Autism symptoms tend to decline with age, but support, monitoring remain beneficial
Early emerging autism spectrum disorder symptom levels often declined across development, according to an analysis of a prospective population-based cohort published in American Journal of Psychiatry.
However, impairment continued to manifest into adulthood for certain individuals.
“This is the first study, to our knowledge, that looks at the developmental course of ASD symptoms from childhood through to young adulthood in a general population sample,” Lucy Riglin, PhD, and Anita Thapar, PhD, FRCPsych, both of the division of psychological medicine and clinical neurosciences at the MRC Centre for Neuropsychiatric Genetics and Genomics in at Cardiff University in the U.K., told Healio Psychiatry. “ASD is currently defined as an early-onset condition, but there is increasing recognition that some people with ASD may not present with symptoms until adolescence or adulthood. Follow-up studies of clinic-ascertained ASD does not allow for the study of individuals before their symptoms present, so we wanted to address this gap in the literature by using a general population sample to help us gain an understanding of when symptoms may start to emerge.”
Specifically, Riglin, Thapar and colleagues sought to identify the development and heterogeneity of symptoms of ASD among a cohort from childhood to age 25. They analyzed data of 8,094 individuals who participated in the prospective U.K. population-based cohort the Avon Longitudinal Study of Parents and Children and had two time points available for the parent-rated Social and Communication Disorders Checklist (SCDC) spanning ages 7 to 25 years, which the researchers used to derive trajectories based on five assessments.
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Results showed three distinct SCDC symptom trajectory classes. These were low (88.5%), declining (5%) and late-emerging (6.5%). The researchers noted that the declining and late-emerging trajectory classes had associations with child and adult ASD measures, low IQ, communication problems, peer problems and worse adult functioning compared with the low trajectory class. They also observed an association between male sex and higher likelihood of being in the declining trajectory class (OR = 52.84; 95% CI, 2.19-3.69); however, they did not observe this sex difference in the late-emerging class (OR = 1; 95% CI, 0.8-1.24) compared with the low trajectory class.
“Individuals with ASD may still benefit from continued monitoring and support across development, even if their symptoms appear to have declined,” Riglin and Thapar said. “We found that for some individuals, ASD symptoms emerged across adolescence and adulthood, although there was evidence of some childhood neurodevelopmental impairment for this group. This challenges the assumption that ASD symptoms always first manifest early in development and suggests that individuals may benefit from referral to clinical services and support even if they do not present with symptoms until later in development.”