Cognitive functioning throughout adulthood and illness stages in individuals with psychotic disorders and their unaffected siblings

Cognitive presentation at psychosis onset through premorbid deterioration and exposure to environmental risk factors

BACKGROUND

Previous studies identified clusters of first-episode psychosis (FEP) patients based on cognition and premorbid adjustment. This study examined a range of socio-environmental risk factors associated with clusters of FEP, aiming a) to compare clusters of FEP and community controls using the Maudsley Environmental Risk Score for psychosis (ERS), a weighted sum of the following risks: paternal age, childhood adversities, cannabis use, and ethnic minority membership; b) to explore the putative differences in specific environmental risk factors in distinguishing within patient clusters and from controls.

METHODS

A univariable general linear model (GLS) compared the ERS between 1,263 community controls and clusters derived from 802 FEP patients, namely, low (n = 223) and high-cognitive-functioning (n = 205), intermediate (n = 224) and deteriorating (n = 150), from the EU-GEI study. A multivariable GLS compared clusters and controls by different exposures included in the ERS.

RESULTS

The ERS was higher in all clusters compared to controls, mostly in the deteriorating (β=2.8, 95% CI 2.3 3.4, η2 = 0.049) and the low-cognitive-functioning cluster (β=2.4, 95% CI 1.9 2.8, η2 = 0.049) and distinguished them from the cluster with high-cognitive-functioning. The deteriorating cluster had higher cannabis exposure (meandifference = 0.48, 95% CI 0.49 0.91) than the intermediate having identical IQ, and more people from an ethnic minority (meandifference = 0.77, 95% CI 0.24 1.29) compared to the high-cognitive-functioning cluster.

CONCLUSIONS

High exposure to environmental risk factors might result in cognitive impairment and lower-than-expected functioning in individuals at the onset of psychosis. Some patients' trajectories involved risk factors that could be modified by tailored interventions.

Schizophrenia-related Xpo7 haploinsufficiency leads to behavioral and nuclear transport pathologies

Recent genetic studies by the Schizophrenia Exome Sequencing Meta-Analysis (SCHEMA) consortium have identified that protein-truncating variants of exportin 7 (XPO7) can increase the risk of schizophrenia (odds ratio, 28.1). Here we show that mice with Xpo7 haploinsufficiency (Xpo7+/- mice) present with cognitive and social behavioral impairments. Through proteome analysis using immunoprecipitation and frontal cortex nuclear isolation of Xpo7+/- mice, we identify 45 molecules interacting with Xpo7, including CutC, Rbfox3, and Gria3. Through single-nucleus RNA sequencing of the frontal cortex and striatum of Xpo7+/- mice differentiating between the onset and progressive stages, we also identify 284 gene expression changes that correlate with these stages. These genes encompass high-odds risk genes of schizophrenia identified by SCHEMA, including Gria3, Grin2A, Herc1, and Trio. Furthermore, our approach reveals 15 gene expression changes in the frontal cortex that correlate with the progressive stages. Our findings indicate the importance of investigating whether the interactions among the high-risk genes identified by SCHEMA contribute to a common schizophrenia pathology and underscore the significance of stage-dependent analysis.

Deconstructing Cognitive Impairment in Psychosis With a Machine Learning Approach

Importance

Cognitive functioning is associated with various factors, such as age, sex, education, and childhood adversity, and is impaired in people with psychosis. In addition to specific effects of the disorder, cognitive impairments may reflect a greater exposure to general risk factors for poor cognition.

Objective

To determine the extent that impairments in cognition in psychosis reflect risk factor exposures.

Design, Setting, and Participants

This cross-sectional study examined the relationship between exposures and cognitive function using data from the Bipolar-Schizophrenia Network on Intermediate Phenotypes studies 1 and 2 across 6 sites. Participants included healthy controls; patients with schizophrenia, schizoaffective disorder, or bipolar I disorder with psychosis; and relatives of patients. Predictive modeling was performed using extreme gradient boosting regression to train a composite cognitive score prediction model with nested cross-validation. Shapley additive explanations values were used to examine the relationship between exposures and cognitive function.

Exposure

Exposures were chosen based on associations with cognition previously identified: age, sex, race and ethnicity, childhood adversity, education, parental education, parental socioeconomic status, parental age at birth, substance use, antipsychotic dose, and diagnosis.

Main Outcomes and Measures

Cognition was assessed using the Brief Assessment of Cognition in Schizophrenia.

Results

A total of 3370 participants were included: 840 healthy controls, 709 patients with schizophrenia, 541 with schizoaffective disorder, 457 with bipolar I disorder with psychosis, and 823 relatives of patients. The mean (SD) age was 37.9 (13.3) years; 1887 were female (56%) and 1483 male (44%). The model predicted cognitive scores with high accuracy: out-of-sample Pearson correlation between predicted and observed cognitive composite score was r = 0.72 (SD = 0.03). Individuals with schizophrenia (z = -1.4), schizoaffective disorder (z = -1.2), and bipolar I disorder with psychosis (z = -0.5) all had significantly worse cognitive composite scores than controls. Factors other than diagnosis and medication accounted for much of this impairment (schizophrenia z = -0.73, schizoaffective disorder z = -0.64, bipolar I disorder with psychosis z = -0.13). Diagnosis accounted for a lesser proportion of this deficit (schizophrenia z = -0.29, schizoaffective disorder z = -0.15, bipolar I disorder with psychosis z = -0.13), and antipsychotic use accounted for a similar deficit across diagnostic groups (schizophrenia z = -0.37, schizoaffective disorder z = -0.33, bipolar I disorder with psychosis z = -0.26).

