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The Signature Biobank is a longitudinal repository of biospecimen, psychological, sociodemographic, and diagnostic data that was created in 2012. The Signature Consortium represents a group of approximately one hundred Quebec-based transdisciplinary clinicians and research scientists with various expertise in the field of psychiatry. The objective of the Signature Biobank is to investigate the multi-faceted underpinnings of psychiatric disorders among patients in crisis. The Signature Consortium is expanding and includes new active members that seek to highlight the contributions made by Signature Biobank since its inception. This article details our research protocol, directions, and summarizes contributions. To date, we have collected biological samples (n = 1,986), and questionnaire data (n = 2,085) from psychiatric emergency patients of the Institut universitaire en santé mentale de Montréal (Quebec, Canada), with a large proportion from whom both data types were collected (n = 1,926). In addition to this, a subsample of patients was followed-up at hospital discharge, and two additional outpatient clinic appointments (n = 958 with at least one follow-up). In addition, a socio-demographically matched comparison group of individuals who were not hospitalized for psychiatric disorders (n = 149) was recruited from the surrounding catchment area. To summarize, a systematic review of the literature shows that the Signature Biobank has contributed to better characterizing psychiatric comorbidities, biological profiles, and psychosocial functioning across some of the most common psychiatric disorders, including psychosis, mood, anxiety, and substance use disorders. The Signature Biobank is now one of the world's largest repositories of data collected from patients receiving care at a psychiatric emergency unit., Competing Interests: Declaration of competing interest The authors report no conflict of interest., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Objective: Although schizophrenia patients are at a heightened risk of exhibiting violent behaviours compared to the general population, few functional neuroimaging studies have explored the aberrant neurocircuitry underpinning such behaviours. This study aimed to identify disrupted resting-state activity and functional connectivity in schizophrenia patients with a history of violence., Methods: Resting state functional magnetic resonance imaging data was collected from 62 schizophrenia patients and 25 healthy controls. Voxel-wise analyses of fractional amplitude of low frequency fluctuations (fALFF) were implemented to investigate disrupted regional patterns of spontaneous brain activity. Brain regions which yielded significant differences between groups were subsequently used as data-driven seeds for functional connectivity analyses. Finally, significant alterations (activity and connectivity) were correlated with lifetime violent behaviours., Results: When compared to healthy controls, schizophrenia patients exhibited reduced fALFF in multiple brain regions including the (subgenual) anterior cingulate cortex (ACC), posterior cingulate cortex, precuneus cortex and left lateral orbitofrontal cortex (OFC). Seed-to-voxel analyses yielded significantly enhanced connectivity between the ACC and left OFC. The heightened functional connectivity between the latter two regions predicted the number of violent behaviours reported by schizophrenia patients., Conclusion: The current study demonstrated that the functional connectivity of brain regions associated with emotion regulation is impaired in schizophrenia and associated with violent antecedents among patients. This result is consistent with predominant theoretical models proposing that the OFC plays a critical role in the neurobiology of violence., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Hollow silica cubes were synthesized by a deposition of a thin silica shell onto micrometer-sized hematite cubes. Ordered mesopores with well-defined pore diameters of 2.8 nm and 3.8 nm were introduced into the silica shell by means of pseudomorphic transformation after removal of the hematite core. The particles retained their cubic morphology upon pseudomorphic transformation, allowing for the preparation of close-packed layers of the hollow mesoporous silica cubes by drop-casting and the visualization of the hollow core by focused ion beam scanning electron microscopy.

Background: Despite individuals with schizophrenia being at an elevated risk of violence compared to the general population, limited efforts have been invested in investigating the neurobiological etiology explaining the increase. Among the few studies examining functional disruptions pertaining to violent schizophrenia patients using fMRI, only one study has considered functional connectivity. The current state of knowledge does not allow to infer deficits in functional connectivity specific to distinct cognitive/emotional states that have been associated with the emergence of violence in schizophrenia, such as negative emotion processing. This study sought to identify disrupted connectivity among men with schizophrenia and a history of violence (SCZ+V), compared to men with schizophrenia without a history of violence (SCZ-V) and healthy controls, during negative emotion processing using fMRI. Methods: Twenty SCZ+V, 19 SCZ-V, and 21 healthy men were scanned while viewing negative images. Results: Negative images elicited an increased connectivity between the dorsal anterior cingulate cortex (dACC) and the bilateral rostral prefrontal cortex (rPFC), as well as a decreased functional connectivity between the frontal regions (bilateral rPFC and dACC) and the putamen and hippocampus in SCZ+V men as compared to SCZ-V men and healthy controls. Concurrently, the centrality of the dACC within the network was reduced in SCV+V subjects. Conclusions: These results suggest an inefficient integration of the information by the dACC between frontal and limbic regions in SCZ+V men during negative emotion processing and highlight the importance of the ACC in the neurobiological bases of violent behavior in schizophrenia., (Copyright © 2020 Tikàsz, Potvin, Dugré, Fahim, Zaharieva, Lipp, Mendrek and Dumais.)

