CHARACTERIZATION OF AGGRESSIVE BEHAVIOR IN CHILDREN WITH AUTISM SPECTRUM ...

186 Pages·2011·1.37 MB·English

CHARACTERIZATION OF AGGRESSIVE BEHAVIOR IN CHILDREN
WITH AUTISM SPECTRUM DISORDERS

DISSERTATION

Presented in Partial Fulfillment of the Requirements for
the Degree Doctor of Philosophy in the Graduate
School of The Ohio State University

Cristan A. Farmer, M.A.

Psychology Graduate Program
The Ohio State University
2011

Dissertation Committee:
Dr Michael G. Aman, Adviser
Dr. Eric Butter
Dr. Luc Lecavalier
Dr. Marc Tassé
Copyright by
Cristan Farmer
2011
ABSTRACT

Aggression is not well characterized in children with autism spectrum disorders (ASD),
although it is commonly claimed that these children engage in more aggressive behaviors
than typically developing children. This is in stark contrast to the myriad reports available on
the normative and developmental patterns of aggression in typically developing children.
Thus, the prevalence and severity of aggressive behavior in a moderately-sized clinical
sample of children with ASDs was assessed using a common measure of childhood
psychopathology, the Child Behavior Checklist (CBCL) and a relatively new scale of
aggression, the Children’s Scale for Hostility and Aggression: Reactive/Proactive (C-
SHARP). Participants were n = 223 children with ASDs and n = 115 children with no ASD
diagnosis from four sites: Nationwide Children’s Hospital (Columbus, Ohio), Thompson
Center for Autism (Columbia, Missouri), University of Illinois at Chicago, and Dayton
Children’s Hospital (Dayton, Ohio). Participants were between the ages of 17 and 224
months (mean = 84.74, standard deviation = 45.82). Item- and subscale- level data were
reported for the CBCL Aggressive Behavior subscale as well as for the five C-SHARP
subscales: Verbal Aggression, Bullying, Covert Aggression, Hostility, and Physical
Aggression. Summary data were also reported for the Provocation scale of the C-SHARP, on
which rater answer the question, “Who starts it?” Diagnostic, demographic, and other
variables were examined as correlates of aggression, including age, sex, comorbid diagnoses,
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psychotropic medication, IQ, adaptive behavior scores, and language ability. C-SHARP data
from the ASD group were also subjected to cluster analysis, in an effort to discover
clinically-meaningful subgroups of children based on profiles of aggressive behavior.
Children with ASDs did engage in aggressive behaviors; the highest average scores were
observed on the Hostility subscale. A larger-than-expected proportion (17%) of the ASD
sample received a CBCL Aggressive Behavior subscale t-score above 70. The control group
had higher scores than the ASD group on two C-SHARP subscales, Covert Aggression and
Physical Aggression. Several correlates of aggressive behavior were observed in the ASD
group. Asperger’s disorder was associated with higher scores than the other diagnostic
groups on several subscales. Older children had higher scores on Verbal Aggression, Covert
Aggression, and Hostility. Members of the ASD group with ADHD diagnoses and/or taking
ADHD medication scored higher on most subscales of the C-SHARP. The selected cluster
solution comprised five clusters: Low Aggression, Primarily Hostile, Physical, Verbal, and
High Aggression. Single-sample and split-sample reliability kappa estimates were above
0.90, indicating excellent agreement. Differences were observed between clusters based on
external variables, supporting the validity of the cluster structure. Children with autistic
disorder were likeliest to be in the Low Aggression group, but those who were aggressive
were over-represented in the Physical group. The Verbal group had a larger-than-expected
proportion of children with PDD-NOS, while the High cluster had more children with
Asperger’s disorder than expected. Results of this study converge with the limited existing
data on aggression in children with ASDs and suggest future directions for areas of focus.