Conclusions and Relevance

This study found that transdiagnostic factors accounted for a meaningful share of the variance in cognitive functioning in psychosis. A significant proportion of the cognitive impairment in psychosis may reflect factors relevant to cognitive functioning in the general population. When considering interventions, a diagnosis-agnostic, symptom-targeted approach may therefore be appropriate.

Exploring Cognitive Deficits and Neuromodulation in Schizophrenia: A Narrative Review

Cognitive deficits are emerging as critical targets for managing schizophrenia and enhancing clinical and functional outcomes. These deficits are pervasive among individuals with schizophrenia, affecting various cognitive domains. Traditional pharmacotherapy and cognitive behavioral therapy (CBT) have limitations in effectively addressing cognitive impairments in this population. Neuromodulation techniques show promise in improving certain cognitive domains among patients with schizophrenia spectrum disorders. Understanding the mechanisms of neural circuits that underlie cognitive enhancement is essential for elucidating the pathophysiological processes of the disorder, and these insights could significantly optimize strategies for managing schizophrenia. Meanwhile, although there is an increasing body of evidence demonstrating the therapeutic effects of neuromodulation in this area, further research is still needed, particularly regarding topics such as different treatment protocols and the long-term effects of treatment.

Unraveling the role of the renin-angiotensin system in severe mental illnesses: An insight into psychopathology and cognitive deficits

Severe mental illnesses (SMI), especially schizophrenia and bipolar disorder (BD), are associated with significant distress to patients, reduced life expectancy and a higher cost of care. There is growing evidence that SMI may increase the risk of dementia in later life, posing an additional challenge in the management of these patients. SMI present a complex and highly heterogeneous pathophysiology, which has hampered the understanding of its underlying pathological mechanisms and limited the success of the available therapies. Despite the advances in therapeutic approaches in psychiatry over the past decades, treatment resistance is still a common problem in clinical practice, highlighting the urgent need for novel therapeutic targets for SMI. The discovery that renin-angiotensin system (RAS) components are expressed in the central nervous system opened new possibilities for investigating a potential role for this system in the neurobiology of SMI. The safety and efficacy of AT1 receptor blockers and angiotensin-converting enzyme inhibitors in cardiovascular and metabolic diseases, common medical comorbidities among SMI patients and well-known risk factors for dementia, suggest the potential scalability of these strategies for the management of SMI outcomes including the risk of subsequent dementia. This review aimed to discuss the available evidence from animal models and human studies of the potential involvement of RAS in the pathophysiology of SMI. We also provided a reflection on drawbacks and perspectives that can foster the development of new related therapeutic strategies.

Cognition and gut microbiota in schizophrenia spectrum and mood disorders: A systematic review

FRILEUX, M., BOLTRI M. and al. Cognition and Gut microbiota in schizophrenia spectrum and mood disorders: a Systematic Review. NEUROSCI BIOBEHAV REV (1) 2024 Schizophrenia spectrum disorders and major mood disorders are associated with cognitive impairments. Recent studies suggest a link between gut microbiota composition and cognitive functioning. Here, we review the relationship between gut microbiota and cognition in these disorders. To do this, we conducted a systematic review, searching Cochrane Central Register of Controlled Trials, EBSCOhost, Embase, Pubmed, Scopus, and Web of Science. Studies were included if they investigated the relationship between gut microbiota composition and cognitive function through neuropsychological assessments in patients with bipolar, depressive, schizophrenia spectrum, and other psychotic disorders. Ten studies were identified. Findings underscore a link between gut dysbiosis and cognitive impairment. This relationship identified specific taxa (Haemophilus, Bacteroides, and Alistipes) as potential contributors to bolstered cognitive performance. Conversely, Candida albicans, Toxoplasma gondii, Streptococcus and Deinococcus were associated with diminished performance on cognitive assessments. Prebiotics and probiotics interventions were associated with cognitive enhancements, particularly executive functions. These results emphasize the role of gut microbiota in cognition, prompting further exploration of the underlying mechanisms paving the way toward precision psychiatry.

