Integrated Naturalistic Developmental Behavioral Interventions for Toddlers with ASD: A Preliminary Analysis of Treatment Effectiveness within a Community Setting

Background: Randomized Controlled Trials (RCTs) of Naturalistic Developmental Behavioral Intervention (NDBI) programs have demonstrated improved symptoms and functioning in toddlers with autism spectrum disorder (ASD). Yet, treatment effectiveness of these RCTs have mainly been demonstrated within university-based research contexts. Thus, examination of treatment efficacy of integrated NDBI implemented in community-based clinics is necessary to evaluate intervention feasibility.

Objectives: We aim to evaluate preliminary effectiveness of a short-term (6 month) NBDI program implemented in a community-based clinic for toddlers with ASD.

Methods: A total of 14 toddlers underwent a 6-month NDBI program that integrates multiple intervention modalities (see Table 1 for the details of the program). Child assessments and parent interviews were conducted at treatment entry (Time 1; mean age= 24.1 months, SD= 4.6) and treatment exit (Time 2; mean age= 32 months, SD=5.98) based on Autism Diagnostic Observation Schedule (ADOS), Mullen Scales of Early Learning-Second Edition (MSEL), Vineland Adaptive Behavior Scales-Second Edition (Vineland-II), and the Early Start Denver Model-Curriculum Checklist (ESDM-CC). Generalized Linear Mixed Models (GLMM) were used to examine the changes in autism symptom severity (ADOS), developmental skills (Mullen, ESDM-CC), adaptive functioning (Vineland) while controlling for baseline cognitive levels, symptom severity, language level, and age, and other demographic factors (i.e., race, gender, and maternal education).

Results: Despite the small sample size, significant improvements were found in these areas (p<0.05; see Table 2); 1) nonverbal and verbal domains measured by the MSEL, including visual reception, fine motor, receptive and expressive language as well as several areas of development measured by the ESDM-CC, including Expressive Communication, Social Skills, Imitation, Cognitive, Fine Motor, Joint Attention and Personal Independence; 2) autism symptom severity measured by the ADOS algorithm total scores; 3) adaptive expressive language and personal daily living skills measured by the Vineland-II. Effect sizes (Cohen’s D ranged from .3-1.5). In addition, baseline symptom severity and language levels consistently predicted improvements across these domains.

Conclusions: Based on 14 toddlers who received a short-term NDBI program implemented in a state-funded, community-based setting, significant improvements across various developmental nonverbal and verbal domains, ASD symptom severity, and adaptive functioning were found using (non-treating) clinician ratings, parent report, and therapist ratings. Results indicate that baseline clinical features such as language and symptom severity may mediate the improvements in these skills over the course of treatment. Our research did not include a control group for treatment; therefore, based on these promising results for the potential feasibility of the community-implemented NDBI program, a randomized control trial is underway to examine the treatment efficacy and the mechanisms of treatment effects in toddlers with ASD.