THE REPETITIVE BEHAVIOR SCALE REVISED: INDEPENDENT VALIDATION AND THE EFFECTS OF SUBJECT VARIABLES DISSERTATION

Transcription

1 THE REPETITIVE BEHAVIOR SCALE REVISED: INDEPENDENT VALIDATION AND THE EFFECTS OF SUBJECT VARIABLES DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of The Ohio State University By Kristen S.L. Lam, M.A. * * * * * The Ohio State University 2004 Dissertation Committee: Dr. Michael G. Aman, Adviser Dr. Betsey A. Benson Dr. Luc Lecavalier Approved by Adviser Department of Psychology

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3 ABSTRACT A key feature of autistic disorder is restricted repetitive behavior (RRB), which can be manifested in a variety of ways. Despite the clinical significance of RRBs, relatively little is known about their phenomenology, assessment, and treatment. The Repetitive Behavior Scale Revised (RBS-R) is a recently-developed rating tool that appears to capture the breadth of repetitive behavior in autism. In order to validate the RBS-R in an independent sample, a survey was conducted within the parent mailing list of the South Carolina Autism Society (SCAS). A total of 320 care providers (32%) responded to the survey. Factor analyses produced a five-factor solution that was both clinically meaningful and statistically sound. These factors were labeled Ritualistic/Sameness Behavior, Stereotypic Behavior, Self-Injurious Behavior, Compulsive Behavior, and Restricted Interests. Measures of internal consistency were good for this five-subscale solution, and interrater reliability data suggested that the RBS-R may be well suited for outpatient settings. The effects of a variety of subject variables (age, sex, race, level of mental retardation, severity of autism, type of autism spectrum disorder, school placement, co-morbid behavior problems, family history of mood disturbance, and medication use) were examined using analyses of ii

4 variance. Many significant relationships were revealed, and these may provide directions for future study. The RBS-R appears to be a valid instrument for the assessment of restricted repetitive behavior in individuals with autism in outpatient settings, and it may prove to be useful in the study of genetic or neurobiological correlates of autism, as well as in the assessment of treatment effects. iii

5 ACKNOWLEDGMENTS I wish to thank my adviser, Michael Aman, for the support, guidance and encouragement that made this dissertation possible. I am grateful to have such a wonderful mentor. Many thanks to Betsey Benson and Luc Lecavalier for their thoughtful suggestions and input. I thank the South Carolina Autism Society for allowing me to conduct a survey within their membership. I would like to thank the caregivers and parents who completed the surveys that made this dissertation possible. Lastly, I wish to thank my family and friends for their encouragement. To my husband, Greg, thanks for cheering me on and keeping me smiling. To my parents, Hal and Nikki Langworthy, thank you for your amazing support. iv

6 VITA September 11, Born Rochester, New York B.A. Neuroscience and Behavior, Mount Holyoke College University Fellow, The Ohio State University 2001.M.A. Psychology, The Ohio State University Graduate Research Associate, The Ohio State University Predoctoral Research Associate, The University of North Carolina Chapel Hill Research Publications PUBLICATIONS 1. Arnold, L.E., Chuang, S., Davies, M., Abikoff, H.B., Conners, C.K., Elliott, G.R., Greenhill, L.L., Hechtman, L., Hinshaw, S.P., Hoza, B., Jensen, P.S., Kraemer, H.C., Langworthy-Lam, K.S., March, J.S., Newcorn, J.H., Pelham, W.E., Severe, J.B., Swanson, J.M., Vitiello, B., Wells, K.C., & Wigal, T. (2004). Nine months multicomponent behavioral treatment for ADHD and effectiveness of MTA fading procedures. Journal of Abnormal Child Psychology, 32, Aman, M.G., Lam, K.S.L., & Collier-Crespin, A. (2003). Prevalence and patterns of use of psychoactive medicines among individuals with autism in the Autism Society of Ohio. Journal of Autism and Developmental Disorders, 33, v

7 3. Langworthy-Lam, K.S., Aman, M.G., & Van Bourgondien, M.E. (2002). Prevalence and patterns of use of psychoactive medicines in individuals with autism in the Autism Society of North Carolina. Journal of Child and Adolescent Psychopharmacology, 12, Liptak, G.S., Bolander, H.M., & Langworthy, K. (2001). Screening for ventricular shunt function in children with hydrocephalus secondary to meningomyelocele. Pediatric Neurosurgery, 34, Aman, M.G. & Langworthy, K.S. (2000). Pharmacotherapy for hyperactivity in children with autism and other pervasive developmental disorders. Journal of Autism and Developmental Disorders, 30, FIELDS OF STUDY Major Field: Psychology vi

8 TABLE OF CONTENTS Page Abstract...ii Acknowledgments...iv Vita..v List of Tables...ix List of Figures..xii Chapters: 1. Introduction.1 2. Review of Rating Instruments 8 3. Method Results Discussion References..86 Appendices: Appendix A: Bodfish s Original Six-Factor Principal Components Analysis..97 Appendix B: Copy of RBS-R Used in Factor Analytic Study..100 vii

9 Appendix C: Scree Plot of SCAS Data Appendix D: Two-Factor Solution for SCAS Data..111 Appendix E: Four-Factor Solution for SCAS Data..113 Appendix F: Six-Factor Solution Using Principal Components Analysis with Orthogonal Varimax Rotation: Appendix G: Six-Factor Solution Using Ordinary Least Squares Extraction with Oblique Quartimax Rotation Appendix H: Corrected Item-Total Correlations for Six-Subscale Solution 121 Appendix I: Cronbach s Alpha Values for Six-Subscale Solution Appendix J: Scatterplots of J. Iverson Riddle Interrater Reliability Data viii

