Selective Mutism and Autism: Is There a Link?

Selective mutism and autism can often be confused with one another, and while there are some similarities between the two, are they linked in any way?

Selective mutism can often get misconstrued for autism. There’s a large amount of overlap in social behaviours and the disorders can sometimes be hard to differentiate. The two are, however, separate disorders each with their own diagnostic criteria. Although, research has found there may be more of a link between the two disorders than previously thought.

This post covers, what is selective mutism, the similarities and differences between selective mutism and autism, non-verbalism in autism, non-verbal shutdown vs selective mutism, and if there’s a link between the two disorders.

This post is all about selective mutism and autism!

 

What is Selective Mutism?

Selective mutism is an anxiety disorder that mostly affects children. It prevents them from being able to speak in certain situations where they feel anxious, such as at school or large family gatherings. They can, on the other hand, speak in situations where they are comfortable, such as with immediate family and close friends.

Selective mutism is incredibly rare and affects about 1% of children. Some studies have shown that the disorder is more prevalent in girls than boys, but other studies have shown the opposite, leading researchers to believe there are likely no gender differences in the disorder.

Selective mutism is treatable and can be overcome with the help of therapy and willing adults. Most do overcome the disorder but still suffer from social anxiety symptoms, while others may still meet the criteria into adulthood.

 

Here are the diagnostic criteria for selective mutism:

1. A consistent failure to speak in specific social situations where there is an expectation to do so despite speaking in other situations.
2. Being unable to speak interferes with your social, academic, or work life.
3. The inability to speak in a specific context lasts at least a month and is not limited to the first month of school.
4. Not speaking is unrelated to language barriers.
5. It is also not related to a communication disorder and does not occur exclusively during the course of autism spectrum disorder, schizophrenia, or another psychotic disorder.

 

Most parents recognize something is off when their child begins school. Teachers may inform them of their child’s nonverbal behaviour in the classroom. This may surprise the parents if their child is chatty at home but often sparks them to get their child into counselling.

 

Other signs of selective mutism include:

• Other signs of anxiety, social and separation anxiety are common
• Using non-verbal communication such as pointing or writing
• Being highly sensitive to the feelings of others
• Struggling to make eye contact
• Speech or language delays
• Difficulty engaging with peers
• Not eating or using the bathroom at school
• Sensory sensitivities

 

Related Post: What is Selective Mutism? And Why is It So Unheard of?

 

The Difference Between Selective Mutism and Autism

Autism or ASD, on the other hand, is considered a spectrum disorder. This is because the level of impairment can differ greatly for each individual, each dealing with different challenges and strengths. ASD is also commonly diagnosed in childhood. Children with autism often demonstrate difficulty in social situations, repetitive behaviours, and communication deficits.

 

Signs of autism include:

• Becoming fixated on certain topics or routines
• Displaying repetitive behaviours
• Signs of anxiety, such as phobias, social anxiety, or obsessive-compulsive tendencies
• Difficulty understanding non-verbal communication
• Struggling to understand the feelings of others
• Difficulty maintaining eye contact
• Speech or language delays
• Periods of regression in speech or language abilities
• Repeating words or phrases
• Difficulty interacting with peers
• Sensory sensitivities

 

As you can see, there is some crossover in symptoms of selective mutism and autism, such as anxiety symptoms, difficulty engaging with peers or making eye contact, and sensory sensitivities. There are, however, also a lot of differences. The main distinction is that a person with selective mutism will only display these social traits when faced with anxiety, and exhibits typical social abilities the rest of the time. Whereas, someone with autism would display the same social traits in all circumstances.

Another difference between these disorders is that children with SM have a great sense of empathy and understanding of others’ feelings. Someone with autism, on the other hand, may struggle to understand others’ emotions. Children with SM are often proficient in non-verbal communication and have no difficulty understanding this type of communication, whereas people with autism can struggle with this.

 

Non-verbalism in Autism

While some people with autism can be entirely non-verbal, this is different from SM where they can speak in some situations but not others. However, other people with autism may only become non-verbal at times, making it harder to differentiate from selective mutism. It then comes down to the reason behind the mutism, if it’s caused by anxiety, they may also have selective mutism if they meet the rest of the criteria.

The criteria for SM states, the disorder “cannot occur exclusively during the course of autism spectrum disorder”, which makes it sound as if the two cannot coexist, but actually differentiates between a person with autism who can speak in some situations but not others for reasons unrelated to anxiety. The two disorders can coexist and in fact, do so quite commonly.

 

Non-Verbal Shutdown vs Selective Mutism

People with autism often experience overwhelm by their environment or social situations which can lead to shutdown or sensory overload, which may cause them to become non-verbal. This can cause what appear to be SM traits, but this doesn’t necessarily indicate SM.

In most cases a non-verbal shutdown wouldn’t fit the criteria for SM unless it happened consistently over time in the same situations, then it might. One difference to keep in mind, however, is the cause of becoming non-verbal. In the case of a shutdown, it is often due to overwhelm rather than anxiety. Whereas, a person with SM is unable to speak due to their anxiety about speaking.

 

Is There a Link Between SM and Autism?

Psychometrics, such as the Social Responsiveness Scale (SRS) which measures social behaviours and communication traits, aren’t the most reliable when it comes to differentiating between the two disorders. SRS scores of those with selective mutism and those with autism tend to overlap, meaning it’s not always easy to differentiate between the social behaviours of the two.

Studies have found that 63-80% of children with SM also fit the diagnostic criteria for autism, yet many children with SM are missed in being diagnosed with autism. Their lack of speech often becomes the main focus and other autistic behaviours get glossed over.

There appears to be an association between SM traits and autistic traits. Studies have shown that children with more autism traits often display more traits of SM, meaning that to a degree, autism traits can predict the likelihood of SM traits.

A common thread between selective mutism and autism is sensory sensitivities. In some cases, this can lead a child with autism into overwhelm which may cause them to be unable to speak. Research also shows that children with SM who display sensory sensitivities are more likely to have autism.

A genetic link was found linking autism, selective mutism, and social anxiety. These disorders have been referred to as allied conditions since they so frequently occur together and can be challenging to differentiate.

This research indicates an overlap between selective mutism and autism. Therefore, it’s suggested that if you are diagnosed with SM it’s worth exploring the possibility of an autism diagnosis as well.

 

As you can see, there’s a lot of overlap between selective mutism and autism often making it challenging to differentiate between the two. They occur together quite commonly and chances are if you display traits of one, you also display traits of the other. This can cause missed diagnosis when signs of one disorder are focused on more than the other. So, if you have selective mutism it may be worth also looking into an autism diagnosis.

 

Post by Morgan Peters

 

Other Posts You May Like:

How to Help a Child With Selective Mutism

What Causes Selective Mutism? Misconceptions & More!

What is Selective Mutism & Why is It So Unheard Of?

 

Sources:

“Selective Mutism.” PsychDB, 29 Mar. 2021, www.psychdb.com/anxiety/selective-mutism.

Delano, Claire. “Selective Mutism and Autism: Is My Child Mute or Autistic?” Autism Parenting Magazine, 22 Oct. 2021, www.autismparentingmagazine.com/selective-mutism-autistic/.