SM: Diagnosis

Diagnosis should be made by a professional familiar with selective mutism who can rule out other conditions that present similar symptoms. Since young, anxious children have difficulty participating in interviews—particularly if they have SM—the expert making the diagnosis will rely heavily on reports from parents and other adults in the child’s life, to determine a pattern of behavior across situations. They might request home videos of the child’s behavior in her “place of strength” and/or observe her alone with her parents (though a one-way mirror). To be diagnosed with SM a child must be able to speak in some settings but not in others, the condition must have lasted for a month that is not the first month of school, and it must interfere with schooling and social activities.