10 LIST OF TABLES Table Page 1 Demographic characteristics of respondents from the South Carolina Autism Society 40 2 Item prevalence for each item on the RBS-R within the SCAS 42 3 Five-factor solution using ordinary least squares extraction with oblique quartimax rotation Interfactor correlations Corrected item-total correlations for five-factor solution Subscale statistics: Cronbach s alpha and interrater reliability.46 7 Subscale correlations with RBS-R Total Score and Global Severity Score Summary of the ANOVA results for the main effect of age.47 9 Summary of the ANOVA results for the main effect of sex Summary of the ANOVA results for the main effect of race Summary of the ANOVA results for the main effect of type of autism spectrum condition Summary of the ANOVA results for the main effect of degree of autism Summary of the ANOVA results for the main effect of level of mental retardation ix

11 14 Summary of the ANOVA results for the main effect of school placement Summary of the ANOVA results for the main effect of irritability Summary of the ANOVA results for the main effect of aggression Summary of the ANOVA results for the main effect of ADHD symptoms Summary of the ANOVA results for the main effect of depression Summary of the ANOVA results for the main effect of anxiety Summary of the ANOVA results for the main effect of anxiety in nuclear family Summary of the ANOVA results for the main effect of depression in nuclear family Summary of the ANOVA results for the main effect of obsessive compulsive disorder (OCD) in nuclear family Summary of the ANOVA results for the main effect of bipolar disorder in nuclear family Summary of the ANOVA results for the main effect of antipsychotic use Summary of the ANOVA results for the main effect of selective serotonin reuptake inhibitor (SSRI) use Summary of the ANOVA results for the main effect of anxiolytic use Summary of the ANOVA results for the main effect of stimulant use Summary of one-way ANOVAs examining the effect of subject variables on RBS-R scores RBS-R subscale and total scores by age and level of mental retardation 68 x

12 30 Bodfish s original six-factor principal components analysis Two-factor solution using Ordinary Least Square extraction with oblique quartimax rotation Four-factor solution using Ordinary Least Squares extraction with oblique quartimax rotation Six-factor solution using Principal Components Analysis with orthogonal varimax rotation Six-factor solution using Ordinary Least Squares extraction with oblique quartimax rotation Corrected item-total correlations for six-subscale solution Cronbach s alpha values for six-subscale solution..125 xi

13 LIST OF FIGURES Figure Page 1 Scree plot of SCAS data Ritualistic/Sameness Behavior subscale interrater reliability data: J. Iverson Riddle sample Stereotypic Behavior subscale interrater reliability data: J. Iverson Riddle sample Self-Injurious Behavior subscale interrater reliability data: J. Iverson Riddle sample Compulsive Behavior subscale interrater reliability data: J. Iverson Riddle sample Restricted Interests subscale interrater reliability data: J. Iverson Riddle sample..129 xii

14 CHAPTER 1 INTRODUCTION Autism is a pervasive developmental disorder characterized by impaired social interaction, deficits in verbal and nonverbal communication, and repetitive interests and behaviors. Although the estimated prevalence in the general population ranges from 0.04% to 0.2% (Sponheim & Skjeldal, 1998; Chakrabarti & Fombonne, 2001), its emergence early in life, its profound impact on families, and its chronic course have resulted in enormous emotional and financial costs (Bristol et al., 1996). It is now widely accepted that autism is a neurobiological disorder, and autism is likely to have multiple etiologies with a strong genetic basis (e.g., Wassink, Piven, & Patil, 2001). In recent years, there has been growing interest in the study of autism. However, much of this work has focused on the social and communication deficits of the disorder, rather on restricted and repetitive behavior (Lewis & Bodfish, 1998; Rutter, 1996). In the Diagnostic and Statistical Manual of Mental Disorders 4 th Edition (DSM-IV), this third necessary feature of autism is described as restricted, repetitive and stereotyped patterns of behavior, interests, and activities (DSM-IV, American Psychiatric Association, 1994). Criteria for this class of behavior can be met by a person exhibiting at least one of the following: (a) encompassing preoccupation with one or more 1

15 stereotyped and restricted patterns of interest that is abnormal either in intensity or focus; (b) apparently inflexible adherence to specific, nonfunctional routines or rituals; (c) stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping or twisting or complex whole-body movements); or (d) persistent preoccupation with parts of objects (DSM-IV, American Psychiatric Association, 1994). Some individuals with autism may have multiple forms of restricted repetitive behavior (RRB) that may consume the majority of their waking hours; others may only have a few which are less problematic. What becomes clear upon examination of these criteria is that they are very broad. However, what these behaviors have in common are their repetition, invariance, and inappropriateness. Restricted, repetitive behaviors have been loosely divided into two subcategories: lower-level behaviors that are characterized by repetition of movement (such as stereotyped movements, repetitive manipulations of objects, and self-injurious behavior); and higher-level, more complex behaviors (such as object attachments, repetitive language, and circumscribed interests) (Turner, 1999). Though this classification serves as a useful shorthand method of discussing RRB, it should be used with caution as it could obscure important differences between its various forms (Turner, 1997). Repetitive behaviors do not occur exclusively in autistic disorder. They also occur in mental retardation, psychiatric disorders (e.g., schizophrenia, obsessive-compulsive disorder [OCD]), and neurological disorders (Tourette s syndrome, Parkinson s disease, and Sydenham s chorea) (Bodfish, Symons, Parker, & Lewis, 2000). Researchers have recently begun to examine the specificity of repetitive behaviors in autism and how (or if) they differ from other disorders. If certain RRB are found exclusively in autism, such 2

