Severity Of Repetitive Behaviors Research Articles

The Relationship Between Augmentative and Alternative Communication Use by Pediatric Psychiatric Inpatients With Autism Spectrum Disorder and Interfering Behaviors.

Previous research conducted by Williams et al. (2018) using data from the Autism Inpatient Collection (AIC) found a weak and inconsistent association between verbal ability and the severity of interfering behaviors; however, adapting/coping scores were significantly associated with self-injury, stereotypy, and irritability (including aggression and tantrums). The previous study did not account for access to or use of alternative forms of communication in their sample population. This study uses retrospective data to investigate the association between verbal ability and augmentative and alternative communication (AAC) use and the presence of interfering behaviors in individuals with autism who have complex behavioral profiles. The sample included 260 autistic inpatients, ages 4-20 years, from six psychiatric facilities, enrolled during the second phase of the AIC when detailed information about AAC use was collected. Measures included AAC use, method, and function; comprehension and production of language; receptive vocabulary; nonverbal IQ; severity of interfering behaviors; and the presence and severity of repetitive behaviors. Lower language/communication abilities were related to increased repetitive behaviors and stereotypies. More specifically, these interfering behaviors appeared to be related to communication in those individuals who were candidates for AAC but who were not reported to have access to it. Although the use of AAC did not predict a decrease in interfering behaviors, receptive vocabulary scores-as measured by the Peabody Picture Vocabulary Test-Fourth Edition-were positively correlated with the presence of interfering behaviors in participants with the most complex communication needs. The communication needs of some individuals with autism may be unmet, prompting the use of interfering behaviors as a form of communication. Further investigation of the functions of interfering behaviors and the related functions of communication skills may provide greater support for an increased focus on the provision of AAC to prevent and ameliorate interfering behaviors in individuals with autism.

Multidimensional motor performance in children with autism mostly remains stable with age and predicts social communication delay, language delay, functional delay, and repetitive behavior severity after accounting for intellectual disability or cognitive delay: A SPARK dataset analysis.

When motor difficulties continue into adolescence/adulthood, they could negatively impact an individual with autism spectrum disorder (ASD)'s daily living skills, physical fitness, as well as physical and mental health/well-being. Few studies have examined motor difficulties in children with ASD as a function of sex or age; however, greater cognitive challenges are associated with worse general motor performance. Based on the Developmental Coordination Disorder-Questionnaire (DCD-Q) data from the SPARK study sample, 87%-88% children with ASD were at-risk for a general motor impairment that persisted until 15 years and was related to their core and co-occurring difficulties. Bhat et al. confirmed motor difficulties in children with ASD on multiple motor dimensions that predicted core and co-occurring conditions after accounting for age and sex. However, presence of intellectual disability (ID) or cognitive delay was not controlled in the previous analysis. Additionally, the effects of age, sex, and cognitive ability on multidimensional motor difficulties of the SPARK sample have not been discussed before. Therefore, this analysis examines the effects of age, sex, and cognitive ability (presence of ID or level of cognitive delay) on the motor performance of children from the SPARK sample using the DCD-Q. Except fine motor skills, multiple motor domains did not change with age in children with ASD. Females without ID improved their fine motor scores with age, and performed better compared to males without ID. Children with ASD and ID had greater motor difficulties across multiple motor domains than those without ID. Even after controlling for age, sex, and presence of ID/cognitive delay; motor performance was predictive of social communication skills, repetitive behavior severity, as well as language and functional delays. Gross motor skills contributed more than fine motor and general motor competence skills in predicting social communication delay. However, fine motor and general motor competence skills contributed more than gross motor skills in predicting repetitive behavior severity and language delay. Both, fine and gross motor skills predicted functional delay. In light of consistent findings on motor difficulties in children with ASD, adding motor issues as a specifier within the ASD definition could provide a clear clinical route for movement clinicians to address motor difficulties of individuals with ASD.

A further study of relations between motor impairment and social communication, cognitive, language, functional impairments, and repetitive behavior severity in children with ASD using the SPARK study dataset.

