbal learning and memory, executive function, and social cognition. Some verbal impairments, like language abilities at age 3 and verbal learning and memory at age 7, may develop as static deficits. Conversely, some non-verbal impairments, like mental processing speed, visuospatial abilities, and visual working memory manifest as developmental lag and become significant later in life. Most effect sizes were small to moderate, except for verbal fluency (d' = 0,85), implying this impairment as central in high-risk participants who develop SSD. The present review documents extensive cognitive impairments pre-onset of SSD, and that these impairments start early in life, in line with the neurodevelopmental hypothesis of schizophrenia. Increased knowledge about cognitive impairments preonset can provide a better basis for understanding the complex pathogenesis of SSD as well as informing cognitive remediation programs.

Verbal memory performance predicts remission and functional outcome in people at clinical high-risk for psychosis

Robust deficits in cognitive functioning are present in people with psychosis and are evident in the early stages of the disorder. Impairments in verbal memory and verbal fluency are reliably seen in individuals at clinical high-risk for psychosis (CHR) compared to healthy populations. As previous studies have shown a relationship between cognition and longer-term outcomes in schizophrenia, the aim of this paper was to explore whether verbal memory and verbal fluency performance predicted outcomes in a large CHR sample recruited as part of the EU-GEI High Risk Study. Participants included 316 CHR individuals, 90.8% of whom were not currently on antipsychotic medication, and 60 healthy controls. Verbal memory and verbal fluency performance were measured at baseline. At two-year follow-up, CHR individuals were assessed by three different outcome measures, those who did and did not (1) transition to psychosis, (2) experience burdening impairment or disabilities, or (3) remit clinically from CHR status. Individuals with CHR displayed significant verbal memory and verbal fluency deficits at baseline compared to healthy controls (Hedges' g effect size = 0.24 to 0.66). There were no significant differences in cognitive performance of those who did and did not transition to psychosis. However, impaired immediate verbal recall predicted both functional disability and non-remission from the CHR state. Results remained significant when analyses were restricted to only include antipsychotic-free CHR participants. These findings may inform the development of early interventions designed to improve cognitive deficits in the early stages of psychosis.

Evidence of discontinuity between psychosis-risk and non-clinical samples in the neuroanatomical correlates of social function

Objective

Social dysfunction is a major feature of clinical-high-risk states for psychosis (CHR-P). Prior research has identified a neuroanatomical pattern associated with impaired social function outcome in CHR-P. The aim of the current study was to test whether social dysfunction in CHR-P is neurobiologically distinct or in a continuum with the lower end of the normal distribution of individual differences in social functioning.

Methods

We used a machine learning classifier to test for the presence of a previously validated brain structural pattern associated with impaired social outcome in CHR-P (CHR-outcome-neurosignature) in the neuroimaging profiles of individuals from two non-clinical samples (total n = 1763) and examined its association with social function, psychopathology and cognition.

Results

Although the CHR-outcome-neurosignature could be detected in a subset of the non-clinical samples, it was not associated was adverse social outcomes or higher psychopathology levels. However, participants whose neuroanatomical profiles were highly aligned with the CHR-outcome-neurosignature manifested subtle disadvantage in fluid (P_FDR = 0.004) and crystallized intelligence (P_FDR = 0.01), cognitive flexibility (P_FDR = 0.02), inhibitory control (P_FDR = 0.01), working memory (P_FDR = 0.0005), and processing speed (P_FDR = 0.04).

Conclusions

We provide evidence of divergence in brain structural underpinnings of social dysfunction derived from a psychosis-risk enriched population when applied to non-clinical samples. This approach appears promising in identifying brain mechanisms bound to psychosis through comparisons of patient populations to non-clinical samples with the same neuroanatomical profiles.