16 knowledge could guide research to the neurobiological underpinnings of the disorder, as these behaviors may be the end result of very different brain regions or systems (Militerni, Bravaccio, Falco, Fico, & Palermo, 2002). In particular, workers have studied how repetitive behaviors in autism differ in frequency, severity, and typography from those found in mental retardation and obsessive compulsive disorder. Comparison of repetitive behaviors found in mental retardation with those found in autism is informative and important, because (a) there is a high occurrence of these behaviors in nonspecific mental retardation (Bodfish, et al., 1995) and (b) the majority of individuals (about 75%) with autism also have some level of mental retardation. Examining any differences could then elucidate what types of repetitive behavior are associated with autistic disorder rather than with cognitive impairment Research which directly compares the frequency and typography of repetitive behaviors in mental retardation and autism is in its infancy; to date, only one study could be located (Bodfish et al., 2000). In this study, 32 adults with autism were compared to 34 adults with mental retardation who were matched to the group with autism on age, IQ, and gender. All but four subjects (2 in each group) functioned within the severe to profound range of mental retardation. Bodfish and colleagues found that subjects with autism showed a higher incidence of repetitive behaviors when compared to subjects without autism; this is not surprising considering that abnormal repetitive behaviors are required for the diagnosis of autism (and not for mental retardation). Individuals with autism also exhibited more severe compulsions, SIB, and stereotypy when compared to controls, and the severity of repetitive behaviors predicted the overall severity of autism within the sample. 3

17 These results, while emphasizing the prevalence and severity of repetitive behavior in autism, do not provide any clear evidence for qualitative differences between the types of behavior found in people with autistic disorder those and with nonspecific mental retardation. This may be due, in part, to the inclusion of primarily severely- and profoundly-retarded subjects in that study (Bodfish et al., 2000). Level of functioning could certainly affect the types of repetitive behaviors observed. Therefore, future studies would address this question better if they include subjects with mild and moderate levels of cognitive impairment. In addition, in Bodfish and colleagues study, only the observable, more easily quantified repetitive behaviors (such as stereotypy and compulsions) were measured. Research is needed to examine the more complex, higher-order types of repetition, such as the need for sameness and restricted interests, for it is believed that these kinds of behavior are particularly characteristic of, if not restricted to, autistic disorder (U. Frith, 1989; Kanner, 1943; Wing & Gould, 1979). In doing so, it would become clearer how (or if) repetitive behaviors differ between individuals with autism and those with nonspecific mental retardation. Another natural comparison group for individuals with autism are individuals who have obsessive-compulsive disorder (OCD). This comparison, unlike the one described with mental retardation, has focused on more of the higher order, complex repetitive behaviors found in autism, such as the need for sameness and resistance to change. These behaviors, unlike stereotypies or self-injurious behavior, assume a relationship between the behavior and a corresponding internal emotional or mental state, similar to OCD (McDougle et al., 1995). This internal state of mind is often difficult to assess in individuals with autism due to communication difficulties. However, an 4

18 inability to articulate a feeling does not imply its absence (McDougle et al., 1995). The similarities between the repetitive thoughts and behaviors of individuals with autism and those with OCD have been a topic of interest for some researchers (McDougle et al., 1995, McDougle, Kresch, & Posey, 2000). In a study of 50 adults with autism, McDougle and colleagues compared the types of repetitive thoughts and behaviors to those in 50 adults with OCD, matched for age and sex (McDougle et al.,1995). The Yale-Brown Obsessive Compulsive Scale Symptom Checklist (Y-BOCS SCL) (Goodman et al., 1989a, 1989b) was used to determine the presence of obsessive-compulsive symptoms. Specifically, the presence of eight kinds of obsessions (Aggressive, Contamination, Sexual, Hoarding, Religious, Symmetry, Somatic, and Need to Know or Remember) and nine categories of compulsions (Cleaning, Checking, Repeating, Counting, Ordering, Hoarding, Need to tell or Ask, Need to Touch, Tap, or Rub, and Self-Damaging or Self-Mutilating behaviors) were recorded by interviewing participants and their primary caregivers. It was found that patients with autistic disorder could be distinguished from those with OCD by the types of repetitive behaviors they displayed. When compared with subjects with OCD, individuals with autism generally displayed more compulsions than obsessions, and the repetitive behaviors were less well-organized and complex. Analyses showed that membership of certain specific variables could predict membership in the group with autism. The following were predictive of autism: the presence of (a) hoarding; (b) touching, tapping, or rubbing; (c) self-injurious behavior; and the absence of (d) checking, (e) thoughts relating to aggression; and (f) preoccupation with symmetry. However, some of these findings could be attributed to differences in intellectual ability, 5

19 as the two groups were not matched on IQ. Further studies into the nature of repetitive behaviors in autism and OCD would be helpful to replicate and clarify these findings. Though there is still much to be known about the nature of repetitive behaviors in autism and their similarities to other neurological/psychiatric conditions, it is clear that these behaviors often are excessive and may cause significant impairment to individuals with autism (Gordon, 2000). These rituals can often consume the waking hours of an individual. Preventing or stopping such behavior is often quite difficult, as affected individuals may become anxious, agitated, or aggressive if they are interrupted (Gordon, 2000). These behaviors also are often socially inappropriate and stigmatizing. Stereotyped behaviors have also been shown to interfere with observational learning (Varni, Lovaas, Koegel, & Everett, 1979), attempts to teach play skills (Koegel, Firestone, Kramme, & Dunlap, 1974), responses to auditory stimuli (Lovaas, Littownik, & Mann, 1971), and performance of discrimination tasks (Koegel & Covert, 1972). Given the significant problems these behaviors can pose (for both the individuals with autism as well as their families), relatively little is known about their phenomenology and treatment. This lack of research focus could be due to several factors. As described above, RRBs are a relatively heterogeneous class of behaviors which are not exclusive to autism. Even within the diagnosis of autistic disorder, RRB show significant variability across individuals, and there are few data to indicate their stability over time (Cuccaro et al., 2003). Lastly, the lack of a validated assessment instrument that allows for the measurement and independent categorization of the 6

