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Autism

Long-Term Outcomes of Regression in Autism Spectrum Disorder Uncovered

Strategic Insights

— 1 min read

Research conducted in Yokohama, Japan has shed light on the long-term outcomes of regression in autism spectrum disorder (ASD). The study, funded by the Ministry of Education, Culture, Sports, Science and Technology, analyzed data from 168 participants who were diagnosed with ASD by age seven and were born between 1988 and 1996. The participants were divided into two groups: those with regression and those without regression. The researchers compared four outcomes: IQ at age five, IQ in adulthood, incidence of epilepsy, and composite social ability score. The results showed no significant differences between the two groups, with small to intermediate effect sizes indicating that the impact of regression on IQ and psychosocial adaptation in adulthood, if present, is likely to be small to intermediate.

Key Takeaways:

  • The study found no significant differences in IQ at age five, IQ in adulthood, incidence of epilepsy, and composite social ability score between autistic individuals with and without regression.
  • The standardized effect size for the composite social ability score was 0.06 (95% CI: -0.08 to 0.21), indicating a small positive effect.
  • The risk ratio of epilepsy in the regression group compared to the non-regression group was 0.59 (95% CI: 0.22 to 1.5), suggesting a lower risk of epilepsy in the regression group.
  • The research concluded that the confidence intervals of the effect sizes indicate that the impact of regression on IQ and psychosocial adaptation in adulthood, if present, is likely to be small to intermediate.
  • The study's findings provide new insights into the long-term outcomes of regression in ASD, suggesting that the impact of regression may be smaller than previously thought.
  • The research emphasizes the importance of population-based birth cohort studies in understanding the long-term outcomes of individuals with ASD.

Statistics:

  • 168 participants were included in the study.
  • The standardized effect size for the composite social ability score was 0.06 (95% CI: -0.08 to 0.21).
  • The risk ratio of epilepsy in the regression group compared to the non-regression group was 0.59 (95% CI: 0.22 to 1.5).
  • The impact of regression on IQ and psychosocial adaptation in adulthood is likely to be small to intermediate.

Sources:

  • Iwasa, M. et al. (2025). Comparison of Adulthood Outcomes in Autism Spectrum Disorder With and Without Regression: A Population-Based Birth Cohort Study. Autism Research.
  • Yokohama Rehabilitation Center. Developmental Psychiatry, Yokohama, Japan.
  • Ministry of Education, Culture, Sports, Science and Technology.

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