Autism current issue

Editorial

Zwaigenbaum, L., Stone, W. — 2008-09-19

Clinical assessment of autism in high-risk 18-month-olds

2008-09-19

Earlier intervention improves outcomes for children with autism spectrum disorders (ASDs), but existing identification tools are at the limits of standardization with 18-month-olds. We assessed potential behavioural markers of ASD at 18 months in a high-risk cohort of infant siblings of children with ASD. Prospective data were collected using the Autism Diagnostic Observation Schedule (ADOS) and Autism Observation Scale for Infants (AOSI) on 155 infant siblings and 73 low-risk controls at 18 months. Infants were classified into three groups (ASD sibs, non-ASD sibs, controls) based on blind best-estimate diagnosis at age 3. Fisher's exact tests, followed by discriminant function analyses, revealed that the majority of informative ADOS items came from the social and behavioural domains, and AOSI items measuring behavioural reactivity and motor control contributed additional information. Findings highlight the importance of considering not only social-communication deficits, but also basic dimensions of temperament including state regulation and motor control when assessing toddlers with suspected ASD.

Atypical object exploration at 12 months of age is associated with autism in a prospective sample

Ozonoff, S., Macari, S., Young, G. S., Goldring, S., Thompson, M., Rogers, S. J. — 2008-09-19

This prospective study examined object exploration behavior in 66 12-month-old infants, of whom nine were subsequently diagnosed with an autism spectrum disorder. Previous investigations differ on when the repetitive behaviors characteristic of autism are first present in early development. A task was developed that afforded specific opportunities for a range of repetitive uses of objects and was coded blind to outcome status. The autism/ASD outcome group displayed significantly more spinning, rotating, and unusual visual exploration of objects than two comparison groups. The average unusual visual exploration score of the autism/ASD group was over four standard deviations above the mean of the group with no concerns at outcome. Repetitive behaviors at 12 months were significantly related to cognitive and symptomatic status at 36 month outcome. These results suggest that repetitive or stereotyped behaviors may be present earlier than initially thought in very young children developing the autism phenotype.

Visual disengagement in the infant siblings of children with an autism spectrum disorder (ASD)

Ibanez, L. V., Messinger, D. S., Newell, L., Lambert, B., Sheskin, M. — 2008-09-19

Children with autism spectrum disorders (ASDs) are impaired in visually disengaging attention in both social and non-social contexts. These impairments may, in subtler form, also affect the infant siblings of children with ASD (ASD-sibs). We investigated patterns of visual attention (gazing) in 6-month-old ASD-sibs (n = 17) and the siblings of typically developing children (COMP-sibs: n =17) during the Face-to-Face/Still-Face Protocol (FFSF), in which parents are sequentially responsive, non-responsive, and responsive to their infants. Throughout the protocol, ASD-sibs shifted their gaze to and from their parents' faces less frequently than did COMP-sibs. The mean durations of ASD-sibs' gazes away from their parents' faces were longer than those of COMP-sibs. ASD-sibs and COMP-sibs did not differ in the mean durations of gazes at their parents' faces. In sum, ASD-sibs showed no deficits in visual interest to their parents' faces, but greater interest than COMP-sibs in non-face stimuli.

Validation of the Infant--Toddler Checklist as a broadband screener for autism spectrum disorders from 9 to 24 months of age

Wetherby, A. M., Brosnan-Maddox, S., Peace, V., Newton, L. — 2008-09-19

There is an urgent requirement for the improvement of early detection of ASDs. This article provides a brief review of research on the accuracy of screeners for children with ASD that have been administered to general pediatric samples and then present results of a population-based study with a broadband screener to detect children with communication delays including children with ASD.

Screening for autism in older and younger toddlers with the Modified Checklist for Autism in Toddlers

2008-09-19

The Modified Checklist for Autism in Toddlers (M—CHAT) was used to screen younger (16—23 months) versus older (24—30 months) high- and low-risk toddlers. Refusal rates for follow-up interview showed no group differences, but parents of younger/low-risk children were more likely to refuse evaluation than parents of high-risk children. PPP for an ASD diagnosis was: younger/high-risk 0.79, older/high-risk 0.74, younger/low-risk 0.28, and older/low-risk 0.61, with PPP differing by age within the low-risk group. Most of the children in all groups, however, were diagnosed with a developmental disorder. Symptom severity generally did not differ among groups. Cognitive and adaptive measures showed minimal group differences. Therefore, older and younger toddlers had similar symptomatology and developmental delays; PPP for ASD is better at 24 than 18 months for low-risk children; however, these children are still highly likely to show a developmental disorder. Clinical decision making should balance early identification against the lower specificity of M—CHAT screening for the younger/low-risk group.

Screening for autism spectrum disorders in primary care settings

Robins, D. L. — 2008-09-19

The need for autism-specific screening during pediatric well-child visits has been established. However, additional support for specific screening instruments is needed. The current study used the Modified Checklist for Autism in Toddlers (M—CHAT) and the M—CHAT Follow-Up Interview to screen 4797 children during toddler checkups. Of the 4797 cases, 466 screened positive on the M—CHAT; of the 362 who completed the follow-up interview, 61 continued to show risk for autism spectrum disorders (ASDs). A total of 41 children have been evaluated; 21 children have been diagnosed with ASD, 17 were classified with non-ASD delays, and three were typically developing. The PPV of M—CHAT plus interview was .57. It is notable that only four of the 21 cases of ASD were flagged by their pediatrician. These findings suggest that the M—CHAT is effective in identifying ASD in primary care settings. Future research will follow this sample longitudinally.

Use of the Screening Tool for Autism in Two-Year-Olds (STAT) for children under 24 months: An exploratory study

Stone, W. L., McMahon, C. R., Henderson, L. M. — 2008-09-19

The study examined the properties of the Screening Tool for Autism in Two-Year-Olds (STAT) for children under 24 months. The STAT provides a standard context for observing social-communicative behavior in play, imitation, and communication. Seventy-one children received the STAT between 12 and 23 months of age and a follow-up diagnostic evaluation after 24 months. All had an older sibling with an autism spectrum diagnosis (n = 59) or had been referred for evaluation for concerns about autism (n = 12). Signal detection analysis resulted in a cut score of 2.75 for this sample, which yielded a sensitivity of 0.95, specificity of 0.73, positive predictive value of 0.56, and negative predictive value of 0.97. False positives were highest for the 12- to 13-month-old age group; STAT screening properties were improved when the sample was limited to children 14 months and older. Implications for using the STAT with children under 24 months are discussed.

Reaction to diagnosis and parenting styles among mothers of young children with ASDs

Wachtel, K., Carter, A. S. — 2008-09-19

When a child is diagnosed with an autism spectrum disorder (ASD) parents often experience a range of difficult feelings, which typically are not addressed in child-focused interventions. This study examined the relationship between a mother's acceptance of and sense of resolution regarding her child's diagnosis of an ASD and maternal interaction style, controlling for child competence, autism symptoms and maternal depression. Participants included 63 children with an ASD between 20 and 50 months of age and their mothers. Mothers who were more emotionally resolved were rated as higher in Cognitive Engagement and Supportive Engagement in play interactions, reflecting greater verbal and nonverbal scaffolding to enhance the child's play and attention to activities and greater reciprocity and mutual enjoyment. This study highlights the importance of considering a mother's resolution about her child's diagnosis, suggesting that maternal emotions and cognitions associated with the diagnosis may be potential targets for intervention.