The Effectiveness of Pivotal Response Treatment (PRT) in School-Aged Children and Adolescents with Autism Spectrum Disorder: A Randomized Controlled Trial

Background: Pivotal Response Treatment (PRT) is a naturalistic behavioral intervention targeting core deficits in social communication and motivation. The treatment has been shown to enhance social skills, language skills, and adaptive behavior (Koegel et al., 1999; Mohammadzaheri et al., 2015). The majority of studies on the effectiveness of PRT focus on preschool children (e.g., Koegel et al. 2003, 2014). Studies on the effectiveness of PRT for school-aged children and adolescents are lacking or have methodological limitations (i.e. lack of control group, no blinded measurements). Since children with ASD often face challenges in social communication when entering school, examination of PRT as a promising intervention is needed for this population.

Objectives: The current study aims to explore the effectiveness of PRT, compared to treatment-as-usual (TAU), on improving social communication skills and clinical functioning of school-aged children and adolescents with ASD.

Methods: A randomized controlled trial was conducted to evaluate the effectiveness of PRT for children aged 9-15 years with ASD and a total/verbal IQ above 80. Participants (n=44) were randomly assigned to PRT or TAU (i.e. other treatment or waitlist control). In the PRT group, parents were trained to apply PRT techniques and the teacher of the child was also informed about how to incorporate PRT in the classroom. At baseline, week 12, 20 and 28 (follow-up), social communication skills of the child were assessed with the Social Responsiveness Scale (SRS, Roeyers et al., 2011) completed by parents and teachers. Clinically significant improvement was examined using the Clinical Global Impression-Improvement Scale (CGI-I, Guy, 1976) completed by a blinded child and adolescent psychiatrist. Clinical responders were defined as being much or very much improved on the CGI-I.

Results: There were no baseline differences of participant characteristics between groups (see table 1). Repeated measures analysis performed over the currently finished cases (n=27), indicated a significant main effect of time (F(3,23) = 5.56, p = .005) and a time x group interaction effect (F(3,23) = 3.54, p = .03) on the parent-rated SRS score, with a steeper improvement of social communication skills over time in the PRT group. For the teacher-rated SRS score a significant main effect of time was found (F(3,21) = 4.53, p = .013), but no significant time x group interaction effect (F(3,21) = .90, p = .457). There were no significant differences in percentage of clinical responders between groups at week 12 (PRT (45,0 %) vs. TAU (36,4%): χ² (1) = 0.32, p = .75) and week 20 (PRT (57,9 %) vs. TAU (47,6 %): χ² (1) = 0.42, p = .51). However, at follow-up results showed a significant higher percentage clinical responders in the PRT group compared to the TAU group (PRT (91,7 %) vs. TAU (47,6 %): χ² (1) = 6.4, p = .011).

Conclusions: The preliminary findings of this study suggest that PRT is effective in improving social communication skills and clinical functioning of school-aged children and adolescents with ASD. Results of the complete dataset (available May 2019), implications of findings, and future research will be discussed.