Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 70
Filtrer
1.
medRxiv ; 2024 Jun 07.
Article de Anglais | MEDLINE | ID: mdl-38883764

RÉSUMÉ

Background: Past studies associating personality with psychosis have been limited by small nonclinical samples and a focus on general symptom burden. This study uses a large clinical sample to examine personality's relationship with psychosis-specific features and compare personality dimensions across clinically and neurobiologically defined categories of psychoses. Methods: A total of 1352 participants with schizophrenia, schizoaffective disorder, and bipolar with psychosis, as well as 623 healthy controls (HC), drawn from the Bipolar-Schizophrenia Network for Intermediate Phenotypes (BSNIP-2) study, were included. Three biomarker-derived biotypes were used to separately categorize the probands. Mean personality factors (openness, conscientiousness, extraversion, agreeableness, and neuroticism) were compared between HC and proband subgroups using independent sample t-tests. A robust linear regression was utilized to determine personality differences across biotypes and diagnostic subgroups. Associations between personality factors and cognition were determined through Pearson's correlation. A canonical correlation was run between the personality factors and general functioning, positive symptoms, and negative symptoms to delineate the relationship between personality and clinical outcomes of psychosis. Results: There were significant personality differences between the proband and HC groups across all five personality factors. Overall, the probands had higher neuroticism and lower extraversion, agreeableness, conscientiousness, and openness. Openness showed the greatest difference across the diagnostic subgroups and biotypes, and greatest correlation with cognition. Openness, agreeableness, and extraversion had the strongest associations with symptom severity. Conclusions: Individuals with psychosis have different personality profiles compared to HC. In particular, openness may be relevant in distinguishing psychosis-specific phenotypes and experiences, and associated with biological underpinnings of psychosis, including cognition. Further studies should identify potential causal factors and mediators of this relationship.

3.
Psychiatry Res ; 326: 115254, 2023 08.
Article de Anglais | MEDLINE | ID: mdl-37267670

RÉSUMÉ

Treatment discontinuation during clinical trials in schizophrenia is a critical challenge, especially for longer-term interventions in the early course. This research explored predictors of treatment discontinuation in an outpatient early course schizophrenia sample (N = 102) during an 18-month multi-site trial of Cognitive Enhancement Therapy (n = 58) and Enriched Supportive Therapy (n = 44). Fifty-three (52%) participants discontinued, with no significant difference between the treatment groups in discontinuation rate. Univariate and multivariate binary logistic regression models explored differences in key demographic and cognitive and behavioral outcomes between participants who completed and discontinued treatment. Significant multivariate predictors of discontinuation included IQ (linear) and problem solving (curvilinear). The concave shape of the problem solving prediction demonstrated that initially as scores were increasing the probability of non-completion was increasing. However, after a score of 41 (below average problem solving), the probability of being a non-completer decreased as performance increased. Non-completers had significantly lower IQ scores compared to completers. Post-hoc analyses indicated that participants who discontinued prior to mid-treatment exhibited the greatest intellectual challenges, with comparisons moderate-to-large in strength. IQ and problem solving are likely important factors to assess at pre-treatment in early course schizophrenia trials to identify those most vulnerable to discontinuation.


Sujet(s)
Thérapie cognitive , Schizophrénie , Humains , Schizophrénie/traitement médicamenteux , Cognition
4.
Schizophr Res ; 255: 102-109, 2023 05.
Article de Anglais | MEDLINE | ID: mdl-36989667

