To evaluate the effects of the Parent-Child Sandplay Therapy (PCST) Program on autism behaviors, social responsiveness and sleep quality among preschool children with autism spectrum disorder (ASD), and their mothers' parenting stress.

A prospective, randomized controlled, parallel-group trial was employed. Fifty-two child-mother dyads were randomly assigned to an intervention group (n = 26) or a control group (n = 26) from February 2017 to February 2019. The intervention group was treated with a 20-week PCST Program plus an Applied Behavior Analysis-based program (ABA-based program), whereas the control group received only the ABA-based program. Outcome measures included the Autism Behavior Checklist total scores, Social Responsiveness Scale scores, Children's Sleep Habits Questionnaire scores, and Parenting Stress Index-Short Form scores, measured at baseline, post-intervention (20 weeks after baseline) and follow-up assessments (32 weeks after baseline).

Finally, 43 dyads completed the study. The linear mixed model analysis resulted in a significant group*time interaction effect of ABC score (Est = 2.027, t = 3.277; p < 0.01), SRS score (Est = 3.377, t = 6.095; p < 0.01), PSI-SF score (Est = 3.873, t = 4.253, p < 0.01), and CSHQ score (Est = 3.158, t = 6.485; p < 0.05).

Our findings suggested that the PCST Program could potentially improve social interaction and sleep quality of preschool children with ASD while decreasing parenting stress.

The PCST Program was found to be a feasible and a promising treatment for children with mild-to-moderate ASD as well as for their parents. It was a nurse-led program, which could be integrated into the usual nursing care of children with autism spectrum disorder in special education schools.

Trial registration: Chinese Clinical Trials Registry, ChiCTR2100047699.