Objective: Very few controlled trials have evaluated targeted treatment methods for childhood selective mutism (SM); the availability of evidence-based services remains limited. This study is the first controlled trial to evaluate an intensive group behavioral treatment (IGBT) for children with SM.
Method: Twenty-nine children with SM (5-9 years; 76% female; 35% ethnic minority) were randomized to immediate SM 5-day IGBT or to a 4-week waitlist with psychoeducational resources (WLP), and were assessed at Week 4 and again 8 weeks into the following school year.
Results: IGBT was associated with high satisfaction and low perceived barriers to treatment participation. At Week 4, 50% of the immediate IGBT condition and 0% of the WLP condition were classified as "clinical responders." Further, Time × Condition interactions were significant for social anxiety severity, verbal behavior in social situations, and global functioning (but not for SM severity, verbal behavior in home settings, or overall anxiety). School-year follow-up assessments revealed significant improvements across all outcomes. Eight weeks into the following school year, 46% of IGBT-treated children were free of an SM diagnosis. In addition, teachers in the post-IGBT school year rated less school impairment and more classroom verbal behavior relative to teachers in the pre-IGBT school year.
Conclusions: Findings provide the first empirical support for the efficacy and acceptability of IGBT for SM. Further study is needed to examine mechanisms of IGBT response, and other effective SM treatment methods, in order to clarify which treatment formats work best for which affected children. (PsycINFO Database Record (c) 2019 APA, all rights reserved).