Twelve-Month Cognitive Trajectories in Individuals at Ultra-High Risk for Psychosis: A Latent Class Analysis

Understanding longitudinal cognitive performance in individuals at ultra-high risk for psychosis (UHR) is important for informing theoretical models and treatment. A vital step in this endeavor is to determine whether there are UHR subgroups that have similar patterns of cognitive change over time. The aims were to: i) identify latent class trajectories of cognitive performance over 12-months in UHR individuals, ii) identify baseline demographic and clinical predictors of the resulting classes, and iii) determine whether trajectory classes were associated with transition to psychosis or functional outcomes. Cognition was assessed using the Brief Assessment of Cognition in Schizophrenia (BACS) at baseline, 6- and 12-months (N = 288). Using Growth Mixture Modeling, a single unimpaired improving trajectory class was observed for motor function, speed of processing, verbal fluency, and BACS composite. A two-class solution was observed for executive function and working memory, showing one unimpaired and a second impaired class. A three-class solution was found for verbal learning and memory: unimpaired, mildly impaired, and initially extremely impaired, but improved ("caught up") to the level of the mildly impaired. IQ, omega-3 index, and premorbid adjustment were associated with class membership, whereas clinical variables (symptoms, substance use), including transition to psychosis, were not. Working memory and verbal learning and memory trajectory class membership was associated with functioning outcomes. These findings suggest there is no short-term progressive cognitive decline in help-seeking UHR individuals, including those who transition to psychosis. Screening of cognitive performance may be useful for identifying UHR individuals who may benefit from targeted cognitive interventions.

Omega-3 fatty acid in ultra-high-risk psychosis: A systematic review based on functional outcome

AIM

Among different types of poly unsaturated fatty acids, omega-3 fatty acids (FA) play a substantial role in brain development and functioning. This review was designed to evaluate and synthesize available evidence regarding omega-3 FAs and functional outcome in the ultra-high-risk (UHR) population.

METHODS

An electronic search in PubMed, EMBASE, PSYCINFO and COCHRANE search engines has been performed for all articles published until January 2019. The studies that have data regarding omega-3 FAs and functional outcome in UHR population were included.

RESULTS

Out of 397 nonduplicate citations, 19 articles met selection criteria. These articles were from four different primary studies, namely the Program of Rehabilitation and Therapy (PORT), the North American Prodromal Longitudinal Studies (NAPLS), Vienna High Risk study (VHR) and the NEURAPRO. The data from the NAPLS study found a positive correlation between functional improvement and frequency of dietary intake omega-3 FA. Moreover, among the erythrocyte omega-3 FA only eicosapentaenoic acid (EPA) showed a positive correlation with functional score. The VHR study found long-term improvement in functional outcome in omega-3 group compared to control, whereas such difference was noticed in the NEURAPRO. In the VHR study both omega-3 and omega-6 together predicted the functional improvement at 12 weeks.

CONCLUSIONS

The number of studies available remains insufficient and more studies with standardized outcome measures in a clinically comparable UHR population would be of more value to understand the clinical benefits of omega-3 FA in the UHR population.

European Psychiatric Association guidance on assessment of cognitive impairment in schizophrenia

Background

Impairment in a wide range of cognitive abilities has been consistently reported in individuals with schizophrenia. Both neurocognitive and social cognitive deficits are thought to underlie severe functional disabilities associated with schizophrenia. Despite the key role in schizophrenia outcome, cognition is still poorly assessed in both research and clinical settings.

Methods

In this guidance paper, we provide a systematic review of the scientific literature and elaborate several recommendations for the assessment of cognitive functions in schizophrenia both in research settings and in real-world clinical practice.

Results

Expert consensus and systematic reviews provided guidance for the optimal assessment of cognitive functions in schizophrenia. Based on the reviewed evidence, we recommend a comprehensive and systematic assessment of neurocognitive and social cognitive domains in schizophrenia, in all phases of the disorder, as well as in subjects at risk to develop psychosis. This European Psychiatric Association guidance recommends not only the use of observer reports but also self-reports and interview-based cognitive assessment tools. The guidance also provides a systematic review of the state of the art of assessment in the first episode of psychosis patients and in individuals at risk for psychosis.