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ACKNOWLEDGEMENTS

I wish to thank my adviser, Dr. Michael Aman, for his unparalleled patience and
expertise. His guidance made this project possible.
I thank my committee, Dr. Eric Butter, Dr. Luc Lecavalier, and Dr. Marc Tassé,
for their helpful comments and suggestions.
Without the participation of several researchers, including Dr. Eric Butter
(Nationwide Children’s Hospital), Dr. Edwin Cook, Jr. (University of Illinois at
Chicago), Dr. MaryBeth DeWitt (Dayton Children’s Hospital), and Dr. Micah Mazurek
(University of Missouri), this project would not have left the planning stages. Thanks is
also due to various members of the teams, including Mr. Christopher Cope (Nationwide
Children’s Hospital), Ms. Meghan Ellingsworth (University of Missouri), Mr. Stephen
Guter (University of Illinois at Chicago), and Ms. Caroline Sansbury (Ohio State
University).
I am grateful for the monetary support of the Organization for Autism Research
and the Ohio State University Alumni Association.

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VITA
July 25, 1983……………………………… Born, Ottumwa, Iowa, USA

2005……………………………………….. B.S. (Honors), Psychology,
Iowa State University

2005-2006………………………………… University Fellow,
Ohio State University

2006-2008………………………………… Graduate Teaching Associate,
Ohio State University

2008……………………………………….. M.A., Psychology,
Ohio State University

2008-2011………………………………… Graduate Research Associate,
Ohio State University

PUBLICATIONS
Farmer, C. (Accepted for publication). Leiter International Performance Scale-Revised.
In F. Volkmar, Ed. Encyclopedia of Autism Spectrum Disorders.

Farmer, C., Lecavalier, L., Yu, S., Arnold., L., McDougle, C., Scahill, L., Handen, B.,
Johnson, C., Stigler, K., Bearss, K., Swiezy, N., & Aman, M. (In press).
Predictors and moderators of response to behavioral treatment in children with
autism spectrum disorders and serious behavioral problems. Journal of Autism
and Developmental Disorders.

Aman, M.G., Farmer, C.A., Lindsay, R.L., & Arnold, L.E. (2011). Individuals with
intellectual disability. In A. Martin, L. Scahill, & C. Kratochvil, (Eds.), Pediatric
Psychopharmacology: Principles and Practice (Second edition). New York:
Oxford University Press.

Farmer, C. & Aman, M. (2011). Aggressive behavior in a sample of children with autism
spectrum disorders. Research in Autism Spectrum Disorders, 5(1), 317-323.
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Farmer, C. & Aman, M. (2011). Aripiprazole for the treatment of irritability associated
with autism. Expert Opinion on Pharmacotherapy,
DOI:10.1517/14656566.2011.557661.

Aman, M. & Farmer, C. (2010). Self injury, aggression, and related problems in autism
spectrum disorders. In E. Hollander, A. Kolevzon, and J. Coyle (Eds.) Textbook of
Autism Spectrum Disorders. Arlington, VA: American Psychiatric Publishing.

Arnold, L., Farmer, C., Kraemer, H., Davies, M., Witwer, A., Chuang, S., DiSilvestro, R.,
McDougle, C., McCracken, J., Vitiello, B., Aman, M., Scahill, L., Posey, D., &
Swiezy, N. (2010). Moderators, mediators, and other predictors of risperidone
response in children with autistic disorder and irritability. Journal of Child and
Adolescent Psychopharmacology, 20(2), 83-93.

Calarge, C., Farmer, C., DiSilvestro, R., & Arnold, L.E. (2010). Serum ferritin and
amphetamine response in youth with ADHD. Journal of Child and Adolescent
Psychopharmacology, 20(6), 495-502.

Farmer, C. & Aman, M. (2010). Psychometric Properties of the Children's Scale of
Hostility and Aggression: Reactive/Proactive (C-SHARP). Research in
Developmental Disabilities, 31, 270-280.