Neuroimaging features of cognitive impairments in schizophrenia and major depressive disorder

Cognitive dysfunctions are one of the key symptoms of schizophrenia (SZ) and major depressive disorder (MDD), which exist not only during the onset of diseases but also before the onset, even after the remission of psychiatric symptoms. With the development of neuroimaging techniques, these non-invasive approaches provide valuable insights into the underlying pathogenesis of psychiatric disorders and information of cognitive remediation interventions. This review synthesizes existing neuroimaging studies to examine domains of cognitive impairment, particularly processing speed, memory, attention, and executive function in SZ and MDD patients. First, white matter (WM) abnormalities are observed in processing speed deficits in both SZ and MDD, with distinct neuroimaging findings highlighting WM connectivity abnormalities in SZ and WM hyperintensity caused by small vessel disease in MDD. Additionally, the abnormal functions of prefrontal cortex and medial temporal lobe are found in both SZ and MDD patients during various memory tasks, while aberrant amygdala activity potentially contributes to a preference to negative memories in MDD. Furthermore, impaired large-scale networks including frontoparietal network, dorsal attention network, and ventral attention network are related to attention deficits, both in SZ and MDD patients. Finally, abnormal activity and volume of the dorsolateral prefrontal cortex (DLPFC) and abnormal functional connections between the DLPFC and the cerebellum are associated with executive dysfunction in both SZ and MDD. Despite these insights, longitudinal neuroimaging studies are lacking, impeding a comprehensive understanding of cognitive changes and the development of early intervention strategies for SZ and MDD. Addressing this gap is critical for advancing our knowledge and improving patient prognosis.

Revisiting Cognitive Deficits in Outpatients with Psychotic Disorders: A Transdiagnostic Comparison of Cognitive Performance While Accounting for Putative Confounding Factors

Recent research suggests that cognitive deficits in individuals with psychotic disorders could be overestimated because poor cognitive test performance is partly attributable to non-cognitive factors. To further test this, we included non-hospitalized individuals with psychotic disorders (PSY, n = 38), individuals with attenuated psychotic symptoms (n = 40), individuals with obsessive-compulsive disorders (n = 39), and healthy controls (n = 38). Relevant cognitive domains were assessed using the MATRICS Consensus Cognitive Battery. Putative confounding non-cognitive factors-heart rate, self-reported stress, negative affect, performance-related beliefs, and actigraphy-derived sleep-were assessed before cognitive testing. A multivariate analysis of covariance was calculated to examine group differences in cognitive performance while controlling for non-cognitive factors. PSY showed decreased test performance in graphomotor speed, attention, and verbal tasks compared to the other groups, whereas non-verbal/visual-spatial tasks were unimpaired. After accounting for non-cognitive factors, group differences diminished in verbal learning, whereas differences in the other domains remained significant. Against our hypotheses, the present findings indicate that some cognitive deficits in PSY cannot be attributed to momentary confounding factors.

Association of antidepressant and benzodiazepine use, and anticholinergic burden with cognitive performance in schizophrenia

Schizophrenia is characterized by cognitive impairment affecting everyday functioning. Earlier research has hypothesized that antidepressants may associate with better cognitive functioning, but results are mixed. This study explored the association between antidepressant use and cognitive performance in terms of reaction time and visual learning in a clinical sample. In addition, we examined benzodiazepine use and anticholinergic burden. Study participants were drawn from the SUPER-Finland cohort, collected among patients with psychotic illnesses in 2016-2018 throughout Finland (n = 10,410). The analysis included adults with a schizophrenia diagnosis (F20) and results from a cognitive assessment (n = 3365). Information about medications and psychosocial factors were gathered through questionnaire and interview. Cognitive performance was assessed with the Cambridge Neuropsychological Test Automated Battery (CANTAB) with two subtests measuring reaction time and visual learning. Almost 36 % of participants used at least one antidepressant. The use of antidepressants in general was not associated with performance in the reaction time and visual learning tasks. However, the use of SNRI antidepressants was associated with a faster reaction time. Benzodiazepine use and a higher anticholinergic burden were associated with poorer performance in both tests. The results strengthen earlier findings that there is no association between antidepressant use in general and cognitive performance in schizophrenia. However, the association of SNRI medications with a faster reaction time warrants further research. Moreover, the results suggest that more attention should be paid to the anticholinergic burden of the medications used by patients with schizophrenia, as well as avoiding continuous benzodiazepine use.

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

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

Cognitive deficits profiles in the first-episode of schizophrenia, clinical high risk of psychosis, and genetically high-risk of psychosis

Background

Cognitive deficits are core characteristics of schizophrenia, presenting before the emergence of psychotic symptoms. Individuals with a clinical high-risk for psychosis (CHR) and those with genetically high-risk of psychosis (GHR) also exhibit cognitive impairments. Nonetheless, it remains uncertain in which domains of cognitive impairments in these two groups were more similar to those of schizophrenia patients. Moreover, it is unclear which domains of impairment are caused by quality factors and which are more related to the state of disease. This research initiative aimed to extensively examine the distinct cognitive impairment profiles among the CHR, GHR, and first-episode schizophrenia (FES) cohorts.

Methods

We compared the cognitive functions of the three groups and a healthy control group (HCs) using the MATRICS Consensus Cognitive Battery (MCCB). The participants for this study were recruited from the Beijing Anding Hospital of Capital Medical University. Our sample consisted of 56 patients with FES, 42 with CHR, 26 with GHR, and 62 HCs. The participants across all groups were matched in terms of gender, age, and level of education.

