Patricia Conrod

Patricia Conrod
Université de Montréal | UdeM · Department of Psychiatry

PhD
Professor of Psychiatry and Addiction, U Montreal, Canada Research Chair on Preventative Mental Health and Addiction

About

375
Publications
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Publications

Publications (375)
Preprint
Full-text available
Neuroscience has contributed to uncover the mechanisms underpinning substance use disorders (SUD). The next frontier is to leverage these mechanisms as active ingredients to create more effective interventions for SUD. Recent large-scale cohort studies are generating multiple levels of neuroscience-based information with potential to inform the dev...
Article
Full-text available
Childhood maltreatment (CM) and genetic vulnerability are both risk factors for psychosis, but the relations between them are not fully understood. Guided by the recent identification of genetic risk to CM, this study investigates the hypothesis that genetic risk to schizophrenia also increases the risk of CM and thus impacts psychosis risk. The re...
Article
We extracted items to create a brief version of Taylor et al.’s (2020a) COVID‐19 Stress Scales (i.e., CSS‐B) and examined its psychometric properties in young adults. A sample of 1318 first‐ and second‐year undergraduates from five Canadian universities (mean[SD] age = 19.27[1.35] years; 77.6% women) completed an online cross‐sectional survey that...
Article
Objectives:This study characterizes service provider needs, gaps, and problem areas in the provision of opioid-related services for young people ages 15 to 25 across Canada.Methods:A total of 154 service providers completed a 25-question survey that was comprised of closed-ended and open-ended questions about opioid-related services for youth. Desc...
Article
Objective: To assess the efficacy of a selective, personality-targeted intervention for reducing suicidal ideation in adolescents. Design: Post hoc analysis of survey data collected in the Climate and Preventure (CAP) study, a cluster randomised controlled trial that compared strategies for reducing alcohol misuse by adolescents, 2012-2015. Set...
Article
Full-text available
Background Youth and young adults have been significantly impacted by the opioid overdose and health crisis in North America. There is evidence of increasing morbidity and mortality due to opioids among those aged 15–29. Our review of key international reports indicates there are few youth-focused interventions and treatments for opioid use. Our sc...
Article
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...
Preprint
Mechanisms underpinning age-related variations in cortical thickness in the human brain remain poorly understood. We investigated whether inter-regional age-related variations in cortical thinning (in a multicohort neuroimaging dataset from the ENIGMA Lifespan Working Group totalling 14,248 individuals, aged 4-89 years) depended on cell-specific ma...
Article
Bullying victimization is common in adolescence and has been associated with a broad variety of psychopathology and alcohol use. The present study assessed time-varying associations between bullying victimization and alcohol use through internalizing and externalizing symptoms and whether this indirect association throughout time is moderated by pe...
Conference Paper
Background/Aim: Cannabis is commonly used by Canadian emerging adults (ages 18-25 years), many of whom attend post-secondary institutions. Frequent cannabis use has been linked with psychotic-like experiences (PLEs); however, the exact nature of this complex relationship remains to be fully understood. Anxiety is a prevalent mental health concern i...
Article
Background and aims Graph theoretic analysis of structural covariance networks (SCN) provides an assessment of brain organization that has not yet been applied to alcohol dependence (AD). We estimated whether SCN differences are present in adults with AD and heavy drinking adolescents at age 19 and age 14, prior to substantial exposure to alcohol....
Article
Objective Although the peak onset of depressive symptoms occurs during adolescence, very few studies have directly examined depression-related changes in resting-state DMN activity during adolescence, controlling for potential neural markers of risk. Design The current study used data from a longitudinal adolescent cohort to investigate age-specif...
Article
Objective Alcohol use is a leading cause of burden of disease among young people. Prevention strategies can be effective in the short-term, however little is known about their longer-term effectiveness. The aim of this study was to examine the sustainability of universal, selective and combined alcohol use prevention across the critical transition...
Article
Background Nicotine and illicit stimulants are very addictive substances. Although associations between grey matter and dependence on stimulants have been frequently reported, white matter correlates have received less attention. Methods Eleven international sites ascribed to the ENIGMA-Addiction consortium contributed data from individuals with d...
