Irwin Waldman

Professor of Psychology

Office: 475 Psychology Building

Phone: 404-727-7430

Fax: 404-727-0372

Email: psyiw@emory.edu

Additional Contact Information

Mailing Address:

Department of Psychology

36 Eagle Row
Emory University

Atlanta, GA 30322

Additional Websites

Biography

I did my undergraduate degree in Human Development and Family Studies at Cornell University, graduating in 1982. Following graduation, I attended graduate school in clinical psychology at the University of Waterloo in Ontario, Canada and earned my Ph.D. in 1988.

In my Master's and dissertation research, I examined the relations among non-social information processing (i.e., inattention and impulsivity), social perception, and aggressive and withdrawn behavior in 7 to 12 year old children.

Following my year-long clinical internship at the Lafayette Clinic in Detroit (1987-88), I completed a three-year, NIMH-funded Postdoctoral Fellowship in Behavioral Genetics at the University of Minnesota. I began as a faculty member in the Psychology Department at Emory University in the fall of 1991.

During the spring of 1996, I was a Visiting Faculty Scholar at the Henry A. Murray Research Center at Harvard, and a Visiting Professor at the Institute for Behavioral Genetics at the University of Colorado, Boulder. In the fall of 1998, I was a Visiting Professor and Honorary Lecturer at the Centre for Social, Genetic, and Developmental Psychiatry Research at the Institute of Psychiatry, University of London, UK.

I am an Associate Editor of the journal, Behavior Genetics, and am on the editorial boards of two other journals (Journal of Abnormal Psychology, Clinical Psychological Science). I have also reviewed grants for NIH, as well as for the Medical Research Council and Wellcome Trust in the UK. I was a member-at-large of the Executive Committee of the Behavior Genetics Association from 1998-2000, and a member of the task force on social, legal, and research implications of behavioral genetics of the American Society of Human Genetics from 1995-96. I was also a statistical consultant to the DSM-IV Disruptive Behavior Disorders Field Trials.

I am currently Principal Investigator on an NIMH grant to study the molecular genetics of childhood disruptive disorders, and am Co-Principal Investigator on an NIMH grant which funds a behavior genetic study of child externalizing problems.

Courses Currently Taught

Graduate:

  • PSYC 770: Latent Variable Modeling MPlus
  • PSYC 561: Multiple Regression/General Linear Model

Undergraduate:

I also have supervised six honors theses.

Research

Research Interests 

In my lab we work at the intersection of psychology, statistics, and biology to understand the causes, classification, and biological bases of childhood psychopathology and relevant personality traits. My overarching interests are in developmental psychopathology and developmental behavior genetics. In my lab we aim to understand the causes, classification, and development of childhood disruptive disorders (e.g., ADHD, Conduct Disorder) and externalizing behavior problems (e.g., aggression, psychopathic traits), as well as related personality and temperament traits (e.g., prosociality, Negative Emotionality), social cognitive mechanisms (e.g., perception of facial displays of emotion), and neurocognitive executive functions. A major focus of my research centers on disentangling the genetic and environmental influences that underlie these traits and disorders, as well as understanding how such causal factors combine to influence risk for childhood psychopathology. 

Behavior Genetics

To address these issues, I use developmental behavior genetic methods (primarily twin study designs) in which the genetic and environmental influences that underlie such disorders and behavior problems can be disentangled and their magnitude can be quantified. I also use these methods to gain a better understanding of comorbidity, in particular the extent to which common genetic and environmental influences may account for the overlap within and among childhood externalizing and internalizing disorders, and the covariation of these disorders with temperament and personality traits. 

Molecular Genetics

In addition to conducting twin studies to estimate genetic and environmental influences, I use molecular genetic methods to search for specific genes that may account for the genetic influences on these disorders and traits. Historically, most of the genes we studied underlie various neurotransmitter systems, though recently we have begun examining neuropeptide genes such as the arginine vasopressin 1a receptor (AVPR1a) and oxytocin receptor gene (OXTR). We genotype multiple markers to capture genetic variation across the genes and use omnibus gene-based tests, thus increasing the likelihood of obtaining replicable associations with disorders and traits. We also are transitioning from examining associations with specific genes selected a priori to conducting gene-based tests of data from Genome Wide Association Scans (GWAS) of ADHD, Conduct Disorder, aggression, and psychopathic traits, as GWAS provides more comprehensive and unbiased tests of genetic associations. 

