Alexandre Dumais

Université de Montréal | UdeM · Department of Psychiatry

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...

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...

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: 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 f...

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...

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...

Purpose The COVID-19 pandemic led to exacerbation of mental health symptoms and deterioration in psychological well-being in individuals suffering from schizophrenia. The primary objective of this study is to evaluate the impacts of the COVID-19 pandemic on patients suffering from treatment-resistant schizophrenia (TRS) with auditory verbal halluci...

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: 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...

While research focus remains mainly on psychotic symptoms, it is questionable whether we are placing enough emphasis on improving the quality of life (QoL) of schizophrenia patients. To date, the predictive power of QoL remained limited. Therefore, this study aimed to accurately predict the QoL within schizophrenia using supervised learning methods...

The legalization of cannabis raises many queries, one of which regards the criminal liability of users under the influence of cannabis when crimes against the person are committed. This perspective review consequently aims to examine the defense of mental disorder (also referred to as the insanity defense) in Canadian criminal law and revise court...

Background: Cannabis is among the most consumed psychoactive substances world-wide. Considering changing policy trends regarding the substance, it is crucial to understand more clearly its potential acute and residual adverse effects from a public health viewpoint. Cognitive function is one of the targeted areas with conflicting findings. This met...

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 un- derpinning such behaviours. This study aimed to identify disrupted resting-state activity and functional con- nectivity in schizoph...

Given the increasing literature on forensic assertive community treatment (FACT), we conducted a systematic review and meta-analysis to explore the effectiveness of FACT among justice-involved individuals with severe mental illness. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. Sixteen stu...

Abstract Background:A growing body of literature has detailed the use of qualitative analyses to measure the therapeutic processes and intrinsic effectiveness of psychotherapies, which yield small databases. Nonetheless, these approaches have several limitations and machine learning algorithms are needed. Objective:The objective of this study is...

Abstract: Objectives. The COVID-19 pandemic has had many public health impacts, especially on vulnerable individuals including adults with neurocognitive disorders (NCD). With increasing literature, this systematic literature review aimed to address the mental health effects of COVID-19 on people with NCD in addition to examine the impact of the pa...

Introduction Mounting evidence has begun establishing a link between cannabis use and adverse psychotic outcomes in patients affected by psychosis. However, we have yet to determine if this relationship is maintained when controlling for important confounding variables. As such, the following systematic review aims to investigate if the association...

Objectives Schizophrenia, particularly treatment-resistant schizophrenia (TRS), is one of the most disabling psychiatric disorders in terms of adverse effects on the quality of life (QOL) of patients. Subjective QOL has become a particularly crucial target that should be improved with treatment, since improved QOL may lead to recovery in patients w...

Introduction Schizophrenia is a chronic and severe mental disorder. While research focus remains mainly on negative outcomes, it is questionable whether we are placing enough emphasis on improving their sense of well-being and functioning. This could be accessed through the study of the quality of life (QoL). To date, QoL prediction models mainly f...

Past evidence suggests that hippocampal subregions, namely the anterior and posterior parts, may be engaged in distinct networks underlying the memory functions which may be altered in patients with schizophrenia. However, of the very few studies that have investigated the hippocampal longitudinal axis subdivisions functional connectivity in patien...

Purpose Since conduct problems (CP) vary distinctly across youths, better subtyping CP may be an important vehicle to study specific risk factors associated to differential patterns of CP. In a sample of 63,196 adolescents, we employed a two-step method to the identify such CP patterns and to help classify youths based on several sociodemographic a...

The gold-standard cognitive–behavioral therapy (CBT) for psychosis offers at best modest effects. With advances in technology, virtual reality (VR) therapies for auditory verbal hallucinations (AVH), such as AVATAR therapy (AT) and VR-assisted therapy (VRT), are amid a new wave of relational approaches that may heighten effects. Prior trials have s...

Objective Since the therapeutic processes of Avatar Therapy remain equivocal, the current study aims to further extend our previous findings by analyzing the evolution of the avatars’ and patients’ speech and changes in patient responses as sessions progressed. Design Eighteen patients with treatment‐resistant schizophrenia were selected from two...

Background The high rates of suicidal behaviours (SBs) in psychiatric populations remain an important preoccupation to address. The literature reveals emotional instability as an important risk factor for SBs. However, the neural mechanisms underpinning this risk factor have never been investigated in schizophrenia patients with SBs. The following...

