A Multisite Randomized Controlled Trial Comparing the Effects of Intervention Intensity and Intervention Style on...

Area of Science:

• Developmental Psychology
• Pediatric Neurology
• Clinical Psychology

Background:

• Autism Spectrum Disorder (ASD) is a complex neurodevelopmental condition affecting young children.
• Early intervention is crucial for improving outcomes in children with ASD.
• Understanding the impact of intervention intensity and style is vital for optimizing treatment efficacy.

Purpose of the Study:

• To investigate the effects of two treatment intensities (15 vs. 25 hours/week) and two styles (naturalistic developmental/behavioral vs. discrete trial teaching) on young children with ASD.
• To determine if initial symptom severity moderates the impact of treatment intensity and style on child progress.
• To assess changes in autism symptom severity, expressive communication, receptive language, and nonverbal ability.

Main Methods:

• A randomized, multisite, intent-to-treat study involving 87 children with ASD (mean age 23.4 months).
• Children were assigned to one of four conditions for 12 months.
• Caregiver coaching was provided twice monthly, with assessments at four time points.

Main Results:

• No significant main effects of treatment style or intensity on the four outcome domains were observed.
• Initial severity did not moderate the effects of treatment style on any outcome.
• Initial severity showed a moderating effect on treatment intensity for autism symptom severity in a secondary analysis at one site.

Conclusions:

• Neither treatment style nor intensity demonstrated overall efficacy in improving child outcomes.
• Initial severity did not predict differential response to treatment styles.
• Limited evidence suggests higher intervention intensity may be more beneficial for symptom reduction in some cases.