Motor impairments are pervasive and persistent in children with autism spectrum disorder (ASD) throughout childhood and adolescence. Based on recent studies examining motor impairments in children with ASD between 5 and 15 years (i.e., SPARK study sample), 87-88% of this population is at-risk for a motor impairment, these problems persisted until 15 years, and related to their core (social communication skills and repetitive behaviors [RBs]) and comorbid (language, cognitive, and functional) impairments. Persistent motor impairments extending into adolescence/adulthood could negatively impact their independent daily living skills, physical fitness/activity levels, and physical/mental health. While multiple studies have examined relations between motor dimensions and core/comorbid impairments in young children with ASD, few studies have examined such relations in school-age children/adolescents with ASD. This paper conducts a further multidimensional study of which motor domains (i.e., gross-motor including visuo-motor or multilimb coordination/planning, fine motor [FM] or general coordination [GC] skills) best distinguish subgroups of school-age children/adolescents with ASD and help predict core and comorbid impairments after accounting for age and sex. Visuomotor, FM and certain GC skills were better at explaining variations in/predicting social communication impairments whereas FM skills were slightly better at explaining variations in/predicting RB severity. Multilimb coordination/planning and FM skills explained variations in/predicted cognitive delays whereas visuomotor and FM skills explained variations in and better predicted language delays. All three motor dimensions explained variations in/predicted functional delays. This study provides further evidence for inclusion of motor impairments within the ASD definition (criteria or specifiers). LAY SUMMARY: Gross-motor skills were related to social communication and functional delays of children with ASD (visuomotor skills related to language delays and multilimb coordination/planning skills related to cognitive delays). Fine-motor skills were related to repetitive behavior severity, language, cognitive, and functional delays in ASD. Diagnosticians should recommend systematic motor screening, further evaluations, and treatments for children at-risk for and diagnosed with ASD. Motor advocacy and enhanced public/clinical community awareness is needed to fulfill the unmet motor needs of children with ASD.

Relationship between Sensory Alterations and Repetitive Behaviours in Children with Autism Spectrum Disorders: A Parents' Questionnaire Based Study.

The relationship between sensory profile and repetitive behaviours in autism spectrum disorder (ASD) has long been known. However, there is no consensus on the type of relationship that exists between them. This monocentric retrospective–prospective observational study aimed (a) to detect a clinical correlation between the severity of repetitive behaviours and the alterations of sensory profile in a sample of 50 children diagnosed with ASD; (b) to evaluate how different patterns of stereotypies and sensory alterations correlate with each other and with the main clinical–instrumental variables in the same sample. We enrolled 29 children in the retrospective phase of the study and 21 in the prospective phase. The Repetitive Behaviour Scale-Revised (RBS-R) and the Short Sensory Profile (SSP) were administered to the caregivers, and clinical–instrumental data were collected. SSP and RBS-R total scores directly correlated with a high significance rate. Among the subscales, the strongest correlations involved “Visual/Auditory Sensitivity”, related to “Stereotyped Behaviour” and “Sameness Behaviour”. “Under-Responsive/Seeks Sensation” related to “Stereotyped Behaviour”. Sex and intellectual disability significantly influenced both the stereotypies and the sensory alterations of the examined population. In conclusion, this study provides new insights into the relationship between sensory alterations and repetitive behaviours in ASD children by using direct medical observation and parent observation.

Motor Impairment Increases in Children With Autism Spectrum Disorder as a Function of Social Communication, Cognitive and Functional Impairment, Repetitive Behavior Severity, and Comorbid Diagnoses: A SPARK Study Report.