Results

Individuals with FES, GHR, and CHR showed significant impairment across the majority of MCCB domains, with the exception of visual learning, in comparison to HCs. None of the MCCB domains demonstrated a discerning ability to accurately differentiate between individuals with CHR and those with GHR. In the speed of processing and attention/vigilance domains, individuals with GHR and CHR exhibited scores between those of FES and HCs, with all group differences reaching statistical significance. This pattern of results indicates an intermediate level of cognitive function in individuals with GHR and CHR. Conversely, the levels of impairment observed in working memory and verbal learning were relatively consistent across all three groups: FES, CHR, and GHR. Notably, individuals in the CHR group exhibited performance akin to that of the HCs in the reasoning/problem-solving domain, while showing significant differences from the FES group, with the CHR individuals demonstrating better performance. Additionally, individuals with GHR displayed performance in social cognition similar to that of the HCs, while also demonstrating significant distinctions from the FES group, with the GHR individuals demonstrating better performance.

Conclusion

Significant cognitive deficits exist in individuals with CHR, GHR, and FES, and these deficits vary across domains. Processing speed and attention/vigilance could potentially serve as robust biomarkers for identifying individuals at a risk of psychosis. The impairment observed in reasoning/problem-solving abilities might signify a qualitative trait, whereas deficits in social recognition could indicate a state characteristic specific to schizophrenia.

The relationship between genetic liability, childhood maltreatment, and IQ: findings from the EU-GEI multicentric case-control study

This study investigated if the association between childhood maltreatment and cognition among psychosis patients and community controls was partially accounted for by genetic liability for psychosis. Patients with first-episode psychosis (N = 755) and unaffected controls (N = 1219) from the EU-GEI study were assessed for childhood maltreatment, intelligence quotient (IQ), family history of psychosis (FH), and polygenic risk score for schizophrenia (SZ-PRS). Controlling for FH and SZ-PRS did not attenuate the association between childhood maltreatment and IQ in cases or controls. Findings suggest that these expressions of genetic liability cannot account for the lower levels of cognition found among adults maltreated in childhood.

Analysis of Educational Attainment in a Mexican Psychiatric Patient Population with Bipolar or Psychotic Disorders

Schizophrenia has been associated with premorbid poor educational performance and low educational attainment (EA). However, some studies have found positive associations between psychotic disorders and excellent scholastic performance. In the present study, we examined the association between EA and several clinical and nonclinical characteristics in psychiatric patients diagnosed with psychotic or bipolar disorders. Data were obtained from the files of 1132 patients who entered a major Mexico City psychiatric hospital during the years 2009-2010 for the treatment of psychotic symptoms and who were subsequently diagnosed with schizophrenia, bipolar, schizoaffective, or another psychotic disorder. Chi-squared tests, t-tests, and Cox regression analysis were applied to explore associations between EA and factors including gender, familial history of mental illness, premorbid personality characteristics, age of symptom onset, diagnosis, civil status, and current employment. Family history of mental illness decreased the hazard of having lower EA (B = -0.137, p = 0.025, ExpB = 0.872, 95% CI = 0.774-0.983), while a schizophrenia diagnosis independently increased it (B = 0.201, p = 0.004, ExpB = 1.223, 95% CI = 1.068-1.401). In male patients (but not in females), family history of mental illness was significantly associated with higher EA, while in female patients, premorbid schizoid-like personality characteristics were associated with lower EA. For both genders, lower EA was associated with having more children and being employed in manual labor, while higher EA was associated with professional employment. Conclusions: Compared with bipolar disorder, a schizophrenia diagnosis is associated with lower EA; however, familial history of mental illness and premorbid schizoid-like characteristics independently favor higher and lower EA in males and females, respectively. Since lower EA is generally associated with a lower economic status, special preventative attention should be given to students at high risk for schizophrenia, particularly those displaying a schizoid-like personality.

Cognitive impairment in schizophrenia: aetiology, pathophysiology, and treatment

Cognitive deficits are a core feature of schizophrenia, account for much of the impaired functioning associated with the disorder and are not responsive to existing treatments. In this review, we first describe the clinical presentation and natural history of these deficits. We then consider aetiological factors, highlighting how a range of similar genetic and environmental factors are associated with both cognitive function and schizophrenia. We then review the pathophysiological mechanisms thought to underlie cognitive symptoms, including the role of dopamine, cholinergic signalling and the balance between GABAergic interneurons and glutamatergic pyramidal cells. Finally, we review the clinical management of cognitive impairments and candidate novel treatments.