Schizophrenia is a severe psychiatric disorder characterized by important cognitive deficits, which ultimately compromise the patients' ability to make optimal decisions. Unfortunately, the neurobiological bases of impaired reward-related decision-making in schizophrenia have rarely been studied. The objective of this study is to examine the neural mechanisms involved in reward-related decision-making in schizophrenia, using functional magnetic resonance imaging (fMRI). Forty-seven schizophrenia patients (DSM-IV criteria) and 23 healthy subjects with no psychiatric disorders were scanned using fMRI while performing the Balloon Analogue Risk Task (BART). A rapid event-related fMRI paradigm was used, separating decision and outcome events. Between-group differences in grey matter volumes were assessed with voxel-based morphometry. During the reward outcomes, increased activations were observed in schizophrenia in the left anterior insula, the putamen, and frontal sub-regions. Reduced grey matter volumes were observed in the left anterior insula in schizophrenia which spatially overlapped with functional alterations. Finally, schizophrenia patients made fewer gains on the BART. The fact that schizophrenia patients had increased activations in sub-cortical regions such as the striatum and insula in response to reward events suggests that the impaired decision-making abilities of these patients are mostly driven by an overvaluation of outcome stimuli., (Copyright © 2019. Published by Elsevier B.V.)

We investigated the influence of anger processing on cognitive control in male schizophrenia patients presenting violent behaviors. We recruited 23 patients without and 24 patients with (SCZ+V) a history of violent behaviors, as well as 22 healthy non-violent men. Participants were administered an affective (angry-neutral faces) Go/NoGo task while undergoing functional magnetic resonance imaging. We found a reduced activation in the dorsolateral prefrontal cortex in SCZ+V patients specifically when inhibiting a response while viewing angry faces. These results show an inability of SCZ+V to recruit a core region of the (inhibitory) cognitive control network in the context of anger., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Difficulties in Facial Emotion Recognition (FER) are commonly associated with individuals diagnosed with Autism Spectrum Disorder (ASD). However, the mechanisms underlying these impairments remain inconclusive. While atypical cortical connectivity has been observed in autistic individuals, there is a paucity of investigation during cognitive tasks such as FER. It is possible that atypical cortical connectivity may underlie FER impairments in this population. Electroencephalography (EEG) Imaginary Coherence was examined in 22 autistic adults and 23 typically developing (TD) matched controls during a complex, dynamic FER task. Autistic adults demonstrated reduced coherence between both short and long range inter-hemispheric electrodes. By contrast, short range intra-hemispheric connectivity was increased in frontal and occipital regions during FER. These findings suggest altered network functioning in ASD.

Schizophrenia is a chronic and severe mental illness that poses significant challenges. While many pharmacological and psychosocial interventions are available, many treatment-resistant schizophrenia patients continue to suffer from persistent psychotic symptoms, notably auditory verbal hallucinations (AVH), which are highly disabling. This unmet clinical need requires new innovative treatment options. Recently, a psychological therapy using computerized technology has shown large therapeutic effects on AVH severity by enabling patients to engage in a dialogue with a computerized representation of their voices. These very promising results have been extended by our team using immersive virtual reality (VR). Our study was a 7-week phase-II, randomized, partial cross-over trial. Nineteen schizophrenia patients with refractory AVH were recruited and randomly allocated to either VR-assisted therapy (VRT) or treatment-as-usual (TAU). The group allocated to TAU consisted of antipsychotic treatment and usual meetings with clinicians. The TAU group then received a delayed 7weeks of VRT. A follow-up was ensured 3months after the last VRT therapy session. Changes in psychiatric symptoms, before and after TAU or VRT, were assessed using a linear mixed-effects model. Our findings showed that VRT produced significant improvements in AVH severity, depressive symptoms and quality of life that lasted at the 3-month follow-up period. Consistent with previous research, our results suggest that VRT might be efficacious in reducing AVH related distress. The therapeutic effects of VRT on the distress associated with the voices were particularly prominent (d=1.2). VRT is a highly novel and promising intervention for refractory AVH in schizophrenia., (Copyright © 2018. Published by Elsevier B.V.)