Eighty-seven percent of a large sample of children with autism spectrum disorder (ASD) are at risk for motor impairment (Bhat, Physical Therapy, 2020, 100, 633-644). In spite of the high prevalence for motor impairment in children with ASD, it is not considered among the diagnostic criteria or specifiers within DSM-V. In this article, we analyzed the SPARK study dataset (n = 13,887) to examine associations between risk for motor impairment using the Developmental Coordination Disorder-Questionnaire (DCD-Q), social communication impairment using the Social Communication Questionnaire (SCQ), repetitive behavior severity using the Repetitive Behaviors Scale - Revised (RBS-R), and parent-reported categories of cognitive, functional, and language impairments. Upon including children with ASD with cognitive impairments, 88.2% of the SPARK sample was at risk for motor impairment. The relative risk ratio for motor impairment in children with ASD was 22.2 times greater compared to the general population and that risk further increased up to 6.2 with increasing social communication (5.7), functional (6.2), cognitive (3.8), and language (1.6) impairments as well as repetitive behavior severity (5.0). Additionally, the magnitude of risk for motor impairment (fine- and gross-motor) increased with increasing severity of all impairment types with medium to large effects. These findings highlight the multisystem nature of ASD, the need to recognize motor impairments as one of the diagnostic criteria or specifiers for ASD, and the need for appropriate motor screening and assessment of children with ASD. Interventions must address not only the social communication and cognitive/behavioral challenges of children with ASD but also their motor function and participation. LAY ABSTRACT: Eighty-eight percent of the SPARK sample of children with ASD were at risk for motor impairment. The relative risk for motor impairment was 22.2 times greater in children with ASD compared to the general population and the risk increased with more social communication, repetitive behavior, cognitive, and functional impairment. It is important to recognize motor impairments as one of the diagnostic criteria or specifiers for ASD and there is a need to administer appropriate motor screening, assessment, and interventions in children with ASD.

Repetitive Behavior Severity as an Early Indicator of Risk for Elevated Anxiety Symptoms in Autism Spectrum Disorder

A significant proportion of children with autism spectrum disorder (ASD) will develop an anxiety disorder during childhood. Restricted and repetitive behavior severity in ASD positively correlates with anxiety severity in cross-sectional surveys. The longitudinal relationship between restricted/repetitive behavior and future anxiety symptoms is unclear. In a longitudinal cohort of children with ASD (n= 421), restricted/repetitive behavior severity at enrollment (age 2-5 years) was categorized as "mild," "moderate," or "severe" using the Autism Diagnostic Interview-Revised. Elevated anxiety symptoms were defined by a Child Behavior Checklist (parent report) Anxiety subscale T-score of >65 at ages 8 to 11 years. Multivariable logistic regression with multiple imputation for missing data was used to examine the association between restricted/repetitive behavior severity and elevated anxiety symptoms while adjusting for age, sex, adaptive functioning, baseline anxiety, income, and parenting stress, generating adjusted odds ratios (aORs) and 95% CIs. Approximately 58% of children with severe restricted/repetitive behavior at enrollment had elevated anxiety symptoms by age 11, compared to 41% of those with moderate, and 20% of those with mild restricted/repetitive behavior, respectively. Moderate and severe restricted/repetitive behavior were both associated with increased odds of elevated anxiety (moderate aOR: 2.5 [1.2-5.3]; severe aOR: 3.2 (1.4-7.5]). Restricted/repetitive behavior severity at time of ASD diagnosis indicates risk for future anxiety symptoms. This finding increases our understanding of which children with ASD will develop anxiety disorders and may guide research concerning early interventions and etiological mechanisms.

Prevalence and predictors of psychotropic medication use in adolescents and adults with autism spectrum disorder in Italy: A cross-sectional study

Autism spectrum disorder (ASD) is a group of life-long neurodevelopmental conditions with a prevalence of 1.5% in developed countries. Beside core symptomatology, ASD people are frequently affected by psychiatric comorbidities and behavioral problems. To date, only risperidone and aripiprazole have been approved for the pharmacological treatment of ASD-associated irritability in children and adolescents, while no guidelines exist for adults. The present cross-sectional study examined the prevalence and predictors of psychotropic medication use in 195 autistic subjects, aged between 14 and 58, treated in two Italian tertiary care centers. 58.5% of the sample were taking at least one medication; one third of the sample were on polypharmacotherapy. Antipsychotics were prescribed to 40% of the sample. Nearly 30% of the sample were on anticonvulsants/mood stabilizers. Both antidepressants and benzodiazepines were prescribed to approximately 16% of the subjects. IQ, epilepsy and psychiatric comorbidities were regarded as independent predictors of both mono- and polypharmacotherapy, while severity of repetitive behaviors predicted only polypharmacotherapy. Our data highlighted that medications prescribed to adolescents and adults with ASD are heterogeneous and often rely only on clinicians’ experience. Future research should investigate the effectiveness of psychotropic drugs in this specific population, to promote the development of appropriate treatment guidelines.

