Laura A. Carpenter

Potential Impact of DSM-5 Criteria on Autism Spectrum Disorder Prevalence Estimates

IMPORTANCE The DSM-5 contains revised diagnostic criteria for autism spectrum disorder (ASD) from the DSM-IV-TR. Potential impacts of the new criteria on ASD prevalence are unclear. OBJECTIVE To assess potential effects of the DSM-5 ASD criteria on ASD prevalence estimation by retrospectively applying the new criteria to population-based surveillance data collected for previous ASD prevalence estimation. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional, population-based ASD surveillance based on clinician review of coded behaviors documented in childrens medical and educational evaluations from 14 geographically defined areas in the United States participating in the Autism and Developmental Disabilities Monitoring (ADDM) Network in 2006 and 2008. This study included 8-year-old children living in ADDM Network study areas in 2006 or 2008, including 644 883 children under surveillance, of whom 6577 met surveillance ASD case status based on the DSM-IV-TR. MAIN OUTCOMES AND MEASURES Proportion of children meeting ADDM Network ASD criteria based on the DSM-IV-TR who also met DSM-5 criteria; overall prevalence of ASD using DSM-5 criteria. RESULTS Among the 6577 children classified by the ADDM Network as having ASD based on the DSM-IV-TR, 5339 (81.2%) met DSM-5 ASD criteria. This percentage was similar for boys and girls but higher for those with than without intellectual disability (86.6% and 72.5%, respectively; P < .001). A total of 304 children met DSM-5 ASD criteria but not current ADDM Network ASD case status. Based on these findings, ASD prevalence per 1000 for 2008 would have been 10.0 (95% CI, 9.6-10.3) using DSM-5 criteria compared with the reported prevalence based on DSM-IV-TR criteria of 11.3 (95% CI, 11.0-11.7). CONCLUSIONS AND RELEVANCE Autism spectrum disorder prevalence estimates will likely be lower under DSM-5 than under DSM-IV-TR diagnostic criteria, although this effect could be tempered by future adaptation of diagnostic practices and documentation of behaviors to fit the new criteria.

Enhanced Cortisol Response to Stress in Children in Autism.

Children with Autism often show difficulties in adapting to change. Previous studies of cortisol, a neurobiologic stress hormone reflecting hypothalamic–pituitary–adrenal (HPA) axis activity, in children with autism have demonstrated variable results. This study measured cortisol levels in children with and without Autism: (1) at rest; (2) in a novel environment; and (3) in response to a blood draw stressor. A significantly higher serum cortisol response was found in the group of children with autism. Analysis showed significantly higher peak cortisol levels and prolonged duration and recovery of cortisol elevation following the blood-stick stressor in children with autism. This study suggests increased reactivity of the HPA axis to stress and novel stimuli in children with autism.

Changes in autism spectrum disorder prevalence in 4 areas of the United States

BACKGROUND We sought to describe autism spectrum disorder (ASD) population characteristics and changes in identified prevalence across 3 time periods. METHODS Children with a potential ASD were identified through records abstraction at multiple sources with clinician review based on Diagnostic and Statistical Manual (DSM-IV-TR) criteria. Multisite, population-based data from the Autism and Developmental Disabilities Monitoring (ADDM) Network were analyzed from areas of Arizona (AZ), Georgia (GA), Maryland (MD), and South Carolina (SC). Participants were 8-year-old children (born in 1992, 1994, or 1996) in 2000, 2002, or 2004 (and children born in 1988 residing in metropolitan Atlanta in 1996) who had been evaluated for a variety of developmental concerns at education and/or health sources. RESULTS From 2000 to 2004, the identified prevalence of the ASDs per 1,000 8-year-old children showed significant increases of 38% in GA and 72% in MD and a nonsignificant increase of 26% in AZ. ASD prevalence was relatively stable in SC with a nonsignificant decrease of 17%. Males had a higher identified prevalence of ASD in all years. Increases among racial, ethnic, and cognitive functioning subgroups varied by site and surveillance year. More children were classified with an ASD by community professionals over time, except in AZ. CONCLUSIONS There was a trend toward increase in identified ASD prevalence among 8-year-old children who met the surveillance case definition in 3 of the 4 study sites from 2000 to 2004. Some of the observed increases are due to improved ascertainment; however, a true increase in ASD symptoms cannot be ruled out. These data confirm that the prevalence of ASDs is undergoing significant change in some areas of the United States and that ASDs continue to be of urgent public health concern.