Conclusion

The comprehensive review of the evidence and the recommendations might contribute to advance the field, allowing a better cognitive assessment, and avoiding overlaps with other psychopathological dimensions. The dissemination of this guidance paper may promote the development of shared guidelines concerning the assessment of cognitive functions in schizophrenia, with the purpose to improve the quality of care and to obtain recovery.

Short-term functional outcome in psychotic patients: results of the Turku early psychosis study (TEPS)

BACKGROUND

Functional recovery of patients with clinical and subclinical psychosis is associated with clinical, neuropsychological and developmental factors. Less is known about how these factors predict functional outcomes in the same models. We investigated functional outcomes and their predictors in patients with first-episode psychosis (FEP) or a confirmed or nonconfirmed clinical high risk of psychosis (CHR-P vs. CHR-N).

METHODS

Altogether, 130 patients with FEP, 60 patients with CHR-P and 47 patients with CHR-N were recruited and extensively examined at baseline (T0) and 9 (T1) and 18 (T2) months later. Global Assessment of Functioning (GAF) at T0, T1 and T2 and psychotic, depression, and anxiety symptoms at T1 and T2 were assessed. Functional outcomes were predicted using multivariate repeated ANOVA.

RESULTS

During follow-up, the GAF score improved significantly in patients with FEP and CHR-P but not in patients with CHR-N. A single marital status, low basic education level, poor work situation, disorganization symptoms, perceptual deficits, and poor premorbid adjustment in patients with FEP, disorganization symptoms and poor premorbid adjustment in patients with CHR-P, and a low basic education level, poor work situation and general symptoms in patients with CHR-N predicted poor functional outcomes. Psychotic symptoms at T1 in patients with FEP and psychotic and depression symptoms at T1 and anxiety symptoms at T2 in patients with CHR-P were associated with poor functioning.

CONCLUSIONS

In patients with FEP and CHR-P, poor premorbid adjustment and disorganization symptomatology are common predictors of the functional outcome, while a low education level and poor work situation predict worse functional outcomes in patients with FEP and CHR-N. Interventions aimed at improving the ability to work and study are most important in improving the functioning of patients with clinical or subclinical psychosis.

Establishing a clinical high-risk program in Tunisia, North Africa: A pilot study in early detection and identification

BACKGROUND

Early identification and prevention research has provided huge advances in our understanding of early screening and identification of young people at clinical high-risk (CHR). Most of these procedures were developed in high-income countries, yet middle-income countries in North Africa such as Tunisia can benefit from these empirically-based assessment approaches.

METHODS

Using established procedures, nine Tunisian psychiatric raters were trained on structured assessments: the CAARMS, BPRS, and SCID to high standards of interrater reliability. These raters developed a clinical high-risk program (CHiRP) in Tunisia and recruited 10 patients who were exhibiting possible signs of CHR. These patients were evaluated to determine if they met criteria for a CHR group, such as Attenuated Psychosis.

RESULTS

Trained raters met the following interrater reliability criteria for the CAARMS and BPRS (ICC = .80 or greater) and the SCID (Kappa = .75 or greater). Of 10 pilot patients, six were classified as CHR and belonging to the Attenuated Psychosis Group. One of the six patients converted to psychosis 3 months after study entry for a conversion rate of 17% which is comparable with currently published rates globally.

DISCUSSION

The first CHR program has been established in Tunisia, a middle-income country using methods developed in high income countries. Efforts aimed at assembling a group of prevention-oriented psychiatrists, obtaining administrative support, and training raters to high levels of interrater reliability were successful. The feasibility was demonstrated for screening, assessing, treating, and following-up of 10 CHR patients suggesting that conversion rates are comparable to those of Western and European countries.