Article
Background Substance use motives (i.e., reasons for using a substance) are thought to be the most proximal variable leading to substance use. These motives have been described by various typologies, the most well known being the four-factor drinking motives model which separates motives into enhancement, social, coping, and conformity (Cooper, 1994...
Article
Full-text available
Background It has not yet been determined if the commonly reported cannabis–psychosis association is limited to individuals with pre-existing genetic risk for psychotic disorders. Methods We examined whether the relationship between polygenic risk score for schizophrenia (PRS-Sz) and psychotic-like experiences (PLEs), as measured by the Community...
Article
This is the first study to investigate the effectiveness of Preventure, a selective personality-targeted prevention program, in reducing the uptake of tobacco smoking over a three-year period in adolescence. A cluster randomised controlled trial was conducted to assess the effectiveness of Preventure. Schools were block randomised to either the Pre...
Article
Early initiation of polysubstance use (PSU) is a strong predictor of subsequent addiction, however scarce individuals present resilience capacity. This neuroimaging study aimed to investigate structural correlates associated with cessation or reduction of PSU and determine the extent to which brain structural features accounted for this resilient o...
Article
Importance Animal studies have shown that the adolescent brain is sensitive to disruptions in endocannabinoid signaling, resulting in altered neurodevelopment and lasting behavioral effects. However, few studies have investigated ties between cannabis use and adolescent brain development in humans. Objective To examine the degree to which magnetic...
Article
Full-text available
Males and females show different patterns of cannabis use and related psychosocial outcomes. However, the neuroanatomical substrates underlying such differences are poorly understood. The aim of this study was to map sex differences in the neurobiology (as indexed by brain volumes) of dependent and recreational cannabis use. We compared the volume...
Article
Full-text available
Background Alcohol use is a major public health challenge in France, where at the age of 17 half the young people report an episode of severe alcohol intoxication in the month preceding the survey. Numerous prevention programmes have a general objective, but in adolescence individual vulnerabilities towards addictions differ significantly with pers...
Article
Full-text available
Genetic markers of the endocannabinoid system have been linked to a variety of addiction-related behaviors that extend beyond cannabis use. In the current study we investigate the relationship between endocannabinoid (eCB) genetic markers and alcohol use disorder (AUD) in European adolescents (14–18 years old) followed in the IMAGEN study ( n = 2,0...
Preprint
Full-text available
Peer victimization is common in adolescence and have been associated with a broad variety of psychopathology and alcohol use. The present study assessed whether peer victimization has a time-varying effect on alcohol use through internalizing and externalizing symptoms and whether this indirect association throughout time is moderated by personalit...
Article
Full-text available
Background: Fifteen to 25-year-olds are the age group most likely to misuse prescription drugs. Few studies have tested theory-driven models of adolescent risk for prescription drug misuse. Moreover, rarely are distinct pathways to different forms of prescription drug misuse considered. Methods: We tested mediational paths from personality to menta...
Article
Full-text available
Males and females with alcohol dependence have distinct mental health and cognitive problems. Animal models of addiction postulate that the underlying neurobiological mechanisms are partially distinct, but there is little evidence of sex differences in humans with alcohol dependence as most neuroimaging studies have been conducted in males. We exam...
Article
Full-text available
Gender-related differences in the susceptibility, progression and clinical outcomes of alcohol dependence are well-known. However, the neurobiological substrates underlying such differences remain unclear. Therefore, this study aimed to investigate gender differences in the neuroanatomy (i.e. regional brain volumes) of alcohol dependence. We examin...
Article
Full-text available
Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large-scale studies. In response, we used cross-sectional data from 17,07...
Article
Full-text available
Delineating the association of age and cortical thickness in healthy individuals is critical given the association of cortical thickness with cognition and behavior. Previous research has shown that robust estimates of the association between age and brain morphometry require large‐scale studies. In response, we used cross‐sectional data from 17,07...
Article
Full-text available
Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resource...
Article
Full-text available
Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalized on the resource...
Article
Full-text available
Changing sleep rhythms in adolescents often lead to sleep deficits and a delay in sleep timing between weekdays and weekends. The adolescent brain, and in particular the rapidly developing structures involved in emotional control, are vulnerable to external and internal factors. In our previous study in adolescents at age 14, we observed a strong r...
