The Department of Counseling, Educational Psychology, and Special Education and the Department of Psychiatry at Michigan State University have coordinated efforts to provide a diagnostic and treatment investigation for children, ages seven to eighteen, with Selective Mutism. The purpose of this study is to examine the utility of fluoxetine for the treatment of this debilitating disorder. Fluoxetine is expected to improve social anxiety and selective mutism symptomology.

Children with selective mutism (SM) are at risk for current and continuing academic and socio-emotional difficulties. Unfortunately, this issue is complicated by the fact these children often respond poorly to psychosocial intervention. This leaves parents with the overwhelming decision to attempt a trial of medication regardless of the little available data on the evidence base of this approach. Despite the paucity of research, psychiatrists are prescribing fluoxetine for children with SM "off label", as the Food and Drug Administration (FDA) has yet to approve fluoxetine for this indication. This study blends the psychopharmacological expertise of psychiatrists with the mental health, systems, and psychological evaluation expertise of school psychologists to identify an appropriate psychopharmacological solution for children and adolescents with this debilitating disorder. To that end, this study will examine the utility of fluoxetine for the treatment of five children and adolescents, ages seven to eighteen, diagnosed with SM through the use of a non-concurrent multiple-baseline single-case design with a single-blind placebo-controlled procedure. Treatment effectiveness will be evaluated by visual analysis of the data, the Wampold and Worsham multiple-baseline design randomization test, and the Kendall's Tau + Mann-Whitney U effect size. Multiple methods of assessment including standardized measures, such as the Selective Mutism Questionnaire (SMQ), and behavior ratings, such as Direct Behavior Ratings (DBRs), will be used to gather baseline and treatment data. Multiple informants (i.e., parents, teachers, and psychiatrists) will provide information on treatment effect across settings (i.e., school and community). Information regarding adverse effects associated with fluoxetine treatment including a measure of behavioral disinhibition, parental acceptance of the fluoxetine intervention, and compliance with taking the medication will also be gathered.

Inclusion Criteria:

• Male or female from seven to seventeen years of age at their last birthday
• Meet DSM-IV-TR criteria for selective mutism
• No history of medication treatment for selective mutism
• Child has an immediate biological family member who is diagnosed with an anxiety disorder or has experienced symptoms of an anxiety disorder at some point in time
• Child has received 10 weeks of an evidence-based psychosocial treatment
• Child has never had a negative reaction to a psychopharmacological medication
• Child exhibits symptoms of social anxiety

Exclusion Criteria:

• Child is diagnosed with a speech condition, mental retardation, pervasive developmental disorder, or schizophrenia
• Child is an English language learner or from a different culture than the culture predominately represented within his or her school
• Child is taking or has taken any kind of a psychopharmacological medication (e.g., SSRI, MAO-I, stimulant, etc.)
• Child has a medical illness that may be complicated through the use of a psychopharmacological treatment

Participants serve as their own controls by being randomly assigned to switch from placebo to active medication at staggered start dates per single case design methodology.