GAPIN, JENNIFER I., Ph.D. Associations Among Physical Activity, ADHD Symptoms, and Executive ...

123 Pages·2009·0.38 MB·English

GAPIN, JENNIFER I., Ph.D. Associations Among Physical Activity, ADHD Symptoms,
and Executive Function in Children with ADHD. (2009)
Directed by Dr. Jennifer L. Etnier. 112 pp.

Attention Deficit Hyperactivity Disorder (ADHD) is one of the leading childhood
psychiatric disorders and is a costly public health problem. ADHD causes multiple
impairments and while stimulant medications are effective in treating core symptoms of
ADHD, some children are not responsive to medications, there is little known about their
long-term effects, and they can cause numerous deleterious side effects. Research
suggests that physical activity positively impacts some of the same neurobiological
mechanisms that have been implicated in ADHD and may have a particularly beneficial
effect for children with ADHD by moderating fundamental cognitive deficiencies and
behavioral symptoms that characterize this disorder. One of the primary cognitive
impairments in ADHD children is executive function (EF). Children with ADHD
consistently perform worse on a range of EF tasks relative to those without ADHD
(Wilcutt et al., 2005). There is extensive research to support that physical activity
selectively improves EF performance in older adults (Colcombe & Kramer, 2003) and
some evidence that it has a small effect on cognition in children (Sibley & Etnier, 2003;
Tomporowski et al., 2008). Despite evidence and rationale supporting the potential for
physical activity to benefit children with ADHD, there is very little research in this area.
Therefore, the purpose of this study was to investigate the extent to which physical
activity is associated with ADHD symptoms and EF task performance in children with
ADHD. Eighteen boys (M age = 10.61, SD = 1.50), who had been diagnosed by a
medical professional and were currently taking stimulant medication, were recruited from
the community for participation in the study. Children came to the testing site to
complete four measures of EF: planning (Tower of London); working memory (Digit
Span); processing speed (Children’s Colors Trails Test 1 and 2); and inhibition (Conner’s
Continuous Performance Test, CPT II). Parents completed rating scales (ADHD Rating
Scale IV; Behavior Assessment System for Children, 2nd Edition) to assess their child’s
ADHD symptoms. The most relevant outcome variables from each task and the rating
scales were chosen for analysis. Physical activity was measured with an accelerometer
(Yamax NL-1000) that participants wore for seven consecutive days providing daily step
counts (steps) and minutes per day spent in moderate-to-vigorous intensity physical
activity (MVPA). Regression analyses were used with physical activity as a predictor of
EF performance and ADHD symptoms. Results revealed that MVPA was a significant
predictor of performance on the Tower of London, adjusted R2 = .28, F (1, 16) = 7.61,
p < .05. Additionally, although non-significant, correlations for 5 of the other 6 EF
outcome measures with both measures of physical activity (steps and MVPA) were in the
hypothesized direction, with higher physical activity predictive of better EF performance.
There were no significant results for ADHD symptoms. This study provides promising
results that physical activity is associated with EF, specifically planning abilities, in
children with ADHD. These findings are especially encouraging given that the
participants were all receiving medication treatment for ADHD. Given that EF deficits in
ADHD children negatively affect their school experience and performance, further
research is warranted to examine the impact of physical activity on EF in ADHD
children.
ASSOCIATIONS AMONG PHYSICAL ACTIVITY, ADHD SYMPTOMS, AND
EXECUTIVE FUNCTION IN CHILDREN WITH ADHD

by
Jennifer I. Gapin

A Dissertation Submitted to
the Faculty of the Graduate School at
The University of North Carolina at Greensboro
in Partial Fulfillment
of the Requirements for the Degree
Doctor of Philosophy

Greensboro
2009

Approved by
______________________________
Committee Chair
© 2009 by Jennifer I. Gapin
APPROVAL PAGE
This dissertation has been approved by the following committee of the Faculty of
The Graduate School at The University of North Carolina at Greensboro.

Committee Chair ____________________________
Committee Members ____________________________
____________________________
____________________________

____________________________
Date of Acceptance by Committee

____________________________
Date of Final Oral Examination

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“To my parents, Mike and Sandy Gapin, for their unwavering faith and
support throughout this process. ”

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ACKNOWLEDGEMENTS

I would first like to thank my advisor, Dr. Jennifer Etnier for her amazing
guidance and support throughout this process. She has been instrumental in the
development of my research and writing skills and her expertise has enabled me to learn
so much about the field and myself. I feel grateful to have had such a wonderful mentor
while at UNCG. I would also like to thank the members of my committee, Dr. Gill, Dr.
Karper, and Dr. Anastopoulos for their critical reflections, feedback, and dedication to
making this research successful. I would like to thank my parents for their unconditional
love, support, and encouragement. They always manage to make everything better. In
addition, I would like to thank Jeffrey Labban, Lisa Barella, and Yu Kai Chang for their
friendship and countless conversations that have helped me develop academically and
personally. Their insight and advice have enabled me to grow in so many ways and I will
always be thankful for that. Finally, I would like to acknowledge that this research was
made possible by funding from a UNCG Regular Faculty Grant.