20 varieties of RRB has been an obstacle to their study. Such an assessment tool would provide an important step in advancing our knowledge of the phenomenology and treatment of restricted repetitive behavior in autism. 7

21 CHAPTER 2 REVIEW OF RATING INSTRUMENTS As stated previously, the study of RRB in autism has been hindered by the lack of an appropriate rating scale; however, tools that measure aspects of repetitive behavior (e.g., stereotypy and self-injurious behavior only, or compulsions only) do exist. The following is a review of these rating instruments which assess various forms of repetitive behavior in individuals with developmental disabilities. Multidimensional Rating Scales The Aberrant Behavior Checklist (ABC) The Aberrant Behavior Checklist (Aman, Singh, Stewart, & Field, 1985) is an informant-based rating scale that was created primarily to measure treatment effects in individuals with mental retardation. The ABC was developed using factor analysis on a sample of 418 individuals (primarily institutionalized adults and adolescents); this factor structure was subsequently validated in an independent sample of 509 participants (Aman et al., 1985). The ABC has 58 items which are divided into five subscales: (1) Irritability, Agitation, Crying (15 items), (2) Lethargy, Social Withdrawal (16 items), (3) Stereotypic Behavior (7 items), (4) Hyperactivity/Noncompliance (16 items), and (5) Inappropriate 8

22 Speech (4 items). Items are rated on a 4-point scale, ranging from 0 (not at all a problem) to 3 (the problem is severe in degree). Though developed using data from adults, researchers have found it to have a similar factor structure with younger individuals as well (Brown, Aman, & Havercamp, 2002; Marshburn & Aman, 1992; Rojahn & Helsel, 1991). The ABC s psychometric characteristics have proven to be robust by multiple independent studies, and it is one of the most established instruments in the developmental disabilities field. The ABC has been widely used in studies of developmental disabilities (including autism), and has proved to be useful in the measurement of drug effects as well as subject comparisons (Aman, 2003). However, it is not an appropriate choice when the primary focus is on RRB. The Stereotypy subscale (e.g., Meaningless, recurring body movements ) does assess one aspect of RRB, but the other, higher-order repetitive behaviors are not included in the ABC. Behavior Problems Inventory (BPI-01) The BPI-01 (Rojahn, Matson, Lott, Esbensen, & Smalls, 2001) is a 52-item informant-based rating scale which measures self-injurious, stereotypic, and aggressive/destructive behavior in people with mental retardation and other developmental disabilities. This rating tool has been refined over time since its first inception in the early 1980s (Rojahn, 1984). Originally assessing only stereotypy and self-injurious behavior, the content of the BPI was broadened by adding items which tapped aggressive and destructive behavior (Widaman, Gibbs, & Geary, 1987; McGrew 9

23 et al, 1991). The most recent revision involved replacing the original five stereotyped behavior items with items from the independently-developed Stereotyped Behavior Scale (SBS; Rojahn, Matlock, & Tassé, 2000). This latest version of the BPI-01 was developed using data from 432 individuals with mental retardation who were residents at a large residential center. Factor analysis confirmed a three factor structure and supported its subscales of (a) Self-Injurious Behavior (14 items), (b) Stereotyped Behavior (24 items), and (c) Aggressive/Destructive Behavior (11 items). Each item is scored on two scales, a five-point frequency scale [ranging from 0 (never) to 4 (hourly)] and a four-point severity scale [ranging from 0 (no problem) to 4 (severe problem)]. These frequency and severity scales were highly correlated with one another, suggesting that little additional information is gained from retaining them both. However, it was noted that using these scales in combination may be useful when making clinical decisions about a given individual (Rojahn et al., 2000). Analysis of the BPI-01 s reliability and validity data show that it is a sound rating scale, and it is a good option when the focus of measurement is on self-injurious behavior, stereotypies, and aggressive behavior. However, in the context of measuring the broad spectrum of repetitive behaviors found in autism, the BPI-01 s scope is limited to the lower-level stereotypies (such as rocking, spinning, and hand-waving) and selfinjurious behavior (such as self-biting and hair-pulling). 10

