Definition: Selective Mutism (SM) is an anxiety disorder which often appears in early childhood, characterized by the PERSISTENT failure to engage in speech in specific social situations where speech is typically expected, despite technically possessing the full capability (the necessary physical structures and speech motor processes) to being able to speak and hear.

Selective Mutism often co-exists with Social Anxiety Disorder (SAD).

The DSM-IV-TR criteria for Selective Mutism specifies that this persistent failure to speak should not be attributed to these following reasons:

1. An organic inability rooted in the individual's language capability (e.g. comprehension, in-fluency in language, etc)
2. Another communication disorder (e.g. stuttering)
3. A diagnosis of another psychotic disorder (e.g. Pervasive Development Disorder, Schizophrenia, etc)

Please note that a comprehensive and uniform theory about the etiology, assessment, and treatment of SM does not exist; Historically, varying definitions and criteria have been applied to individuals with SM, and so this provided definition and diagnostic criteria may not be yet as inclusive as it can be.

Image citation: Journal of American Academy of Psychology. Factors That May Influence Speech and Social Inhibition., 17 Feb. 1995, www.sciencedirect.com/science/article/abs/pii/S0890856709635930. Accessed 22 June 2023.