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TABLE OF CONTENTS

Page

LIST OF TABLES ............................................................................................................ vii
LIST OF FIGURES ......................................................................................................... viii
CHAPTER

I. INTRODUCTION ............................................................................................ 1
II. REVIEW OF THE LITERATURE ................................................................... 4
ADHD Mechanisms .................................................................................... 6
Neurobiological factors ................................................................... 6
The role of executive function ........................................................ 9
ADHD Mechanisms and the Potential Role of Physical Activity ............ 14
BDNF ............................................................................................ 14
Cerebral structure and function ..................................................... 16
Catecholamine function ................................................................ 17
Executive function ........................................................................ 19
Benefits of Physical Activity and Fitness on Children ............................. 20
Cognition....................................................................................... 21
Academic performance ................................................................. 24
Behavior ........................................................................................ 25
Summary ................................................................................................... 27
Hypotheses ................................................................................................ 29

III. METHODS .................................................................................................... 30
Overview of Research Design .................................................................. 30
General Procedure ..................................................................................... 30
Sample Recruitment and Selection ........................................................... 32
Descriptive Measures ................................................................................ 33
General demographic, ADHD information and physical activity
questionnaire .............................................................................. 33
Physical Activity Measures....................................................................... 35
New Lifestyles NL-1000 accelerometer ....................................... 35
Physical Activity Questionnaire for Older Children (PAQ-C) ..... 36
Daily physical activity log ............................................................ 37
ADHD Behavioral Symptoms .................................................................. 39
The Behavior Assessment System for Children, 2nd edition,
Parent Rating Scale .................................................................... 39
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The ADHD Rating Scale-IV ......................................................... 40
Executive Function Measures ................................................................... 41
Inhibition ....................................................................................... 41
Planning ........................................................................................ 42
Working memory .......................................................................... 44
Processing speed ........................................................................... 45
Treatment of Accelerometer Data ............................................................. 46
Treatment of PAQ-C Data ........................................................................ 47
Statistical Analyses ................................................................................... 48

IV. RESULTS ...................................................................................................... 50
Descriptive Results ................................................................................... 50
Participants .................................................................................... 50
ADHD characteristics ................................................................... 50
ADHD symptoms.......................................................................... 52
Executive function performance ................................................... 56
Physical activity measures ............................................................ 56
Physical activity survey items ....................................................... 57
Regression Analyses ................................................................................. 58
Associations among physical activity variables ........................... 58
Associations among body mass index, physical activity,
ADHD symptoms, and executive function variables ................. 58
Associations between the predictor and criterion variables .......... 59

V. DISCUSSION ................................................................................................ 62
Summary of the Findings .......................................................................... 62
Associations Among Physical Activity Variables .................................... 63
Physical Activity and ADHD Symptoms ................................................. 63
Physical Activity and Executive Function ................................................ 65
Interpretation of Physical Activity Behavior ............................................ 68
PAQ-C........................................................................................... 68
NL-1000 accelerometer data ......................................................... 68
Limitations ................................................................................................ 73
Recommendations for Future Research .................................................... 76

REFERENCES ................................................................................................................. 79
APPENDIX A. CONSENT FORMS .............................................................................. 110

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LIST OF TABLES
Page
Table 1. Physical Activity Variables Used in Statistical Analyses ....................................38

Table 2. ADHD Behavioral Symptoms Variables Used in Statistical Analyses .............. 41

Table 3. Executive Function Variables Used in Statistical Analyses ............................... 46

Table 4. Linear Regression Analyses Used to Test the Hypotheses of the Study ............ 49

Table 5. Descriptive Information for Demographics of the ADHD Sample .................... 51

Table 6. Frequency Counts and Percentages for Self-Reported ADHD Type
and Age at Diagnosis .......................................................................................52

Table 7. Descriptive Information for ADHD Rating Scale .............................................. 53

Table 8. Means and Standard Deviations for Severity Counts on the ADHD
Rating Scale .....................................................................................................53

Table 9. Means, Standard Deviations, and Ranges for the BASC-2 PRS
Subscales and Composites (Represented as T-scores).....................................55

Table 10. Descriptive Information for Executive Function Measures .............................. 56

Table 11. Descriptive Information for the Accelerometer Data and PAQ-C ................... 57

Table 12. Correlation Matrix for the ADHD Symptoms and Physical Activity
Measures ..........................................................................................................59

Table 13. Correlation Matrix for the Executive Function Variables and
Physical Activity Measures............................................................................ 60

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