Changes in the cognitive function of Chinese college students with a clinical high risk of psychosis

The purpose of our study was to explore the value of measuring cognitive functions for predicting the conversion to psychosis in Chinese college students with a clinical high risk (CHR). A total of 115 CHR students and 99 healthy controls were enrolled. All included participants were recruited from colleges in Wuhan, China. The MATRICS Consensus Cognitive Battery was used to evaluate cognitive function. CHR individuals were followed for 2 years, and the cognitive function of CHR individuals who later converted to psychosis (CHR-C) was compared to CHR individuals who did not convert (CHR-NC). Of the 107 CHR individuals that completed the 2- year follow-up, 29 (27.1%) developed a psychotic disorder. CHR individuals demonstrated poorer performance on all cognitive function tests compared to controls. CHR-C participants exhibited poorer performance on all cognitive tests except the Trail Making Test A and Continuous Performance Test-Identical Pairs compared to CHR-NC participants. The most significant differences displayed between CHR-C and CHR-NC groups were in visual learning, working memory, and reasoning and problem solving. The degree of cognitive impairment in visual learning and working memory may be a predictive marker for individuals who are at risk of developing psychosis.

Do neurocognitive functions in cannabis induced psychosis groups differ from schizophrenia with cannabis use? A controlled cross-sectional study

OBJECTIVE

Cannabis-induced psychosis (CIP) has received little research attention. We compared neurocognitive functions in CIP, Schizophrenia with cannabis use (SZC) and healthy control group (CG).

METHODS

Twenty age, education, and handedness-matched participants were recruited in each of the three groups. CIP and SZC were diagnosed with Psychiatric research interviews for substance use and mental disorders. Level of cannabis exposure, global intelligence, executive function, attention, vigilance, working, and verbal memory, and motor speed were compared by analysis of variance with post-hoc Scheffe's test. We did a post-hoc power calculation.

RESULTS

Age at initiation, frequency, duration, and preparation of cannabis use did not differ significantly between CIP and SZC. CIP performed significantly better (than SZC) in tests of general cognitive ability or intelligence and attention, perceptual tracking and sequencing. SZC showed significant dysfunctions (than CG) in all parameters of the tests for executive dysfunction, sustained attention, short-term verbal memory and psychomotor functioning. CIP and CG did not differ in any cognitive domains except for non-perseverative errors in the test for executive functioning.

CONCLUSIONS

CIP and SZC had different degrees of impairment compared to controls, but on direct comparisons CIP had better general intelligence and attention.KEY POINTSCannabis-induced psychosis (CIP) may have different neurocognitive impairment than Schizophrenia with cannabis use (SZC)CIP performed better in tests for general intelligence and visual attention than SZCSZC had significant impairment in executive function, attention, verbal memory, and psychomotor speed than controlsCompared to controls, CIP performed significantly worse in some domains of executive functionCIP and SZC had different degrees of cognitive impairments as compared to the controls.

Omega-3 fatty acids and neurocognitive ability in young people at ultra-high risk for psychosis

BACKGROUND

Neurocognitive impairments are core early features of psychosis and are observed in those at ultra-high risk (UHR) for psychosis. The aim of the present study was to explore whether neurocognition is associated with polyunsaturated fatty acids (PUFAs), as has been observed in other clinical populations.

METHOD

Erythrocyte levels of total omega-3-and omega-6 PUFAs the omega-3/omega-6 ratio, were measured in 265 UHR individuals. Six domains of neurocognition as well a Composite Score, were assessed using the Brief Assessment of Cognition in Schizophrenia. Pearson's correlations were used to assess the relationship between PUFAs and neurocognition. All analyses were controlled for tobacco smoking.

RESULTS

Verbal Fluency correlated positively with eicosapentaenoic acid (P = .024) and alpha-linolenic acid (P = .01), and negatively with docosahexanoic acid (P = .007) and Working Memory positively correlated with omega-3/omega-6 ratio (P = .007).

CONCLUSIONS

The current results provide support for a relationship between Verbal Fluency and omega-3 PUFAs in UHR. Further investigation is required to elucidate whether these biomarkers are useful as risk markers or in understanding the biological underpinning of neurocognitive impairment in this population.

