Background: Randomized controlled psychosocial treatment studies on selective mutism (SM) are lacking. Method: Overall, 24 children with SM, aged 3-9 years, were randomized to 3 months treatment (n = 12) or wait list (n = 12). Primary outcome measure was the School Speech Questionnaire. Results: A significant time by group interaction was found (p = .029) with significantly increased speech in the treatment group (p = .004) and no change in wait list controls (p = .936). A time by age interaction favoured younger children (p = .029). Clinical trail registration: Norwegian Research CouncilNCT01002196. Conclusions: The treatment significantly improved speech. Greater improvement in the younger age group highlights the importance of an early intervention.
Key Practitioner Message• Early detection and treatment of children with selective mutism is crucial due to the elevated risk for chronicity of symptoms.• The preschool arena is an important setting for the recognition of anxious and withdrawn behaviour that often precedes selective mutism.• Evidence supports the use of a home-and school-based psychosocial intervention to increase speech.• Greater improvement in younger children (preschool) highlights the importance of early intervention.Keywords: Selective mutism; randomized controlled trial; behavioural intervention; social phobia; childhood anxiety
IntroductionChildren with SM are characterized by a consistent lack of speech in specific social situations in which there is an expectation for speaking (e.g. school) despite speaking in other situations (e.g. home) (American Psychiatric Association, 2000). SM is found to be associated with comorbid anxiety diagnoses, in particular with social anxiety disorder, as well as neurodevelopmental disorders (Kristensen, 2000). Age of onset is typically before age 5 years (Black & Uhde, 1995). SM is relatively rare, with a prevalence of about 0.7-0.8% in childhood, somewhat more frequent in girls (Bergman, Piacentini, & McCracken, 2002). A 0.1% prevalence of SM was found in a representative sample of Norwegian 4 year olds using a preschool diagnostic interview (Wichstrom et al., 2012).SM is considered to be hard to treat and the literature on treatment for SM is dominated by case studies or case series. One review describes that the few existing studies (since 1980) with samples above five children have mainly used behavioural, cognitive-behavioural or multimodal interventions (Manassis, 2009). Another review states that behavioural interventions (including stimulus fading, desensitization, shaping, modelling and contingency management) are most frequently used (Cohan, Chavira, & Stein, 2006). Only two studies include a comparison group. The first study examined retrospectively the records for 25 children with SM treated either with behavioural therapy or a school-based remediation programme. The children treated with behavioural therapy showed a greater improvement compared to the group which received the school-based remediation intervention (Sluckin, Foreman, & Herbert,...