Although recent studies have shown a moderately strong association between cannabis use and violence among people with severe mental disorders, the direction of this association has not been investigated prospectively in a population with schizophrenia. Therefore, this study aims to determine, using cross-lag models, whether a temporal relationship...

Background Restraint and seclusion (R&S) are controversial methods of intervention aimed at protecting children from immediate harm in residential treatment centers (RTC). Previous studies have mainly focused on situational factors and youth characteristics to predict its use. Objectives This study sought to evaluate the role other potential predi...

Background: Combining cognitive behavioral therapy (CBT) for psychosis with another psychosocial intervention comprising virtual reality (VR)-assisted therapy (VRT) may improve targeted outcomes in treatment-resistant schizophrenia patients. Methods: Ten participants having followed CBT were part of our comparative clinical trial comparing VRT t...

Past functional magnetic resonance imaging on antisocial subjects have shown important inconsistencies and methodological problems (e.g. heterogeneity in fMRI tasks domain, small sample sizes, analyses on regions-of-interest). We aimed to conduct a meta-analysis of whole-brain fMRI studies on antisocial individuals based on distinct neurocognitive...

Recidivism among released inmates is associated with a substantial societal burden given the financial and medical consequences of victimization. Among incarcerated North Americans, approximately 7% are housed in solitary confinement (SC). Studies show SC can lead to psychological deterioration and dispute it can effectively reduce institutional mi...

There has been a shift surrounding societal and legal perspectives on cannabis reflecting changing public attitudes towards the perceived safety and social acceptability of cannabis use. With cannabis liberalization internationally, the focus of most cannabis-related harms has been on effects with users themselves. Harm-to-others including injuries...

Background Among all diseases globally, mental illnesses are one of the major causes of burden. As many people are resistant to conventional evidence-based treatments, there is an unmet need for the implementation of novel mental health treatments. Efforts to increase the effectiveness and benefits of evidence-based psychotherapy in psychiatry have...

Objectives To systematically review and meta-analyze the psychological effects and mortality rate in inmates having been exposed to solitary confinement in correctional settings.Methods PubMed, PsycINFO, Web of Science, and Google Scholar were searched using keywords describing solitary confinement in combination with keywords for psychological or...

BACKGROUND Avatar therapy (AT) is a modern therapeutic alternative for schizophrenic patients with persistent auditory hallucinations. The effectiveness of psychotherapy is generally measured by semi-structured interviews or self-reported questionnaires. To complement, an increasing number of research teams have started to use qualitative analyses,...

BACKGROUND Among all diseases globally, mental illnesses are one of the major causes of burden. As many people are resistant to conventional evidence-based treatments, there is an unmet need for the implementation of novel mental health treatments. Efforts to increase the effectiveness and benefits of evidence-based psychotherapy in psychiatry have...

Objective: The aim of this meta-analysis was to investigate the extent to which cannabis use among youths is associated with the risk of perpetrating physical violence. Methods: Searches were conducted in PubMed, PsycINFO, Web of Science, and Google Scholar for articles published from the inception of each database to July 2019. All studies that...

The aim of this meta‐analysis was to examine the association between any mental health problem and the risk of being placed into solitary confinement in correctional settings. PubMed, PsycINFO, Web of Science and Google Scholar were searched from each database’s inception date to November 2019. All publications assessing both mental health problems...

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 on...

This study aims to identify the factors that need to be considered in the implementation of the integrated psychological treatment (IPT), a cognitive-behavioral group approach for individuals with schizophrenia, in correctional and forensic psychiatric settings. To meet this objective, a multiple case study ( n = 2) was conducted. Stakeholders invo...

Youth violence is a complex and multifactorial issue that has severe health and social consequences. While treatment options exist to treat/reduce violence in at-risk populations such as schizophrenia, there remains limitations in the efficacy of current interventions. Virtual reality (VR) appears to be a unique possibility to expose offenders and...

Objective: It has long been assumed that paranoid ideation may stem from an aberrant limbic response to threatening stimuli. However, results from functional neuroimaging studies using negative emotional stimuli have failed to confirm this assumption. One of the potential reasons for the lack of effect is that study participants with psychosis may...

