Richard E Tremblay

McGill University, Montréal, Quebec, Canada

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Publications (460)1559.47 Total impact

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    ABSTRACT: Background Little is known about how children differ in the onset and evolution of separation anxiety (SA) symptoms during the preschool years, and how SA develops into separation anxiety disorder. In a large, representative population-based sample, we investigated the developmental trajectories of SA symptoms from infancy to school entry, their early associated risk factors, and their associations with teachers' ratings of SA in kindergarten.Methods Longitudinal assessment of SA trajectories and risk factors in a cohort of 1,933 families between the ages of 1.5 and 6 years.ResultsAnalyses revealed a best-fitting, 4-trajectory solution, including a prevailing, unaffected Low-Persistent group (60.2%), and three smaller groups of distinct developmental course: a High-Increasing (6.9%), a High-Decreasing (10.8%), and a Low-Increasing group (22.1%). The High-Increasing group remained high throughout the preschool years and was the only trajectory to predict teacher-assessed SA at age 6 years. Except for the High-Increasing, all trajectories showed substantial reduction in symptoms by age 6 years. The High-Increasing and High-Decreasing groups shared several early risk factors, but the former was uniquely associated with higher maternal depression, maternal smoking during pregnancy, and parental unemployment.Conclusions Most children with high SA profile at age 1.5 years are expected to progressively recover by age 4–5. High SA at age 1.5 that persists over time deserves special attention, and may predict separation anxiety disorder. A host of child perinatal, parental and family-contextual risk factors were associated with the onset and developmental course of SA across the preschool years.
    Journal of Child Psychology and Psychiatry 04/2015; DOI:10.1111/jcpp.12419 · 5.67 Impact Factor
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    ABSTRACT: This study aims to document the prevalence of repeated patterns of dating victimization and to examine, within the frameworks of an ecological model and lifestyle/routine activities theories, associations between such patterns and family, peer, and individual factors. Dating victimization in adolescence (age 15) and early adulthood (age 21) was evaluated in 443 female participants. Multinomial logistic regression analyses revealed that history of family violence, childhood behavior problems, and adolescent high-risk behaviors were associated with an increased risk for girls of being victimized (psychologically and/or physically/sexually) in their dating relationships, either in adolescence or early adulthood, or at both developmental periods. © The Author(s) 2015.
    Violence Against Women 04/2015; 21(4):435-59. DOI:10.1177/1077801215570481 · 1.33 Impact Factor
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    ABSTRACT: In the current prospective study, we investigated (1) whether high and low BMI in early childhood puts a child at risk of victimization by their peers, and (2) whether being victimized increases BMI over the short- and long-term, independent of the effect of BMI on victimization. We also examined whether gender moderated these prospective associations. Participants were 1,344 children who were assessed yearly from ages 3 to 10 years as part of the Québec Longitudinal Study of Child Development (QLSCD). BMI predicted annual increases in victimization for girls aged 6 years and over; for boys aged 7 and 8 years of age, higher BMI reduced victimization over the school year. Further, victimization predicted annual increases in BMI for girls after age 6 years. When these short-term effects were held constant, victimization was also shown to have a three and 5-year influence on annual BMI changes for girls from age 3 years. These short- and long-term cross-lagged effects were evident when the effects of family adversity were controlled. The findings support those from previous prospective research showing a link between higher BMI and victimization, but only for girls. Further, being victimized increased the likelihood that girls would put on weight over time, which then increased future victimization. The implications of these prospective findings for interventions are considered. Aggr. Behav. 9999:XX–XX, 2015. © 2015 Wiley Periodicals, Inc.
