Summary of Advances
In Autism Spectrum Disorder Research
Effectiveness of developmental screening in an urban setting - Guevara JP, Gerdes M, Localio R, Huang YV, Pinto-Martin J, Minkovitz CS, Hsu D, Kyriakou L, Baglivo S, Kavanagh J, Pati S. Pediatrics. 2013 Jan;131(1):30–37. [PMID: 23248223]
Research suggests that early identification paired with early intervention leads to better outcomes in children with ASD. Currently, the number of children receiving early intervention (EI) services falls short of the number estimated to need them, suggesting that developmental issues are often not being identified in a timely manner. In the pediatrician's office, general developmental delays and specific conditions such as ASD can be caught either by developmental screening tools or by the general observations of parents and physicians. This study examined whether using developmental screening tools enabled quicker and more efficient identification of developmentally delayed children, and led to faster referral to EI services. The 2,092 children enrolled in this study belonged to four urban pediatric practices in the Philadelphia area, were mostly African-American, and were from households with an annual income of less than $30,000. Each child was randomly assigned to one of three treatment groups. In the first treatment group, parents filled out the Ages and Stages Questionnaire-II (ASQ-II) at the child's 9-, 13-, and 30-month well-baby visits, and the Modified Checklist for Autism in Toddlers (M-CHAT) at the 18- and 24-month visits. Both the ASQ-II and M-CHAT are questionnaires filled out by the parent to check for normal physical and social development, and the M-CHAT also contains questions that help screen specifically for ASD. The second treatment group was identical to the first, with the addition of assistance from the doctor's office staff in completing the questionnaires. The third group of children attended the same well-baby visits, but no specific screening tools were used, so identification relied upon the interactions and observations of the parent and physician. Results showed that developmentally delayed children who were screened using the ASQ-II and M-CHAT were about twice as likely to be identified, referred and found eligible for EI services as children who were not specifically screened. The study also found that screening did not over-identify, or create false positives among normally developing children when compared with surveillance alone. There were no significant differences between the outcomes for the children whose parents did or did not receive help on the surveys. These findings suggest that the use of specific screening tools greatly enhances the identification and referral of children for EI services. This study shows that use of these screening tools is effective in an urban, low-income population and suggests that more widespread use could ensure that children with developmental delays and specific conditions such as ASD have the best chance of early intervention.
Attention to eyes is present but in decline in 2-6-month-old infants later diagnosed with autism - Jones W, Klin A. Nature. 2013 Dec 19;504(7480):427-31. [PMID: 24196715]
A new study identifies signs of ASD that emerge in the first months of life. Within a few hours of being born, babies begin to focus their gaze on human faces, learning to pick up social cues by paying special attention to other people's eyes. Since ASD was first described, a disruption in this eye contact has been one of the key predictors that a child might have the condition, making this feature a strong component of many screeners and diagnostic tests. The question that arises is whether those with ASD are born with this lack of interest in looking at others' eyes, or if it is something that develops gradually over the first 2 years of life. Researchers prospectively studied high-risk infant siblings of children with ASD from birth until 3 years of age, using eye-tracking technology to measure the way they looked at and responded to videos of the faces of caregivers socially interacting with them. At 2 months of age, babies who were later diagnosed with ASD showed no difference in eye-looking compared to those who did not receive an ASD diagnosis. However, from 2 to 6 months of age, these babies showed an abrupt decline in attention to eyes, whereas those who did not go on to be diagnosed showed no such drop. This decrease in eye-looking continued throughout the course of the study, and by 24 months these children focused on the caregiver's eyes half as long as did their typically developing peers. This measurable difference, emerging from 2 months of age onwards, is the earliest sign of ASD ever observed in an ASD research study, and holds promise for the development of tools for early identification. Interestingly, since the difference only begins to develop after the 2-month mark, this finding disproves the hypothesis that eye contact in those with ASD is diminished from birth; it appears, instead, that social eye gaze starts out at normal levels and then declines. The timing of this decrease in eye contact highlights a developmental window that is central to the development of brain circuits involved in social cognition, and presents a potential target for early intervention strategies for ASD. If infants are identified before this decline in attention to social cues, interventions could build on the levels of eye contact that are still intact, which is a more promising proposition than trying to induce the development of a function that was absent from birth.