RÉSUMÉ

BACKGROUND: Cannabis use (CA) and childhood trauma (CT) independently increase the risk of earlier psychosis onset; but their interaction in relation to psychosis risk and association with endocannabinoid-receptor rich brain regions, i.e. the hippocampus (HP), remains unclear. The objective was to determine whether lower age of psychosis onset (AgePsyOnset) is associated with CA and CT through mediation by the HP volumes, and genetic risk, as measured by schizophrenia polygene scores (SZ-PGRS). METHODS: Cross-sectional, case-control, multicenter sample from 5 metropolitan US regions. Participants (n = 1185) included 397 controls not affected by psychosis (HC); 209 participants with bipolar disorder type-1; 279 with schizoaffective disorder; and 300 with schizophrenia (DSM IV-TR). CT was assessed using the Childhood Trauma Questionnaire (CTQ); CA was assessed by self-reports and trained clinical interviewers. Assessment included neuroimaging, symptomatology, cognition and calculation of the SZ polygenic risk score (SZ-PGRS). RESULTS: In survival analysis, CT and CA exposure interact to be associated with lower AgePsyOnset. At high CT or CA, CT or CA are individually sufficient to affect AgePsyOnset. CT relation with AgePsyOnset is mediated in part by the HP in CA users before AgePsyOnset. CA before AgePsyOnset is associated with higher SZ-PGRS and correlated with younger age at CA usage. DISCUSSION: CA and CT interact to increase risk when moderate; while severe CT and/or CA abuse/dependence are each sufficient to affect AgePsyOnset, indicating a ceiling effect. Probands with/out CA before AgePsyOnset differ on biological variables, suggesting divergent pathways to psychosis. FUNDING: MH077945; MH096942; MH096913; MH077862; MH103368; MH096900; MH122759.


Sujet(s)
Expériences défavorables de l'enfance , Trouble bipolaire , Cannabis , Troubles psychotiques , Humains , Enfant , Études transversales , Trouble bipolaire/psychologie , Troubles psychotiques/psychologie , Hippocampe/imagerie diagnostique
6.
BMC Psychiatry ; 22(1): 583, 2022 09 01.
Article de Anglais | MEDLINE | ID: mdl-36050663

RÉSUMÉ

BACKGROUND: Schizophrenia and related disorders are highly disabling and create substantial burdens for families, communities, and health care systems. Although pharmacological treatments can often lessen the psychotic symptoms that are a hallmark of schizophrenia, they do not lessen the social and cognitive deficits that create the greatest impediments to community engagement and functional recovery. This study builds on prior research on psychosocial rehabilitation by comparing the effectiveness of two treatments demonstrated as efficacious in improving social and community functioning, Cognitive Enhancement Therapy (CET) and a version of Social Skills Training (HOPES/SST). METHODS: The study uses a randomized cluster design in which a pair of clinicians at community- and hospital-based mental service centers deliver either CET or HOPES to at least one group of 6-8 eligible clients for 12 months. Clinicians are trained and then supervised weekly, with ongoing process measurement of treatment fidelity, attendance, satisfaction, and retention, and use of other services. Measures administered at baseline and at 6 and 12 months while in treatment, and then at 18 and 24 months after treatment include social adjustment, quality of life, social skills, positive and negative symptoms, and neuro- and social cognition. We hypothesize that CET will be associated with greater improvements than SST in both the primary outcome of community functioning and the secondary outcomes of neuro- and social cognition and social skills. Secondarily, we hypothesize that more cognitive impairment at baseline and younger age will predict more benefit from CET compared to HOPES. DISCUSSION: Resource shortages endemic in mental health services and exacerbated by the pandemic highlight the importance of identifying the most effective approach to improving social and community functioning. We aim to improve understanding of the impact of two efficacious psychosocial treatments and to improve clinicians' ability to refer to both treatments the individuals who are most likely to benefit from them. We expect the result to be programmatic improvements that improve the magnitude and durability of gains in community functioning. TRIAL REGISTRATION: ClinicalTrial.gov NCT04321759 , registered March 25, 2020.


Sujet(s)
Thérapie cognitive , Schizophrénie , Cognition , Humains , Qualité de vie , Schizophrénie/diagnostic , Compétences sociales , Résultat thérapeutique
8.
Mol Psychiatry ; 27(9): 3719-3730, 2022 09.
Article de Anglais | MEDLINE | ID: mdl-35982257

RÉSUMÉ

Cognitive deficits are among the best predictors of real-world functioning in schizophrenia. However, our understanding of how cognitive deficits relate to neuropathology and clinical presentation over the disease lifespan is limited. Here, we combine multi-site, harmonized cognitive, imaging, demographic, and clinical data from over 900 individuals to characterize a) cognitive deficits across the schizophrenia lifespan and b) the association between cognitive deficits, clinical presentation, and white matter (WM) microstructure. Multimodal harmonization was accomplished using T-scores for cognitive data, previously reported standardization methods for demographic and clinical data, and an established harmonization method for imaging data. We applied t-tests and correlation analysis to describe cognitive deficits in individuals with schizophrenia. We then calculated whole-brain WM fractional anisotropy (FA) and utilized regression-mediation analyses to model the association between diagnosis, FA, and cognitive deficits. We observed pronounced cognitive deficits in individuals with schizophrenia (p < 0.006), associated with more positive symptoms and medication dosage. Regression-mediation analyses showed that WM microstructure mediated the association between schizophrenia and language/processing speed/working memory/non-verbal memory. In addition, processing speed mediated the influence of diagnosis and WM microstructure on the other cognitive domains. Our study highlights the critical role of cognitive deficits in schizophrenia. We further show that WM is crucial when trying to understand the role of cognitive deficits, given that it explains the association between schizophrenia and cognitive deficits (directly and via processing speed).