The validity and reliability study of the Repetitive Behavior Scale-Revised- Turkish Version in autism spectrum disorder

Objective: One of the diagnosis criteria for autism spectrum disorders (ASD) is repetitive behaviors and the severity of the repetitive behaviors is an important variable in identifying the severity of the disorder as well. In the current study the Repetitive Behavior Scale-Revised (RBS-R-TV), which is used to assess the severity and types of re-petitive behaviors in individuals with ASD, is adapted to Turkish and psychometric characteristics of the Turkish form are examined. Method: The participants consisted of 292 individuals with ASD, who were 3 to 23 years old (M=240, F=52). The parents of the participant individuals were asked to fill the RBS-R-TV. The ASD diagnosis of the participants were confirmed by Gilliam Autism Rating Scale-2-Turkish Form (TV-GARS-2). To measure validity of the scale; content, construct, criterion, and predictive validity analyses were conducted, and for reliability the scale’s internal consistency was examined by calculating the Cronbach’s alpha coefficients. Findings: The analyses showed that RBS-R-TV has good content validity, confirmatory factor analysis (CFA) revealed that it has a six factor structure, and model fit indices showed a good fit (χ2/df=2.00, RMSEA=0.059, SRMR=0.067, NNFI=0.94, CFI=0.94). Discriminant validity indicated that children with ASD had significantly higher scores than the children with intellectual disabilities in RBS-R-TV and predictive validity analysis showed that total scores obtained from RBS-R-TV significantly predicted the severity of autistic disorder. As the reliability analysis, internal consistency coefficients were between 0.73 to 0.94 for sub scales and the total score. Discussion: Analyses showed that RBS-R-TV is a valid and reliable tool for the use of diagnosticians, researchers, and educators.

Dissecting the Heterogeneous Cortical Anatomy of Autism Spectrum Disorder Using Normative Models

BackgroundThe neuroanatomical basis of autism spectrum disorder (ASD) has remained elusive, mostly owing to high biological and clinical heterogeneity among diagnosed individuals. Despite considerable effort toward understanding ASD using neuroimaging biomarkers, heterogeneity remains a barrier, partly because studies mostly employ case-control approaches, which assume that the clinical group is homogeneous. MethodsHere, we used an innovative normative modeling approach to parse biological heterogeneity in ASD. We aimed to dissect the neuroanatomy of ASD by mapping the deviations from a typical pattern of neuroanatomical development at the level of the individual and to show the necessity to look beyond the case-control paradigm to understand the neurobiology of ASD. We first estimated a vertexwise normative model of cortical thickness development using Gaussian process regression, then mapped the deviation of each participant from the typical pattern. For this, we employed a heterogeneous cross-sectional sample of 206 typically developing individuals (127 males) and 321 individuals with ASD (232 males) (6–31 years of age). ResultsWe found few case-control differences, but the ASD cohort showed highly individualized patterns of deviations in cortical thickness that were widespread across the brain. These deviations correlated with severity of repetitive behaviors and social communicative symptoms, although only repetitive behaviors survived corrections for multiple testing. ConclusionsOur results 1) reinforce the notion that individuals with ASD show distinct, highly individualized trajectories of brain development and 2) show that by focusing on common effects (i.e., the “average ASD participant”), the case-control approach disguises considerable interindividual variation crucial for precision medicine.