Within the context of behavioral and molecular genetic designs, we have also examined specific environmental influences at a number of different levels (e.g., pre- and peri-natal influences, parenting behavior, neighborhood characteristics), neurocognitive endophenotypes (e.g., measures of inattention and impulsivity), and social cognitive mechanisms (e.g., hostile perceptual biases, and deficits and biases in the processing of facial emotions) that may underlie externalizing disorders and the development of aggression and psychopathic traits. We also are using twin study designs and sophisticated statistical methods (e.g., Confirmatory Factor Analysis [CFA], Exploratory Structural Equation Modeling [ESEM], and Item Response Theory [IRT]) to test alternative models for the hierarchical dimensional structure of psychopathology. Finally, I've recently co-authored or edited several pieces focusing explicitly on replication issues in our field. 

Prospective Students

Prospective students should have an interest in behavioral and molecular genetic methods as well as in sophisticated statistical analyses. The research in our lab emphasizes evaluating different techniques and approaches for analyzing genetic and phenotypic data. Although a background in genetics and statistics is not required, students will be expected to become proficient in these areas.

Waldman Lab Research Topics

(* graduate student author; + postdoctoral fellow author; ^ undergraduate student author) 

1. Using Genome-Wide Data to Find Genes for Externalizing Psychopathology, including Attention Deficit Hyperactivity Disorder, Conduct Disorder, Aggression, Psychopathic Traits, and Antisocial Behavior

Over the past decade, technological and statistical advances have made it possible to economically and efficiently genotype large samples and to test millions of genetic markers for association with traits and disorders. We are using genome-wide data from our own sample and other samples in a series of collaborative studies to conduct genome-wide association scans (GWAS) of various forms of Externalizing Psychopathology, including Attention Deficit Hyperactivity Disorder (ADHD), Conduct Disorder (CD), Aggression, Psychopathic Traits, and Antisocial Behavior. Across these GWAS projects we are particularly interested in the use of gene-based tests and multivariate analyses to increase power and the likelihood of finding replicable associations, as well as exploring similarities and differences in genetic risk factors across different ethnic groups. 

  1. With regard to ADHD, I am part of the Psychiatric Genetics Consortium (PGC) ADHD workgroup and we currently have 12 genome-wide significant loci and a forthcoming paper on this that is currently in preparation.
  2. For Conduct Disorder, I am co-leading a GWAS of ODD+CD diagnoses in the PGC ADHD plus Danish iPsych samples. I am also leading a GWAS of Conduct Disorder symptoms - and symptoms of the Aggressive and Rule-Breaking CD factors - in the Yale-Penn and SAGE multi-site samples recruited for substance use and abuse. Across the two samples we have ~5000 European-American and  ~5000 African-American participants and are in the process of expanding the number of samples.
  3. For psychopathic traits, we've conducted a GWAS in the TEDS sample in the UK and will be trying to replicate the top associations in my sample here in Georgia, as well as trying to find other youth samples with both GWAS genotypes and similar measures of psychopathic traits.
  4. And finally, I am part of the BROAD collaboration on GWAS of antisocial behavior broadly construed co-led by Danielle Posthuma and Sarah Medland. 

Relevant Publications: In progress. Click for full list.

2. Tests of Specific Genes as Risk Factors for Externalizing Psychopathology

In addition to genome-wide studies, we have conducted and are conducting studies that focus on the association of specific genes with various forms of Externalizing Psychopathology, including Attention Deficit Hyperactivity Disorder, Oppositional Defiant Disorder, Conduct Disorder, Aggression, Psychopathic Traits, and Antisocial Behavior. These genes are chosen based on neurobiological findings in humans and animal models for the biological plausibility of their etiological role in these traits and disorders. These projects include:

a. Association of the Oxytocin Receptor gene with Autism, Aggression, and Social Behavior 

Relevant Publications: Click for full list.

b. Finding Dopamine & Noradrenergic Genetic Risk Factors for ADHD 

Relevant Publications: Click for full list.