Extrapyramidal symptoms predict cognitive performance after first-episode psychosis

Extrapyramidal (EP) symptoms such as tremor, rigidity, and bradykinesia are common side effects of most antipsychotics, and may associate with impaired performance in neurocognitive testing. We studied EP symptoms in first-episode psychosis (FEP; n = 113). Cognitive testing and EP symptoms (three items of the Simpson-Angus Scale) were assessed at baseline and follow-up (mean follow-up time 12 months). Mild EP symptoms were present at treatment onset in 40% of the participants. EP symptoms were related with lower performance in neurocognitive testing at baseline and at follow-up, especially among those with nonaffective psychotic disorder, and especially in tasks requiring speed of processing. No associations between EP symptoms and social cognition were detected. In linear regression models, when positive and negative symptom levels and chlorpromazine equivalents were accounted for, baseline EP symptoms were associated with worse baseline global neurocognition and visuomotor performance. Baseline EP symptoms also longitudinally predicted global, verbal, and visuomotor cognition. However, there were no cross-sectional associations between EP symptoms and cognitive performance at follow-up. In sum, we found both cross-sectional and longitudinal associations between EP symptoms and neurocognitive task performance in the early course of psychosis. Those without EP symptoms at the start of treatment had higher baseline and follow-up neurocognitive performance. Even mild EP symptoms may represent early markers of long-term neurocognitive impairment.

Intelligence trajectories in individuals at ultra-high risk for psychosis: An 8-year longitudinal analysis

Cognitive impairment is a well-documented predictor of transition to a full-threshold psychotic disorder amongst individuals at ultra-high risk (UHR) for psychosis. However, less is known about whether change in cognitive functioning differs between those who do and do not transition. Studies to date have not examined trajectories in intelligence constructs (e.g., acquired knowledge and fluid intelligence), which have demonstrated marked impairments in individuals with schizophrenia. This study aimed to examine intelligence trajectories using longitudinal data spanning an average of eight years, where some participants completed assessments over three time-points. Participants (N = 139) at UHR for psychosis completed the Wechsler Abbreviated Scale of Intelligence (WASI) at each follow-up. Linear mixed-effects models mapped changes in WASI Full-Scale IQ (FSIQ) and T-scores on Vocabulary, Similarities, Block Design, and Matrix Reasoning subtests. The sample showed stable and improving trajectories for FSIQ and all subtests. There were no significant differences in trajectories between those who did and did not transition to psychosis and between individuals with good and poor functional outcomes. However, although not significant, the trajectories of the acquired knowledge subtests diverged between transitioned and non-transitioned individuals (β = -0.12, 95 % CI [-0.29, 0.05] for Vocabulary and β = -0.14, 95 % CI [-0.33, 0.05] for Similarities). Overall, there was no evidence for long-term deterioration in intelligence trajectories in this UHR sample. Future studies with a larger sample of transitioned participants may be needed to explore potential differences in intelligence trajectories between UHR transition groups and other non-psychosis outcomes.

Cognitive Dysfunction and Prefrontal Cortical Circuit Alterations in Schizophrenia: Developmental Trajectories

Individuals with schizophrenia (SZ) exhibit cognitive performance below expected levels based on familial cognitive aptitude. One such cognitive process, working memory (WM), is robustly impaired in SZ. These WM impairments, which emerge over development during the premorbid and prodromal stages of SZ, appear to reflect alterations in the neural circuitry of the dorsolateral prefrontal cortex. Within the dorsolateral prefrontal cortex, a microcircuit formed by reciprocal connections between excitatory layer 3 pyramidal neurons and inhibitory parvalbumin basket cells (PVBCs) appears to be a key neural substrate for WM. Postmortem human studies indicate that both layer 3 pyramidal neurons and PVBCs are altered in SZ, suggesting that levels of excitation and inhibition are lower in the microcircuit. Studies in monkeys indicate that features of both cell types exhibit distinctive postnatal developmental trajectories. Together, the results of these studies suggest a model in which 1) genetic and/or early environmental insults to excitatory signaling in layer 3 pyramidal neurons give rise to cognitive impairments during the prodromal phase of SZ and evoke compensatory changes in inhibition that alter the developmental trajectories of PVBCs, and 2) synaptic pruning during adolescence further lowers excitatory activity to a level that exceeds the compensatory capacity of PVBC inhibition, leading to a failure of the normal maturational improvements in WM during the prodromal and early clinical stages of SZ. Findings that support as well as challenge this model are discussed.

Exploring Links Between Psychosis and Frontotemporal Dementia Using Multimodal Machine Learning: Dementia Praecox Revisited

Importance

The behavioral and cognitive symptoms of severe psychotic disorders overlap with those seen in dementia. However, shared brain alterations remain disputed, and their relevance for patients in at-risk disease stages has not been explored so far.

Objective

To use machine learning to compare the expression of structural magnetic resonance imaging (MRI) patterns of behavioral-variant frontotemporal dementia (bvFTD), Alzheimer disease (AD), and schizophrenia; estimate predictability in patients with bvFTD and schizophrenia based on sociodemographic, clinical, and biological data; and examine prognostic value, genetic underpinnings, and progression in patients with clinical high-risk (CHR) states for psychosis or recent-onset depression (ROD).

Design, Setting, and Participants

This study included 1870 individuals from 5 cohorts, including (1) patients with bvFTD (n = 108), established AD (n = 44), mild cognitive impairment or early-stage AD (n = 96), schizophrenia (n = 157), or major depression (n = 102) to derive and compare diagnostic patterns and (2) patients with CHR (n = 160) or ROD (n = 161) to test patterns' prognostic relevance and progression. Healthy individuals (n = 1042) were used for age-related and cohort-related data calibration. Data were collected from January 1996 to July 2019 and analyzed between April 2020 and April 2022.

