S. Potvin

Université de Montréal | UdeM · Department of Psychiatry

Background: An increasing body of literature highlights the integration of machine learning with genomic data in psychiatry, particularly for complex mental health disorders such as schizophrenia. These advanced techniques offer promising potential for uncovering various facets of these disorders. A comprehensive review of the current applications...

Contexte Créée en 2004, la Chaire Eli Lilly Canada de recherche en schizophrénie a été financée par la compagnie Eli Lilly, l’Institut universitaire en santé mentale de Montréal, l’Hôpital Sacré-Coeur et le Centre hospitalier de l’Université de Montréal. L’objectif du présent article est d’effectuer un survol historique des activités scientifiques...

Background Studies suggest severe mental disorders (SMDs), such as schizophrenia, major depressive disorder and bipolar disorder, are associated with common alterations in brain activity, albeit with a graded level of impairment. However, discrepancies between study findings likely to results from both small sample sizes and the use of different fu...

Objective: Two conditions alter socio-communicative behaviors in humans: autism and schizophrenia. However, it is not well-known if these disorders share the same neural alterations during socio-emotional tasks. The main objective was to examine neural alterations in autism and schizophrenia during emotional and social cognition tasks. Our second o...

Social cognition is commonly altered in people with psychosis. Two main brain networks have been implicated: the default-mode network (DMN), which is associated with socio-cognitive processing, and the salience network (SN) associated with socio-affective processing. Disturbances to the resting-state functional connectivity of these networks have b...

Accumulating evidence suggests that aggression and rule-breaking may have distinct origins. However, grouping these heterogeneous behaviors into a single dimension labelled Conduct Problems (CP) has become the norm rather than the exception. Yet, the neurobiological features that differentiate aggression and rule-breaking remain largely unexplored....

Our laboratory previously developed a method for assessing experimentally induced pain perception through a 2-min constant heat pain stimulation. However, the traditional analysis relying on group means struggles to interpret the considerable inter-individual variability due to the dynamic nature of the response. Recently, trajectory analysis techn...

Background Pain is a complex and multifaced sensory and emotional experience. Virtual reality (VR) has shown promise in reducing experimental pain and chronic pain. This study examines an immersive VR environment initially designed for endometriosis patients, which demonstrated short-term analgesic effects. The research aims to determine the impact...

Conduct disorder (CD) is among the most prevalent and burdensome disorders in early adolescence. Over the past decade, there has been growing interest in identifying reliable and localized neurobiological markers of conduct disorder (CD). However, recent meta-analyses have highlighted the weak reliability of these so-called markers, thereby limitin...

Background: An increasing body of literature highlights the integration of machine learning with genomic data in psychiatry, particularly for complex mental health disorders such as schizophrenia. These advanced techniques offer promising potential for uncovering various facets of these disorders. A comprehensive review of the current applications...

Background An increasing body of literature highlights the integration of machine learning with genomic data in psychiatry, particularly for complex mental health disorders such as schizophrenia. These advanced techniques offer promising potential for uncovering various facets of these disorders. A comprehensive review of the current applications o...

Adolescence is a key period for neurocognitive maturation where deviation from normal developmental trajectories may be tied to adverse mental health outcomes. Cognitive disruptions have been noted in populations at risk for psychosis and are known to accompany periods of sleep deprivation. This study aims to assess the role of cognition as a media...

Objective: Recreational cannabis legalization (RCL) is expanding rapidly. RCL's effects on mental health issues are of particular concern because cannabis use is more frequent among people receiving psychiatric care and is associated with several psychiatric disorders. The authors conducted a scoping review to examine the evidence and discern gaps...

Background: Youths with thought problems (TP) are at risk to develop psychosis and obsessive-compulsive disorder (OCD). Yet, the pathophysiological mechanisms underpinning TP are still unclear. Functional magnetic resonance imaging (fMRI) studies have shown that striatal and limbic alterations are associated with psychosis-like and obsessive-like s...

