Many children with Selective Mutism do also have a diagnosis of Autism. One study showed that 7% of children with selective mutism also had Asperger’s disorder (now called Autism), however another study using a sample of children treated at a hospital outpatient clinic showed a massive 63% of children with Selective Mutism had Autism (these were obviously a more severe sample, but a very high comorbidity). However we also see cases where selective mutism has been misdiagnosed as autism.
One telling indicator of whether a child has selective mutism or autism is the difference between communication at home and at school and other social situations. A child with Autism would show impairments in social/emotional communication (amongst other factors) across all settings, whereas in Selective Mutism, the impairments in communication are only seen in situations where the child is anxious, such as school or even home when there are visitors.
At the start of treatment we conduct a comprehensive assessment of the child’s current and past communication and developmental and family history to help determine whether there is a diagnosis of Selective Mutism alone, or a possible additional diagnosis of Autism. When we do suspect the child might have both diagnoses we generally treat the Selective Mutism first before we recommend testing for Autism.