Background: In youth, anxiety-depressive traits (ADT) and trait-aggression (TA) are important risk factors of exhibiting maladaptive behaviors in adulthood (i.e. violence and substance use). However, the developmental co-occurrence of these traits in youth remains unknown. We thus sought to investigate the developmental trajectories of ADT and TA...

Children placed in residential treatment centers (RTCs) typically present challenging behavior including aggression. In this context, restraint and seclusion (R&S) are seen as “last resort” strategies for educators to manage youth aggression. The use of R&S is controversial, as they can lead to psychological and physical consequences for both the c...

Background: Individuals with severe mental illnesses are at greater risk of offenses and violence, though the relationship remains unclear due to the interplay of static and dynamic risk factors. Static factors have generally been emphasized, leaving little room for temporal changes in risk. Hence, this longitudinal study aims to identify subgroups...

Objective: Impulsivity is a multidimensional construct that has an important role for the understanding of diverse psychopathologies and problematic behaviors. The UPPS-P impulsive behavior scale, measuring five distinct facets of impulsivity, has been subject to several studies. No study has investigated the clinical utility of this questionnaire...

Background: The relationship between cannabis and violence remains unclear, especially amid those with severe mental illnesses (SMI). The objective of this meta-analysis was to investigate the cannabis-violence association in a population of individuals with a SMI. Method: A systematic search of literature using PubMed, PsychINFO, Web of Science an...

Objective: Compared to the general population, tobacco smoking cessation rates are lower in populations with schizophrenia. Unfortunately, the potential neurophysiologic mechanisms underlying these low cessation rates in schizophrenia have been seldom studied using functional neuroimaging. Recently, it has been shown that tobacco cravings are incr...

Emotional regulation is defined as a set of processes responsible for the control, evaluation and adjustment of emotional reactions to achieve a specific goal. It helps to make flexible responses, thus facilitating social interactions or certain cognitive tasks. Earlier results were mainly derived from studies in functional magnetic resonance imagi...

Schizophrenia (SCZ) is a severe chronic disease associated with significant functional impairments. Prior to a diagnosis of SCZ, some nonspecific symptoms may occur (i.e., anxiety, insomnia, depressive symptoms) and may progress into psychosis. While these may be attenuated or not of sufficient severity for psychosis, many will seek help for these...

Peer support promotes the overall wellness of people with mental illness by establishing mutual partnerships throughout their different stages of recovery. In health research, investments in patient-oriented research have become prioritized. However, peer-contributed research remains relatively rare, especially in the study of psychosis. Our resear...

Background Reward seeking and avoidance of punishment are key motivational processes. Brain-imaging studies often use the Monetary Incentive Delay Task (MIDT) to evaluate motivational processes involved in maladaptive behavior. Although the bulk of research has been done on the MIDT reward events, little is known about the neural basis of avoidance...

Rationale and contributions of the meta-analysis

Supplementary tables and figure

There is little consensus regarding the prevalence of methamphetamine-induced psychotic disorder (MIPD). A search of the literature was performed, effect size estimates were calculated with event rates and were aggregated with a random-effects model. Seventeen studies were included in the meta-analysis, resulting in a composite event rate of 36.5%....

Purpose The purpose of this paper is to identify the psychosocial approaches that have been studied and for which positive outcomes have been reported for individuals with schizophrenia in correctional and forensic psychiatric settings. Design/methodology/approach A rapid review of the literature was undertaken. A search was conducted on MEDLINE...

Background While many pharmacological and psychosocial interventions are available, many treatment-resistant schizophrenia patients continue to suffer from persistent psychotic symptoms, mainly auditory verbal hallucinations (AVH). Recently, a psychological therapy using computerized technology has shown large therapeutic effects on AVH severity by...

Effective treatment strategies for schizophrenia remain very challenging and many treatment-resistant patients will suffer from persistent auditory verbal hallucinations (AVH). While clozapine is the gold-standard medication for this complex population, many will not respond to this molecule. For these ultra-resistant patients, limited options are...

Despite the high prevalence of suicidal ideas/attempts in schizophrenia, only a handful of neuroimaging studies have examined the neurobiological differences associated with suicide risk in this population. The main objective of the current exploratory study is to examine the neurofunctional correlates associated with a history of suicide attempt i...