24 Diagnostic Assessment for the Severely Handicapped-II (DASH-II) The DASH-II (Matson, 1995; Matson, Gardner, Coe, & Sovner, 1991), is a broadbased rating tool used to screen for the presence of psychopathological symptoms in people who have severe and profound mental retardation, and it was designed to follow DSM-III-R criteria. It s 84 items are divided into thirteen subscales, which are: (1) Anxiety, (2) Depression, (3) Mania, (4) Autism and other PDDs, (5) Schizophrenia, (6) Stereotypies, (7) Self-Injurious Behavior, (8) Elimination Disorder, (9) Eating Disorders, (10) Sleep Disorders, (11) Sexual Disorders, (12) Organic Syndromes, and (13) Impulse Control and Other Miscellaneous Behaviors. The DASH-II is administered by a trained clinician who interviews the direct caregivers of the person being evaluated. Each item is rated on dimensions of frequency, duration, and severity. The reliability of the DASH-II varies by subscale (for example, internal consistency reliability ranges from.39 to.83). The validity of some of the subscales has been assessed since its development (e.g., Matson et al., 1996; Matson et al., 1999; Packlowskyj, Matson, Bamburg, & Baglio, 1997). This measure is among the most widely-used tool to assess adolescents and adults with profound mental retardation (Lecavalier & Aman, in press). The DASH-II has items within the Autism and other PDD subscale that taps restricted, repetitive behavior (such as becomes upset with routine or surroundings ), though these items are also combined with items that assess social deficits (such as resists or ignores attempts by others to interact with her/him ). The DASH-II also has subscales that measure stereotypies and self-injurious behavior, which are important elements of RRB. However, this tool is not appropriate when the intent of measurement is the variety of RRBs found in individuals with autism spectrum conditions. 11

25 The Nisonger Child Behavior Rating Form (NCBRF) The NCBRF (Aman, Tassé, Rojahn, & Hammer, 1996) is an informant-based rating scale developed to assess behavior and emotional problems in children with mental retardation. Adapted from the Child Behavior Rating Form (CBRF; Edelbrock 1985), the NCBRF was developed using data from 369 outpatients referred for evaluation at the Nisonger Center for Mental Retardation and Developmental Disabilities. Factor analysis of parent-completed data revealed two Social Competence subscales [(1) Compliant/Calm (6 items), and (2) Adaptive/Social (4 items)] and six Problem Behavior subscales [(1) Conduct Problem(16 items), (2) Insecure/Anxious (15 items), (3) Hyperactive (9 items), (4) Self-Injury/Stereotypic (7 items), (5) Self-Isolated/Ritualistic (8 items), and (6) Overly Sensitive (5 items). Teacher-completed data showed a very similar factor structure. Independent studies of the psychometric characteristics of the NCBRF have shown it to be a reliable (Girouard, Morin, & Tassé, 1998; Tassé & Lecavalier, 2000) and valid (Lecavalier, Aman, Hammer, Stoica, & Matthews, in press) rating scale. The NCBRF has also been translated into a French version, with an extremely similar factor structure (Tassé, Morin, & Girouard, 2000). Two of the NCBRF s subscales measure some aspects of RRB. In particular, the Self Injury/Stereotypic subscale has elements of the lower-level RRBs that can be found in individuals with autism (e.g., hits self, flaps objects, and rocks objects ). The Self-Isolated/Ritualistic subscale combines elements of social deficits or problems with elements of ritualistic behavior (e.g., shy/bashful, refuses to talk, and rituals ). However, the NCBRF is not ideal when the primary focus is on RRB, as these subscales are not designed to capture the breadth of repetitive behaviors in autism. 12

26 The Pervasive Developmental Disorder Behavior Inventory (PDDBI) The PDDBI is an informant-based rating scale which was developed to assess response to treatment in children diagnosed with a pervasive developmental disorder (Cohen, Schmidt-Lackner, Romanczyk, & Sudhalter, 2003; Cohen, 2003). Two versions of the scale were developed; one for parents (176 items divided into ten subscales) and the other for teachers (144 items divided into eight subscales). The a priori-defined subscales assess a variety of maladaptive and adaptive behaviors. The maladaptive subscales include: (1) Sensory/Perceptual Approach Behaviors (stereotyped and ritualistic behaviors); (2) Specific Fears (parent version only; fears of parental separation, sounds, people, etc.), (3) Arousal Problems (parent version only; sleeping problems, etc.), (4) Aggressiveness or Behavior Problems (e.g., irritability, self-injurious behavior), (5) Social Pragmatic Problems (e.g., lack of awareness), and (6) Semantic/Pragmatic Problems (e.g., echolalia, perseveration, tangential speech). The adaptive subscales include: (1) Social Approach Behaviors, (2) Learning, Memory, and Receptive Language, (3) Phonological Skills, and (4) Semantic/Pragmatic Ability. Items are scored using a 0 to 3 Likert scale (0 = Never to 3 = Often/Typically). The authors have conducted a series of principal components analyses that lend support for the overall construct validity of the scale and most of the subscales. Measures of internal consistency and inter-rater reliability were good. In addition, the PDDBI provides age-standardized scores, which may prove particularly useful in the assessment of change in adaptive behavior in long-term treatment studies. Three of its problem behavior subscales (Sensory/Perceptual Approach Behaviors, Aggressiveness or Behavior Problems, and Semantic/Pragmatic Problems) assess elements of repetitive 13

27 behavior. For example, in the Sensory/Perceptual Approach Behaviors subscale, many of the items describe stereotypic body movements (e.g., hand flapping, spinning objects). The Aggressiveness or Behavior Problems subscale includes self-injurious behavior (which can be a form of RRB) as well as problems with tantrums and mood (which are not a form of RRB). Last, the Semantic/Pragmatic Problems subscale assesses some of the verbal deficits in individuals with autism, such as repetitive and perseverative speech (a form of RRB) as well as difficulty in comprehension. The PDDBI appears to be a promising rating scale for individuals with autism spectrum disorders. Though it does assess some features of repetitive behavior, it is not a primary focus of the scale. Questions about RRBs are often included in subscales that have items that are not related to repetitive behaviors. Therefore, when the primary focus of study is on RRB, the PDDBI is not an ideal choice. Special Purpose Repetitive Behavior Rating Scales The Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Child Yale-Brown Obsessive Compulsive Scale (CY-BOCS) Though not intended for use in the developmental disabilities, both the Y-BOCS (Y-BOCS, Goodman et al., 1989a, b) and the CY-BOCS (Scahill et al., 1997) have been used in studies examining RRB in autistic disorder (e.g., McDougle et al., 1995; McDougle et al., 1996). Both the Y-BOCS and the CY-BOCS (which is a developmentally-revised version of the Y-BOCS intended for use in children) were designed to assess obsessive compulsive disorder in typically-developing people. Both instruments are clinician-administered interviews, which have five sections: (1) General 14

