A trained professional familiar with SM and/or childhood anxiety disorders will generally begin by conducting a thorough assessment to accurately diagnose the condition, rule-out similar or comorbid conditions, and formulate a treatment plan. Information will be gathered about the child’s developmental history (including achievement of developmental milestones and whether or not there were any delays in hearing, speech and motor and cognitive development), family history (including determining whether or not other anxiety disorders are present in the family), behavioral characteristics, medical history, and significant stressors (including divorce, frequent moves or a death in the family). The treatment professional may also request permission to contact the child’s school, physician and other significant players in the child’s life to gain further information about the child’s behavior in other settings. It can also be helpful for the professional to view a videotape of the child in a comfortable setting and/or do an observation of the child before the child has met the professional so that the child’s behavior will not be influenced by the professional’s presence.

The professional will then arrange to meet with the child. While most children with SM will not speak to the treating professional, some may be comfortable in the treatment setting and speak normally, although this behavior does not rule out selective mutism. The “selective” nature of the mutism varies from child to child and setting to setting so this needs to be considered in conducting a thorough assessment. It is important that the professional develops rapport with the child and evaluates his/her behaviors, preferably in more than one setting. An appropriate professional will be able to interact with the child whether or not he or she is speaking and use appropriate methods to begin to develop a therapeutic relationship.

Because some children with SM may have difficulties with expressive language or other communication disorders, a speech and language evaluation might also be necessary. In addition, a physical exam (including testing of hearing), standardized testing, psychological assessment and developmental screenings are often recommended, especially if the diagnosis is not clear.