Evidence for ABA Therapy: Summary of Research Articles
Title: Behavioral Treatment and Normal Educational and Intellectual Functioning in Young Autistic Children
Author/Year: Lovaas, O. I.
Publication: Journal of Consulting and Clinical Psychology, Vol 55(1), Feb 1987, 3-9
- This is watershed research that offered persuasive evidence that ABA therapy (if implemented as prescribed) has, on balance of probabilities, a good chance to help ASD kids to achieve “normal intellectual and educational functioning”.
- This study follows 38 young children diagnosed with Autism for 2 or more years. The children were assigned to 2 different groups – (A) Treatment Group, and (B) Control Group 1. Each group consisted of 19 children. There was also a Control Group of 21 children who did not participate in the study, but who data was used for comparison. There were no significant differences between the children at the beginning of the study.
- The children in the Treatment Group received 40 hours a week of intensive 1:1 treatment. Treatment goals consisted of reducing self-stimulatory and aggressive behaviours, building compliance to verbal requests, teaching imitation, toy play, language, school readiness, emotions, and observational learning.
- The children in the Control Group received similar intervention to the children in the Treatment Group, but at a much lower intensity of less than 10 hours a week of 1:1 treatment. The children in this group also received a variety of different treatments from other sources in the community, such as special education classes.
- The study showed that 47% (9 children) of the children in the Treatment Group achieved normal intellectual and educational functioning by the end of the study, with IQ scores in the normal range and were successful in mainstream first grade classrooms. 42% (8 children) were successful in aphasia classrooms and achieved IQ scores in the mildly-retarded range. 10% (2 children) of the children achieved IQ scores in the profoundly retarded range and were in classrooms for autistic children.
- In comparison, none of the children in the Control Group attained normal intellectual and educational functioning. 42% (8 children) from this group were in aphasia classrooms and 57% (11 children) were in classrooms for autistic children.
- Similarly, data from the children from the 2nd Control Group who did not receive any treatment from this study showed that only 1 child obtained normal intellectual and educational functioning. 47% (10 children) were in aphasia classrooms and 47% (10 children) were in classrooms for autistic children.
- Children from the Treatment Group scored an average of 30 IQ points higher (Mean IQ = 83) on the WISC-R than did children in the Control Group (Mean IQ = 52).
- Children in the comparison 2 Control Group scored an average of 57 IQ points on the WISC-R. However, the mean score for this group should be interpreted with caution as 1 child in the group scored 99 IQ points, thus skewing the average score for this group.
Title: Long-Term Outcome for Children With Autism Who Received Early Intensive Behavioral Treatment
Authors/Year: McEachin, J. J., Smith, T., & Lovaas, O. I.
Publication: American Journal on Mental Retardation 1993 Vol 97, No.4
- This research showed that gains from ABA are sustainable in the long run.
- This is a follow-up to the original Lovaas (1987) study (outlined above). This study examines if (A) treatment gains from the children in both groups were maintained and (B) the extent to which the 9 children from the Treatment Group who achieved normal intellectual and educational functioning by the end of first grade could be considered free of autistic symptomatology.
- The study finds that children from the Treatment Group (mean age = 13 years old) maintained their level of intellectual functioning and displayed significantly higher levels of functioning when compared to the children in the Control Group. The children from the Treatment Group (mean = 83pts) maintained an average of 30 IQ points higher than the Control Group children (mean = 52pts).
- Of the 19 children in the Treatment Group of the original study (Lovaas, 1987), 8 of the 9 children who attained normal intellectual and educational functioning at first grade continued in regular education classrooms. The remaining child was subsequently placed in a special education classroom. However, 1 of the remaining 10 children from the Treatment Group was subsequently moved from special education to regular education classroom. The 19 children from the Control Group remained in special education. None were moved to regular education.
- The 9 children in the Treatment Group who had attained normal intellectual and educational functioning by first grade scored a mean IQ of 111 points. 8 of these children also attained and maintained average levels of adaptive functioning. They were able to independently manage themselves and navigate regular education classrooms. They did not show signs of emotional disturbances and had adequate levels of social skills.
Title: A Comparison of Intensive Behavior Analytic and Eclectic Treatments for Young Children with Autism.
Authors/Year: Howard, J. S., Sparkman, C. R., Cohen, H. G., Green, G., & Stanislaw, H.
Publication: Research in Developmental Disabilities 26 (2005) 359–383
- This study shows that treatments based only on ABA produce far more significant results that using a variety of methods.
- With ABA kids learn at a rate that is equal to or even better than normal development, with an eclectic method you get “well below normal” (even if taught intensively).