Sujet(s)
Troubles de la cognition , Schizophrénie , Substance blanche , Humains , Substance blanche/anatomopathologie , Schizophrénie/anatomopathologie , Imagerie par tenseur de diffusion , Troubles de la cognition/complications , Anisotropie , Cognition , Encéphale/anatomopathologie
9.
J Psychiatr Res ; 151: 554-560, 2022 07.
Article de Anglais | MEDLINE | ID: mdl-35636031

RÉSUMÉ

Randomized-controlled trials of Cognitive Enhancement Therapy (CET) reveal its impact on cognitive and functional improvements in schizophrenia and serve as an opportunity for causal claims of potential mediational relationships. In order to examine cognitive gains during CET as a mechanism for improving functional capacity, this secondary analysis included 86 outpatients in the early course of schizophrenia from an 18-month randomized-controlled trial of CET. Functional capacity was measured using the Brief UCSD Performance-Based Skills Assessment (UPSA-B) and cognitive performance by the MATRICS Consensus Cognitive Battery (MCCB) and additional measures of social cognition. Mixed-effects models were used to examine the effects of treatment on the UPSA-B changes and mediation through cognitive improvements. Changes in overall cognition proved to be a significant mediator of CET-related gains in functional capacity at mid-treatment and treatment completion. Exploratory models examining separable cognitive domains further found that improvements in attention, theory of mind, and emotion processing significantly mediated CET effects on functional capacity. This study suggests that CET has potential for improving functional capacity in individuals with schizophrenia, and that cognitive improvements partially mediate this relationship. This evidence can be beneficial for guiding more targeted approaches for rehabilitation in this population.


Sujet(s)
Thérapie cognitive , Schizophrénie , Cognition , Thérapie cognitive/méthodes , Humains , Tests neuropsychologiques , Schizophrénie/complications , Psychologie des schizophrènes
10.
Front Psychiatry ; 13: 874246, 2022.
Article de Anglais | MEDLINE | ID: mdl-35599768

RÉSUMÉ

Objectives: Psychotic-spectrum disorders emerge during adolescence and early adulthood, which corresponds with the peak period for substance use initiation. Clinical and epidemiological data provide support that substance use is associated with psychotic symptom onset and severity. Experience-sampling methodology (ESM) data may provide additional insight into dynamic associations between substance use and psychotic symptoms. This is one of the first efforts to characterize substance use frequency and dynamic associations with psychotic symptoms and negative affect from ESM data in both clinical high risk (CHR) and early psychosis (EP) individuals. Methods: Using ESM, 33 individuals, including 17 with CHR and 16 EP (age range: 15-24), provided information on substance use, negative affect, and psychotic symptoms 6 times a day across a 21-day data collection window. Psychotic symptoms and negative affect included multi-item variables rated on a seven-point Likert Scale. Participants reported recent substance use for 4 drug classes (nicotine, cannabis, depressants, stimulants) via a yes/no item. Descriptive information included data on substance use frequency, and momentary negative affect and psychotic symptoms. Exploratory analyses included multi-level and person-level dynamic structural equation models, which assessed contemporaneous and lagged associations between substance use and symptoms. Results: Twenty-seven individuals (82%) reported recurrent substance use including stimulants (n = 12, 46%), nicotine (n = 9, 27%), cannabis (n = 6, 18%), and depressants (n = 4, 12%). Individuals with any recurrent substance use indicated usage at 47.7% of answered prompts; stimulants at 23.6%; nicotine at 74.2%; cannabis at 39.1%; and depressants at 20.1%. A multi-level dynamic structural equation model reflected that substance use (any class) was associated with lagged negative affect (ß = -0.02, CI: -0.06, < -0.00) but no significant contemporaneous or lagged associations between substance use and psychotic symptoms. Person-level models suggest potentially meaningful inter-individual variability. Conclusions: CHR and EP individuals use a range of substances that may both reflect and influence other experiences in daily life experiences. Data reflected moderate to high rates of recurrent substance use with more consistent use within nicotine and cannabis classes. ESM data have the potential to increase our understanding of the dynamic relationships between substance use and symptoms and to inform treatment for individuals in early course psychosis.

