Delayed first words and speech irregularities are some of the most common symptoms of autism spectrum disorder (ASD). If your child only talks with close family members and friends but shuts down at school or with extended family, you might suspect that autism is the reason.
When a child finds themself unable to speak to certain people, this is called “selective mutism.” But what causes selective mutism? Is it always linked to ASD? Let’s dive into these questions and more.
What is selective mutism?
Mutism, simply put, is when someone is not able to speak. Some people have total mutism, which means they can’t verbally communicate at all. This is usually due to some form of brain damage or severe speech disorder.
Selective mutism means that the failure to speak only occurs in some situations. As mentioned above, many children with this condition can talk with parents and other family members. They may also communicate with close friends and select classmates. But with anyone else, they’re unable to talk, not necessarily unwilling. Some kids with selective mutism may reply to others with non-verbal methods like hand gestures, while some won’t respond at all.
Selective mutism is a recognized disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). It specifies that the following requirements be met for a selective mutism diagnosis:
- The failure to speak isn’t connected to a lack of fluency in the language
- The condition lasts at least one month
- This month shouldn’t be the first month of school, since it may be normal for students to be shy
- It interferes with the person’s academic, occupational, and/or social success
- It can’t be better explained by a communication or fluency disorder
- It doesn’t occur exclusively because of schizophrenia, autism, or other disorders (more on this later)
Parents usually notice the onset of symptoms around three to four years old when children enter preschool. It’s estimated that 0.2% to 0.8% of kids struggle with this, and that more girls are diagnosed with selective mutism than boys. The disorder is most common in children but can last into adulthood.
What causes selective mutism?
The DSM-5 classifies it as an anxiety disorder, and most professionals point to social anxiety as the primary cause. Social anxiety results in excessive stress, self-consciousness, and fear of embarrassment.
Some research has indicated that social anxiety disorder is the most common comorbid condition with selective mutism. It’s been argued that selective mutism is just a very extreme form of social anxiety, rather than a disorder in itself.
That said, a number of other comorbid conditions have been seen in children with selective mutism, such as depression, ADHD, obsessive-compulsive disorder, Fragile X syndrome, speech and language difficulties, and ASD.
Can you have selective mutism and autism?
The short answer is…it’s complicated. The DSM-5 draws a boundary between the two disorders, but this has caused some confusion in the clinical community.
Steffenburg et al. (2018) studied the potential prevalence of autism in children with selective mutism. There were 97 participants between four and 18 years old with a confirmed selective mutism diagnosis. None of them had been diagnosed with ASD, but after an autism screening during the study, researchers concluded that 63% met the diagnostic criteria for ASD.
Steffenburg et al. believe that signs of autism may be missed because the lack of verbal communication becomes the main focus of parents and doctors. This article suggests that ASD and selective mutism may not be mutually exclusive, after all, and that professionals should look for symptoms of both.
It’s also worth noting that an estimated 40% of autistic people have comorbid anxiety disorders. Since social communication is often a challenge for children with ASD, social anxiety is particularly common. This further strengthens the potential relationship between ASD and selective mutism.
However, Steffenburg et al. noticed a different motivation in their participants with both ASD and selective mutism. Although most kids with selective mutism are thought to be “frozen with fear” in a group setting, the researchers observed that the lack of speaking in these children was rooted more in stubbornness and a lack of social interest.
Selective Mutism and Its Relations to Social Anxiety Disorder and Autism Spectrum Disorder by Peter Muris and Thomas H. Ollendick also emphasized that anxiety isn’t the only possible factor for children with ASD. They may also display selective mutism because they don’t “properly understand specific social situations, [have] difficulties to read other people’s minds, [do] not know how to respond to the other person(s), and/or [are] less interested in engaging in the social interaction.”
Muris and Ollendick agree with Steffenburg that the link between selective mutism, anxiety disorders, and ASD needs more attention. They go on to say “we see no reason why ASD is listed as an exclusion criterion for one anxiety disorder—[selective mutism] SM—while being allowed as a comorbid condition for other anxiety disorders including [social anxiety disorder] SAD.”
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Does my child have mutism or autism?
As we’ve seen, it’s possible for kids to show signs of both conditions. If your child has ASD, selective mutism won’t be the only symptom. Keep an eye out for other traits, such as…
- Self-stimulatory behaviors
- Lack of eye contact
- Sensory sensitivities
- Insistence on routines
- Possible meltdowns or shutdowns
- Speech and language delays
…and other behaviors. Check out our article Signs of Autism in Babies and Toddlers for more information about spotting ASD in young children.
What is the treatment for selective mutism?
Children with this condition are typically treated by mental health professionals, speech-language pathologists (SLPs), or both. SLPs will be able to help if your child has difficulties, like stuttering or cluttering, that could make them feel insecure about their voice.
An SLP can also examine your child’s mouth, jaw, and tongue to see if there are any physical issues. They’ll probably also conduct a hearing test to make sure their mutism isn’t due to troubles with understanding others.
Speech therapists may use a variety of tactics to encourage your child to speak more. One, called “shaping,” rewards all attempts at communication: eye contact, pointing, mouthing words, whispering, etc. This helps the child gradually become more comfortable sharing their thoughts. Activities like reading aloud may also be used to work up to speaking in a conversation.
“Stimulus fading” is when the child starts out speaking to someone they’re close with, and another person slowly joins in.
Cognitive Behavioral Therapy (CBT)
CBT, which is also a common treatment for people on the spectrum, has been very effective for kids with selective mutism. This therapy empowers patients to recognize and adjust their emotions and thought patterns. In this case, it would teach children how to manage their distress in scary situations.
Some clinical professionals recommend medication for adolescents with this condition, especially if they also have depression. In more severe cases, medication might be necessary to control their nerves.
If your child will only speak in specific situations, it’s natural to worry that it’s more than just shyness. Anytime you have concerns about your son or daughter’s speaking, it’s best to address them with your doctor as soon as possible. Treatment at an early age is the best option, so your child’s speaking habits don’t become too ingrained.
Selective mutism doesn’t necessarily mean your child is autistic. But some research suggests that more kids have both conditions than previously thought, so consider asking for an ASD screening as well.
Don’t put too much pressure on your child to talk, since that can increase their stress, and remind friends and family not to do so, either. Respond positively to all forms of communication, verbal or not. Ultimately, the best thing you can do as a parent is support your child, wherever they land on their communication journey.
ASHA. (n.d.). Selective Mutism. American Speech-Language-Hearing Association. https://www.asha.org/public/speech/disorders/selective-mutism/
Muris, P., & Ollendick, T. H. (2021, January 19). Selective Mutism and Its Relations to Social Anxiety Disorder and Autism Spectrum Disorder. Clinical Child and Family Psychology Review, 24, 294-325. https://link.springer.com/article/10.1007/s10567-020-00342-0#Abs1
Steffenburg H, Steffenburg S, Gillberg C, Billstedt E. Children with autism spectrum disorders and selective mutism [published correction appears in Neuropsychiatr Dis Treat. 2018 Sep 06;14:2305]. Neuropsychiatr Dis Treat. 2018;14:1163-1169. Published 2018 May 7. doi:10.2147/NDT.S154966
van Zwanenberg, H. (2018, August). Selective mutism treatment. Priory. https://www.priorygroup.com/mental-health/selective-mutism-treatment