Article
Brain asymmetry reflects left‐right hemispheric differentiation, which is a quantitative brain phenotype that develops with age and can vary with psychiatric diagnoses. Previous studies have shown that substance dependence is associated with altered brain structure and function. However, it is unknown whether structural brain asymmetries are differ...
Article
Full-text available
Abstract This review summarizes the last decade of work by the ENIGMA (Enhancing NeuroImaging Genetics through Meta Analysis) Consortium, a global alliance of over 1400 scientists across 43 countries, studying the human brain in health and disease. Building on large-scale genetic studies that discovered the first robustly replicated genetic loci as...
Article
Full-text available
Attention-Deficit/Hyperactivity Disorder (ADHD) and conduct disorder (CD) exemplify top-down dysregulation conditions that show a large comorbidity and shared genetics. At the same time, they entail two different types of symptomology involving mainly non-emotional or emotional dysregulation. Few studies have tried to separate the specific biology...
Article
Full-text available
To identify neuroimaging biomarkers of alcohol dependence (AD) from structural magnetic resonance imaging, it may be useful to develop classification models that are explicitly generalizable to unseen sites and populations. This problem was explored in a mega‐analysis of previously published datasets from 2,034 AD and comparison participants spanni...
Article
Full-text available
For many traits, males show greater variability than females, with possible implications for understanding sex differences in health and disease. Here, the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Consortium presents the largest-ever mega-analysis of sex differences in variability of brain structure, based on international da...
Article
Full-text available
The externalizing psychopathological dimension is associated with alterations in adolescents’ functional brain connectivity. The current study aims to identify the functional correlates of the unique variability in conduct problems within the context of the broad externalizing dimension. The broad externalizing dimension and unique variability in c...
Article
Full-text available
Background The orbitofrontal cortex (OFC) is implicated in depression. The hypothesis investigated was whether the OFC sensitivity to reward and nonreward is related to the severity of depressive symptoms. Methods Activations in the monetary incentive delay task were measured in the IMAGEN cohort at ages 14 years (n = 1877) and 19 years (n = 1140)...
Article
Full-text available
Gray matter volume (GMV) in frontal cortical and limbic regions is susceptible to cocaine‐associated reductions in cocaine‐dependent individuals (CD) and is negatively associated with duration of cocaine use. Gender differences in CD individuals have been reported clinically and in the context of neural responses to cue‐induced craving and stress r...
Article
Objective Irritable mood, a common and impairing symptom in psychopathology, has been proposed to underlie the developmental link between oppositional problems in youth and depression in adulthood. Here, we examined the neural correlates of adolescent irritability in IMAGEN, a sample of 2024 14-year-adolescents from five European countries. Method...
Article
Alcohol use disorder (AUD) and cannabis use disorder (CUD) are associated with brain alterations particularly involving fronto-cerebellar and meso-cortico-limbic circuitry. However, such abnormalities have additionally been reported in other psychiatric conditions , and until recently there has been few large-scale investigations to compare such fi...
Article
Aim To compare the long‐term universal outcomes of the Climate Schools program, the selective Preventure program and their combined implementation to standard substance use education in reducing the uptake of alcohol use, engagement in binge drinking and alcohol‐related harms over a 3‐year period. Design A cluster randomized controlled trial. Set...
Article
Full-text available
A prior meta-analyze using behavioral tasks demonstrated that individuals with subclinical delusional ideations jump to conclusion (JTC). The major aim of our systematic review and meta-analyses was to highlight the relationship between cognitive biases and psychotic-like experiences (PLEs) when both are assessed by self-reports measures. In accord...
Article
Full-text available
Imaging genetics offers the possibility of detecting associations between genotype and brain structure as well as function, with effect sizes potentially exceeding correlations between genotype and behavior. However, study results are often limited due to small sample sizes and methodological differences, thus reducing the reliability of findings....
Preprint
Full-text available
Delineating age-related cortical trajectories in healthy individuals is critical given the association of cortical thickness with cognition and behaviour. Previous research has shown that deriving robust estimates of age-related brain morphometric changes requires large-scale studies. In response, we conducted a large-scale analysis of cortical thi...
Preprint
Full-text available
Age has a major effect on brain volume. However, the normative studies available are constrained by small sample sizes, restricted age coverage and significant methodological variability. These limitations introduce inconsistencies and may obscure or distort the lifespan trajectories of brain morphometry. In response, we capitalised on the resource...