11.
Mol Psychiatry ; 27(4): 2052-2060, 2022 04.
Article de Anglais | MEDLINE | ID: mdl-35145230

RÉSUMÉ

Brain morphology differs markedly between individuals with schizophrenia, but the cellular and genetic basis of this heterogeneity is poorly understood. Here, we sought to determine whether cortical thickness (CTh) heterogeneity in schizophrenia relates to interregional variation in distinct neural cell types, as inferred from established gene expression data and person-specific genomic variation. This study comprised 1849 participants in total, including a discovery (140 cases and 1267 controls) and a validation cohort (335 cases and 185 controls). To characterize CTh heterogeneity, normative ranges were established for 34 cortical regions and the extent of deviation from these ranges was measured for each individual with schizophrenia. CTh deviations were explained by interregional gene expression levels of five out of seven neural cell types examined: (1) astrocytes; (2) endothelial cells; (3) oligodendrocyte progenitor cells (OPCs); (4) excitatory neurons; and (5) inhibitory neurons. Regional alignment between CTh alterations with cell type transcriptional maps distinguished broad patient subtypes, which were validated against genomic data drawn from the same individuals. In a predominantly neuronal/endothelial subtype (22% of patients), CTh deviations covaried with polygenic risk for schizophrenia (sczPRS) calculated specifically from genes marking neuronal and endothelial cells (r = -0.40, p = 0.010). Whereas, in a predominantly glia/OPC subtype (43% of patients), CTh deviations covaried with sczPRS calculated from glia and OPC-linked genes (r = -0.30, p = 0.028). This multi-scale analysis of genomic, transcriptomic, and brain phenotypic data may indicate that CTh heterogeneity in schizophrenia relates to inter-individual variation in cell-type specific functions. Decomposing heterogeneity in relation to cortical cell types enables prioritization of schizophrenia subsets for future disease modeling efforts.


Sujet(s)
Schizophrénie , Encéphale , Cortex cérébral , Cellules endothéliales , Humains , Imagerie par résonance magnétique , Hérédité multifactorielle , Schizophrénie/génétique
12.
Schizophr Res ; 240: 186-192, 2022 02.
Article de Anglais | MEDLINE | ID: mdl-35032903

RÉSUMÉ

BACKGROUND: Schizophrenia spectrum disorders are heritable illnesses that usually manifest in early adulthood but are increasingly viewed as neurodevelopmental disorders. Functional magnetic resonance imaging (fMRI) studies show altered brain activity during performance of working memory (WM) tasks in both individuals with schizophrenia and their first-degree relatives as compared to healthy controls (HC). This study examined whether similar changes are already present in pre-adolescent children at familial high-risk (FHR) for psychosis. METHODS: 37 children (17 FHR, 20 HC) between 7 and 12 years old participated in this study. WM performance was assessed using the Wechsler Intelligence Scale for Children-IV (WISC-IV). To assess brain activation during WM performance, participants completed a visual block-designed n-back task with 2 conditions (2-back and 0-back) during scanning. fMRI data was preprocessed and analyzed using FSL Feat. RESULTS: Compared to HC, FHR children showed significantly lower WISC-IV WM scores. In addition, FHR children exhibited hypoactivation in the 2-back (versus 0-back) condition in a cluster encompassing bilateral precuneus and cuneus and right posterior cingulate cortex. There were no significant group-differences in n-back task performance and brain activation. The precuneus cluster was not correlated with n-back performance or WISC WM scores. CONCLUSIONS: The current results provide preliminary evidence of impaired WM function and altered brain activity during WM performance in children with a familial predisposition for psychosis. Longitudinal studies are needed to determine whether these findings are related to abnormal brain development and predictive of cognitive deficits and psychosis later in life.