Neurocognitive assessments are more important among adolescents than adults for predicting psychosis in clinical high risk

BACKGROUND

Few studies have examined the effects of age on neurocognition to predict conversion to psychosis in individuals with clinical high-risk(CHRs). This study aimed to compare the extent and predictive performance of cognitive deficits between adolescents and adults with CHR.

METHODS

A comprehensive neuropsychological battery was performed on 325 CHRs and 365 healthy controls(HCs). The subjects were first divided into 189 CHR adolescents(age 12-17 years), 136 CHR adults(age 18-45 years), 88 HC adolescents, and 277 HC adults. CHR subjects were then divided into converters(CHR-Cs: adolescents[n=43]; adults[n=34]) and non-converters(CHR-NCs: adolescents [n=146], adults [n=102]) based on their 2-year follow-up clinical status.

RESULTS

The adolescent and adult CHRs performed significantly worse than their control groups on all the neurocognitive tests, except for performance on the continuous performance test in adolescents. In the comparison between adolescents and adults, patterns of neurocognitive deficits seemed to vary in HCs, rather than in CHRs. In the comparison between CHRs and HCs, the rank order of effect sizes across the neurocognitive tests was similar for the top two tests of symbol coding and verbal learning. Comparison between CHR-Cs and CHR-NCs revealed that adolescent CHR-Cs performed significantly worse than CHR-NCs on seven of eight neurocognitive tests; however, adult CHR-Cs performed significantly worse than CHR-NCs only in the visuospatial memory test.

CONCLUSIONS

The role of neurocognitive dysfunction may have different patterns and weights during the onset of psychosis in adolescent and adult CHRs, implicating the development of specific strategies that could monitor and improve cognitive function in adolescents with CHR.

Reduced cortical thickness of the paracentral lobule in at-risk mental state individuals with poor 1-year functional outcomes

Although widespread cortical thinning centered on the fronto-temporal regions in schizophrenia has been reported, the findings in at-risk mental state (ARMS) patients have been inconsistent. In addition, it remains unclear whether abnormalities of cortical thickness (CT) in ARMS individuals, if present, are related to their functional decline irrespective of future psychosis onset. In this multicenter study in Japan, T1-weighted magnetic resonance imaging was performed at baseline in 107 individuals with ARMS, who were subdivided into resilient (77, good functional outcome) and non-resilient (13, poor functional outcome) groups based on the change in Global Assessment of Functioning scores during 1-year follow-up, and 104 age- and sex-matched healthy controls recruited at four scanning sites. We measured the CT of the entire cortex and performed group comparisons using FreeSurfer software. The relationship between the CT and cognitive functioning was examined in an ARMS subsample (n = 70). ARMS individuals as a whole relative to healthy controls exhibited a significantly reduced CT, predominantly in the fronto-temporal regions, which was partly associated with cognitive impairments, and an increased CT in the left parietal and right occipital regions. Compared with resilient ARMS individuals, non-resilient ARMS individuals exhibited a significantly reduced CT of the right paracentral lobule. These findings suggest that ARMS individuals partly share CT abnormalities with patients with overt schizophrenia, potentially representing general vulnerability to psychopathology, and also support the role of cortical thinning in the paracentral lobule as a predictive biomarker for short-term functional decline in the ARMS population.

Predictors of remission from the ultra-high risk state for psychosis

AIM

A significant proportion of individuals at Ultra-High Risk (UHR) for psychosis do not transition to manifest psychosis. Many non-transitioning UHR individuals do, however, display poor long-term outcomes such as persistence of attenuated psychotic symptoms. Evidence is scarce on which variables may predict a better clinical and functional prognosis such as remission from the UHR state.

METHODS

A total of 146 UHR individuals were enrolled in a randomized clinical trial (RCT), with this being analyses secondary to the RCT. Participants were assessed on multiple domains of symptoms, functioning, neuro- and social cognition. Regression analyses elucidated on the predictive power of these measures to remission from the UHR status (ie, not meeting UHR criteria) at 12-month follow-up.

