Selective mutism falls within the category of Anxiety Disorders (APA, 2013, pp. 195–197). According to the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5; APA, 2013, p. 195), the diagnostic criteria for selective mutism are as follows:
- The child shows consistent failure to speak in specific social situations in which there is an expectation for speaking (e.g., at school), despite speaking in other situations.
- The disturbance interferes with educational or occupational achievement or with social communication.
- The duration of the disturbance is at least 1 month (not limited to the first month of school).
- The failure to speak is not attributable to a lack of knowledge of, or comfort with, the spoken language required in the social situation.
- The disturbance is not better explained by a communication disorder (e.g., child-onset fluency disorder) and does not occur exclusively during the course of autism spectrum disorder, schizophrenia, or another psychotic disorder.
These behaviors are a method of self-protection during an experience of intense anxiety but may appear deliberately oppositional (Kotrba, 2015).
Individuals with selective mutism may present with social anxiety and social phobia. Symptoms of social anxiety and social phobias may include the following:
- Lack of eye contact
- Clinging to parents
- Running away
- Tantruming if asked to speak publicly
- Avoidance of eating in public
- Anxious when having picture or video taken
- Anxious to use public restrooms
(Beidel, Turner, & Morris, 1999; Kearney, 2010)
In addition to these features of social anxiety, children with selective mutism avoid initiating and participating in conversations. If they are able to express themselves, they may rely on gesturing, nodding, pointing, or whispering. They may have fears of being ignored, ridiculed, or harshly evaluated if they speak.