Sujet(s)
Troubles psychotiques , Schizophrénie , Adolescent , Adulte , Encéphale/imagerie diagnostique , Cartographie cérébrale/méthodes , Enfant , Humains , Imagerie par résonance magnétique , Mémoire à court terme/physiologie , Troubles psychotiques/imagerie diagnostique
13.
Psychiatr Serv ; 73(5): 501-509, 2022 05.
Article de Anglais | MEDLINE | ID: mdl-34470506

RÉSUMÉ

OBJECTIVE: Cognitive enhancement therapy (CET) is an 18-month comprehensive cognitive remediation intervention designed to improve cognition and functioning among patients with schizophrenia. The current study sought to confirm previously observed benefits of CET on cognitive and behavioral outcomes in the early course of the condition in a large multisite trial. METHODS: Overall, 102 outpatients with early-course schizophrenia were randomly assigned to 18 months of CET (N=58) or enriched supportive therapy (EST; N=44). Participants completed cognitive, social adjustment, and symptom assessments at baseline and at 9 and 18 months. Composite indices were calculated for these outcomes. Mixed-effects models investigated differential changes in outcomes between CET and EST. Because of a high attrition rate, sensitivity analyses of data from treatment completers (N=49) were conducted. RESULTS: The effects of CET on improved overall cognition were confirmed and tentatively confirmed for social cognition in both intent-to-treat and completer analyses, and beneficial effects on attention/vigilance were also observed. An effect of CET on social adjustment was not confirmed in the analyses, because both CET and EST groups had considerably improved social adjustment. Although not statistically significant, the between-group effect size for CET's effect on social adjustment doubled from the intent-to-treat (Cohen's d=0.23) to completer analyses (Cohen's d=0.51) (p=0.057). Both groups displayed similar symptom improvements. CONCLUSIONS: CET effectively improved cognition among patients with early-course schizophrenia. The functional benefits of CET appeared to increase with treatment retention. Further research is needed to understand predictors of attrition and mechanisms of change during CET for this population.


Sujet(s)
Troubles de la cognition , Schizophrénie , Cognition , Troubles de la cognition/diagnostic , Troubles de la cognition/étiologie , Troubles de la cognition/psychologie , Humains , Tests neuropsychologiques , Schizophrénie/diagnostic , Psychologie des schizophrènes , Résultat thérapeutique
14.
Psychol Med ; 52(12): 2245-2254, 2022 09.
Article de Anglais | MEDLINE | ID: mdl-33183362

RÉSUMÉ

BACKGROUND: The ability to manage emotions is an important social-cognitive domain impaired in schizophrenia and linked to functional outcome. The goal of our study was to examine the impact of cognitive enhancement therapy (CET) on the ability to manage emotions and brain functional connectivity in early-course schizophrenia. METHODS: Participants were randomly assigned to CET (n = 55) or an enriched supportive therapy (EST) control group (n = 45). The resting-state functional magnetic resonance imaging scans and measures of emotion management performances were collected at baseline, 9, and 18 months follow-up. The final sample consisted of 37 CET and 25 EST participants, including 19 CET and 12 EST participants with imaging data. Linear mixed-effects models investigated the impact of treatment on emotion management and functional connectivity from the amygdala to ventrolateral and dorsolateral prefrontal cortex (dlPFC). RESULTS: The CET group showed significant improvement over time in emotion management compared to EST. Neither functional connectivity changes nor main group differences were observed following treatment. However, a significant between-group interaction showed that improved emotion management ability was associated with increased functional connectivity between the left amygdala and the left dlPFC in the CET group exclusively. CONCLUSION: Our results replicate the previous work demonstrating that CET is effective at improving some aspects of social cognition in schizophrenia. We found evidence that improvement in emotion management may be associated with a change in amygdala-dlPFC connectivity. This fronto-limbic circuit may provide a mechanistic link between the biology of emotion management processes that can be enhanced in individuals with schizophrenia.


