[Relationship between subclinical psychotic symptoms and cognitive performance in the general population]

Associations between symptom and neurocognitive dimensions in clinical high risk for psychosis

Introduction

Clinical high risk for psychosis (CHR) is associated with mild cognitive impairments. Symptoms are clustered into positive, negative and disorganization symptoms. The association between specific symptom dimensions and cognitive functions remains unclear. The aim of this study was to investigate the associations between cognitive functions and positive, negative, and disorganization symptoms.

Method

53 CHR subjects fulfilling criteria for attenuated psychotic syndrome in the Structural Interview for Prodromal Syndromes (SIPS) were assessed for cognitive function. Five cognitive domain z-scores were defined by contrasting with observed scores of a group of healthy controls (n = 40). Principal Components Analyses were performed to construct general cognitive composite scores; one using all subtests and one using the cognitive domains. Associations between cognitive functions and symptoms are presented as Spearman's rank correlations and partial Spearman's rank correlations adjusted for age and gender.

Results

Positive symptoms were negatively associated with executive functions and verbal memory, and disorganization symptoms with poorer verbal fluency. Negative symptoms were associated with better executive functioning. There were no significant associations between the general cognitive composites and any of the symptom domains, except for a trend for positive symptoms.

Conclusion

In line with previous research, data indicated associations between positive symptoms and poorer executive functioning. Negative symptoms may not be related to executive functions in CHR the same way as in psychosis. Our results could indicate that attenuated positive symptoms are more related to cognitive deficits in CHR than positive symptoms in schizophrenia and FEP.

The use of the Montreal Cognitive Assessment (MoCA) screening tool to evaluate cognitive deficits in Lebanese in-patients with schizophrenia

BACKGROUND

The Montreal Cognitive Assessment (MoCA) is a brief cognitive impairment screening tool suitable for a rapid diagnosis of cognitive functioning. The primary objective was to examine the ability of the MoCA to detect cognitive impairment and functioning (autonomy and social cognition) among Lebanese patients with schizophrenia. The secondary objective was to evaluate factors related to cognition.

METHODS

A cross-sectional study conducted between July 2019 and Mars 2020 that enrolled 120 in-patients diagnosed with schizophrenia. The MoCA tool and the BACS were used to evaluate the patients' cognitive functioning.

RESULTS

The MoCA adjusted total score was significantly correlated with the BACS total score (r = .72, p < .001). The cut-off value of the MoCA for detecting mild cognitive impairment was 21, moderate cognitive impairment was 20.50 and severe cognitive impairment was 19.5. The multivariable analysis showed that the MoCA total score and the BACS score resulted in a non-significant association with autonomy. Also, higher cognition (higher BACS) (B =.10, p < 0.001) was significantly associated with a higher MoCA total score. However, higher depression (B=-.18, p = .02) and higher psychosis (B=-.04, p = .01) were significantly associated with lower MoCA.

CONCLUSION

The Arabic version of the MoCA can be a useful tool for screening cognitive impairment in patients with schizophrenia.

Early adult mental health, functional and neuropsychological outcomes of young people who have reported psychotic experiences: a 10-year longitudinal study

BACKGROUND

Psychotic experiences (PE) are highly prevalent in childhood and are known to be associated with co-morbid mental health disorders and functional difficulties in adolescence. However, little is known about the long-term outcomes of young people who report PE.

METHODS

As part of the Adolescent Brain Development Study, 211 young people were recruited in childhood (mean age 11.7 years) and underwent detailed clinical interviews, with 25% reporting PE. A 10 year follow-up study was completed and 103 participants returned (mean age 20.9 years). Structured clinical interviews for DSM-5 (SCID-5) and interviewer-rated assessments of functioning were conducted. A detailed neuropsychological battery was also administered. Analyses investigated group differences between those who had ever reported PE and controls in early adulthood.

RESULTS

The PE group was at a significantly higher risk of meeting DSM-5 criteria for a current (OR 4.08, CI 1.16-14.29, p = 0.03) and lifetime psychiatric disorder (OR 3.27, CI 1.43-7.47, p = 0.005). They were also at a significantly higher risk of multi-morbid lifetime psychiatric disorders. Significantly lower scores on current social and global functioning measures were observed for the PE group. Overall, there were no differences in neuropsychological performance between groups apart from significantly lower scores on the Stroop Word task and the Purdue Pegboard task for the PE group.

CONCLUSIONS

Our findings suggest that reports of PE are associated with poorer mental health and functional outcomes in early adulthood, with some persisting cognitive and motor deficits. Young people who report such symptoms could be considered a target group for interventions to aid functional outcomes.

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.

