Elective mutism also known as selective mutism. An individual who persistently fails to talk in a given situation where speaking is expected despite speaking in other contexts has elective mutism. The mutism must interfere with the individuals life in order to be diagnosed with this disorder and it must last for at least one month.
Individuals with elective mutism are difficult to work with because they generally have anxiety over meeting new people. I have recently started to work with a child who has elective mutism and have decided to use systematic desensitization also known as graduated exposure therapy which is a type of behavioral therapy in order to treat the child. In systematic desensitization a person will first be taught relaxation skills and then be exposed to the stimuli that causes the anxiety in hierarchy of fears and rewarded for interacting with that stimuli. For example in the beginning I will have the child look at me and then she will receive a reward. Next I will have her do a one word request to receive the reward. This will continue to happen until she is speaking in the situation that causes the anxiety.