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Parent-led intervention has long-term effects on autism symptom severity

Recent findings indicated a parent-mediated social communication intervention for children aged 2 to 4 years with autism had long-term effects on symptom severity.

“The natural history of [autism] is usually enduring and has serious effects on development; lifetime costs (including health, education, social care, family out-of-pocket expenses and productivity losses) are estimated to be between £1 million and £1.5 million in the U.K. and between $1.4 million and $2.4 million in the U.S. Effective early treatment that alters the long-term course of the disorder would therefore have great potential benefits for individuals, families, and society, but has been difficult to demonstrate,” Andrew Pickles, PhD, of Kings College London, and colleagues wrote. “Evidence shows that a range of psychosocial intervention approaches can have short-term effects on various developmental indicators that are thought to be important for later autism outcomes, such as parent-child joint engagement, social communication, child symbolic play, and social imitation.”

To follow-up the Preschool Autism Communication Trial (PACT) and determine if the PACT intervention had long-term effects on autism symptoms, researchers assessed outcomes from the Autism Diagnostic Observation Schedule (ADOS), the Dyadic Communication Assessment Measure (DCMA) and an expressive-receptive language composite at a median of 5.75 years from original trial endpoint. Follow-up included 80% of the original cohort, with 59 participants assigned to the PACT intervention and 62 assigned to treatment as usual. Mean age at follow-up was 10.2 years.

There was a group difference in ADOS scores, favoring PACT, with a log-odds effect size of 0.64 (95% CI, 0.07-1.2) at treatment endpoint and 0.7 (95% CI, –0·05 to 1.47) at follow-up. This indicated an overall reduction in symptom severity of 0.55 (95% CI, 0.14-0.91; P = .004).

Group difference in DCMA scores at follow-up indicated a Cohen’s d effect size of 0.29 (95% CI, –0.02 to 0.57) and was significant throughout the study (effect size = 0.33; 95% CI, 0.11-0.57; P = .004).

There were no group differences in language composite scores at follow-up (effect size = 0.15; 95% CI, –0.23 to 0.53).

“Overall, Pickles and colleagues have made a major contribution to autism research by providing new high-quality evidence to support the potential value of adding the PACT intervention to educational services for young children with autism spectrum disorder,” Jeff Sigafoos, PhD, MA, BA, and Hannah Waddington, a PhD student, of Victoria University of Wellington, New Zealand, wrote in an accompanying editorial. “Pickles and colleagues suggest that their positive long-term outcomes stemmed from optimization of parent-child social communicative interactions, which then become self-sustaining. Another possibility is that early interventions of this type enable neural development and normalize brain activity. Of course, these two possible mechanisms are neither mutually exclusive nor exhaustive. Still, the emerging evidence favoring the PACT intervention and similar programs suggests that some major, yet undetermined, developmental mechanism might be involved.” – by Amanda Oldt

Disclosure: The research reports no relevant financial disclosures.