Selective mutism is characterized by a consistent failure to speak in specific social situations in which there is an expectation for speaking. Children with selective mutism have the ability to both speak and understand language, but fail to use this ability as a result of what we would consider to be social anxiety in adults. Most children with selective mutism function normally in other areas of their lives.

Selective mutism is not a communications disorder and is not part of a developmental disorder. By definition, selective mutism does not include children with conduct disorders, oppositional/defiant behavior, and/or attention-deficit hyperactivity disorder.

The principal problem in children with selective mutism appears to be anxiety. This anxiety (which causes avoidance) seems closest to the definition of social anxiety disorder (social phobia). Indeed, most adults with social anxiety disorder relate strongly and can fully understand selective mutism, even though they themselves were not necessarily children with selective mutism.

It also appears that cognitive-behavioral therapy, with the emphasis being on the behavioral component (depending on the age of the child) is the therapy of choice.

For more information on this important problem, follow the external links below.
 

EXTERNAL LINKS TO INFORMATION 
ABOUT SELECTIVE MUTISM

The Selective Mutism Group

This informative site, constantly updated, offers comprehensive information
on selective mutism, a forum for parents to discuss the problem, and links
to other information on this long-neglected anxiety problem. 
Thanks to Bob Helta for originating this much needed website.

Selective Mutism Foundation, Inc.

The Selective Mutism Foundation offers information, support, pen pals, and
research information about selective mutism. 
Thanks to Michele P. Fineberg, LCSW, for this link.