*3.10.3. Review of literature*

The seminal research for the use of ABA for children with ASD was conducted by Lovaas in 1987. This study specifically investigated DTT on a group of 4 year olds over the course of 2–3 years. Lovaas found that 47% of the children in the ABA demonstrated functional improvements, compared to only 2% in the control group. This study has been replicated numerous times across the years, with similar results, indicating that DTT improves IQ, communication, and socialization in children under 4 years old with ASD [63].

A systematic review of behavioral and developmental interventions for children with ASD was conducted by Ospina and associates [81]. In regard to ABA, this review specifically examined 31 studies with a total sample of 770 subjects. Findings related to DTT were inconsistent, with motor and functional outcomes trending positively, while speech outcomes trended negatively. High intensity Lovaas therapy was found to be superior to low intensity programming, and treatment was consistently found to be better than standard care.

Virues-Ortega conducted a meta-analysis of ABA and autism in 2010 [82]. The review analyzed results from 22 studies that included a total of 323 subjects in intervention groups that ranged in age from 22.6 to 66.3 months old. Results indicated positive effects in IQ (18 studies), receptive language (11 studies), expressive language (10 studies), and adaptive behaviors (communication, daily living skills, and socialization, 11 studies). The author did note that analysis was difficult due to the varying methodology used, but indicated overall that ABA intervention is associated with medium to large positive effects in IQ, language, and adaptive behavior.

Overall, research has demonstrated that ABA can be an effective therapeutic technique to teach children with ASD specific skills. Therapists utilize this technique in a variety of formats in order to help improve functional outcomes.
