Grant description:

Significant progress has been made in the identification of autism spectrum disorder (ASD) in the pre-school period. Age on entry to a program and an emphasis on developing communication skills are important elements of successful early intervention programs. Although several screening (CHAT, M-CHAT, STAT) and diagnostic instruments (ADI-R, ADOS-G) have good clinical utility, they are unlikely to be sensitive measures of intervention effectiveness. In part this is because their primary aim is diagnostic. Further, they focus on measuring impairments in social and communicative capacities. As most intervention programs have increasing social communicative competencies as a key aim, novel instruments that measure competencies in these early social communication abilities are required. Non-verbal social communication abilities including joint attention, imitation, play and reciprocal interactions are "precursors" to later language and social-communicative competence in both children with ASD and typical development. As part of screening and early intervention research studies over the past 8 years, we have assessed 50 children with ASD under the age of 24 months. We developed an interactive assessment measure that focuses on early social and communicative capacities (Pre-school Social Communication Assessment Measure; PSCAM). Systematic analysis of the PSCAM videotapes from the two extant datasets will allow us to evaluate if the PSCAM is a sensitive index of developmental change in pre-school children with ASD and a sensitive index of outcome in pre-school children with ASD enrolled in an ongoing early intervention study.

Funded in partnership with Repligen Corporation

Publications:

Drew A, Baird G, Taylor E, Milne E, Charman T. The Social Communication Assessment for Toddlers with Autism (SCATA): An Instrument to Measure the Frequency, Form and Function of Communication in Toddlers with Autism Spectrum Disorder. J Autism Dev Disord. 2006 Oct 19; [Epub ahead of print] PMID: 17051443
The Social Communication Assessment for Toddlers with Autism had been developed to measure non-verbal communication in young children with ASD. Using the SCATA, the researchers examined the language abilities of two groups of toddlers over time, one over a 12 month period and one over a period of 21 months. They found that while the overall number of non-verbal communicative acts did not change over time, there were changes in the frequency of certain forms of communication, as well the complexity, function and the child's role in the communicative act. Later language proficiency was associated with both frequency and function of communication in toddlerhood.

Charman T, Taylor E, Drew A, Cockerill H, Brown JA, Baird G. Outcome at 7 years of children diagnosed with autism at age 2: predictive validity of assessments conducted at 2 and 3 years of age and pattern of symptom change over time. J Child Psychol Psychiatry. 2005 May;46(5):500-13. PMID: 15845130
Autism is a developmental order, with observed behavioral symptoms reported to change with age. How these changes may affect diagnosis is particularly important to developing better early diagnostic strategies. This study found that diagnoses made at 2 years using standard measures were not predictive of diagnostic outcomes at age 7, but that diagnoses made at age 3 years were. Clinical diagnoses were stable over time, but the children showed variability in categorical diagnoses based on the ADI-R over time. The researchers also showed that there was variability in the pattern of change over time in specific symptoms as measured by the ADI-R. This study highlights the importance of taking into the account that changes in symptoms not only vary over time, but that different symptoms may show different patterns of change. The authors also suggest that when considering very early diagnostic measures, formal IQ and language measures may be less informative than considering general social-communication behaviors.