    Aggressive Behavior 01/2015; 41(2). DOI:10.1002/AB.21580 · 2.27 Impact Factor
  • Nadine Provençal, Linda Booij, Richard E Tremblay
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    ABSTRACT: Longitudinal epidemiological studies with birth cohorts have shown that physical aggression in humans does not appear suddenly in adolescence as commonly thought. In fact, physically aggressive behaviour is observed as early as 12 months after birth, its frequency peaks around 2-4 years of age and decreases in frequency until early adulthood. However, a minority of children (3-7%) maintain a high frequency of physical aggression from childhood to adolescence and develop serious social adjustment problems during adulthood. Genetic factors and early social experiences, as well as their interaction, have been shown to play an important role in the development of chronic aggressive behaviour. However, the biological mechanisms underlying these associations are just beginning to be uncovered. Recent evidence suggests that epigenetic mechanisms are responsive to adverse environments and could be involved in the development of chronic aggression. Using both gene candidate and genomic approaches, recent studies have identified epigenetic marks, such as DNA methylation alterations in genes involved in the stress response and the serotonin and immune systems to be partly responsible for the long-lasting effects of early adversity. Further longitudinal studies with biological, environmental and behavioural assessments from birth onwards are needed to elucidate the sequence of events that leads to these long-lasting epigenetic marks associated with early adversity and aggression. © 2015. Published by The Company of Biologists Ltd.
    Journal of Experimental Biology 01/2015; 218(Pt 1):123-133. DOI:10.1242/jeb.111401 · 3.00 Impact Factor
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    ABSTRACT: Parental educational expectations have been associated with children's educational attainment in a number of long-term longitudinal studies, but whether this relationship is causal has long been debated. The aims of this prospective study were twofold: 1) test whether low maternal educational expectations contributed to failure to graduate from high school; and 2) compare the results obtained using different strategies for accounting for confounding variables (i.e. multivariate regression and propensity score matching). The study sample included 1,279 participants from the Quebec Longitudinal Study of Kindergarten Children. Maternal educational expectations were assessed when the participants were aged 12 years. High school graduation - measuring educational attainment - was determined through the Quebec Ministry of Education when the participants were aged 22-23 years. Findings show that when using the most common statistical approach (i.e. multivariate regressions to adjust for a restricted set of potential confounders) the contribution of low maternal educational expectations to failure to graduate from high school was statistically significant. However, when using propensity score matching, the contribution of maternal expectations was reduced and remained statistically significant only for males. The results of this study are consistent with the possibility that the contribution of parental expectations to educational attainment is overestimated in the available literature. This may be explained by the use of a restricted range of potential confounding variables as well as the dearth of studies using appropriate statistical techniques and study designs in order to minimize confounding. Each of these techniques and designs, including propensity score matching, has its strengths and limitations: A more comprehensive understanding of the causal role of parental expectations will stem from a convergence of findings from studies using different techniques and designs.
    PLoS ONE 01/2015; 10(3):e0119638. DOI:10.1371/journal.pone.0119638 · 3.53 Impact Factor
  • Journal of Child and Family Studies 01/2015; DOI:10.1007/s10826-015-0131-9 · 1.42 Impact Factor
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    ABSTRACT: Background Antisocial personality disorder (ASPD) is characterised by elevated impulsive aggression and increased risk for criminal behaviour and incarceration. Deficient activity of the monoamine oxidase A (MAOA) gene is suggested to contribute to serotonergic system dysregulation strongly associated with impulsive aggression and antisocial criminality. Aims To elucidate the role of epigenetic processes in altered MAOA expression and serotonin regulation in a population of incarcerated offenders with ASPD compared with a healthy non-incarcerated control population. Method Participants were 86 incarcerated participants with ASPD and 73 healthy controls. MAOA promoter methylation was compared between case and control groups. We explored the functional impact of MAOA promoter methylation on gene expression in vitro and blood 5-HT levels in a subset of the case group. Results Results suggest that MAOA promoter hypermethylation is associated with ASPD and may contribute to downregulation of MAOA gene expression, as indicated by functional assays in vitro, and regression analysis with whole-blood serotonin levels in offenders with ASPD. Conclusions These results are consistent with prior literature suggesting MAOA and serotonergic dysregulation in antisocial populations. Our results offer the first evidence suggesting epigenetic mechanisms may contribute to MAOA dysregulation in antisocial offenders. Royal College of Psychiatrists.