3. Meta-Analyses of Genetic and Environmental Influences on ADHD and Antisocial Behavior

Meta-Analysis is a quantitative approach to reviewing the findings in a research literature that bear on a particular question or a set of hypotheses. Using meta-analytic methods allows one to characterize the overall effect size (i.e., the magnitude of an association) and its statistical significance, characterize the precision of that effect size and its heterogeneity across studies, and assess the role of substantive and methodological variables as moderators that may help explain some of the cross-study heterogeneity. We have used meta-analyses to summarize the evidence for genetic and environmental Influences on ADHD and Antisocial Behavior. 

Relevant Publications: Click for full list.

4. Analyses of the Classification and Underlying Structure of Youth Psychiatric Disorders

Despite decades of research, uncertainty remains regarding the valid classification and underlying structure of psychiatric disorders in children and adolescents. Using data from several large population-based twin samples we are conducting sophisticated latent variable modeling and multivariate behavior genetic analyses in an effort to elucidate the underlying structure of both internalizing and externalizing disorders. In our recent efforts in this area we use twin study designs and sophisticated statistical methods to test alternative models for the hierarchical dimensional structure of psychopathology. 

Relevant Publications: Click for full list.

5. Etiological Relation of Temperament and Personality with Youth Psychiatric Disorders

Contemporary approaches to characterizing psychopathology have emphasized the continuities between normal range function and the abnormal extreme of various quantitative dimensions in contrast to qualitative distinctions among categorical diagnoses. Along these lines we have used multivariate behavior genetic analyses to examine the etiological role of various temperament and personality dimensions in general, internalizing, and externalizing dimensions of psychopathology. 

Relevant Publications: Click for full list.

6. Neurocognitive and Social Cognitive Endophenotypes for ADHD and Aggression

Within the context of behavioral and molecular genetic designs, we have examined social cognitive and neurocognitive executive function measures that are putative endophenotypes for ADHD and aggression. These constructs represent specific psychological mechanisms that are posited to underlie the etiology of these disorders and traits and may be influenced by the specific genes that are risk factors for these conditions. Specifically, we are interested in the role of children's inattention, impulsivity, hostile perceptual biases, and deficits and biases in the processing of facial emotions and others’ intentions in the development of aggression and psychopathic traits, and have examined these and related constructs as endophenotypes for childhood disruptive disorders. 

Relevant Publications: Click for full list.

7. Rigorous Tests of Direct Causal Environmental Influences on Child Psychopathology

Traditional approaches to examining putative environmental influences on child psychopathology have relied on simple associations between disorders and variables thought to reflect environmental risk factors. Unfortunately, such associations may reflect background genetic or shared environmental influences rather than the direct causal influences of the “environmental” variables themselves. Over the past decade, in collaboration with a set of colleagues, we have rigorously examined specific environmental influences for conduct problems and ADHD. Specifically, in a large genetically-informative national representative sample of mothers and their children (i.e., the Children of the National Longitudinal Study of Youth, or CNLSY) as well as in 2 large twin samples, we have conducted both between-family and within-family tests of the effects of several putative environmental risk factors, including mother’s smoking and drinking during pregnancy, mother’s age at the birth of each child, neighborhood effects, effects of family income, and birth weight and gestational age. 

Relevant Publications: Click for full list.

8. Exploration of Issues Related to Replicability of Findings of Psychological Research

In addition to testing for replication of behavioral and molecular genetic findings using meta-analysis, I've recently co-authored or edited several pieces focusing explicitly on replication issues in our field. 

Relevant Publications: Click for full list.

Publications

For a full list of Dr. Waldman’s publications and references, please click on the Google Scholar link below.

http://scholar.google.com/citations?user=kg5sHpcAAAAJ&hl=en