Answer by Mark Myers:
Selective Mutism, as you may well know, is predominately found in children. However, some adults do experience it as well. This disorder is characterized by a person persistently failing to speak in select settings, which continues for more than 1 month. These individuals do talk to other people, usually family members.
The diagnosis of Selective Mutism, does fall under the anxiety disorder spectrum. This spectrum would also include OCD. In fact, it is not unusual for OCD, or other types of anxiety disorders to coexist with Selective Mutism. It also does put a person at greater risk to develop other anxiety disorders later in life.
Without having met your son, I can speak in general about what may be going on. The obstinance in childhood you were talking about could have been a way for him to cope with uncomfortable or anxiety provoking situations. It would be informative to see when the behavior would present itself. A stressful situations such as exams that are currently going on, intensify symptoms. The behavior could be indicative of OCD and his inability to cope with stress.
I would strongly suggest having your son see a therapist and psychiatrist to address the symptoms. In most cases, both treatment modalities are needed.
