Autism now occurs in 1 out of 150 births in the United States (Centers for Disease Control, 2008). Increasing numbers and complexity of the disorder make the need for identifying effective interventions critical.

DSM-IVTR identifies core characteristics of autism as significant deficits in communication, social interaction, and symbolic play. Neither intellectual ability nor academic achievement, two variables frequently used for measuring intervention effectiveness, are included as diagnostic criteria. Yet IQ scores are often used as entry criteria for treatment studies (Tsakiris, 2000). Therefore, intervention effectiveness has utilized variables other than the primary deficits and cannot be applied to the wider range (and truer representation) of children with autism..

From 1980 to 1999, Applied Behavior Analysis (Lovaas, 1987) and the Developmental-Individual Differences Relationship model (Greenspan & Wieder, 1998) were associated with improvement for children with autism; they remain the foundation for most current interventions. While researchers have examined gains in language and academic skills for these models, few empirical studies have examined improvement in the core deficits for autism.

This study examined the core affect variables for 28 children with autism who had undergone a minimum of two years of intensive intervention. This study used a retrospective descriptive design to examine treatment effectiveness in development of social interaction, play, and communication competencies. Assessment instruments measured these skills in young children, incorporating both quantitative behavioral data and qualitative psychodynamic interpretation.

Results were analyzed to determine relationships between social interaction, communication, and play with the intervention. Parent interviews and record reviews were used to examine child characteristics that might differentiate the presence or lack of relationship to the selected therapies, including age at symptom onset and treatment initiation, self-stimulation levels, echolalia, motor planning and language skills, and biomedical factors.

No differences were seen between treatment programs on all outcome measures. The individual characteristics of the children played the more significant role in determining social interaction and communication improvements regardless of the child's intellectual functioning level. The results have important implications for determining which treatments may have better potential for addressing the core deficits of autism and identifying skill trajectories that warrant more attention.