BACKGROUND The dual diagnosis of cannabis use disorder (CUD) and severe mental disorder (SMD) results in clinically complex individuals. Cannabis use is known to have negative consequences on psychiatric symptoms, medication compliance, and disease prognosis. Moreover, the effectiveness of currently available psychotherapeutic treatments is limited...

Background The dual diagnosis of cannabis use disorder (CUD) and severe mental disorder (SMD) results in clinically complex individuals. Cannabis use is known to have negative consequences on psychiatric symptoms, medication compliance, and disease prognosis. Moreover, the effectiveness of currently available psychotherapeutic treatments is limited...

Background: Psychotherapeutic approaches such as Avatar Therapy (AT) are novel therapeutic attempts to help patients diagnosed with treatment-resistant schizophrenia. Qualitative analyses of immersive sessions of AT have been undertaken to enhance and refine the existing interventions taking place in this therapy. To account for the time-consuming...

Importance In the last 25 years, functional magnetic resonance imaging drug cue reactivity (FDCR) studies have characterized some core aspects in the neurobiology of drug addiction. However, no FDCR-derived biomarkers have been approved for treatment development or clinical adoption. Traversing this translational gap requires a systematic assessmen...

Background Schizophrenia is associated with an increased risk of aggressive behaviour, which may partly be explained by illness-related changes in brain structure. However, previous studies have been limited by group-level analyses, small and selective samples of inpatients and long time lags between exposure and outcome. Methods This cross-section...

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...

A growing body of research suggests a potential role of cannabis use on aggressive behaviors. In literature on adolescents, the lack of consideration of important confounders, such as adolescent's affiliation with delinquent peers, limits the possibility to determine whether there might be a direct or indirect link between cannabis use and aggressi...

This meta-analysis investigates auditory steady-state responses (ASSRs) as potential biomarkers of schizophrenia, focusing on previously unexplored clinical populations, frequencies, and variables. We examined 37 studies, encompassing a diverse cohort of 1788 patients with schizophrenia, including 208 patients with first-episode psychosis, 281 at-r...

Considering the harmful effects of cannabis on individuals with a severe mental disorder and the limited effectiveness of current interventions, this case report showcases the beneficial results of a 10-session Avatar intervention for cannabis use disorder (CUD) on a polysubstance user with a comorbid schizoaffective disorder. Virtual reality allow...

(1) Background: Approximately 30% of schizophrenia patients are known to be treatment-resistant. For these cases, more personalized approaches must be developed. Virtual reality therapeutic approaches such as avatar therapy (AT) are currently undergoing investigations to address these patients’ needs. To further tailor the therapeutic trajectory of...

Background Disorganization symptoms are a main feature of schizophrenia, which include illogical and incoherent thinking, circumstantiality, tangentiality and loose associations. As these symptoms entail language deficits, several functional neuroimaging studies have been performed in schizophrenia using verbal tasks, producing somewhat heterogenou...

A large body of literature suggests that the primary (high callousness-unemotional traits [CU] and low anxiety) and secondary (high CU traits and anxiety) variants of psychopathy significantly differ in terms of their clinical profiles. However, little is known about their neurobiological differences. While few studies showed that variants differ i...

Background: Fibromyalgia (FM) and major depression disorder (MDD) frequently co-occur. Both disorders may share common serotonergic alterations, although there is less evidence of such alterations in FM. It is also unclear as to whether these alterations are persistent over time or transient. The objectives of this study were to (i) examine the ch...

1) Background: Avatar Therapy (AT) is currently being studied to help patients suffering from treatment-resistant schizophrenia. Facilitating annotations of immersive verbatims in AT by using classification algorithms could be an interesting avenue to reduce the time and cost of conducting such analysis and adding objective quantitative data in the...

Considering the harmful effects of cannabis on individuals with a severe mental disorder and the limited effectiveness of current interventions, this case report showcases the beneficial results of a 10-session Avatar intervention for cannabis use disorder (CUD) on a polysubstance user with a comorbid schizoaffective disorder. Virtual reality allow...

Introduction Auditory verbal hallucinations (AVH), which often present in individuals with schizophrenia, can cause great psychological distress. Although antipsychotic medication can reduce AVH, 30% of patients will be resistant. Treatment resistance could be associated with important consequences, and there are only few treatment alternatives. Un...

