Sensory Integration Therapy for Preschool Children with Au-tism Spectrum Disorder and Intellectual Disability: An Ex-ploratory Single-Group Pre–Post Intervention Study

Background: Occupational therapists often provide sensory integration therapy (SIT) as part of interventions for children with autism spectrum disorder (ASD). However, evi-dence supporting its effectiveness remains limited. Therefore, this study aimed to explore the feasibility and potential benefits of once-weekly SIT for children with ASD and co-occurring intellectual disability (ID). Methods: A non-blinded single-group pre–post study was conducted using SIT once a week for 8 weeks. Participants were children aged 2–6 years who had been diagnosed with ASD, had a developmental index score of ≤70, and were classified as having severe autism according to the Childhood Autism Rating Scale. Outcome measures included the Goal Attainment Scaling (GAS), Vineland Adaptive Behaviour Scales, Second Edition (VABS-II), Short Sensory Profile (SSP), and Parenting Stress Index, Short Form (PSI-SF). Data were analysed using the Wilcoxon signed-rank test to compare pre- and post-intervention results. Results: All 10 participants who completed the study exceeded the expected treatment outcome threshold on the GAS. On the VABS-II, significant improvements were observed in the overall adaptive be-haviour composite score as well as in the subdomains of communication, daily living skills, and socialization. No significant differences were observed for SSP or PSI-SF scores. Conclusions: This study showed the feasibility and potential benefits of once-weekly SIT for children with ASD and co-occurring ID. However, the observed changes involved considerable uncertainty, and the potential influence of concurrent developmental therapies could not be excluded. Trial registration: This study was retrospectively reg-istered in the University Hospital Medical Information Network (UMIN000059427).