Sujet(s)
Thérapie cognitive , Schizophrénie , Cognition , Thérapie cognitive/méthodes , Émotions , Humains , Imagerie par résonance magnétique , Tests neuropsychologiques , Cortex préfrontal/imagerie diagnostique , Schizophrénie/imagerie diagnostique , Schizophrénie/thérapie
16.
Schizophr Res ; 238: 152-160, 2021 12.
Article de Anglais | MEDLINE | ID: mdl-34688117

RÉSUMÉ

About one in 100 people worldwide are diagnosed with schizophrenia. Many people advocate for a name change for the condition, pointing to the stigma and discrimination associated with the term "schizophrenia", as well as to how the name poorly characterizes features of the illness. The purpose of this project was to collect opinions from a broad, diverse sample of stakeholders about possible name changes for schizophrenia. The project represented a partnership between researchers, clinicians, and those with lived experience with psychosis. The group developed a survey to assess opinions about the need for change in the name schizophrenia as well as potential alternate names. We accumulated 1190 responses from a broad array of community stakeholders, including those with lived experience of mental illness, family members, clinicians, researchers, government officials, and the general public. Findings indicated that the majority of respondents (74.1%) favored a name change for schizophrenia. Most (71.4%) found the name stigmatizing. Of the proposed alternate names, those with the most support included "Altered Perception Syndrome", "Psychosis Spectrum Syndrome", and "Neuro-Emotional Integration Disorder". Survey findings provide strong support for renaming schizophrenia. Most expressed hope that a name change will reduce stigma and discrimination.


Sujet(s)
Schizophrénie , Attitude , Famille , Humains , Schizophrénie/diagnostic , Stigmate social , Enquêtes et questionnaires
17.
Front Psychiatry ; 12: 613142, 2021.
Article de Anglais | MEDLINE | ID: mdl-33633608

RÉSUMÉ

Patients with schizophrenia spectrum disorders show disturbances in self-referential processing and associated neural circuits including the default mode network (DMN). These disturbances may precede the onset of psychosis and may underlie early social and emotional problems. In this study, we examined self-referential processing in a group of children (7-12 years) at familial high risk (FHR) for psychosis (N = 17), compared to an age and sex-matched group of healthy control (HC) children (N = 20). The participants were presented with a list of adjectives and asked to indicate whether or not the adjectives described them (self-reference condition) and whether the adjectives described a good or bad trait (semantic condition). Three participants were excluded due to chance-level performance on the semantic task, leaving N = 15 FHR and N = 19 HC for final analysis. Functional MRI (fMRI) was used to measure brain activation during self-referential vs. semantic processing. Internalizing and externalizing problems were assessed with the Child Behavior Checklist (CBCL). Evaluating main effects of task (self > semantic) showed activation of medial prefrontal cortex in HC and precuneus/posterior cingulate cortex (PCC) in FHR. Group-comparison yielded significant results for the FHR > HC contrast, showing two clusters of hyperactivation in precuneus/ PCC (p = 0.004) and anterior cerebellum / temporo-occipital cortex (p = 0.009). Greater precuneus/PCC activation was found to correlate with greater CBCL internalizing (r = 0.60, p = 0.032) and total (r = 0.69, p = 0.009) problems. In all, this study shows hyperactivity of posterior DMN during self-referential processing in pre-adolescent FHR children. This finding posits DMN-related disturbances in self-processing as a developmental brain abnormality associated with familial risk factors that predates not just psychosis, but also the prodromal stage. Moreover, our results suggest that early disturbances in self-referential processing may be related to internalizing problems in at-risk children.

18.
Mol Psychiatry ; 26(9): 5357-5370, 2021 09.
Article de Anglais | MEDLINE | ID: mdl-33483689

RÉSUMÉ

White matter (WM) abnormalities are repeatedly demonstrated across the schizophrenia time-course. However, our understanding of how demographic and clinical variables interact, influence, or are dependent on WM pathologies is limited. The most well-known barriers to progress are heterogeneous findings due to small sample sizes and the confounding influence of age on WM. The present study leverages access to the harmonized diffusion magnetic-resonance-imaging data and standardized clinical data from 13 international sites (597 schizophrenia patients (SCZ)). Fractional anisotropy (FA) values for all major WM structures in patients were predicted based on FA models estimated from a healthy population (n = 492). We utilized the deviations between predicted and real FA values to answer three essential questions. (1) "Which clinical variables explain WM abnormalities?". (2) "Does the degree of WM abnormalities predict symptom severity?". (3) "Does sex influence any of those relationships?". Regression and mediator analyses revealed that a longer duration-of-illness is associated with more severe WM abnormalities in several tracts. In addition, they demonstrated that a higher antipsychotic medication dose is related to more severe corpus callosum abnormalities. A structural equation model revealed that patients with more WM abnormalities display higher symptom severity. Last, the results exhibited sex-specificity. Males showed a stronger association between duration-of-illness and WM abnormalities. Females presented a stronger association between WM abnormalities and symptom severity, with IQ impacting this relationship. Our findings provide clear evidence for the interaction of demographic, clinical, and behavioral variables with WM pathology in SCZ. Our results also point to the need for longitudinal studies, directly investigating the casualty and sex-specificity of these relationships, as well as the impact of cognitive resiliency on structure-function relationships.