Introduction Recent longitudinal studies point towards the existence of a positive relationship between cannabis use and violence in people with severe mental disorders. However, the existence of a dose-response relationship between the frequency and/or the severity of cannabis use and violence has seldom been investigated. Objectives This study a...

Introduction Cannabis use disorder (CUD) is a complex issue, even more so when it is comorbid with a psychotic disorder or a mood disorder. Indeed, this population seems more vulnerable to this substance since the incidence of developing CUD is five to six times higher. Psychotherapies have only shown a modest short-term effect that is not maintain...

Context: Emotion regulation is a set of processes responsible for controlling, evaluating and adjusting reactions to achieve a goal. Results derived from magnetic resonance imaging agreed on the involvement of frontal and limbic structures in this process. Findings using cognition and physiology interactions are still scarce but suggest a role of...

Background Emotional responses are an important component of psychotherapeutic processes. Avatar therapy (AT) is a virtual reality-based therapy currently being developed and studied for patients suffering from treatment resistant schizophrenia. Considering the importance of identifying emotions in therapeutical processes and their impact on the th...

This meta-review aimed to summarize the current state of knowledge provided by meta-analyzes on the efficacy of psychotherapies for substance use disorders. A systematic search was performed in PubMed, PsycINFO, Web of Science and Google Scholar. Meta-analyzes were included if they quantitatively examined the efficacy of a psychotherapy on substanc...

(1) Background: The therapeutic mechanisms underlying psychotherapeutic interventions for individuals with treatment-resistant schizophrenia are mostly unknown. One of these treatment techniques is avatar therapy (AT), in which the patient engages in immersive sessions while interacting with an avatar representing their primary persistent auditory...

Over the past years, research has shown that primary (high callousness and low anxiety) and secondary (high callousness and anxiety) variants of CU traits may be associated with opposite amygdala activity (hypo- and hyper-reactivity, respectively). However, their differences in amygdala functional connectivity remains largely unexplored. We conduct...

Cannabis use disorder (CUD) is a complex issue, even more so when it is comorbid with a severe mental disorder (SMD). Available interventions are at best slightly effective, and their effects are not maintained over time. Therefore, the integration of virtual reality (VR) may increase efficacy; however, it has not yet been investigated in the treat...

A persistent effort in neuroscience has been to pinpoint the neurobiological substrates that support mental processes. The Research Domain Criteria (RDoC) aims to develop a new framework based on fundamental neurobiological dimensions. However, results from several meta-analysis of task-based fMRI showed substantial spatial overlap between several...

Ketamine administration leads to a psychotomimetic state when taken in large bolus doses, making it a valid model of psychosis. Therefore, understanding ketamine’s effects on brain functioning is particularly relevant. This meta-analysis focused on neuroimaging studies that examined ketamine-induced brain activation at rest and during a task. Inclu...

Abstract: (1) Background: Very little is known about the inner therapeutic processes of psychotherapy interventions for patients suffering from treatment-resistant schizophrenia. Avatar therapy (AT) is one such modalities in which the patient is undergoing immersive sessions in which they interact with an Avatar representing their main persistent a...

Avatar Therapy has a significant impact on symptoms, beliefs, and quality of life of patients with treatment-resistant schizophrenia. However, little is known about how these changes are implemented into their lives and to which aspects of their lives these improvements relate. Ten consecutive patients enrolled in an ongoing clinical trial were ass...

Background Early evidence suggests that unexpected non-reward may increase the risk for aggressive behaviors. Despite the growing interest in understanding brain functions that may be implicated in aggressive behaviors, the neural processes underlying such frustrative events remain largely unknown. Furthermore, meta-analytic results have produced d...

Introduction: Recent longitudinal studies point toward the existence of a positive relationship between cannabis use and violence in people with severe mental disorders (SMD). However, the existence of a dose-response relationship between the frequency/severity of cannabis use and violence has seldom been investigated. Therefore, this study aims to...