Article
Importance Alcohol abuse correlates with gray matter development in adolescents, but the directionality of this association remains unknown. Objective To investigate the directionality of the association between gray matter development and increase in frequency of drunkenness among adolescents. Design, Setting, and Participants This cohort study...
Article
Full-text available
Major neurocognitive changes occur during adolescence, making this phase one of the most critical developmental periods of life. Furthermore, this phase in life is also the time in which youth substance use begins. Several studies have demonstrated the differential associations of alcohol and cannabis use concerning the neurocognitive functioning o...
Article
To investigate the biological mechanisms underlying the higher risk for psychosis in those that use cannabis, we conducted a genome-wide environment-interaction study (GWEIS). In a sample of individuals without a psychiatric disorder (N=1262), we analyzed the interactions between regular cannabis use and genotype with psychotic-like experiences (PL...
Article
There is a well‐established link between substance use and four personality traits of anxiety–sensitivity, hopelessness, impulsivity, and sensation‐seeking. However, construct‐level models of personality may conceal indicator‐level personality–outcome associations. The current study aims to investigate evolution of the network constellation of pers...
Poster
Explore autistic traits in general population in order to define their psychopathological and neurological characteristics and to compare it with characteristics of clinical autism.
Preprint
Full-text available
For many traits, males show greater variability than females, with possible implications for understanding sex differences in health and disease. Here, the ENIGMA (Enhancing Neuro Imaging Genetics through Meta-Analysis) Consortium presents the largest-ever mega-analysis of sex differences in variability of brain structure, based on international da...
Preprint
Full-text available
Background The search for neuroimaging biomarkers of alcohol use disorder (AUD) has primarily been restricted to significance testing in small datasets of low diversity. To identify neurobiological markers beyond individual differences, it may be useful to develop classification models for AUD. The ever-increasing quantity of neuroimaging data dema...
Article
Background and aims: It has been proposed that increased screen time contributes to increasing rates of adolescents abstaining from alcohol use. We argue that this proposition depends on the extent to which a type of screen time promotes social norms. We examined whether social norms mediated the association between alcohol use and i) social media...
Article
In Reply We appreciate the opportunity to engage in scholarly discussion surrounding our contribution to JAMA Pediatrics on the association of screen time and depression in adolescence.¹ Teh et al state that our cohort is unlikely to be representative of the entire adolescent population because adolescents within this cohort were originally selecte...
Article
Full-text available
Most psychopathological disorders develop in adolescence. The biological basis for this development is poorly understood. To enhance diagnostic characterization and develop improved targeted interventions, it is critical to identify behavioural symptom groups that share neural substrates. We ran analyses to find relationships between behavioural sy...
Article
Full-text available
Though adolescence is a time of emerging sex differences in emotions, sex-related differences in the anatomy of the maturing brain has been under-explored over this period. The aim of this study was to investigate whether puberty and sexual differentiation in brain maturation could explain emotional differences between girls and boys during adolesc...
Article
There are indications that screen time is associated with symptoms of anxiety in adolescents, but from a longitudinal perspective, the magnitude, specificity, and temporal precedence in this association are relatively under-explored. To address this gap, over the course of 4 years, we annually surveyed adolescents assessing their usage of various t...
Article
While imaging studies have demonstrated volumetric differences in subcortical structures associated with dependence on various abused substances, findings to date have not been wholly consistent. Moreover, most studies have not compared brain morphology across those dependent on different substances of abuse to identify substance-specific and subst...
Article
Full-text available
This systematic review assessed the current evidence base of substance use prevention programs for Indigenous adolescents in the USA, Canada, Australia and New Zealand. The authors investigated (a) the outcomes, type, setting and context of prevention programs; (b) the common components of beneficial prevention programs; and (c) the methodological...
Article
Objective This study examined the secondary mental health outcomes of two contrasting alcohol prevention approaches, whereby one intervention targets common underlying personality risk for alcohol use and mental health problems ( Preventure) and the other targets alcohol- and drug-related behaviours and cognitions ( Climate Schools). Methods A 2 ×...
Article
Heavy drinker adolescents: altered brainstem microstructure. © 2019 Society for the Study of Addiction.