Volumetric Analysis of the Basal Ganglia and Cerebellar Structures in Patients with Phelan-McDermid Syndrome

Phelan-McDermid syndrome is caused by haploinsufficiency of SHANK3 on terminal chromosome 22. Knowledge about altered neuroanatomic circuitry in Phelan-McDermid syndrome comes from mouse models showing striatal hypertrophy in the basal ganglia, and from humans with evidence of cerebellar atrophy. To date, no studies have performed volumetric analysis on Phelan-McDermid syndrome patients. We performed volumetric analysis of baseline brain MRIs of Phelan-McDermid syndrome patients (ages three to 21 years) enrolled in a prospective natural history study (ClinicalTrials.gov NCT02461420). Using MRI segmentations carried out with PSTAPLE algorithm, we measured relative volumes (volume of the structure divided by the volume of the brain parenchyma) of basal ganglia and cerebellar structures. We compared these measurements to those of age- and sex-matched healthy controls part of another study. Among the patients, we performed linear regression of each relative volume using Repetitive Behavior Scale-Revised total score and Aberrant Behavior Checklist stereotypy score. Eleven patients with Phelan-McDermid syndrome (six females, five males) and 11 healthy controls were in this analysis. At time of MRI, the mean age of the patients and controls was 9.24 (5.29) years and 9.00 (4.49) years, respectively (P = 0.66). Compared to controls, patients had decreased caudate (P ≤ 0.013), putamen (P ≤ 0.026), and left pallidum (P = 0.033) relative volumes. Relative volume of cerebellar vermal lobules I to V (beta coefficient = -17119, P = 0.017) decreased with increasing Repetitive Behavior Scale-Revised total score. The volumes of the striatum and left pallidum are decreased in individuals with Phelan-McDermid syndrome. Cerebellar vermis volume may predict repetitive behavior severity in Phelan-McDermid syndrome. These findings warrant further investigation in larger samples.

Feasibility of a play-based intervention set for toddlers with autism

The Meta-play Method is a play-based, naturalistic set of interventions designed to decrease the symptoms associated with autism in toddlers. The purpose of the present study was to explore the feasibility of using this intervention set with a small group of toddlers and their parents. We selected seven toddlers diagnosed with autism and tested these children for autism severity and severity of repetitive behaviors. Parents were trained on the basic concepts of DBTA and the Meta-play activities. Researchers reviewed the integrity of interventions at once- or twice-monthly home visits for a six-month period, and recorded progress as rated by the parent. Activities were adapted at each visit to the interests and progress of the participating toddler. At the end of six months, autism symptoms and repetitive behavior decreased and parents reported high levels of social validity. Additional aspects of data collection and outcome measures, and suitability of interventions and procedures are discussed. While some outcomes were encouraging, a number of changes are recommended for future research.

Factors associated with DSM-5 severity level ratings for autism spectrum disorder.

The newest edition of the Diagnostic and Statistical Manual of Mental Disorders (5th ed., DSM-5) introduced substantial changes to the diagnostic criteria for autism spectrum disorder, including new severity level ratings for social communication and restricted and repetitive behavior domains. The purpose of this study was to evaluate the use of these new severity ratings and to examine their relation to other measures of severity and clinical features. Participants included 248 children with autism spectrum disorder who received diagnostic evaluations at one of six Autism Treatment Network sites. Higher severity ratings in both domains were associated with younger age, lower intelligence quotient, and greater Autism Diagnostic Observation Schedule-Second Edition domain-specific symptom severity. Greater restricted and repetitive behavior severity was associated with higher parent-reported stereotyped behaviors. Severity ratings were not associated with emotional or behavioral problems. The new DSM-5 severity ratings in both domains were significantly associated with behavioral observations of autism severity but not with measures of other behavioral or emotional symptoms. However, the strong associations between intelligence quotient and DSM-5 severity ratings in both domains suggest that clinicians may be including cognitive functioning in their overall determination of severity. Further research is needed to examine clinician decision-making and interpretation of these specifiers.

Child and Adult Factors Related to Quality of Life in Adults with Autism

The WHO Quality of Life-Brief questionnaire was used to assess quality of life (QoL) among 52 adults with autism (mean age 49 years) followed-up since childhood. Overall, assessments of QOL were more positive than measures of objective social outcome (jobs, independence, relationships etc.) but correlations between caregiver and self-reports were low. Informant ratings indicated few correlations between current QoL and any child or adult factors. On self-report ratings, QoL was significantly negatively correlated with severity of repetitive behaviours in childhood; higher QoL was positively associated with better adult social outcomes. However, only a minority of adults (n = 22) could provide self-report data and findings highlight the need to develop valid measures for assessing the well-being of adults with autism.