    The British journal of psychiatry: the journal of mental science 12/2014; DOI:10.1192/bjp.bp.114.144964 · 7.34 Impact Factor
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    ABSTRACT: Background Does poor language ability in early childhood increase the likelihood of physical aggression or is language ability delayed by frequent physical aggression? This study examined the longitudinal associations between physical aggression and language ability from toddlerhood to early childhood in a population sample while controlling for parenting behaviours, non-verbal intellectual functioning, and children’s sex. Methods Children enrolled in the Quebec Longitudinal Study of Child Development (QLSCD) (N = 2, 057) were assessed longitudinally from 17 to 72 months via parent reports and standardized assessments. Results The cross-lagged models revealed modest reciprocal associations between physical aggression and language performance from 17 to 41 months but not thereafter. Conclusions Significant associations between physical aggression and poor language ability are minimal and limited to the period when physical aggression and language performance are both substantially increasing. During that period parenting behaviours may play an important role in supporting language ability while reducing the frequency of physical aggression. Further studies are needed that utilize multiple assessments of physical aggression, assess multiple domains of language abilities, and that examine the potential mediating role of parenting behaviours between 12 and 48 months.
    PLoS ONE 11/2014; 9(11):e112185. DOI:10.1371/journal.pone.0112185 · 3.53 Impact Factor
  • Linda Booij, Richard E Tremblay, Moshe Szyf, Chawki Benkelfat
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    ABSTRACT: Despite more than 60 years of research in the role of serotonin (5-HT) in psychopathology, many questions still remain. From a developmental perspective, studies have provided more insight into how 5-HT dysfunctions acquired in utero or early in life may modulate brain development. This paper discusses the relevance of the developmental role of 5-HT for the understanding of psychopathology. We review developmental milestones of the 5-HT system, how genetic and environmental 5-HT disturbances could affect brain development and the potential role of DNA methylation in 5-HT genes for brain development.
    Journal of psychiatry & neuroscience: JPN 10/2014; 39(5):140099. DOI:10.1503/jpn.140099 · 7.49 Impact Factor
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    ABSTRACT: DNA methylation patterns are characterized by highly conserved developmental programs, but allow for divergent gene expression resulting from stochastic epigenetic drift or divergent environments. Genome-wide methylation studies in monozygotic (MZ) twins are providing insight into the extent of epigenetic variation that occurs, irrespective of genotype. However, little is known about the variability of DNA methylation patterns in adolescence, a period involving significant and rapid physical, emotional, social, and neurodevelopmental change. Here, we assessed genome-wide DNA methylation using the 450 K Illumina BeadChip in a sample of 37 MZ twin pairs followed longitudinally since birth to investigate: 1) the extent of variation in DNA methylation in identical genetic backgrounds in adolescence and; 2) whether these variations are randomly distributed or enriched in particular functional pathways. We also assessed stability of DNA methylation over 3-6 months to distinguish stable trait-like and variable state-like genes. A pathway analysis found high within-pair variability in genes associated with development, cellular mechanisms, tissue and cell morphology, and various disorders. Test-retest analyses performed in a sub-sample of 8 twin pairs demonstrated enrichment in gene pathways involved in organismal development, cellular growth and proliferation, cell signaling, and particular disorders. The variability found in functional gene pathways may plausibly underlie phenotypic differences in this adolescent MZ twin sample. Furthermore, we assessed stability of methylation over 3-6 months and found that some genes were stable while others were unstable, suggesting that the methylome remains dynamic in adolescence and that dynamic sites tend to be organized in certain gene pathways.
