Neurobiological Correlates of Change in Adaptive Behavior in Autism.

Researchers followed 483 people (204 with autism) for 1-2 years, looking at brain scans and adaptive skills changes. They found that people whose daily living skills improved had different brain patterns compared to those who stayed the same or got worse. These brain differences were linked to genes important for brain development. This research may help predict which children might improve over time and develop more targeted treatments.

This longitudinal study followed 483 individuals (204 with autism, 279 neurotypical) aged 6-30 years over 12-24 months to examine relationships between brain anatomy, genetics, and changes in adaptive behavior. Participants with autism were categorized as 'increasers,' 'no-changers,' or 'decreasers' based on adaptive behavior changes. The study found that outcome groups differed in brain structure including cortical volume, thickness, and surface area, particularly in 'social brain' regions. Individual deviations from typical brain anatomy predicted adaptive behavior outcomes.

These neuroanatomical differences were associated with genetic processes relevant to synaptic development and autism-related phenotypes, suggesting potential pathways for precision medicine approaches in autism.

This research suggests brain imaging may help predict which individuals with autism are likely to improve in adaptive skills over time. Understanding these neurobiological differences could inform development of personalized interventions and help clinicians better counsel families about expected outcomes and treatment planning.

Study design details not fully specified in abstract. Unclear how adaptive behavior change groups were defined or validated. Genetic analysis methodology not detailed. Causal relationships between brain anatomy and outcomes cannot be established from this design.

Autism spectrum disorder (ASD) is a lifelong neurodevelopmental condition that is associated with significant difficulties in adaptive behavior and variation in clinical outcomes across the life span. Some individuals with ASD improve, whereas others may not change significantly, or regress. Hence, the development of "personalized medicine" approaches is essential. However, this requires an understanding of the biological processes underpinning differences in clinical outcome, at both the individual and subgroup levels, across the lifespan.

The authors conducted a longitudinal follow-up study of 483 individuals (204 with ASD and 279 neurotypical individuals, ages 6-30 years), with assessment time points separated by ∼12-24 months. Data collected included behavioral data (Vineland Adaptive Behavior Scale-II), neuroanatomical data (structural MRI), and genetic data (DNA). Individuals with ASD were grouped into clinically meaningful "increasers," "no-changers," and "decreasers" in adaptive behavior. First, the authors compared neuroanatomy between outcome groups.

Next, they examined whether deviations from the neurotypical neuroanatomical profile were associated with outcome at the individual level. Finally, they explored the observed neuroanatomical differences' potential genetic underpinnings. Outcome groups differed in neuroanatomical features (cortical volume and thickness, surface area), including in "social brain" regions previously implicated in ASD. Also, deviations of neuroanatomical features from the neurotypical profile predicted outcome at the individual level.

Moreover, neuroanatomical differences were associated with genetic processes relevant to neuroanatomical phenotypes (e.g., synaptic development). This study demonstrates, for the first time, that variation in clinical (adaptive) outcome is associated with both group- and individual-level variation in anatomy of brain regions enriched for genes relevant to ASD. This may facilitate the move toward better targeted/precision medicine approaches.