28 instructions, (2) Obsessions Checklist (a list of commonly-occurring obsessions for rating in #3), (3) Severity Ratings for Obsessions, (4) Compulsions Checklist (again, a list of compulsions for rating in #5), and (5) Severity Ratings for Compulsions. Due to the communication difficulties that individuals with autism have, it is difficult to probe for obsessions in such individuals. Instead, the compulsion sections of these instruments are predominately used to assess visible RRB by report from caregivers. Once the presence of these behaviors is assessed using the Compulsions Checklist, the most prominent behaviors (identified as target symptoms ) are then rated for severity using a 5-point ordinal scale (0 = none, 1 = mild, 2 = moderate, 3 = severe, 4 = extreme). There are five severity questions, which assess the following: Time Occupied, Interference, Distress Associated with Compulsions, Resistance Against Compulsions, and Degree of Control. The Compulsions Severity score is then computed by summing the ratings on each of these items (resulting in a score ranging from 0 to 20 points). Though the Y-BOCS and CY-BOCS have allowed for evaluation of RRB in autism, they both have several weaknesses. First, by nominating target symptoms after completing the Compulsions Checklist, these behaviors are then rated in a global sense, implying that they constitute a homogeneous group of behaviors. For example, a person may exhibit body rocking, as well as repetitive questioning and ritualized routines; any distinction between the severity or frequency of these behaviors is then lost by scoring them as one entity. Second, two of the five severity questions, resistance against compulsions and degree of control, are very hard to assess in people with communication difficulties, as this requires the informant to infer whether the subject is making an effort to control them. Thus, their utility in an autistic population is 15

29 questionable. Last, though these scales have been used to study RRB in autism, I have been unable to locate any investigation into their validity and reliability in this population. These limitations make the Y-BOCS and CY-BOCS less-than-ideal options when the focus of study is on the phenomenology of RRB in autistic disorder. The Repetitive Behavior Scale-Revised (RBS-R) Recently, Bodfish and colleagues (Bodfish, Symons, & Lewis, 2000) refined an informant-based scale, called the Repetitive Behavior Scale (RBS), to create the Repetitive Behavior Scale Revised (RBS R) that was intended to differentiate and assess the variety of RRBs observed in individuals with autism spectrum disorders. The original RBS (Bodfish, Symons, & Lewis, 1999) consisted of three subscales: (1) Stereotypic Behavior, (2) Self-injurious Behavior, and (3) Compulsions. The RBS was administered via a statewide mailing survey to the Autism Society of North Carolina, and results from 498 respondents (aged between 2 and 18 years) indicated acceptable psychometric properties (whole scale total score inter-rater reliability of 0.88 and test-retest reliability of 0.71). However, feedback from parents and clinicians suggested that the RBS did not tap into the more complex behaviors observed in people with autism (Bodfish, personal communication, March 2004). In particular, informants cited instances of ritualized behaviors (daily routines), an insistence on sameness (requiring that things remain a certain way), and restricted interests (e.g., intense fascination with trains, computers, etc). Therefore, Bodfish and colleagues expanded the original RBS to assess these more complex behaviors by compiling items from existing behavior rating scales used to assess repetitive behavior [from the original RBS (Bodfish, Symons, & Lewis, 1999), the 16

30 Autism Diagnostic Interview Revised (Lord, Rutter, & Le Couteur, 1994), the Childhood Routines Inventory (Evans et al., 1997), the Sameness Questionnaire (Prior & MacMillan, 1973), and the Abnormal Focused Affections Checklist (Schultz, & Berkson, 1995)] and from clinical experience. This resulted in the 43-item RBS-R. Items are rated on a four-point Likert scale ranging from (0) behavior does not occur to (3) behavior occurs and is a severe problem, and raters are asked to refer to the previous month when completing the scale. The items of the RBS-R have been conceptually-grouped (i.e., arbitrarily based on clinical experience) into six subscales. These include: (1) Stereotyped Behavior (apparently purposeless movements or actions that are repeated in a similar manner); (2) Self-Injurious Behavior (movements or actions that cause or have the potential to cause redness, bruising, or other injury to the body, and that are repeated in a similar manner); (3) Compulsive Behavior (behavior that is repeated and performed according to a rule or involves things being done just so ); (4) Ritualistic Behavior (performing activities of daily living in a similar manner); (5) Sameness Behavior (resistance to change, insisting that things stay the same); and (6) Restricted Behavior (limited range of focus, interest, or activity). Bodfish et al. have examined the factor structure of the RBS-R and these subscales using exploratory principal components analysis on a sample of 124 ratings (completed by caregivers of individuals with autism who were members of the Autism Society of North Carolina). Findings of these analyses suggested that a 6-factor solution is reasonable [as defined by (a) the scree test, (b) eigenvalues >1.0, (c) salient loading > 0.30, (d) coefficient alpha > 0.60, and (e) item-total correlations between 0.2 and 0.7] {Bodfish, personal communication, March 2004). However, 17