    Epigenetics: official journal of the DNA Methylation Society 10/2014; 9(10):1410-22. DOI:10.4161/15592294.2014.970060 · 5.11 Impact Factor
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    ABSTRACT: Background Little is known about the associations between self-reported offending and official offending whilst considering different types of offences.AimsThe aims of the present study are to identify developmental trajectories of self-reported violent and nonviolent offending (SRVO; SRNVO) and to examine their associations with official violent and nonviolent offences (as juveniles and adults).Methods Developmental trajectories of SRVO and SRNVO from 11 to 17 years of age were estimated with data from the Montreal Longitudinal and Experimental Study, a prospective longitudinal study of 1037 boys from disadvantaged neighbourhoods.ResultsFive trajectories of SRVO (i.e. Chronic, Desisting, Delayed, Moderate and Low) and three trajectories of SRNVO (Chronic, Moderate and Low) were identified. Chronic, Desisting and Delayed trajectories of SRVO were associated with violent and nonviolent official offending in adolescence and early adulthood, over and above the trajectories of SRNVO. In comparison, trajectories of SRNVO were weakly and inconsistently associated with official offending, once controlling for their overlap with trajectories of SRVO.Conclusions Individuals on high trajectories of violent offending during adolescence are most at risk for being exposed to the justice system both concurrently and longitudinally. Differentiating violent and nonviolent offending can help resolve part of the discordance between self-reported and official offending. Copyright © 2014 John Wiley & Sons, Ltd.
    Criminal Behaviour and Mental Health 10/2014; 24(4). DOI:10.1002/cbm.1935 · 1.28 Impact Factor
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    ABSTRACT: Proactive aggression (PA) describes an instrumental behavior that is goal-oriented, whereas reactive aggression (RA) refers to an angry or frustrated aggressive response to a real or perceived threat. Little is known about the respective roles of genetic (G) and environmental (E) factors associated with PA and RA during childhood. The objectives of this study were to investigate a) the G-E etiology of the commonality between PA and RA and b) the presence of G or E components specific to PA or RA throughout childhood (i.e., from 6 to 12 years of age). Participants were 254 monozygotic and 413 dizygotic pairs. Teacher reports of PA and RAwere obtained at 6, 7, 9, 10 and 12 years of age. Throughout childhood, genetic factors accounted for most of the common variance between PAand RA, as well as their specificity. Shared environment played no role. Specifically, genetic factors common to PA and RA explained between 39% and 45% of the variance in PA, and between 27% and 42% of the variance in RA. Genetic factor also uniquely accounted for only but a small percentage (9% at 6 years and 3% at 9 years old) of the variation in PA. As for RA, three distinctive genetic factors contributed to phenotypic variation throughout childhood and explained between 12% and 22% of variance. Dynamic genetic factors accounted for the commonality in PA and RA, and for the specificity of RA. Few genetic factors were unique to PA; in contrast, for RA, an early, specific and persistent genetic factor was found alongside new genetic factors that appeared at later ages. These results challenge theoretical models that focus primarily on the effects of environmental factors in the etiology of reactive and proactive aggression.
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    ABSTRACT: Background The impact of longitudinal psychiatric comorbidity, parenting and social characteristics on attention-deficit hyperactivity disorder (ADHD) medication use is still poorly understood. Aims To assess the baseline and longitudinal influences of behavioural and environmental factors on ADHD medication use. Method Survival regressions with time-dependent covariates were used to model data from a population-based longitudinal birth cohort. The sample (n = 1920) was assessed from age 5 months to 10 years. Measures of children's psychiatric symptoms, parenting practices and social characteristics available at baseline and during follow-up were used to identify individual and family-level features associated with subsequent use of ADHD medication. Results Use of ADHD medication ranged from 0.2 to 8.6% between ages 3.5 to 10 years. Hyperactivity-inattention was the strongest predictor of medication use (hazard ratio (HR) = 2.75, 95% CI 2.35-3.22). Among all social variables examined, low maternal education increased the likelihood of medication use (HR = 2.09, 95% CI 1.38-3.18) whereas immigrant status lowered this likelihood (HR = 0.40, 95% CI 0.17-0.92). Conclusions Beyond ADHD symptoms, the likelihood of receiving ADHD medication is predicted by social variables and not by psychiatric comorbidity or by parenting. This emphasises the need to improve global interventions by offering the same therapeutic opportunities (including medication) as those received by the rest of the population to some subgroups (i.e. immigrants) and by diminishing possible unnecessary prescriptions.