RESULTS

Of the 91 UHR individuals attending 12-month follow-up, 33 (36%) exhibited remission from the UHR state. Regression analyses revealed baseline functioning to be a significant predictor of risk remission, and this was maintained when controlling for the effect of antipsychotic medication, gender and estimated IQ. The individuals with remission from the UHR state showed lower attenuated psychotic- and depressive symptoms along with better functioning at 12-month follow-up.

CONCLUSION

Our findings indicate functioning to be a contributor to the symptomatic recovery of UHR individuals, but a large amount of the variance on risk remission is, however, explained by other factors. Additionally, our findings suggest that UHR individuals with better functioning at ascertainment may present with a better clinical and functional prognosis, which may inform on the need for monitoring and intervention in this subgroup.

Cortical Gyrification, Psychotic-Like Experiences, and Cognitive Performance in Nonclinical Subjects

BACKGROUND

Psychotic-like experiences (PLE) are present in nonclinical populations, yet their association with brain structural variation, especially markers of early neurodevelopment, is poorly understood. We tested the hypothesis that cortical surface gyrification, a putative marker of early brain development, is associated with PLE in healthy subjects.

METHODS

We analyzed gyrification from 3 Tesla MRI scans (using CAT12 software) and PLE (positive, negative, and depressive symptom dimensions derived from the Community Assessment of Psychic Experiences, CAPE) in 103 healthy participants (49 females, mean age 29.13 ± 9.37 years). A subsample of 63 individuals completed tasks from the Wechsler Adult Intelligence Scale and Controlled Oral Word Association Test. Estimated IQ and a composite neuropsychological score were used to explore mediation pathways via cognition.

RESULTS

Positive PLE distress was negatively associated with gyrification of the left precuneus. PLE depression dimension showed a negative association with gyrification in the right supramarginal and temporal region. There was no significant mediating effect of cognition on these associations.

CONCLUSION

Our results support a neurobiological psychosis spectrum, for the first time linking an early developmental imaging marker (rather than volume) to dimensional subclinical psychotic symptoms. While schizophrenia risk, neurodevelopment, and cognitive function might share genetic risk factors, additional mediation analyses did not confirm a mediating effect of cognition on the gyrification-psychopathology correlation.

Cognitive dysfunction in a psychotropic medication-naïve, clinical high-risk sample from the ShangHai-At-Risk-for-Psychosis (SHARP) study: Associations with clinical outcomes

OBJECTIVES

1) to assess generalizability of neurocognitive deficits reported in previous Western clinical high-risk (CHR) for psychosis studies in a prodromal program in Shanghai, China; and 2) to investigate neurocognition in CHR subjects in relation to a broader range of clinical outcomes (e.g. remission) than presence or absence of psychosis.

METHOD

Baseline neurocognitive assessments of CHR (n = 217) and healthy control (HC; n = 133) subjects were compared based on 1-year follow-up clinical status using MANOVA. CHR subjects were first divided into 'converter' (CHR-C; n = 41) and 'non-converter' (CHR-NC; n = 155) to psychosis groups and compared to HC and to each other. CHR subjects were then divided into 'remission' (i.e. achieved remission; n = 102), 'symptomatic' (persistent positive symptoms in the absence of conversion; n = 37) and 'poor-outcome' (converted and symptomatic subjects who did not respond to treatment; n = 57) groups.

RESULTS

CHR neurocognitive performance was broadly impaired compared to HC; CHR-C subjects showed lower performance in processing speed and visual learning than CHR-NC. CHRs with poor clinical outcomes showed lower performance on most MCCB tasks compared to HC, particularly in learning and processing speed, as clinical outcome worsened from remission to symptomatic to poor outcome groups.

CONCLUSIONS

Level and pattern of baseline neurocognitive weaknesses in SHARP CHR subjects were similar to those in NAPLS-2. Outcome stratification into remission, symptomatic and poor groups was associated with increasing cognitive deficits in learning and processing speed. These findings support cross-cultural generalizability and advance understanding of CHR neurocognitive heterogeneity associated with 1-year clinical outcomes.