Attention to novelty versus repetition: Contrasting habituation profiles in Autism and Williams syndrome

BackgroundAbnormalities in habituation have been documented in Autism Spectrum Disorder (ASD) and Williams syndrome (WS). Such abnormalities have been proposed to underlie the distinctive social and non-social difficulties that define ASD, including sensory features and repetitive behaviours, and the distinctive social phenotype characterizing WS. MethodsWe measured habituation in 39 preschoolers with ASD, 20 peers with WS and 19 typically developing (TD) children using an eye-tracking protocol that measured participants’ duration of attention in response to a repeating stimulus and a novel stimulus presented side by side across multiple trials. ResultsParticipants in the TD group and the WS group decreased their attention toward the repeating stimulus and increased their attention to the novel stimulus over time. Conversely, the ASD group showed a similar attentional response to the novel and repeating stimuli. Habituation was correlated with social functioning in the WS but not in the ASD group. Contrary to predictions, slower habituation in ASD was associated with lower severity of repetitive behaviours. ConclusionsHabituation appears to be intact in WS and impaired in ASD. More research is needed to clarify the nature of the syndrome-specific patterns of correlations between habituation and social and non-social functioning in these neurodevelopmental disorders.

Superior Disembedding Performance in Childhood Predicts Adolescent Severity of Repetitive Behaviors: A Seven Years Follow-Up of Individuals With Autism Spectrum Disorder.

Previous research suggests that individuals with autism spectrum disorder (ASD) show a detail-focused cognitive style. The aim of the current longitudinal study was to investigate whether this detail-focused cognitive style in childhood predicted a higher symptom severity of repetitive and restrictive behaviors and interests (RRBI) in adolescence. The Childhood Embedded Figures Test (CEFT) and the Autism Diagnostic Observation Schedule (ADOS) were administered in 87 children with ASD at the age of 6-12 years old (T1), and the ADOS was readministered 7 years later when the participants were 12-19 years old (T2). Linear regression analyses were performed to investigate whether accuracy and reaction time in the complex versus simple CEFT condition and performance in the complex condition predicted T2 ADOS RRBI calibrated severity scores (CSS), while taking into consideration relevant covariates and ADOS RRBI CSS at T1. The CEFT performance (accuracy in the complex condition divided by the time needed) significantly predicted higher ADOS RRBI CSS at T2 (ΔR(2) = 15%). This finding further supports the detail-focused cognitive style in individuals with ASD, and shows that it is also predictive of future RRBI symptoms over time.

Future Target of Treatment for Social Impairment of Autism Spectrum Disorders

Impairment in social and communication function is the core symptoms of autism spectrum disorder (ASD). ASD is a common neurodevelopmental disorder affecting approximately 1% of children. The ability to understand emotion in others is essential for the health development of human. Abnormalities of emotion perception may contribute to psychiatric disorders associated with social problems in ASD. There are no known efficacious treatments for the core social impairment although effects such as risperidone and aripiprazole, and selective serotonin reuptake inhibitors (SSRI) have reported their efficacy in the treatment of disruptive repetitive behaviors [1]. Number of antipsychotic drugs such as risperidone and aripiprazole, and selective serotonin reuptake inhibitors (SSRI) have reported their efficacy in the treatment of disruptive repetitive behaviors [1], however, some adverse effects, particularly weight gain, fatigue, agitation, irritability [1] and tardive dyskinesia (Research Units on Pediatric Psychopharmacology Autism Network 2002) are also associated with these drugs. Amitriptyline has been found instrumental for treatmentresistant youth with ASD accompanied by behavioral symptoms (Bhatti et al. 2012). The use of neuropeptide oxytocin has marked its affectivity in reducing the severity of repetitive behaviors; however, this affectivity was found to last only for a short period of 240 minutes after its infusion (Hollander et al. 2003). There still lies a dearth of any such drugs that can commonly used be used for the treatment of the core social and communication impairment that are the hallmark of ASD.