Developmental trajectories in children with and without autism spectrum disorders: the first 3 years - Landa RJ, Gross AL, Stuart EA, Faherty A. Child Dev. 2013 Mar-Apr;84(2):429–442. [PMID: 23110514]
With little known about the onset and early behavioral developmental courses of children with ASD, previous studies have suggested that two main patterns of symptom onset may exist for children with ASD. In some cases, studies have described an early period of apparently typical development with achievement of expected milestones followed by regression, involving loss of language and/or social skills and the emergence of ASD-related behaviors such as repetitive and stereotypical behaviors/interests. In other cases, studies have noted an early onset of ASD-related signs and impairments that results in failure to meet expected developmental milestones and a plateau in skills, but without regression. Retrospective studies examining these two patterns of ASD symptom onset have developed conflicting assessments regarding the relationship between regression and severity of developmental outcomes. To avoid the limitations of retrospective studies, researchers designed a prospective, longitudinal study that examined social, language, and motor trajectories in a high-risk group consisting of 204 infant siblings of children with ASD, and a low-risk group composed of 31 infants with no family history of ASD. Children were assessed from 6 months to 36 months of age, and classified into one of three groups: the Early-ASD group who received a tentative diagnosis by 14 months (confirmed at the outcome of the study), the Later-ASD group who received a diagnosis after 14 months, and the Non-ASD group. Investigators observed similar patterns of initial development at 6 months among all three groups. However, between 14 and 24 months, the Early-ASD group exhibited greater delays in language development compared with the Later-ASD group. At 36 months, the Later-ASD group indicated impairments of comparable severity to the Early-ASD group, suggesting that an earlier or later diagnosis is not predictive of symptom severity. In addition, the timing of ASD diagnosis did not correlate with a specific developmental pattern—either plateau of skills or regression. With these findings, the researchers who conducted this study suggest that screening practices be amended to account for the fact that children may demonstrate variable ASD-related symptoms at different time points in development. Clinical implications of the study include the need for implementation of general developmental assessments before 1 year of age and continued screening at regular intervals through preschool years.
Pediatrician identification of Latino children at risk for autism spectrum disorder - Zuckerman KE, Mattox K, Donelan K, Batbayar O, Baghaee A, Bethell C. Pediatrics. 2013 Sep;132(3):445–453. [PMID: 23958770]
A recent survey of primary care physicians (PCPs) suggests that language, access, and cultural barriers all contribute to poor early diagnosis of ASD among Latino families. Previous research has indicated that Latino children are diagnosed with ASD less often compared with white children, and those diagnosed are identified later and exhibit more severe symptoms. While many factors, including family access to healthcare and parent knowledge of ASD may influence diagnosis of ASD among Latino children, this study examines the potential role that PCPs play in disparities in diagnosis. Through the examination of a sample of 267 PCPs in California via a mail-based survey, researchers assessed their bilingual ASD developmental screening practices, perceptions of parent ASD knowledge among Latino and white families, difficulties in evaluating for ASD in Latino and white children, and other issues that are potential barriers to early ASD identification for Latino children. Results from the study indicated that while 81% of the PCPs surveyed conducted developmental screening for ASD, only 29% of all PCPs provided screening in Spanish for ASD (and an even smaller fraction of PCPs, 10%, offered both general developmental and ASD screening in Spanish). In addition, a majority of PCPs cited that they felt that Latino parents were less informed of ASD compared to white parents, and had more difficulty evaluating risk for ASD in Latino children. Nearly 75% of PCPs experienced barriers to diagnosing Latino children for ASD with the chief barriers consisting of long waits for appointments at their practices due to a shortage of PCPs, limited access to ASD or developmental specialists to whom they could refer patients, limited access to primary care due to the prevalence of uninsurance or underinsurance among Latino children, and language differences between providers and families. Researchers in this study concluded that several factors contribute to delayed identification of ASD in Latino children, and suggested key steps toward closing this gap: the promotion of language-appropriate screening, dissemination of culturally relevant informational materials to Latino families, and increased support to PCPs for ASD screening and specialist referral.