The effectiveness and methodological rigor of intensive intervention programs for children with autism are critically examined. This report summarizes three critical reviews of intensive behavioral intervention (IBI), a term encompassing up to 40 hours per week of therapy for autistic children, including Lovaas therapy. While children appear to improve with these programs, the reviews found methodological flaws in studies, particularly those on Lovaas therapy. The analysis indicates insufficient evidence to definitively link the intensity or duration of any specific program to improved outcomes in intelligence, language development, or adaptive behavior, and it remains unclear if one program is superior to another.

This publication synthesizes critical reviews of intensive intervention programs for autism, highlighting methodological concerns within existing research. It points to a general improvement in functioning for children undergoing these therapies but underscores the lack of definitive evidence to establish the superiority of any single program or to correlate treatment intensity with specific developmental outcomes. The work serves as a critical overview for understanding the current state of evidence for intensive behavioral interventions in autism.