Main Outcomes and Measures

Case assignments based on diagnostic patterns; sociodemographic, clinical, and biological data; 2-year functional outcomes and genetic separability of patients with CHR and ROD with high vs low pattern expression; and pattern progression from baseline to follow-up MRI scans in patients with nonrecovery vs preserved recovery.

Results

Of 1870 included patients, 902 (48.2%) were female, and the mean (SD) age was 38.0 (19.3) years. The bvFTD pattern comprising prefrontal, insular, and limbic volume reductions was more expressed in patients with schizophrenia (65 of 157 [41.2%]) and major depression (22 of 102 [21.6%]) than the temporo-limbic AD patterns (28 of 157 [17.8%] and 3 of 102 [2.9%], respectively). bvFTD expression was predicted by high body mass index, psychomotor slowing, affective disinhibition, and paranoid ideation (R2 = 0.11). The schizophrenia pattern was expressed in 92 of 108 patients (85.5%) with bvFTD and was linked to the C9orf72 variant, oligoclonal banding in the cerebrospinal fluid, cognitive impairment, and younger age (R2 = 0.29). bvFTD and schizophrenia pattern expressions forecasted 2-year psychosocial impairments in patients with CHR and were predicted by polygenic risk scores for frontotemporal dementia, AD, and schizophrenia. Findings were not associated with AD or accelerated brain aging. Finally, 1-year bvFTD/schizophrenia pattern progression distinguished patients with nonrecovery from those with preserved recovery.

Conclusions and Relevance

Neurobiological links may exist between bvFTD and psychosis focusing on prefrontal and salience system alterations. Further transdiagnostic investigations are needed to identify shared pathophysiological processes underlying the neuroanatomical interface between the 2 disease spectra.

Age-dependent patterns of schizophrenia genetic risk affect cognition

Cognition shares substantial genetic overlap with schizophrenia, yet it remains unclear whether such genetic effects become significant during developmental periods of elevated risk for schizophrenia, such as the peak age of onset. We introduce an investigative framework integrating epidemiological, developmental, and genetic approaches to determine whether genetic effects shared between schizophrenia and cognition are significant across periods of differing risk for schizophrenia onset, and whether these effects are shared with depression. 771 European-American participants, including 636 (ages 15-84 years) from families with at least two first-degree relatives with schizophrenia and 135 unrelated controls, were divided into three age-risk groups based on ages relative to epidemiological age of onset patterns for schizophrenia: Pre-Peak (before peak age-of-onset: 15 to 22 years), Post-Peak (after peak age-of-onset: 23-42 years), and Plateau (during plateau of age-of-onset: over 42 years). For general cognition and 11 specific cognitive traits, we estimated genetic correlations with schizophrenia and with depression within each age-risk group. Genetic effects shared between deficits in general cognition and schizophrenia were nonsignificant before peak age of onset, yet were high and significant after peak age of onset and during the plateau of onset. These age-dependent genetic effects were largely consistent across specific cognitive traits and not transdiagnostically shared with depression. Schizophrenia genetic effects appear to influence cognitive traits in an age-dependent manner, supporting late developmental and perhaps neurodegenerative models that hypothesize increased expression of schizophrenia risk genes during and after the peak age of risk. Our findings underscore the utility of cognitive traits for tracking schizophrenia genetic effects across the lifespan.

The Course of General Cognitive Ability in Individuals With Psychotic Disorders

Importance

Schizophrenia is associated with major cognitive deficits and has been conceptualized as both a neurodevelopmental and a neurodegenerative disorder. However, when deficits develop and how they change over the course of illness is uncertain.

Objective

To trace cognition from elementary school to old age to test neurodevelopmental and neurodegenerative theories of psychotic disorders.

Design, Setting, and Participants

Data were taken from the Suffolk County Mental Health Project, a first-admission longitudinal cohort study of individuals with psychotic disorders. Participants were recruited from all 12 inpatient psychiatric facilities in Suffolk County, New York. This analysis concerns the 428 participants with at least 2 estimates of general cognitive ability. Data were collected between September 1989 and October 2019, and data were analyzed from January 2020 to October 2021.

Exposures

Psychiatric hospitalization for psychosis.

Main Outcomes and Measures

Preadmission cognitive scores were extracted from school and medical records. Postonset cognitive scores were based on neuropsychological testing at 6-month, 24-month, 20-year, and 25-year follow-ups.

Results

Of the 428 included individuals (212 with schizophrenia and 216 with other psychotic disorders), 254 (59.6%) were male, and the mean (SD) age at psychosis onset was 27 (9) years. Three phases of cognitive change were observed: normative, declining, and deteriorating. In the first phase, cognition was stable. Fourteen years before psychosis onset, those with schizophrenia began to experience cognitive decline at a rate of 0.35 intelligence quotient (IQ) points per year (95% CI, 0.29-0.42; P < .001), a significantly faster decline than those with other psychotic disorders (0.15 IQ points per year; 95% CI, 0.08-0.22, P < .001). At 22 years after onset, both groups declined at a rate of 0.59 IQ points per year (95% CI, 0.25-0.94; P < .001).

