Selective mutism (SM) is an anxiety related behavioral disorder that results in a child’s failure to speak in some situations (typically school) despite the presence of normal speech in other situations. The failure to speak causes significant impairment at school and/or in social situations. Most, but not all children with SM also exhibit additional symptoms of social anxiety that are not related to speaking. The onset of SM tends to be very early and is usually recognized when children enter school (4-5 years old). Cognitive behavior therapy (CBT) focused on exposure to speaking and/or SSRI medication are believed to be the most effective treatments for selective mutism.