Selective Mutism
Selective mutism is an anxiety disorder where a person is unable to speak in certain social situations, such as with classmates at school or to relatives they do not see very often. It usually starts during childhood and, if left untreated, can persist into adulthood. It’s not at all selective quite the opposite. Often they try to say something but the words never come out and they are incapable of speaking at all. The intensity can differ from person to person
Diagnostic Criteria
A. 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.
B. The disturbance interferes with educational or occupational achievement or with social communication.
C. The duration of the disturbance is at least 1 month (not limited to the first month of school).
D. The failure to speak is not attributable to a lack of knowledge of, or comfort with, the spoken language required in the social situation.
E. The disturbance is not better explained by a communication disorder (e.g., childhoodonset fluency disorder) and does not occur exclusively during the course of autism spectrum disorder, schizophrenia, or another psychotic disorder.