Diagnostic Criteria

1. 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.
2. The disturbance interferes with educational or occupational achievement or with social communication.
3. The duration of the disturbance is at least 1 month (not limited to the first month of school).
4. The failure to speak is not attributable to a lack of knowledge of, or comfort with, the spoken language required in the social situation.
5. The disturbance is not better explained by a communication disorder (e.g., childhood onset fluency disorder) and does not occur exclusively during the course of autism spectrum disorder, schizophrenia, or another psychotic disorder.