Developmental Trajectories of Adaptive Behavior from Toddlerhood to Middle Adulthood in Autism

Adaptive behavior skills are a significant predictor of adult outcomes. However, few studies have examined developmental trajectories in autistic individuals from early childhood into mid-adulthood and how these trajectories are associated with adult outcomes.

This study uses a longitudinal sample (n = 266) to investigate age-related adaptive behavior developmental growth trajectories across ages 1-55 years. The study investigated clinic records, including questionnaires, interviews, and diagnostic assessments. Caregivers completed the majority of questionnaires.

A linear spline model best fits the data, suggesting that from early childhood to young adulthood (ages 1-20; autistic individuals gained adaptive behavior skills, but scores declined from young adulthood to mid-adulthood [ages 21-55]). Higher IQs and fewer clinician-endorsed autism characteristics across childhood into mid-adulthood were associated with greater adaptive behavior skill growth over time. Caregiver reports of a higher quality of life and daily living skills in adulthood were related to adaptive behavior growth over time.

Overall, the growth of adaptive behavior skills is positive from young childhood to young adulthood but begins to decline during adulthood. It appeared that there was a potential decline in adaptive behavior towards mid-adulthood. Results confirm the importance of adaptive behavior in caregiver perceptions of quality of life for autistic adults and suggest adaptive behavior is essential to support throughout the lifespan.

Why is this an important issue?: Adaptive behavior skills are tasks that support an individual in their everyday lives. Autistic individuals often have difficulties with these skills from childhood to adulthood, regardless of their cognitive skills. There is not much longitudinal research measuring adaptive behavior beyond young adulthood.What was the purpose of this study?: The study aimed to look at how adaptive behavior changes from childhood to mid-adulthood and how the quality of life, experiences in employment and postsecondary education, and cognitive skills such as flexibility, memory, and organization support adaptive behavior skills in adulthood.What did the researchers do?: The researchers analyzed data from a sample of 266 autistic individuals who lived in North Carolina. Some participants had first been diagnosed with autism spectrum disorder in the late 1960s-1970s at the University of North Carolina TEACCH Autism Program. Participants had multiple evaluations done over time in the clinics. A follow-up survey was sent to caregivers for autistic adults diagnosed before 2000 and who were ages 21-55. Caregivers reported on the autistic adults' daily life activities, such as if they had jobs or went to school and where they lived. The researchers measured changes in adaptive behavior skills in early childhood (age 1 year) into adulthood (age 55). The researchers also examined the relationship between adaptive behavior, daily activities, quality of life, and participation in employment and postsecondary education.What were the results of the study?: In this sample, autistic individuals gained adaptive behavior skills from early childhood to adulthood. They gained adaptive behavior skills at a slower rate once they turned 21, and abilities may have declined into later adulthood. Individuals with higher IQs and fewer clinician-rated autistic traits from childhood to adulthood made higher gains in adaptive behavior. Caregiver reports of adaptive behavior during childhood (ages 1-20) were related to a higher quality of life, higher daily living skills, and more vocational or educational experiences in adulthood. Caregiver reports of a higher quality of life and higher daily living skills were related to adaptive behavior skills gained during adulthood (ages 21-55).What do these findings add to what was already known?: Longitudinal research on adaptive behavior across the lifespan is limited. Less is known about how the growth of adaptive behavior skills is related to quality of life and what predicts adaptive behavior skill growth during adulthood. This study has provided helpful information on how adaptive behavior changes across the lifespan.What are the potential weaknesses in the study?: The majority of adaptive behavior measures were from caregiver reports; thus, the study lacked self-report measures.How will these findings help autistic adults now or in the future?: The findings in this study identified how important adaptive behavior is for autistic adults. Adaptive behavior during childhood was related to quality of life, daily living skills, and vocational and educational experiences in adulthood. Adaptive behavior growth during adulthood was related to quality of life and daily living skills, suggesting the importance of supporting adaptive behaviors across the lifespan and continuing into middle adulthood. Furthermore, we hope that caregivers and clinicians will work to consider the priorities of autistic adults with whom adaptive behaviors may be targeted.