    The British journal of psychiatry: the journal of mental science 08/2014; 205(4). DOI:10.1192/bjp.bp.113.141952 · 7.34 Impact Factor
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    ABSTRACT: Heart rate variability (HRV) is a non-invasive quantitative marker of cardiac autonomic function derived from continuous electrocardiogram (ECG) recordings. Normative HRV values and development factors have not been established in pediatric populations. The objective was to derive referent time- and frequency-domain HRV values for a population-based sample of children. Children aged 9-11 years (N = 1,036) participated in the Québec Longitudinal Study of Child Development cohort cardiovascular health screening. Registered nurses measured anthropometrics (height, weight) and children wore an ambulatory Holter monitor to continuously record an ECG signal. HRV variables included time (SDNN, pNN50, RMSSD, SDANN) and frequency (HF, LF, LF/HF ratio) domain variables. Normative HRV values, stratified by age, sex, and heart rate, are presented. Greater heart rate (β avg = -0.60, R avg (2) = 0.39), pubertal maturation (β avg = -0.11, R avg (2) = 0.01), later ECG recording times (β avg = -0.19, R avg (2) = 0.07), and higher diastolic blood pressure (β avg = -0.11, R avg (2) = 0.01) were significantly associated with reduced HRV in 10-year-old children. The normative HRV values permit clinicians to monitor, describe, and establish pediatric nosologies in primary care and research settings, which may improve treatment of diseases associated with HRV in children. By better understanding existing values, the practical applicability of HRV among clinicians will be enhanced. Lastly, developmental (e.g., puberty) and procedural (e.g., recording time) factors were identified that will improve recording procedures and interpretation of results.
    Pediatric Cardiology 07/2014; 36(1). DOI:10.1007/s00246-014-0962-y · 1.55 Impact Factor
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    ABSTRACT: In this 16-year longitudinal study, a new trajectory estimation approach was used to verify whether the developmental course of childhood inattention significantly predicted functional impairment. A rising childhood inattention trajectory significantly predicted graduation failure (OR: 1.76 [1.32-2.34]) independently of averaged inattention levels. Rising inattention is, in itself, important for prognosis.
    Psychiatry Research 06/2014; DOI:10.1016/j.psychres.2014.06.022 · 2.68 Impact Factor
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    ABSTRACT: Chronic physical aggression (CPA) is characterized by frequent use of physical aggression from early childhood to adolescence. Observed in approximately 5% of males, CPA is associated with early childhood adverse environments and long-term negative consequences. Alterations in DNA methylation, a covalent modification of DNA that regulates genome function, have been associated with early childhood adversity. To test the hypothesis that a trajectory of chronic physical aggression during childhood is associated with a distinct DNA methylation profile during adulthood. We analyzed genome-wide promoter DNA methylation profiles of T cells from two groups of adult males assessed annually for frequency of physical aggression between 6 and 15 years of age: a group with CPA and a control group. Methylation profiles covering the promoter regions of 20 000 genes and 400 microRNAs were generated using MeDIP followed by hybridization to microarrays. In total, 448 distinct gene promoters were differentially methylated in CPA. Functionally, many of these genes have previously been shown to play a role in aggression and were enriched in biological pathways affected by behavior. Their locations in the genome tended to form clusters spanning millions of bases in the genome. This study provides evidence of clustered and genome-wide variation in promoter DNA methylation in young adults that associates with a history of chronic physical aggression from 6 to 15 years of age. However, longitudinal studies of methylation during early childhood will be necessary to determine if and how this methylation variation in T cells DNA plays a role in early development of chronic physical aggression.