Farmer, C. & Aman, M. (2009). Development of the Children’s Scale for Hostility and
Aggression: Reactive/Proactive. Research in Developmental Disabilities, 30,
1155-1167.

Aman, M.G., Farmer, C.A., Hollway, J.A., & Arnold, L.E. (2008). Treatment of
Inattention, overactivity, and impulsiveness in autism spectrum disorders. Child
and Adolescent Psychiatric Clinics of North America (D. Posey & C. McDougle,
Guest Editors), 17, 713–738.

Aman , M.G. & Farmer, C.A. (2008). Psychotropic medication research in children and
adolescents: Ethical implications. Journal of Empirical Research on Human
Research Ethics, pp. 39–47. PRINT ISSN 1556-2646, ONLINE ISSN 1556-2654.

Aman, M., Benson, B., Farmer, C., Hall, K., and Malone, K. (2007). Project MED:
Effects of a medication education booklet series for individuals with intellectual
disabilities. Intellectual and Developmental Disabilities, 45(1), 33-45.

FIELDS OF STUDY

Major Field: Psychology
Specialization: Intellectual and Developmental Disabilities; Psychometrics and Data
Analysis Minor
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TABLE OF CONTENTS

Abstract…………………………………………………………………… ii
Acknowledgements……………………………………………………….. iv
Vita………………………………………................................................... v
List of Tables……………………………………………………………… viii
Chapter 1: Introduction…………………………………………………… 1
Chapter 2: Methods……………………………………………………….. 41
Chapter 3: Results…………………………………………………………. 62
Chapter 4: Discussion……………………................................................... 78
References…………………………………………………………………. 105
Tables……………………………………………………………………… 118
Figures……………………………………………………………………. 161
Appendix A……………………………………………………………….. 167
Appendix B……………………………………………………………….. 171
Appendix C……………………………………………………………….. 174

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LIST OF TABLES

Table 1. Full Sample by Site………………………………………………… 118
Table 2. Final Sample Characteristics……………………………………….. 120
Table 3. C-SHARP Summary …………….………………………………… 123
Table 4. C-SHARP Item Ratings for Moderate and Severe……………......... 128
Table 5. CBCL Summary Statistics………………………………………… 132
Table 6. CBCL Item Ratings for Moderate and Severe……………………... 135
Table 7. Categorical Variables Associated with C-SHARP and CBCL…….. 137
Table 8. Continuous Variables Associated with C-SHARP and CBCL……... 140
Table 9. Categorical Variables Associated with C-SHARP Provocation........ 141
Table 10. Continuous Variables Associated with C-SHARP Provocation….. 144
Table 11. ASD as Moderator………………………………………………… 145
Table 12. Correlations between CBCL and C-SHARP in ASD Group……… 146
Table 13. Results of K-Means Procedure without Provocation Scale……….. 148
Table 14. Pseudo-F Statistics………………………………………………... 149
Table 15. Results of K-Means Procedure with Provocation Scale………….. 150
Table 16. Reliability Analyses without Provocation Scale…………………. 151
Table 17. Reliability Analyses with Provocation Scale……………………... 152
Table 18. Validity Analyses without Provocation Scale…………………….. 153
Table 19. Validity Analyses with Provocation Scale………………………... 156
Table 20. Factor Analysis of CBCL Aggressive Behavior: 1.5-5…………… 159
Table 21. Factor Analysis of CBCL Aggressive Behavior: 6-18……………. 160

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LIST OF FIGURES

Figure 1. ASD Moderates the Effect of Age on Verbal Aggression………….. 161
Figure 2. ASD Moderates the Effect of Age on Covert Aggression…………… 162
Figure 3. ASD Moderates the Effect of Age on Hostility……………………….. 163
Figure 4. ASD Moderates the Effect of Age on Bullying……………………….. 164
Figure 5. ASD Moderates the Effect of Age on Physical Aggression………… 165
Figure 6. ASD Moderates the Effect of IQ on Verbal Aggression…………….. 166

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