Family and School Contexts Predict Patterns of Change in Functioning over 10 Years Among Adolescents and Adults with Autism Spectrum Disorders

Background: Adults with autism spectrum disorders (ASD) constitute a population with growing significance, given increases in the rate of diagnosis and life expectancy. Yet little research has documented the life course of ASD. Prospective, longitudinal research is needed to identify antecedents of change. A supportive family environment is central to promoting optimal outcomes, since many day-to-day interactions occur within the family context. As children age, the school environment becomes an increasingly salient context for development.

Objectives: The present study jointly employs variable-centered and person-centered approaches to identify classes of individuals with ASD who have similar profiles of change over a 10-year period across three critical domains of functioning: maladaptive behavior, autism symptoms, and daily living skills. Above and beyond individual characteristics, aspects of the family (maternal positivity and criticism) and school (level of inclusion) contexts were examined as predictors of the likelihood of following a positive pattern of change.

Methods: The sample included 364 individuals with ASD and their mothers. ASD diagnoses were confirmed by the Autism Diagnostic Interview-Revised (ADI-R). Most participants were male (74%) and most also had intellectual disability (ID; 70%). They ranged in age from 10 to 52 (M=21.85, SD=9.42) at the start of the study. Six waves of data were collected across approximately 10 years. Maladaptive behaviors were based on the Problem Behavior Subscale of the Scales of Independent Behavior-Revised (SIB-R). The ADI-R was used to measure autism symptoms. Independence in activities of daily living was measured using the Waisman Activities of Daily Living Scale (W-ADL). Individual characteristics measured at the start of the study included age, gender, comorbid ID, and childhood verbal language ability and autism symptom severity. The Five Minute Speech Sample was used to code the number of maternal positive and critical remarks. Parents reported on the extent of their child’s inclusion with typically developing peers while in school. Change in each outcome variable was first examined through multilevel modeling. Next, latent profile analysis was conducted on the growth parameters across outcomes to cluster individuals with similar trajectories of change across domains of functioning. Lastly, individual and contextual factors measured at the start of the study were used to predict the likelihood of class membership.

Results: Two distinct profiles of change were identified. Participants in Class 1 displayed fewer maladaptive behaviors and autism symptoms and higher daily living skills at the start of the study compared to Class 2. Over the course of the study, participants in Class 1 showed greater improvements in autism symptoms and daily living skills. Above and beyond individual characteristics, partial or full inclusion in school as well as higher levels of maternal positivity increased the likelihood of following a positive pattern of change (Class 1).

Conclusions: Autism symptoms, maladaptive behaviors and daily living skills were observed to improve over time, although there was variability in the rate of improvement. Implementing evidence-based interventions that target the school and home environments during childhood may have lasting impacts on functioning into adulthood for individuals with ASD.