    PLoS ONE 04/2014; 9(4):e89839. DOI:10.1371/journal.pone.0089839 · 3.53 Impact Factor
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    ABSTRACT: Background Research on associations between children's prosocial behaviour and mental health has provided mixed evidence. The present study sought to describe and predict the joint development of prosocial behaviour with externalizing and internalizing problems (physical aggression, anxiety and depression) from 2 to 11 years of age.Method Data were drawn from the National Longitudinal Survey of Children and Youth (NLSCY). Biennial prosocial behaviour, physical aggression, anxiety and depression maternal ratings were sought for 10,700 children aged 0 to 9 years at the first assessment point.ResultsWhile a negative association was observed between prosociality and physical aggression, more complex associations emerged with internalizing problems. Being a boy decreased the likelihood of membership in the high prosocial trajectory. Maternal depression increased the likelihood of moderate aggression, but also of joint high prosociality/low aggression. Low family income predicted the joint development of high prosociality with high physical aggression and high depression.Conclusions Individual differences exist in the association of prosocial behaviour with mental health. While high prosociality tends to co-occur with low levels of mental health problems, high prosociality and internalizing/externalizing problems can co-occur in subgroups of children. Child, mother and family characteristics are predictive of individual differences in prosocial behaviour and mental health development. Mechanisms underlying these associations warrant future investigations.
    Journal of Child Psychology and Psychiatry 04/2014; 55(10). DOI:10.1111/jcpp.12235 · 5.67 Impact Factor

Publication Stats

15k Citations
1,559.47 Total Impact Points


  • 1997–2015
    • McGill University
      • • Department of Psychiatry
      • • Department of Psychology
      • • Department of Medicine
      Montréal, Quebec, Canada
    • University of Texas Health Science Center at Houston
      • Center for Health Promotion and Prevention Research
      Houston, TX, United States
  • 2014
    • L'Institut universitaire en santé mentale de Québec
      Quebec City, Quebec, Canada
    • Tomsk State University
      Tomsk, Tomsk, Russia
  • 2008–2014
    • University College Dublin
      • School of Public Health, Physiotherapy & Population Science
      Dublin, Leinster, Ireland
  • 1988–2014
    • Université de Montréal
      • • School of Psycho-Education
      • • Department of Pediatrics
      Montréal, Quebec, Canada
  • 2005–2013
    • Laval University
      • School of Psychology
      Québec, Quebec, Canada
    • The University of Winnipeg
      • Department of Economics
      Winnipeg, Manitoba, Canada
  • 2011
    • CHU Sainte-Justine
      Montréal, Quebec, Canada
    • Université René Descartes - Paris 5
      Lutetia Parisorum, Île-de-France, France
    • Centre jeunesse de Montréal-Institut universitaire
      Montréal, Quebec, Canada
  • 1999–2011
    • Université du Québec à Montréal
      • Department of Psychology
      Montréal, Quebec, Canada
    • Netherlands Institute for the Study of Crime and Law Enforcement (NSCR)
      Amsterdamo, North Holland, Netherlands
  • 1992–2011
    • University of Ottawa
      • School of Psychology
      Ottawa, Ontario, Canada
  • 2000–2008
    • Hôpital du Sacré-Coeur de Montréal
      • Center for Advanced Research in Sleep Medicine
      Montréal, Quebec, Canada
  • 2007
    • McMaster University
      Hamilton, Ontario, Canada
    • Université du Québec
      Quebec City, Quebec, Canada
  • 2005–2007
    • University of Toronto
      • Department of Psychology
      Toronto, Ontario, Canada
  • 2004
    • Childcare Resource and Research Unit
      Toronto, Ontario, Canada
    • University of Oslo
      • Department of Psychology
      Oslo, Oslo, Norway
  • 2003
    • University of New Mexico
      • Department of Sociology
      Albuquerque, NM, United States
  • 2001
    • Carnegie Mellon University
      • School of Public Policy & Management
      Pittsburgh, PA, United States
  • 1996
    • Harvard University
      Cambridge, Massachusetts, United States
  • 1994
    • University of Jyväskylä
      • Department of Psychology
      Jyväskylä, Western Finland, Finland