Which disorder is defined by a persistent failure to speak in expected situations primarily due to fear?

The correct answer, Selective Mutism, refers to a childhood anxiety disorder characterized by a consistent inability to speak in specific social situations where there is an expectation to communicate, despite the individual being able to speak in other contexts, such as at home with family. The key element of this disorder is the persistent and marked fear that interferes with verbal communication, and it is not due to a lack of knowledge or comfort with the language expected in that setting. Typically, the symptoms of Selective Mutism can be observed for at least one month (not just during the first month of school) and can significantly impact educational and social functioning.

In contrast, while Social Anxiety Disorder also involves fear of social situations, it encompasses a broader range of anxieties beyond just speaking, such as fear of being judged or embarrassed in various social contexts, not limited to speaking situations. Panic Disorder involves recurrent unexpected panic attacks and not a persistent fear related to speaking. Unspecified Depressive Disorder is related to mood disturbances rather than communication concerns. Thus, the focus on the specific context of speaking due to fear distinctly identifies Selective Mutism as the accurate definition within the given options.