Working memory deficits have been widely reported in schizophrenia, and may result from inefficient binding processes. These processes, and their neural correlates, remain understudied in schizophrenia. Thus, we designed an FMRI study aimed at investigating the neural correlates of both passive and active binding in working memory in schizophrenia. Nineteen patients with schizophrenia and 23 matched controls were recruited to perform a working memory binding task, in which they were instructed to memorize three letters and three spatial locations. In the passive binding condition, letters and spatial locations were directly presented as bound. Conversely, in the active binding condition, words and spatial locations were presented as separated, and participants were instructed to intentionally create associations between them. Patients exhibited a similar performance to the controls for the passive binding condition, but a significantly lower performance for the active binding. FMRI analyses revealed that this active binding deficit was related to aberrant activity in the posterior parietal cortex and the ventrolateral prefrontal cortex. This study provides initial evidence of a specific deficit for actively binding information in schizophrenia, which is linked to dysfunctions in the neural networks underlying attention, manipulation of information, and encoding strategies. Together, our results suggest that all these dysfunctions may be targets for neuromodulation interventions known to improve cognitive deficits in schizophrenia., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Cigarette smoking is highly prevalent in schizophrenia and is one of the main factors contributing to the significantly decreased life expectancy in this population. Schizophrenia smokers, compared to their counterparts with no comorbid psychiatric disorder, are largely unaware and indifferent to the long-term negative consequences of cigarette smoking. The objective of this study was to determine, for the first time, if these meta-cognitive deficits are associated with neuro-functional alterations in schizophrenia smokers., Methods: Twenty-four smokers with no psychiatric disorder and 21 smokers with schizophrenia (DSM-IV criteria) were scanned using functional magnetic resonance imaging and exposed to anti-smoking images. Granger causality analyses were used to examine the effective connectivity between brain regions found to be significantly activated., Results: Across groups, potent activations were observed in the left ventro-lateral prefrontal cortex, the left amygdala (AMG), and the dorsomedial prefrontal cortex (dmPFC). Using the dmPFC as a seed region, we found an abnormal negative connectivity from the dmPFC to the AMG in schizophrenia smokers during the viewing of anti-smoking stimuli. This abnormal connectivity was not present during the viewing of aversive stimuli unrelated to tobacco., Discussion: Given the well-established roles of the dmPFC in social cognition and of the AMG in emotional processing, our results suggest that the relative indifference of schizophrenia smokers regarding the negative consequences of tobacco smoking could be explained by a cognitive-affective dissonance.

Background: Highly prevalent in schizophrenia, tobacco smoking substantially increases the risk of cardiac-related death. Compared to the general population, tobacco smoking cessation rates are lower in schizophrenia. Unfortunately, the reasons for these low cessation rates remain poorly understood. Recently, it has been shown that tobacco cravings are increased in schizophrenia smokers compared to smokers with no comorbid psychiatric disorder. In view of these results, we sought to examine - for the first time - the neurophysiologic responses elicited by cigarette cues in schizophrenia smokers. We hypothesized that cigarettes cues would elicit increased activations in brain regions involved in drug cravings in schizophrenia smokers relative to control smokers., Methods: Smokers with (n=18) and without (n=24) schizophrenia (DSM-IV criteria) were scanned using functional magnetic resonance imaging (fMRI) while viewing appetitive cigarette images., Results: Schizophrenia smokers and smokers with no psychiatric comorbidity did not differ in subjective cravings in response to appetitive smoking cues. However, in schizophrenia smokers relative to control smokers, we found that appetitive cigarette cues triggered increased activations of the bilateral ventro-medial prefrontal cortex, a core region of the brain reward system. Moreover, a negative correlation was observed between cigarette cravings and activations of the right ventro-medial prefrontal cortex in schizophrenia smokers., Discussion: The current results highlight a key role of the brain reward system in cigarette craving in schizophrenia, and suggest that the neurophysiologic mechanisms involved in the regulation of cue-induced cigarette craving are impaired in this population., (Copyright © 2016 Elsevier B.V. All rights reserved.)