The Effect of Virtual Reality Homework Exercises as an Add-On to Behavioural Therapy for Children with Selective Mutism

Selective mutism (SM) is a rare anxiety disorder that first manifests itself in
early childhood. Children with selective mutism do not speak in certain
situations where this is expected of them. For example, a child may talk at
home, but is afraid to speak at school. Selective mutism is treated with a
behavioural therapy protocol in which the child is gradually stimulated to
speak at school. The treatment usually takes place at school. During the
COVID-19 lockdown, therapists had to switch to digital solutions to treat
children with SM. Virtual reality exposure (VRE) therapy is a proven to be
effective method for treating anxiety disorders. This led to the development of
a VR homework exercises as an add-on to the behavioral treatment.

Primary Objective:
- To investigate the effectiveness of the combined treatment *Speaking at
school, a matter of doing* with the addition of the VR homework exercises.

Secondary Objectives:
- To identify factors that predict adherence to the VR homework exercises.
- To identify factors that predict the treatment outcome of the combined
treatment *Speaking at school, a matter of doing* with the addition of the VR
homework exercises.
- Compare the level of anxiety induced by the VR homework exercises compared to
the level of anxiety induced during individual therapy.
- To explore the underlying principles that contribute to the therapeutic
effect of the VR homework exercises
- To evaluate the use of the VR homework exercises in young children with SM.

Single Case Experimental Design (SCED). SCED can provide a detailed examination
of the effect of the treatment on SM symptoms over time; it provides more
detailed insight into within-person effects; it is suitable for innovative
interventions and for small and more rare populations. Parents and teacher
asked to fill out a micro assessment thrice a week. The assessment consists of
9 short yes/no questions on the child*s speaking behaviour.

There are 6 moments of assessment*:
1) A comprehensive baseline assessment (T0) will be conducted with the child,
parents and the teacher after receiving informed consent.
2) Short assessment (T1) At the start of the treatment.
3) Short assessment (T2) After the child has finished step 5 of individual
therapy.
4) Short assessment (T3) After the child has finished step 10 of individual
therapy.
5) Post treatment assessment (T4) At the end of treatment.
6) Follow-up assessment (T5) 3 months after the end of treatment.

In the comprehensive assessments (T0, T4, and T5), parents and the teacher are
asked to report on the psychosocial functioning of the client. The client also
fills out one questionnaire. At these times, a clinical interview takes place
with parents, and they fill out questionnaires about family functioning. At the
short assessments (T1, T2, and T3), contains only theprimary study variable (SM
symptoms).

The treatment in this study consists of behavioural therapy for selective
mutism (with the protocol 'Talking at school, a matter of doing') with the
addition of the VR homework exercises. The protocol consists of 10 steps that
help the child to gain confidence while speaking at school. For every treatment
step there are VR homework exercises available. Families receive a VR headset
for the duration of the study. Parents are instructed to work on the VR
homework exercises at least once a week and encouraged to work on the VR
homework exercises several times a week.

The risks associated with participation are negligible, and the burden is
minimal.

Risks: Children might experience some anxiety when completing the VR homework
exercises. However, it is necessary to simulate a stressful situation to break
the pattern of not speaking. Parents receive guidance from the therapist on how
to support their child in this process. Children might experience motion
sickness while using the VR headset. In case the child experiences motion
sickness, the VR headset can be removed. Motion sickness is temporary and does
not have any lasting effects.

Burden: Parents and children do not have any additional visits for the extra
assessments. The majority of the questionnaires used in this study are part of
standard care.Therefore the study burden on parents and children is minimal.
Children will be asked to fill out questionnaire (together with their parents)
at 3 different times. During the individual therapy sessions, children asked to
indicate how they are feeling (using pictures). After individual therapy and
the VR homework exercises, children rate their level on Visual Analogue Scale
(VAS). Parents and the child are asked to do the VR homework exercises at least
once a week for a short time. The exercises are playful, and positive
reinforcement is used.