The efficacy of home-based virtual reality exposure therapy as an add-on to behavioral therapy for children with selective mutism: Protocol for a single-case experimental design.

Background: Selective Mutism (SM) is a rare childhood anxiety disorder characterized by an inability to speak in specific social situations, despite speaking freely in others. School is typically the environment where the disorder manifests itself most clearly. Children with SM often have difficulty generalizing speaking across different social situations. Parents and teachers often struggle to practice speaking with the child outside of therapy due to practical reasons and time constraints. Virtual Reality Exposure Therapy (VRET) at home has potential to enhance the treatment of SM by providing an alternative and engaging method for delivering exercises that support behavioral treatment. Methods: This paper describes the development of the VRET application Speaking at School-VR and the methodology of the single case experimental design (SCED) to evaluate the feasibility and preliminary effects of the behavioral treatment at school, complemented with VRET at home, for children with SM, aged 4-13. A secondary aim is to evaluate the feasibility and adherence of home-based VRET based on qualitative information to capture participants' experiences. A total of 15 children with SM and their families will be enrolled in the study to examine the potential effectiveness of the combined treatment. The treatment consists of 10 behavioral steps, each accompanied by complementary VRET exercises. Conclusion: This is the first study to examine the feasibility and the potential effectiveness of home-delivered VRET as an adjunct to behavioral treatment for children with SM. The addition of VRET to behavioral treatment has the potential to enhance the generalization and transfer of skills across different situations in a facilitative and engaging way.