High Prescription Drug Use and Associated Costs among Medicaid-Eligible Children with Autism Spectrum Disorders Identified by a Population-Based Surveillance Network

PURPOSE We assessed medication use and associated costs among 8- and 15-year-old children with autism spectrum disorders (ASD) identified by the South Carolina Autism and Developmental Disabilities Monitoring (SCADDM) Network. METHODS All Medicaid-eligible SCADDM-identified children with ASD from surveillance years 2006 and 2007 were included (n = 263). Children were classified as ASD cases when documented behaviors consistent with the DSM-IV-TR criteria for autistic disorder, Asperger disorder, or pervasive developmental disorder-not otherwise specified were present in health and education evaluation records. Medication and cost data were obtained by linking population-based and Medicaid data. RESULTS All 263 SCADDM-identified children had Medicaid data available; 56% (n = 147) had a prescription of any type, 40% (n = 105) used psychotropic medication, and 20% (n = 52) used multiple psychotropic classes during the study period. Common combinations were (1) attention deficit hyperactivity disorder medications and an antihypertensive, antidepressant or antipsychotic; and (2) antidepressants and an antipsychotic. Multiple psychotropic classes were more common among older children. Both the overall distribution of the number of prescription claims and medication costs varied significantly by age. CONCLUSIONS Results confirm that medication use in ASD, alone or in combination, is common, costly, and may increase with age.

Autism Spectrum Disorders in Preschool-Aged Children: Prevalence and Comparison to a School-Aged Population

PURPOSE The purpose of this study was to determine the prevalence and case characteristics of children with autism spectrum disorders (ASDs) among 4-year-olds and to compare findings to previous prevalence estimates for 8-year-olds in the same geographic area. METHODS South Carolina (SC) has been a participant in the Centers for Disease Control and Preventions active, population-based, multiple-site ASD surveillance network for 8-year-olds since 2000. The 8-year-old methodology, designed to identify children both with and without prior diagnosis, was applied in SC with modification to include information sources for younger children. RESULTS The ASD prevalence among 4-year-olds in 2006 was 8.0 per 1000 (95% confidence interval [CI], 6.1-9.9), or 1 in 125. In comparison, ASD prevalence among 8-year-olds in the same geographic area was 7.6 (95% CI, 5.7-9.5) in 2000 and 7.0 (95% CI 5.1-8.9) in 2002. Developmental concerns were documented at earlier ages across time, and while most cases received services, only 20% to 29% received services specific to ASD. CONCLUSIONS Findings should provide useful information for the planning of health/education policies and early intervention strategies for ASD.

The prevalence of youth with autism spectrum disorders in the criminal justice system.

Past surveys have reported high rates of youth with disabilities in the juvenile justice system, however, little research has examined the frequency with which youth with Autism spectrum disorders (ASD) are in contact with law enforcement. Using records linkage with the Department of Juvenile Justice and the South Carolina Law Enforcement Division and the South Carolina Autism and Developmental Disabilities Monitoring Program (SC ADDM), this study compares the frequency, type, and outcome of criminal charges for youth with ASD and non-ASD youth. Youth with ASD had higher rates of crimes against persons and lower rates of crimes against property. Youth with ASD were more likely to be diverted into pre-trial interventions and less likely to be prosecuted than comparison youth. When compared to the overall SC ADDM sample, charged youth were less likely to have comorbid intellectual disability.

Recent advances in autism spectrum disorders.

Objective: This review article provides an overview of the most recent developments in the literature regarding autism spectrum disorders including epidemiology, etiology, assessment, and management/treatment. Method: A review of the recent literature was conducted using Medline and the search term “Autism Spectrum Disorders.” Results: Autism Spectrum Disorders are more common than previously believed (1 in 166), and etiology appears to be multifaceted including both heritable and non-heritable factors. State of the art treatment includes comprehensive medical monitoring as well as behavioral intervention. Conclusions: Current and anticipated federal funding, policy changes, and large scale research projects provide promise for increasing knowledge about Autism Spectrum Disorders.