Sujet(s)
Schizophrénie , Substance blanche , Anisotropie , Encéphale/imagerie diagnostique , Démographie , Imagerie par tenseur de diffusion , Femelle , Humains , Mâle , Substance blanche/imagerie diagnostique
19.
Front Psychiatry ; 11: 573002, 2020.
Article de Anglais | MEDLINE | ID: mdl-33329111

RÉSUMÉ

Background: Psychotic disorders are characterized by impairment in social cognitive processing, which is associated with poorer community functioning. However, the neural mechanisms of social impairment in psychosis remain unclear. Social impairment is a hallmark of other psychiatric illnesses as well, including autism spectrum disorders (ASD), and the nature and degree of social cognitive impairments across psychotic disorders and ASD are similar, suggesting that mechanisms that are known to underpin social impairments in ASD may also play a role in the impairments seen in psychosis. Specifically, in both humans and animal models of ASD, a cerebellar-parietal network has been identified that is directly related to social cognition and social functioning. In this study we examined social cognition and resting-state brain connectivity in people with psychosis and in neurotypical adults. We hypothesized that social cognition would be most strongly associated with cerebellar-parietal connectivity, even when using a whole-brain data driven approach. Methods: We examined associations between brain connectivity and social cognition in a trans-diagnostic sample of people with psychosis (n = 81) and neurotypical controls (n = 45). Social cognition was assessed using the social cognition domain score of the MATRICS Consensus Cognitive Battery. We used a multivariate pattern analysis to correlate social cognition with resting-state functional connectivity at the individual voxel level. Results: This approach identified a circuit between right cerebellar Crus I, II and left parietal cortex as the strongest correlate of social cognitive performance. This connectivity-cognition result was observed in both people with psychotic disorders and in neurotypical adults. Conclusions: Using a data-driven whole brain approach we identified a cerebellar-parietal circuit that was robustly associated with social cognitive ability, consistent with findings from people with ASD and animal models. These findings suggest that this circuit may be marker of social cognitive impairment trans-diagnostically and support cerebellar-parietal connectivity as a potential therapeutic target for enhancing social cognition.

20.
Psychiatry Res Neuroimaging ; 305: 111159, 2020 11 30.
Article de Anglais | MEDLINE | ID: mdl-32919288

RÉSUMÉ

Schizophrenia (SZ) is proposed as a disorder of dysconnectivity underlying cognitive impairments and clinical manifestations. Although previous studies have shown extracellular changes in white matter of first-episode SZ, little is known about the transition period towards chronicity and its association with cognition. Free-water (FW) imaging was applied to 79 early course SZ participants and 29 controls to detect white matter axonal and extracellular differences during this phase of illness. Diffusion-weighted images were collected from two sites, harmonized, and processed using a pipeline separately modeling water diffusion in tissue (FAt) and extracellular space (FW). Tract-Based Spatial Statistics was performed using the ENIGMA-DTI protocols. SZ showed FAt reductions in the posterior thalamic radiation (PTR) and FW elevations in the cingulum compared to controls, suggesting FAt and FW changes in the early course of SZ. In SZ, greater FAt of the fornix & stria terminalis (FXST) was positively associated with Theory of Mind performance; average whole-brain FAt, FAt of the FXST and the PTR were positively associated with greater working memory performance; average whole-brain FAt was positively associated with visual learning. Further studies are necessary to better understand the neurobiological mechanisms of SZ for developing intervention strategies to preserve brain structure and function.


Sujet(s)
Schizophrénie , Substance blanche , Cognition , Imagerie par tenseur de diffusion/méthodes , Humains , Eau , Substance blanche/imagerie diagnostique
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...