Psychomotor Slowing in Schizophrenia: Implications for Endophenotype and Biomarker Development

Motor abnormalities (e.g., dyskinesia, psychomotor slowing, neurological soft signs) are core features of schizophrenia that occur independent of drug treatment and are associated with the genetic vulnerability and pathophysiology for the illness. Among this list, psychomotor slowing in particular is one of the most consistently observed and robust findings in the field. Critically, psychomotor slowing may serve as a uniquely promising endophenotype and/or biomarker for schizophrenia considering it is frequently observed in those with genetic vulnerability for the illness, predicts transition in subjects at high-risk for the disorder, and is associated with symptoms and recovery in patients. The purpose of the present review is to provide an overview of the history of psychomotor slowing in psychosis, discuss its possible neural underpinnings, and review the current literature supporting slowing as a putative endophenotype and/or biomarker for the illness. This review summarizes substantial evidence from a diverse array of methodologies and research designs that supports the notion that psychomotor slowing not only reflects genetic vulnerability, but is also sensitive to disease processes and the pathophysiology of the illness. Furthermore, there are unique deficits across the cognitive (prefix "psycho") and motor execution (root word "motor") aspects of slowing, with cognitive processes such as planning and response selection being particularly affected. These findings suggest that psychomotor slowing may serve as a promising endophenotype and biomarker for schizophrenia that may prove useful for identifying individuals at greatest risk and tracking the course of the illness and recovery.

Comparison of the neurocognitive profiles of individuals with elevated psychotic or depressive symptoms

AIM

Neurocognitive deficits are pervasive and enduring features of severe mental illness that appear before the onset of clinical symptoms and contribute to functional disability. However, it remains unclear how individuals who display warning signs for psychotic or mood disorders compare on their neurocognitive profiles since previous studies have separately examined neurocognition in both groups. Therefore, the purpose of this study was to directly compare performance on a range of neurocognitive tasks in individuals with emerging psychotic or mood symptoms.

METHODS

Participants were drawn from a database of individuals who completed a comprehensive assessment at a university-based assessment centre. We examined 3 groups: individuals who endorsed elevated psychotic symptoms (EPS; n = 64), individuals who endorsed elevated depressive symptoms (EDS; n = 58), or non-clinical comparisons (NCC; n = 57) without any elevated psychiatric symptoms or diagnoses.

RESULTS

EPS participants performed worse than NCC and EDS groups on verbal comprehension, working memory and cognitive flexibility, and worse than NCC, but not EDS, on perceptual reasoning. There were no significant differences between groups on processing speed, verbal fluency and set-shifting. EDS performed worse than both EPS and NCC groups on psychomotor speed. Dimensionally, poorer cognitive functioning was more strongly related to EPS than depressive symptoms.

CONCLUSIONS

These findings highlight the distinct yet overlapping neurocognitive profiles of both groups with emerging psychiatric symptoms, and suggest that, despite having no formal diagnosis, individuals with EPS exhibit observable cognitive impairment and may still benefit from interventions within academic and workplace contexts.

Disruptions in White Matter Maturation and Mediation of Cognitive Development in Youths on the Psychosis Spectrum

BACKGROUND

Psychosis onset typically occurs in adolescence, and subclinical psychotic experiences peak in adolescence. Adolescence is also a time of critical neural and cognitive maturation. Using cross-sectional data from the Philadelphia Neurodevelopmental Cohort, we examined whether regional white matter (WM) development is disrupted in youths with psychosis spectrum (PS) features and whether WM maturation mediates the relationship between age and cognition in typically developing (TD) youths and youths with PS features.

METHODS

We examined WM microstructure, as assessed via diffusion tensor imaging, in 670 individuals (age 10-22 years; 499 TD group, 171 PS group) by using tract-based spatial statistics. Multiple regressions were used to evaluate age × group interactions on regional WM indices. Mediation analyses were conducted on four cognitive domains-executive control, complex cognition, episodic memory, and social cognition-using a bootstrapping approach.

RESULTS

There were age × group interactions on fractional anisotropy (FA) in the superior longitudinal fasciculus (SLF) and retrolenticular internal capsule. Follow-up analyses revealed these effects were significant in both hemispheres. Bilateral SLF FA mediated the relationship between age and complex cognition in the TD group, but not the PS group. Regional FA did not mediate the age-associated increase in any of the other cognitive domains.

CONCLUSIONS

Our results showed aberrant age-related effects in SLF and retrolenticular internal capsule FA in youths with PS features. SLF development supports emergence of specific higher-order cognitive functions in TD youths, but not in youths with PS features. Future mechanistic explanations for these relationships could facilitate development of earlier and refined targets for therapeutic interventions.