31 analysis of specific item loadings showed that items did not always load most heavily on their hypothesized subscale (please see Table 30 in Appendix A). The results of these factor analyses have been used to support the assumption that there is considerable structure within the domain of RRB, but have not been used in order to assess the validity of the subscale structure of the RBS-R. Interrater and test-retest reliability analyses suggested sound psychometric characteristics; subscale interrater reliability ranged from 0.55 (Sameness Behavior) to 0.78 (Self-Injurious Behavior), and test-retest data ranged from 0.52 (Ritualistic Behavior) to 0.96 (Restricted Interests). The RBS-R is unique in its ability to assess such a variety of restricted repetitive behaviors. However, independent study of this new rating tool is needed in order to validate its utility. Bodfish and colleagues preliminary factor was based on a sample of 124 subjects, which is relatively small for a scale with 43 items. As a consequence of this, Bodfish et al. s factor analysis solution is likely to be unstable and inaccurate. Therefore, it is important to examine how the current six subscales of the RBS-R compare to the latent variables revealed by a rigorous factor analysis with an adequate sample size. This will empirically determine the subscale structure of the RBS-R so that the dimensions of restricted repetitive behavior may be accurately measured. Objectives of the Current Study Primary Objective It appears that relatively little is known about RRB in autism, and further study in this area is needed. A crucial step towards advancing research of restricted repetitive behavior is the validation of a rating scale that will help in the assessment of these 18

32 complex behaviors. The RBS-R appears to be a very promising rating tool in this area, as it is the only rating instrument that appears to capture the full range of RRB that are found in individuals with autism. Therefore, the primary objective of the present study was to assess the factor structure and some psychometric characteristics of the RBS-R in an independent sample of individuals with autism spectrum disorders. It was hypothesized that the six-factor structure of the RBS-R would be confirmed via exploratory factor analysis. Secondary Objectives There were also several secondary objectives of this study. The first was to add dimensions of frequency, distress upon interruption, and interference to each subscale of the RBS-R using visual analogue scaling (VAS). These dimensions have been used in other scales that assess repetitive and/or compulsive behavior (Y-BOCS, Goodman et al., 1989; CY-BOCS, Scahill et al., 1997) and have allowed for more specific information about the severity and impact of these problem behaviors. The addition of these items could potentially make the RBS-R more sensitive to treatment effects. It was hypothesized that these dimensions would correlate with each other to some degree; in particular, the frequency and interference measures might overlap considerably, while distress might be a more distinct dimension. In a scale assessing a variety of problem behaviors (SIB, stereotypy, and aggression) in mental retardation, Rojahn and colleagues found that ratings of frequency and severity were highly correlated and did not yield any additional information (Rojahn, Matson, Lott, Esbensen, & Smalls, 2001). However, 19

33 repetitive behaviors found in autism may have an affective component, so it was thought that the inclusion of distress upon interruption might yield additional information. An additional secondary objective was to determine if there were any patterns of repetitive behavior that were moderated by the following variables: (a) severity of autism, (b) level of mental retardation, (c) type of autism spectrum disorder, (d) age, (e) sex, (f) medication use, (g) co-morbid behavioral problems, and (h) family history of mood disorders. In line with previous research (Militerni, Bravaccio, Falco, Fico, & Palermo, 2002), it was expected that a direct relationship between severity of autism and amount of repetitive behavior would be found, with the most severe cases of autism having the highest scores on the RBS-R. With regard to level of mental retardation, I hypothesized that degree of cognitive impairment would be related to types of repetitive behaviors shown, with higher-functioning individuals displaying more higher-order repetitive behaviors (such as restricted interests and compulsions) whereas individuals with more severe intellectual impairment would display more lower-order behaviors (such as stereotypies and self-injury) (Turner, 1999). In addition, as suggested by previous studies (Berkson, McQuiston, Jacobson, Eyman, & Borthwick, 1985; Rojahn, Tassé, & Morin, 1998), I expected age to show a curvilinear relationship with repetitive behavior, with the highest levels occurring during adolescence. It was difficult to predict the effect medication use would have on repetitive behavior as measured in this study. However, I examined this variable due to the likelihood that a sizable proportion of the sample would be taking some form of psychoactive medication. In a recent survey of over 1,500 individuals with autism, it was found that nearly 46% of the sample was taking a psychoactive drug, with 20

34 antidepressants, antipsychotics, and stimulants being the most commonly-prescribed agents, respectively (Langworthy-Lam, Aman, & Van Bourgondien, 2002). It is quite possible that medication affects repetitive behaviors; for example, antipsychotics may help decrease stereotypic behaviors (Aman, 1997) while antidepressants may help to treat ritualistic behaviors (Aman, Arnold, & Armstrong, 1999). However, without access to the prescribing physicians intent, it was difficult to postulate what effect a given medication may have. Furthermore, it was unlikely that the majority of caregivers would have accurate knowledge of the reasons certain medications were administered. This is a limitation of this study. In the absence of information on prescriber intent, I predicted that there would be no significant relationship between medication use and repetitive behaviors. Psychiatric and behavioral symptoms beyond the core characteristics of autism occur at high rates (Tsai & Ghaziuddin, 1996). For example, researchers have found rates of anxiety in individuals with autism to range between 7 and 84% (Lainhart, 1999). Attentional problems have been observed in 21-72% of subjects with autism (Lainhart, 1999), whereas estimates of depressed mood, irritability, agitation, and inappropriate affect have ranged between 9 and 44% (Tsai & Ghaziuddin, 1996). Based on the rationale that repetitive behaviors may fall into an obsessive-compulsive spectrum, a positive relationship between co-morbid anxiety and reported repetitive behavior was expected. In a similar vein, I hypothesized that the presence of obsessive-compulsive disorder (OCD) or an anxiety disorder in an immediate family member (i.e., within the nuclear family) might be related with amount of repetitive behavior shown, given the evidence for a genetic component in anxiety disorders (e.g., Cavallini, et al., 1999; 21