Conclusions and Relevance

In this cohort study, cognitive trajectories in schizophrenia were consistent with both a neurodevelopmental and neurodegenerative pattern, resulting in a loss of 16 IQ points over the period of observation. Cognitive decline began long prior to psychosis onset, suggesting the window for primary prevention is earlier than previously thought. A window for secondary prevention emerges in the third decade of illness, when cognitive declines accelerate in individuals with schizophrenia and other psychotic disorders.

Schizophrenia: A developmental disorder with a risk of non-specific but avoidable decline

The onset of schizophrenia is determined by biological and social risk factors operating predominantly during development. These result in subtle deviations in brain structure and cognitive function. Striatal dopamine dysregulation follows, causing abnormal salience and resultant psychotic symptoms. Most people diagnosed as having schizophrenia do not progressively deteriorate; many improve or recover. However, poor care can allow a cycle of deterioration to be established, stress increasing dopamine dysregulation, leading to more stress consequent on continuing psychotic experiences, and so further dopamine release. Additionally, long-term antipsychotics can induce dopamine supersensitivity with resultant relapse and eventually treatment resistance. Some patients suffer loss of social and cognitive function, but this is a consequence of the hazards that afflict the person with schizophrenia, not a direct consequence of genetic predisposition. Thus, brain health and cognition can be further impaired by chronic medication effects, cardiovascular and cerebrovascular events, obesity, poor diet, and lack of exercise; drug use, especially of tobacco and cannabis, are likely to contribute. Poverty, homelessness and poor nutrition which become the lot of some people with schizophrenia, can also affect cognition. Regrettably, the model of progressive deterioration provides psychiatry and its funders with an alibi for the effects of poor care.

Childhood Maltreatment, Educational Attainment, and IQ: Findings From a Multicentric Case-control Study of First-episode Psychosis (EU-GEI)

BACKGROUND AND HYPOTHESIS

Evidence suggests that childhood maltreatment (ie, childhood abuse and childhood neglect) affects educational attainment and cognition. However, the association between childhood maltreatment and Intelligence Quotient (IQ) seems stronger among controls compared to people with psychosis. We hypothesised that: the association between childhood maltreatment and poor cognition would be stronger among community controls than among people with first-episode of psychosis (FEP); compared to abuse, neglect would show stronger associations with educational attainment and cognition; the association between childhood maltreatment and IQ would be partially accounted for by other risk factors; and the association between childhood maltreatment, educational attainment, and IQ would be stronger among patients with affective psychoses compared to those with nonaffective psychoses.

STUDY DESIGN

829 patients with FEP and 1283 community controls from 16 EU-GEI sites were assessed for child maltreatment, education attainment, and IQ.

STUDY RESULTS

In both the FEP and control group, childhood maltreatment was associated with lower educational attainment. The association between childhood maltreatment and lower IQ was robust to adjustment for confounders only among controls. Whereas childhood neglect was consistently associated with lower attainment and IQ in both groups, childhood abuse was associated with IQ only in controls. Among both patients with affective and nonaffective psychoses, negative associations between childhood maltreatment and educational attainment were observed, but the crude association with IQ was only evident in affective psychoses.

CONCLUSIONS

Our findings underscore the role of childhood maltreatment in shaping academic outcomes and cognition of people with FEP as well as controls.

A review of risky decision-making in psychosis-spectrum disorders

The investigation of risky decision-making has a prominent place in clinical science, with sundry behavioral tasks aimed at empirically quantifying the psychological construct of risk-taking. However, use of differing behavioral tasks has resulted in lack of agreement on risky decision-making within psychosis-spectrum disorders, as findings fail to converge upon the typical, binary conceptualization of increased risk-seeking or risk-aversion. The current review synthesizes the behavioral, risky decision-making literature to elucidate how specific task parameters may contribute to differences in task performance, and their associations with psychosis symptomatology and cognitive functioning. A paring of the literature suggests that: 1) Explicit risk-taking may be characterized by risk imperception, evidenced by less discrimination between choices of varying degrees of risk, potentially secondary to cognitive deficits. 2) Ambiguous risk-taking findings are inconclusive with few published studies. 3) Uncertain risk-taking findings, consistently interpreted as more risk-averse, have not parsed risk attitudes from confounding processes that may impact decision-making (e.g. risk imperception, reward processing, motivation). Thus, overgeneralized interpretations of task-specific risk-seeking/aversion should be curtailed, as they may fail to appropriately characterize decision-making phenomena. Future research in psychosis-spectrum disorders would benefit from empirically isolating contributions of specific processes during risky decision-making, including the newly hypothesized risk imperception.

