With selective mutism, it can be difficult to speak to others in unfamiliar social settings. Learning the signs may help you cope.

Selective mutism is a childhood anxiety disorder characterized by a person being unable to speak in certain social situations. But they’re able to communicate effectively with others when they feel safe, usually around family or at home.

Fewer than 1% of children have selective mutism, and it affects more girls than boys. Selective mutism may begin between ages 3 and 6. Diagnosis is usually given between ages 5 and 8, after a child starts school.

Most children outgrow selective mutism, but there may be lingering anxiety or social phobia once the inability to speak resolves. The child’s academic and social progress may be affected too.

But help is available in the form of therapy or a combination of therapy and medication.

According to the Diagnostic and Statistical Manual of Mental Disorders, 5th edition (DSM-5) and other diagnostic tools, selective mutism is diagnosed when:

  • Your child consistently does not speak in a social situation where speaking is expected, like school, even though they speak at home or in other situations.
  • Your child is easily understood when they do speak.
  • Your child is fluent in the language used in situations where they’re mute.

Your child may also have symptoms of separation anxiety disorder and social anxiety disorder (social phobia), including but not limited to:

  • clinginess
  • avoiding speaking in public, taking photos in public, or using public facilities
  • hiding, running away, or having tantrums when asked to speak publicly

Adolescents and adults may have selective mutism, but symptoms do not usually appear for the first time after childhood.

An older individual with selective mutism has likely had the disorder since they were little but never received treatment.

Not speaking at all in a certain social situation but usually speaking in others

Your child may be entirely mute at school then return home and speak as usual with their parents, siblings, and other members of their household.

This behavior is one of the biggest indicators of selective mutism. Your child’s inability to speak in a particular situation may come off as defiant or oppositional, but it’s not a behavioral issue. It’s rooted in anxiety.

The mutism hampers your child’s academic or social progress

If you notice that your child’s grades are dropping or their teacher is concerned about whether they’re learning the material being taught, it may be another sign of selective mutism.

Keep in mind that the way selective mutism presents itself can be different in each person.

While some children experiencing selective mutism may be unable to communicate with anyone in specific social settings, others may feel comfortable talking with a select few people.

The behavior is consistent for more than 1 month, not including the first month of a new situation

Many children starting school are shy and might be hesitant to speak up in class.

But if your child is entirely mute beyond 1 month in that situation and the mutism is consistent, it can be a sign of selective mutism.

Try to stay aware of how they interact with other students or if they draw back from communicating with others in the class setting.

Your child is not learning or adjusting to a new language

A child who does not know the language being used in a classroom or is just starting to learn it may not speak at first.

For example, if you have just moved to a new country or your child has just started a dual-language program, it may take time for them to comfortably speak that language.

A selective mutism diagnosis will only occur in a child comfortable with the language but still not speaking at all.

Research does not show a single cause of selective mutism. However, research from 2016 suggests selective mutism appears to have roots in a mix of the following factors:

  • genetic
  • environmental
  • developmental
  • temperamental

A family history of anxiety disorders, especially social anxiety, may also play a part.

If your child is already prone to anxiety and shows signs of social anxiety or social phobia, these may be precursors to selective mutism.

Research from 2019 shows that 69% of children with selective mutism also have social phobia.

Children with social phobia may have separation anxiety, which is excessive fear or anxiety concerning separation from someone they’re attached to.

A 2007 study of 6 adults who had selective mutism as children found that trauma may play a role in your child’s inability to speak in certain situations.

That same study indicated that social factors, like bullying, may also play a role in your child’s selective mutism.

Cognitive behavioral therapy (CBT) is the usual treatment for selective mutism. But one study that looked at children 5 years after CBT for selective mutism found that half of them still reported selective mutism symptoms and had difficulty speaking in certain social situations.

CBT treatment focuses on decreasing your child’s anxiety around school or other situations where they’re selectively mute. It may involve exposure therapy in a safe environment, where your child will be encouraged to speak while exposed to the situation that makes them anxious.

Medication for anxiety, like selective serotonin reuptake inhibitors (SSRIs), is also effective in combination with therapy. But there is currently limited evidence for their effectiveness for those living with selective mutism.

When selective mutism was reclassified as an anxiety disorder in the DSM-5, mental health professionals began to use SSRIs as a treatment.

Selective mutism is an anxiety disorder. It is not a physical inability to speak. It is also not rooted in developmental causes.

If you believe your child may have selective mutism, consider discussing their symptoms with a speech-language pathologist to rule out communication disorders, like a physical issue with the muscles around the mouth or the tongue.

You might also consider speaking with a qualified mental health professional, like a licensed psychologist or psychiatrist, to help diagnose selective mutism.

A developmental pediatrician can also help give you a diagnosis and rule out developmental disorders like autism.

While there is likely a genetic component to selective mutism, it may be worth exploring whether your child has been traumatized in some way or shows other symptoms of social anxiety or social phobia.

These environmental factors are often mentioned by adults who had selective mutism as children.

A licensed mental health professional can help explore the different possible environmental factors that might be influencing your child’s selective mutism, like social anxiety. Trauma may also be explored, but this is an uncommon explanation for selective mutism.

There is help available for your child. Therapy is highly effective in targeting the root cause of your child’s anxiety. You may also consider medication since it can be helpful when therapy alone is not enough.