Self-perceived cognitive impairments in psychosis ultra-high risk individuals: associations with objective cognitive deficits and functioning

There is a scarcity of evidence on subjectively reported cognitive difficulties in individuals at ultra-high risk (UHR) for psychosis and whether these self-perceived cognitive difficulties may relate to objective cognitive deficits, psychopathology, functioning, and adherence to cognitive remediation (CR). Secondary, exploratory analyses to a randomized, clinical trial were conducted with 52 UHR individuals receiving a CR intervention. Participants completed the Measure of Insight into Cognition—Self Report (MIC-SR), a measure of daily life cognitive difficulties within the domains of attention, memory, and executive functions along with measures of neuropsychological test performance, psychopathology, functioning, and quality of life. Our study found participants with and without objectively defined cognitive deficits reported self-perceived cognitive deficits of the same magnitude. No significant relationship was revealed between self-perceived and objectively measured neurocognitive deficits. Self-perceived cognitive deficits associated with attenuated psychotic symptoms, overall functioning, and quality of life, but not with adherence to, or neurocognitive benefits from, a CR intervention. Our findings indicate that UHR individuals may overestimate their cognitive difficulties, and higher levels of self-perceived cognitive deficits may relate to poor functioning. If replicated, this warrants a need for both subjective and objective cognitive assessment in at-risk populations as this may guide psychoeducational approaches and pro-functional interventions. Self-perceived cognitive impairments do not seem to directly influence CR adherence and outcome in UHR states. Further studies are needed on potential mediator between self-perceived cognitive deficits and functioning and quality of life.

Characteristics of child psychiatric outpatients with slow processing speed and potential mechanisms of academic impact

While slow processing speed (PS) is well documented in youth with ADHD, growing evidence suggests that this difficulty affects children with other neuropsychiatric conditions. Clarifying the relationship between slow PS and different forms of psychopathology is important clinically, given the potential impact of PS on academic functioning, and conceptually. In 751 youth, ages 6-21, consecutively referred for neuropsychiatric evaluation, we examined the association between slow PS (i.e., Wechsler PS Index < 85) and seven neuropsychiatric diagnostic groups. In 492 of these youth, we also related slow PS to eight psychopathology symptom dimensions. Finally, we modeled the relationship between PS, other cognitive functions and academic achievement. Data are from the Longitudinal Study of Genetic Influences on Cognition. Analyses included one-sample t tests, ANOVA, logistic regression, mixed modeling, and structural equation modeling (SEM), controlling for age, sex, and medication. Compared to normative data, all clinical groups showed PS decrements. Compared to referred youth without full diagnoses and accounting for other psychopathology, risk for slow PS was elevated in youth with autism spectrum disorder (OR = 1.8), psychotic disorders (OR = 3.4) and ADHD-inattentive type (OR = 1.6). Having multiple comorbidities also increased risk for slow PS. Among dimensions, inattention (OR = 1.5) associated with slow PS but did not fully explain the association with autism or psychosis. In SEM, PS had direct effects on academic achievement and indirect effects through working memory. Findings extend evidence that PS relates to multiple aspects of child psychopathology and associates with academic achievement in child psychiatric outpatients.

Depth-dependent abnormal cortical myelination in first-episode treatment-naïve schizophrenia