Aberrant Behaviors and Co-occurring Conditions as Predictors of Psychotropic Polypharmacy among Children with Autism Spectrum Disorders

OBJECTIVES The purpose of this study was to identify rates and predictors of psychotropic medication polypharmacy among Medicaid-eligible children in South Carolina with autism spectrum disorder (ASD) from 2000 to 2008. METHODS Population-based surveillance data were linked with state Medicaid records to obtain a detailed demographic, behavioral, educational, clinical, and diagnostic data set for all Medicaid-eligible 8-year-old children (n=629) who were identified and diagnosed with ASD using standardized criteria. Polypharmacy was defined as having interclass psychotropic medication claims overlapping for ≥30 consecutive days at any time during the 2-year study period. Multivariable logistic regression was used to model predictors of any polypharmacy, and for the three most common combinations. RESULTS Overall, 60% (n=377) used any psychotropic medication, and 41% (n=153) of those had interclass polypharmacy. Common combinations were attention-deficit/hyperactivity disorder (ADHD) medications with an antidepressant (A/AD), antipsychotic (A/AP) or a mood stabilizer (A/MS). Black children had lower odds of any polypharmacy, as did those eligible for Medicaid because of income or being foster care versus those eligible because of disability. There were no significant associations between polypharmacy and social deficits in ASD for any combination, although children with communication deficits diagnostic of ASD had lower odds of any polypharmacy and A/AP polypharmacy. Children with argumentative, aggressive, hyperactive/impulsive, or self-injurious aberrant behaviors had higher odds of polypharmacy, as did children with diagnosed co-occurring ADHD, anxiety or mood disorders, or conduct/oppositional defiant disorder (ODD) in Medicaid records. CONCLUSIONS Future research is warranted to investigate how child-level factors impact combination psychotropic medication prescribing practices and outcomes in ASD.

Factors Associated with Self-Injurious Behaviors in Children with Autism Spectrum Disorder: Findings from Two Large National Samples

In this study, we explored potential associations among self-injurious behaviors (SIB) and a diverse group of protective and risk factors in children with autism spectrum disorder from two databases: Autism and Developmental Disabilities Monitoring (ADDM) Network and the Autism Speaks-Autism Treatment Network (AS-ATN). The presence of SIB was determined from children’s records in ADDM and a parent questionnaire in AS-ATN. We used multiple imputation to account for missing data and a non-linear mixed model with site as a random effect to test for associations. Despite differences between the two databases, similar associations were found; SIB were associated with developmental, behavioral, and somatic factors. Implications of these findings are discussed in relation to possible etiology, future longitudinal studies, and clinical practice.

Pilot Study and Review: Physiological Differences in BDNF, a Potential Biomarker in Males and Females with Autistic Disorder

Aims There is a need for more biologic research in autistic disorder (AD) to determine if biomarkers exist that would be useful for correlating to symptom severity and/or clinical improvement during treatment. Given the fact that AD is 4 times more common in males than females, gender differences in physiological biomarkers may be present. One potential biomarker that has begun to be studied is brain-derived neurotropic factor (BDNF), a peptide involved in the regulation of neuronal cell survival, differentiation, and plasticity, and possessing an ability to influence neurotransmitter systems by modulating gene expression. This pilot study examined whether serum BDNF differed according to gender in children with AD and whether differences were associated with a behavioral phenotype or severity of illness. Study Design Data for this investigation were collected during the participants’ baseline visit of an intervention study. Participants were males (n=29) and females (n=7), aged 5 to 12 years diagnosed with AD. Baseline serum BDNF concentration was determined for comparison to clinical ratings using an autism severity measure and the Pervasive Developmental Disorder-Behavior Inventory (PDD-BI). Results BDNF serum concentrations were higher in females (p<0.049). The baseline BDNF value corresponded significantly to hyperactivity in females (p<0.0002) but not in males. BDNF did not correlate with severity of disease in either gender. Conclusion Although this is a small study, a better understanding of the central role of BDNF may provide insight into the pathophysiology of the disease and elucidate why gender differences exist in prevalence and behavioral phenotype of AD.