A recent meta-analysis of resting-state functional connectivity studies revealed that individuals exhibiting anti- social behaviors or conduct problems may show disrupted brain connectivity in networks underpinning socio- affective and attentional processes. However, studies included in the meta-analysis generally rely on small sample sizes and sub...

The objective of this cross-sectional study was to identify cannabis-related features and other characteristics predictive of violence using a data-driven approach in patients with severe mental disorders (SMDs). A Least Absolute Shrinkage and Selection Operator regularization regression model was used on the database consisting of 97 patients with...

Background A growing number of studies highlight the importance of emotion regulation in the treatment and recovery of individuals with psychosis and concomitant disorders such as substance use disorder (SUD), for whom access to integrated dual-disorder treatments is particularly difficult. In this context, dedicated smartphone apps may be useful t...

Background Ineffective cannabis regulatory frameworks such as prohibition have sparked interest in alternative solutions to reduce individual and societal harms. While it has been suggested that the recreational legalization process has yielded early successes, the relatively recent implementation of the novel policies has provided a modest time fr...

SSRN is an open-access online preprint community providing valuable services to leading academic schools and government institutions. Specializing primarily in social sciences, including economics, law, corporate governance, and humanities, SSRN is branching out in to other science disciplines providing opportunities for scholars to post their earl...

Etats des lieux sur les biais cognitifs chez les jeunes personnes psychotiques : évaluation et prise en charge des biais cognitifs spécifiques à la psychose.

A network of early psychosis-specific intervention programs at the University of Montreal in Montreal, Quebec, Canada, conducted a longitudinal naturalistic five-year study at two Urban Early Intervention Services (EIS). In this study, 198 patients were recruited based on inclusion/exclusion criteria and agreed to participate. Our objectives were t...

Objectives Increasing evidence implicates cannabis consumption as a key risk factor in the development of psychosis, but the mechanisms underpinning this relationship remain understudied. This study proposes to determine whether sleep disruption acts as a mediator of the cannabis-to-psychosis relationship. Study design This longitudinal study asses...

Avatar Therapy (AT) is a modern therapeutic alternative for patients with schizophrenia suffering from persistent auditory verbal hallucinations. Its intrinsic therapeutical process is currently qualitatively analyzed via human coders that annotate session transcripts. This process is time and resource demanding. This creates a need to find potenti...

Extensive literature suggests that the brain reward system is crucial in understanding the neurobiology of substance use disorders. However, evidence of reliable deficits in functional connectivity across studies on substance use problems remains limited. Therefore, a voxel‐wise seed‐based meta‐analysis using brain regions of the reward system as s...

Background The offset of a painful and unpleasant sensation can elicit pleasure. This phenomenon, namely pleasant pain relief (PPR), is attracting growing interest in research. While the cold pressor test (CPT) has been frequently used to study the inhibition of pain by the administration of another painful stimulation (inhibitory conditioned pain...

This study aimed to investigate the association between past-reported violent/aggressive behaviors and brain functional connectivity in male patients suffering from schizophrenia using a task modeling the interaction between negative emotion processing and response inhibition. Forty-four male patients with schizophrenia and twenty-two healthy male...

In the past decades, a growing body of evidence has suggested that some individuals may exhibit antisocial behaviors following brain lesions. Recently, some authors have shown that lesions underpinning antisocial behaviors may disrupt a particular brain network during resting-state. However, it remains unknown whether these brain lesions may alter...

Introduction: When investigating the role of facilitatory and inhibitory pain mechanisms such as conditioned pain modulation (CPM) and temporal summation of pain (TSP), it is important to take both into consideration in a single experimental model to provide the most information on subgroups of patients. Therefore, the objective of this study was...

Self-disturbances constitute a hallmark of psychosis, but it remains unclear whether these alterations are present in at-risk populations, and therefore their role in the development of psychosis has yet to be confirmed. The present study addressed this question by measuring neural correlates of self-other processing in youth belonging to three dev...

BACKGROUND: Psychiatric diseases are increasingly conceptualized as brain network disorders. Hundreds of resting-state functional magnetic resonance imaging (rsfMRI) studies have revealed patterns of functional brain dysconnectivity in disorders such as major depression disorder (MDD), bipolar disorder (BD) and schizophrenia (SZ). Although these di...