35 Alsobrook, et al., 1999). It should be noted, however, that any relationship between mood disorders in the family and repetitive behaviors in individuals with autism does not assume causality in any direction. For example, it is possible that the presence of psychiatric difficulties in family members could be due to biological factors and/or the stress caused by caring for an autistic family member (Lainhart, 1999). The following chapter describes the procedures used to test these predictions. 22

36 CHAPTER 3 METHOD Participants The participants in the factor analytic study of the RBS-R were individuals with autism spectrum disorders (ASDs) whose parents or caregivers were members of the South Carolina Autism Society (SCAS). There were several reasons why the study was conducted within the SCAS. First, it was important that the sample used for the factor analytic analyses be reasonably diverse. The Autism Society of America (ASA) seems to have a large membership that reflects families throughout the country with one or more members having autistic disorder. However, it is certainly possible that ASA members may be more committed to care, better educated, and perhaps better informed than the entire population of families in this country having a member with autism. Variability in age, sex, level of mental retardation, severity of autism, and other subject characteristics was also important in order to elucidate any relationships between these demographic variables and patterns of repetitive behavior. The Autism Society of America and their numerous state chapters have become one of the leading sources of information and referral for individuals with autism. These societies do not advocate for one particular theory or philosophy. Therefore, their membership often represents a broad and diverse 23

37 sampling of individuals with autism and their families, which makes them ideal for surveys of this type. In addition, a relatively large sample was needed in order to obtain the number of responses necessary for a well-powered factor analysis. At the time of this survey, the SCAS had a mailing list for parents and caregivers of people with autism that totaled 1,245 individuals. Anticipating a response rate of approximately 30% in this sample would allow for a robust sample size. Due to Health Insurance Portability and Accountability Act (HIPAA) regulations, Autism Societies at the time of the study were prohibited from releasing their mailing lists to anyone outside their organization. Therefore, HIPAA regulations limited possible participating groups in this study to agencies who had the resources to affix mailing labels at their own site. The SCAS was willing to invest some of their staffing time to assist with this task, which made them a good group with which to conduct the study. In addition to the factor analytic study, interrater reliability ratings were obtained from pairs of caregivers of individuals with ASDs. These participants were recruited from the psychopharmacological research databases at the Nisonger Center, through the Autism Society of Ohio, and from the J. Iverson Riddle Developmental Center in Western North Carolina. For the purposes of obtaining reliability, I did not feel that a random sample was essential. These samples are considered exemplary of what one might find in general when assessing reliability. 24

38 Instrument. The Repetitive Behavior Scale Revised (RBS R) is a 43-item questionnaire intended to assess six dimensions of repetitive behavior (Stereotyped Behavior, Self- Injurious Behavior, Compulsive Behavior, Ritualistic Behavior, Sameness Behavior, and Restricted Behavior). Items are rated on a four-point Likert scale ranging from (0) behavior does not occur to (3) behavior occurs and is a severe problem. At the end of each subscale, questions on frequency, interference, and distress upon interruption were added for this study using a visual analogue scaling (VAS) method, which involved horizontal lines, 100 mm in length, anchored by word descriptors at each end. Respondents were asked to place a mark somewhere along the line to indicate their response to each VAS item. The scores for these items was then determined by measuring in millimeters from the left side of the line to the point that the respondents marked. A VAS approach was chosen for these experimental items as it has shown to be a simple and sensitive method for assessing subjective feelings and experiences (Boogaerts, et al., 2000; Huskinsson, 1974). Lastly, an all-encompassing summary score (called the Global Severity Score) was added to the end of the scale, where participants were asked to rate, in a global sense, how much of a problem these repetitive behaviors were on a scale ranging from 1 to 100 (where 1 = not a problem at all, and 100 = as bad as you can imagine). In order to assess the effects of subject variables on repetitive behavior, brief demographic questions on age, sex, type of autism spectrum disorder (autistic disorder, Asperger s disorder, Pervasive Developmental Disorder Not Otherwise Specified), severity of autism, level of mental retardation, educational placement, medication use, 25

39 comorbid behavioral problems (including anxiety, aggression, depression, irritability, and overactivity), and family history of mood disorders were included. A copy of the modified instrument used for this study can be found in Appendix B. Procedures. Prior to starting the survey, approval was obtained from Ohio State University s Behavioral and Social Sciences Institutional Review Board, as well as from the SCAS and the J. Iverson Riddle Developmental Center. The president of the Ohio Autism Society also agreed to distribute information about the survey via the Ohio ASA membership listserv. For the main factor analytic study, 1245 mailings were assembled in stamped, sealed envelopes and then sent to the SCAS, where staff members affixed mailing labels and sent them to their parent mailing list. Each mailing included the following: (a) a personally signed cover letter, (b) the questionnaire, (c) three dollars in cash, and (d) a business reply envelope. Among other things, the cover letter explained the purpose of the study, the advantages of obtaining a high response rate, an assurance that the main results of the study would appear in the South Carolina Autism Society s newsletter, and the fact that all results were anonymous. In addition, each mailing contained an insert on brightly-colored paper asking professionals or individuals who were not caregivers of an individual with autism spectrum disorder to return the blank questionnaire to us with either professional or no autism written at the top. 26