Selective Mutism

Selective Mutism is a disorder in which a person who is normally capable of speech is unable/unwilling to speak in given situations or to specific people.  Selective mutism usually co-exists with shyness or social anxiety.

In fact, the majority of children diagnosed with selective mutism also have social anxiety. Therefore, some researchers speculate that selective mutism may be an avoidance strategy used by a subgroup of children with social anxiety disorder to reduce their distress in social situations.