Myelination is key to effective message passing in the central nervous system and is likely linked to the pathogenesis of schizophrenia (SZ). Emerging evidence indicates that a large portion of intracortical myelin insulates inhibitory interneurons that are highly relevant to pathogenesis of schizophrenia. Here for the first time, we characterized intracortical myelination across the entire cortical surface in first‐episode treatment‐naïve patients with schizophrenia (FES) using T1w/T2w ratio of structural MRI, FES patients exhibited significantly higher myelin content in the left inferior parietal lobe, supramarginal gyrus, and superior temporal gyrus in the superficial layer, as well as left IPL in the middle layer, but significantly lower myelin content in the left middle insula and posterior cingulate gyrus. Years of education, a proxy for onset of functional decline, significantly altered the relationship between abnormal parietal and posterior cingulate myelination and clinical symptoms, indicating that the pathoplastic role of myelination hinges on the age of onset of functional decline. In addition, higher myelination generally related to better cognitive function in younger subjects but worse cognitive function in older subjects. We conclude that FES is characterized by increased myelination of the superficial layers of the parietal–temporal association cortex, but reduced myelination of the cingulo‐insular midcortical layer cortex. Intracortical myelin content affects both cognitive functioning and symptom burden in FES, with the effect conditional upon age and timing of onset of functional decline. These results suggest myelination might be a critical biological target for procognitive interventions in SZ.

Cognitive functioning in ultra-high risk for psychosis individuals with and without depression: Secondary analysis of findings from the NEURAPRO randomized clinical trial

Neurocognitive impairments are well established in both ultra-high risk (UHR) for psychosis and major depressive disorder (MDD). Despite this understanding, investigation of neurocognitive deficits in UHR individuals with MDD and its association with MDD within this population, has been scarce. Hence, this study aimed to examine any differences in neurocognition at baseline between those with MDD at baseline and those with no history of MDD, as well as determine whether neurocognitive variables are significantly associated with meeting criteria for MDD at follow-up, while controlling for relevant clinical variables, within a UHR cohort. Data analysis was conducted on 207 participants whose baseline neurocognition was assessed using Brief Assessment of Cognition for Schizophrenia, as part of a trial of omega-3 fatty acids (NEURAPRO) for UHR individuals. While baseline MDD was the strongest predictor, poorer verbal memory and higher verbal fluency were significantly associated with MDD at 12 months (p = .04 and 0.026, respectively). Further, higher processing speed was significantly associated with MDD at medium-term follow-up (p = .047). These findings outline that neurocognitive skills were independently associated with meeting criteria for MDD at follow-up within UHR individuals, with novel findings of better verbal fluency and processing speed being linked to MDD outcomes. Hence, neurocognitive performance should be considered as a marker of risk for MDD outcomes and a target for management of MDD in UHR.

Assessing Youth with Psychotic Experiences: A Phenomenological Approach

Psychotic experiences may be part of normal development or indicate a wide range of mental disorders. This article shows how a systematic, domain-based, phenomenological approach to assessing psychotic symptoms in youth facilitates the gathering of the nuanced clinical information necessary to understand a child's specific experience. Mapping this information onto a narrative timeline, while understanding the evolution and developmental context of psychotic experiences, is essential in making an accurate diagnostic formulation and appropriate treatment plan for youth presenting with psychotic experiences.

Recent Advances in the Early Intervention in Schizophrenia: Future Direction from Preclinical Findings

PURPOSE OF REVIEW

In the past decade, there has been increasing interest in the potential benefit of early intervention in schizophrenia. Patients with schizophrenia show cognitive impairment for several years preceding the onset of psychosis. The author discusses the recent topics on prevention of schizophrenia.

RECENT FINDINGS

Preclinical findings suggest that maternal immune activation (MIA) produces cognitive deficits as a prodromal symptom in juvenile offspring in rodents. Treatment with anti-inflammatory compounds, such as D-serine, 7,8-dihydroxyflavone (a TrkB agonist), sulforaphane (or its precursor glucoraphanin), and TPPU (1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl) urea: a soluble epoxide hydrolase inhibitor), during adolescence might prevent the onset of behavioral abnormalities and parvalbumin immunoreactivity in the medial prefrontal cortex of adult offspring after MIA. Based on the role of inflammation and cognitive impairment in the prodromal state, early intervention using anti-inflammatory compounds (i.e., D-serine, sodium benzoate, TrkB agonist, Nrf2 agonist, soluble epoxide hydrolase inhibitor) may reduce the risk of subsequent transition to schizophrenia.