Standardizing ADOS domain scores: separating severity of social affect and restricted and repetitive behaviors.

Standardized Autism Diagnostic Observation Schedule (ADOS) scores provide a measure of autism severity that is less influenced by child characteristics than raw totals (Gotham et al. in Journal of Autism and Developmental Disorders, 39(5), 693-705 2009). However, these scores combine symptoms from the Social Affect (SA) and Restricted and Repetitive Behaviors (RRB) domains. Separate calibrations of each domain would provide a clearer picture of ASD dimensions. The current study separately calibrated raw totals from the ADOS SA and RRB domains. Standardized domain scores were less influenced by child characteristics than raw domain totals, thereby increasing their utility as indicators of Social-Communication and Repetitive Behavior severity. Calibrated domain scores should facilitate efforts to examine trajectories of ASD symptoms and links between neurobiological and behavioral dimensions.

Brief Report: Glutamate Transporter Gene (SLC1A1) Single Nucleotide Polymorphism (rs301430) and Repetitive Behaviors and Anxiety in Children with Autism Spectrum Disorder

Investigated association of single nucleotide polymorphism (SNP) rs301430 in glutamate transporter gene (SLC1A1) with severity of repetitive behaviors (obsessive-compulsive behaviors, tics) and anxiety in children with autism spectrum disorder (ASD). Mothers and/or teachers completed a validated DSM-IV-referenced rating scale for 67 children with autism spectrum disorder. Although analyses were not significant for repetitive behaviors, youths homozygous for the high expressing C allele had more severe anxiety than carriers of the T allele. Allelic variation in SLC1A1 may be a biomarker for or modifier of anxiety symptom severity in children with ASD, but study findings are best conceptualized as tentative pending replication with larger independent samples.

A Comparison of Repetitive Behaviors in Aspergers Disorder and High Functioning Autism

In this study we compared 33 IQ and age matched pairs of individuals with Aspergers Disorder (ASP) and high functioning autism (HFA) on measures of repetitive behavior. On the Repetitive Behavior Scale-Revised (RBS-R), the ASP and HFA groups showed no differences in RBS-R Intensity score (severity) score or Frequency score (number of problems present). This suggests that the two groups are similar with respect to the intensity or severity of repetitive behaviors and the presence of repetitive behaviors. At the item level there were no differences on scales typically associated with autism (Stereotyped Behavior) and ASP (Restricted Interests). Similarly, there were no differences between the groups on the Aberrant Behavior Checklist Stereotypy scale. These findings add to the body of literature showing that HFA and ASP fail to differ with respect to repetitive behaviors. The implications of the findings for neurobiologic and genetic studies are discussed.

Striatal Volume on Magnetic Resonance Imaging and Repetitive Behaviors in Autism

The repetitive behaviors seen in autism phenotypically resemble those seen in obsessive-compulsive disorder (OCD) and Tourette Syndrome (TS), disorders in which structural and functional abnormalities of the basal ganglia (BG) are present and correspond to the severity of repetitive behaviors. Seventeen subjects with autism by DSM-IV and Autism Diagnostic Interview (ADI) and 17 matched controls completed a 1.5 T magnetic resonance image (MRI) of the brain. Two blinded researchers, with good inter-rater reliability, outlined the right and left caudate and putamen. Autistic and control BG volumes covaried for total brain volume were compared using analysis of covariance. BG volumes within the autistic group were correlated with the ADI Repetitive Behavior scores (ADI-C domain). Right caudate volume controlled for total brain volume was significantly larger in autistic subjects than in controls. In addition, right caudate and total putamen volumes correlated positively with repetitive behavior scores on the ADI-C domain, particularly the higher order OCD-like repetitive behaviors. Increased right caudate volume in autism is of interest, since this has also been observed in OCD patients. Increased volume of the right caudate and total putamen positively correlated with greater repetitive behaviors, supporting the hypothesis of BG dysfunction associated with repetitive behaviors in autistic adults.