- This study follows 61 children diagnosed with Autistic Disorder or Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS). The children were assigned to 3 different groups: (A) Intensive Behavior Analytic Treatment Group (IBT), (B) Autism Educational Programming Group (AP), or (C) Generic Educational Programming Group (GP). The IBT group consisted of 29 children. The AP and GP group consisted of 16 children each.
- Children in the IBT group received 25-30 hours of 1:1 (under 3yrs old) or 35-40 hours of 1:1 (over 3 years old) of intervention across multiple settings (home, school, community). This group was run by graduate and undergraduate students of psychology or special education and supervised by a BCBA. Treatment goals consisted of both structured lessons and unstructured play dates with typically developing peers. Parents of children in this group also received training in ABA strategies.
- Children in the AP group received 25-30 hours of 1:1 or 1:2 intervention in an autism classroom setting run by paraprofessional aides and supervised by special education teachers. Intervention is eclectic and included methods such as discrete trials, sensory integration, TEACCH, and PECS, as well as other common preschool activities. 7 of the children in this group also received individual or small group speech therapy once or twice a week.
- Children in the GP group received 15 hours of 1:6 intervention within a special education classroom run by paraprofessional aides and supervised by special education teachers or speech and language pathologists. The intervention focused on language, play activities, and sensory needs. 13 of the children in this group also received individual or small group speech therapy once or twice a week.
- The study finds no significant differences between the mean IQ score of the children in the AP and GP group at intake or follow-up. The IBT group, on the other hand, made a significant improvement in IQ, with an average of a 30point increase in IQ score between intake and follow-up (mean = 58.54 at intake and mean = 89.88 at follow-up). Children in the IBT group also scored an average of 21-27 IQ points higher than the children in the AP and GP group. Children in the AP and GP group scored an average of 8 IQ points higher at follow-up than at intake (no significant improvement).
- Children in the IBT group acquired skills in most domains (non-verbal, receptive language, expressive language, overall communication, social skills) at a rate that matched or exceeded the normal rate of development. In contrast, the learning rates of children in the AP and GP group remained well below normal.
- As evident by the outcomes of the children in the AP group, eclectic treatment did not prove to be very effective for children with Autism even when provided intensively and in specifically designed autism classrooms.
Title: Change in Autism Core Symptoms with Intervention
Authors/Year: Zachor, D. A., Ben-Itzchak, E., Rabinovich, A., Lahat, E.
Publication: Research in Autism Spectrum Disorders 1 (2007) 304–317
- This article reinforces the view that focusing just on ABA is better than trying to undertake a host of various intervention methods. Sometimes, this can prove unwise, as this experiment showed that ABA group enjoyed significant gains in language and communication – while the eclectic group made no progress. It is also encouraging in suggesting that there is close to a 50-50 chance that core symptoms can improve in a year.
- This study compares 2 intervention approaches for Autism: (A) Eclectic-Developmental (ED) and (B) Applied Behavioral Analysis (ABA). Of 39 children, 19 were assigned to the ED group and 20 were assigned to the ABA group. Each group received 8 hours of intervention a day.
- Intervention for children in the ED group was based on a combination of different approaches and strategies such as TEACCH, DIR, and ABA, supervised by special education teachers. Children in this group received 1:1 speech therapy, occupational therapy, music therapy, and structured cognitive teaching a week. They also received 1 hour of group therapy a week. Parents of children in this group were thought how to play with their children and deal with challenging behaviours. Some of the children in this group also attended inclusion preschool.
- Intervention for children in the ABA group received purely ABA therapy provided 1:1 by skilled behaviour therapists 35 hours a week and supervised by a trained behaviour analyst. Focus of therapy included imitation, language, joint attention, non-verbal communication, pre-academic skills, motor and adaptive living skills. Children in this group were also exposed to regular preschool activities such as circle time, meals, and play-dates. In addition, some of the children in this group also attended inclusion preschool.
- The study finds that the children in the ABA group improved more significantly than did the children in the ED group. Children in the ABA group showed significant improvement in language and communication and reciprocal social interaction. The children in the ED group showed significant improvement only in reciprocal social interaction, and to a lesser extent than compared to the ABA group.
- After 1 year of intervention, 20% of the children in the ABA group no longer met criteria for autism/ASD, and 20% were re-assigned from an Autism diagnosis to the less severe ASD diagnosis. Only 15.8% of the children in the ED group were re-assigned as ASD from the more severe Autism diagnosis. All of the children in the ED group continued to meet criteria for Autism or ASD.