Introduction White matter abnormalities have been identified in major depressive disorder (MDD). Although several diffusion tensor imaging studies found decreased fractional anisotropy (FA) in MDD, the effect of antidepressants (AD) treatment on white matter integrity has been insufficiently studied. Objectives We sought to examine the effect of A...

Background Recent evidence suggests that adolescents exhibiting conduct problems (CP) may have disrupted brain connectivity at rest. However, these studies are generally characterized by small sample sizes and differ in terms of neuroimaging methodologies and chosen psychometric scales to assess CP. In parallel, evidence from genetic and structural...

Background Auditory hallucinations in patients with psychotic disorders may be very distressing. Unfortunately, a large proportion of individuals are resistant to pharmacological interventions and the gold-standard cognitive-behavioral therapy for psychosis offers at best modest effects. To improve therapeutic outcomes, several therapies have been...

Background Given the increasing acceptability and legalization of cannabis in some jurisdictions, clinicians need to improve their understanding of the effect of cannabis use on mood disorders. Objective The purpose of this task force report is to examine the association between cannabis use and incidence, presentation, course and treatment of bip...

Background: The association between cannabis and cognitive functions has been thoroughly studied in psychotic disorders, but conflictual/paradoxical results have emerged. This critical meta-review examined the magnitude of effects of cannabis on neurocognitive functions in patients with psychotic disorders provided by meta-analyses and evaluated th...

Purpose This study aims to develop immersive scenarios (immersive videos) to foster generalization of learning while addressing social cognition, a factor associated to violence in schizophrenia. The authors sought to develop immersive videos that generate a sense of presence; are socially realistic; and can be misinterpreted and, if so, lead to an...

Objectives: To describe, in a naturalistic setting, the impact of the early use of LAI-AP on functional outcomes of early psychosis patients as compared to oral antipsychotics (OAP). Methods: Longitudinal prospective 3-year naturalistic study of all consecutive admissions (n = 416) to two Early intervention services (EIS) for psychosis comparing...

BACKGROUND Chronic pelvic pain is a frequent debilitating condition in women suffering from endometriosis. Pharmacological and surgical treatments are not always efficient in controlling pain and present important restriction. Digital Therapeutics (DTx) are emerging as major non-pharmacological alternatives, aiming to extend the analgesic therapeut...

Background Chronic pelvic pain is a common and disabling condition in women living with endometriosis. Pharmacological and surgical treatments are not always effective at controlling pain and present important restrictions. Digital therapeutics (DTx) are emerging as major nonpharmacological alternatives that aim to extend the analgesic therapeutic...

Introduction Over the years, many psychosocial interventions for individual having both a psychotic spectrum disorder and a substance use disorder diagnoses have been developed and studied. However, there is a high dropout rate among this clinical population. Objectives This meta-analysis aims to replicate a previous meta-analysis on the effects o...

Background Impairment in cognition is frequently associated with acute ketamine administration. However, some questions remain unanswered as to which deficits are most prominent and what variables modulate these effects. Methods A literature search yielded 56 experimental studies of acute ketamine administration that assessed cognition in 1041 hea...

Background: In accordance with continuum and cognitive behaviour models of psychosis, cognitive biases precede the onset and the maintenance of positive symptoms. The Davos Assessment of Cognitive Biases Scale (DACOBS), a self-report measure, was developed to explore the prevalence of specific cognitive biases. This study aims to validate the Fren...

The aim of this study was to investigate the neural bases of facial emotion processing before the onset of clinical psychotic symptoms in youth belonging to well-defined developmental trajectories of psychotic-like experiences (PLEs). A unique sample of 86 youths was recruited from a population-based sample of over 3800 adolescents who had been fol...

As many as 43% of methamphetamine users will have a psychotic episode in their lifetime. Of these, 30% will develop a primary psychotic disorder, such as schizophrenia. The current state of the literature does not currently allow us to determine who will develop a primary psychotic disorder following a methamphetamine-induced psychosis (MIPD). This...