Neurobiological Highlights of Cognitive Impairment in Psychiatric Disorders

This review is focused on several psychiatric disorders in which cognitive impairment is a major component of the disease, influencing life quality. There are plenty of data proving that cognitive impairment accompanies and even underlies some psychiatric disorders. In addition, sources provide information on the biological background of cognitive problems associated with mental illness. This scientific review aims to summarize the current knowledge about neurobiological mechanisms of cognitive impairment in people with schizophrenia, depression, mild cognitive impairment and dementia (including Alzheimer's disease).The review provides data about the prevalence of cognitive impairment in people with mental illness and associated biological markers.

Metabolic risk factors of cognitive impairment in young women with major psychiatric disorder

BACKGROUND

Cognitive performance improves clinical outcomes of patients with major psychiatric disorder (MPD), but is impaired by hyperglycemia. Psychotropic agents often induce metabolism syndrome (MetS). The identification of modifiable metabolic risk factors of cognitive impairment may enable targeted improvements of patient care.

OBJECTIVE

To investigate the relationship between MetS and cognitive impairment in young women with MPD, and to explore risk factors.

METHODS

We retrospectively studied women of 18-34 years of age receiving psychotropic medications for first-onset schizophrenia (SCH), bipolar disorder (BP), or major depressive disorder (MDD). Data were obtained at four time points: presentation but before psychotropic medication; 4-8 and 8-12 weeks of psychotropic therapy; and enrollment. MATRICS Consensus Cognitive Battery, (MCCB)-based Global Deficit Scores were used to assess cognitive impairment. Multiple logistic analysis was used to calculate risk factors. Multivariate models were used to investigate factors associated with cognitive impairment.

RESULTS

We evaluated 2,864 participants. Cognitive impairment was observed in 61.94% of study participants, and was most prevalent among patients with BP (69.38%). HbA1c within the 8-12 week-treatment interval was the most significant risk factor and highest in BP. Factors in SCH included pre-treatment waist circumference and elevated triglycerides during the 8-12 weeks treatment interval. Cumulative dosages of antipsychotics, antidepressants, and valproate were associated with cognitive impairment in all MPD subgroups, although lithium demonstrated a protect effect (all P < 0.001).

CONCLUSIONS

Cognitive impairment was associated with elevated HbA1c and cumulative medication dosages. Pre-treatment waist circumference and triglyceride level at 8-12 weeks were risk factors in SCH. Monitoring these indices may inform treatment revisions to improve clinical outcomes.

A network analysis and empirical validation of executive deficits in patients with psychosis and their healthy siblings

BACKGROUND

Psychopathological symptoms and cognitive impairment are core features of patients with psychotic disorders. Executive dysfunctions are commonly observed and typically assessed using tests like the Wisconsin Card Sorting Test (WCST). However, the structure of executive deficits remains unclear, and the underlying processes may be different. This study aimed to explore and compare the network structure of WCST measures in patients with psychosis and their unaffected siblings and to empirically validate the resulting network structure of the patients.

METHODS

The subjects were 298 patients with a DSM 5 diagnosis of a psychotic disorder and 89 of their healthy siblings. The dimensionality and network structure of the WCST were examined by means of exploratory graph analysis (EGA) and network centrality parameters.

RESULTS

The WCST network structure comprised 4 dimensions: perseveration (PER), inefficient sorting (IS), failure to maintain set (FMS) and learning (LNG). The patient and sibling groups showed a similar network structure, which was reliably estimated. PER and IS showed common and strong associations with antecedent, concurrent and outcome validators. The LNG dimension was also moderately associated with these validators, but FMS did not show significant associations.

CONCLUSIONS

Four cognitive processes underlying WCST performance were identified by the network analysis. PER, IS and LNG were associated with and shared common antecedent, concurrent and outcome validators, while FMS was not associated with external validators. These four underlying dysfunctions might help disentangle the neurofunctional basis of executive deficits in psychosis.

A comparison of cognitive performance in the Suffolk County cohort and their unaffected siblings

People diagnosed with schizophrenia and other psychoses demonstrate impaired neuropsychological performance. Their unaffected siblings exhibit mild impairments relative to unrelated controls, suggesting genetic and shared environmental risk for psychosis account for some portion of cognitive impairments observed in cases. However, most sibling studies were conducted early in illness course. Studying cases and unaffected siblings later in life is valuable because diagnostic misclassification is common early in illness, possibly leading to spurious conclusions. This study compared neuropsychological performance of individuals with psychotic disorders (schizophrenia and other psychoses), their unaffected siblings, and controls. Assessments were conducted 20 years after case enrollment in the Suffolk County Mental Health Project, when siblings and controls were added to the protocol. Results showed individuals with schizophrenia and other psychoses performed worse than their matched siblings across domains. Relative to controls, siblings of participants with schizophrenia showed mild deficits in executive function and processing speed, while no significant differences were observed between siblings of those with other psychoses and controls. These findings suggest pre- and post-onset factors impact cognitive deficits in psychosis, but pre-onset factors are more salient in schizophrenia. Additionally, schizophrenia and other psychoses exist on a neurodevelopmental continuum, with schizophrenia being a more severe manifestation.