Selective mutism: a parent's guide when your child can't speak in certain places

What selective mutism actually is (and isn't)

Selective mutism is a recognised anxiety disorder in which a child who can speak fluently in some settings consistently cannot speak in others. The not-speaking is real, not chosen.

The diagnostic criteria, set out in the DSM-5 and ICD-11, require consistent failure to speak in specific social situations (most commonly school) despite speaking in others (usually home), lasting at least a month and not in the first month of starting school. The child must be able to speak the language; selective mutism is not a language disorder, though the two can co-occur. (DSM-5 / ICD-11; SMIRA, 2025.)

The UK charity SMIRA (Selective Mutism Information & Research Association) puts the central point clearly in their 2025 position statement: selective mutism is an anxiety response, not a behavioural choice, and intervention must be individualised and never “one size fits all.” (SMIRA, 2025. See References.)

What selective mutism is not:

• Not shyness. Shy children speak after warming up. Selectively mute children do not speak in the situation at all, even after months or years of familiarity.
• Not stubbornness. The child usually wants to speak and can't.
• Not trauma in itself. Although it can co-occur with trauma, selective mutism most often arises in a child who has an anxious temperament and is in a new and demanding social environment.
• Not the same as autism. But around 30 to 40% of children with selective mutism are also autistic, which shapes the support that helps.
• Not something they grow out of with time alone. Some do, but waiting passively is the largest source of preventable harm.

The iceberg: what you see vs what is happening

The not-speaking is the surface. Underneath, the child's nervous system is in a freeze response.

The mechanism: in certain settings, the child experiences intense anxiety. The body's fight-flight-freeze system activates. For most selectively mute children, freeze wins. Speech is the first thing to go. Sometimes movement, too. The child looks blank, still, polite, “well-behaved.” From the outside it can look like calm. From the inside it is a system locked.

This is why “just say hello” or “use your words” from a well-meaning adult cannot work. You can't will yourself out of a freeze. The route out is calming the nervous system enough that speech becomes possible again. Pressure does the opposite.

Why teachers and family often misread it

Three common readings, all wrong.

• “She's just shy, she'll grow out of it.” Said by 90% of family members and many GPs at first contact. Sometimes true. Often not. The cost of assuming it is high.
• “She talks at home, so she can talk at school if she wants to.” Misreads selective mutism as choice. Volitional framing reliably makes it worse.
• “She's very well-behaved.” The quiet, frozen child is sometimes praised at school for being “easy.” The praise feels good and is misleading. A child who never asks for the toilet, never asks for help, never tells the teacher they don't understand is not well-behaved; they are silenced by their own anxiety.

A particularly hard pattern: girls with selective mutism are much more likely to be missed at school. The criteria for notice in primary classrooms tilt towards disruption. Silent, anxious girls slip through. Many of the same girls will later be assessed for autism with a fuller picture emerging.

What makes selective mutism worse

The list is long, and most of it is what kind adults instinctively do.

• Prompting speech. “Say hello to Granny.” “Use your words.” “Just try.” All add demand to a frozen system.
• Rewards for speaking. Sticker charts, certificates, public praise. Add pressure; produce more freezing.
• Public attention. “Listen everyone, she said hello!” Often ends speech in that setting for months.
• Speaking for them as a habit. A sibling or parent who always orders for the child, answers questions for the child, is reasonable in the moment but cements the pattern.
• Telling the school it's a problem. Some schools respond by removing the child to the SENDCO office to “help her find her voice.” This usually backfires.
• Punishment or consequences. A small minority of schools still treat the not-speaking as non-compliance. Inexcusable, occasionally still happens. Push back hard.

What actually helps at home and school

The principle is the opposite of the instinct: lower the pressure to speak so far that the child's nervous system relaxes and speech becomes possible.

1. Accept non-verbal communication fully. Nodding, pointing, written notes, a whiteboard, sign, picture cards. Treat these as full communication, not stepping stones.
2. Comment, don't question. “That looks like fun” rather than “What are you doing?” Questions force a response and trigger the freeze.
3. Play alongside, not face-to-face. Side-on play, parallel activity, no eye contact demands. Speech tends to emerge in side-on play before face-to-face talk.
4. Build the speaking circle outward, slowly. Start with the people they speak to (usually parents). Add a new person who comes into the child's safe space gradually. Speech extends to the new person over weeks, not days. SMIRA and most NHS SLT services call this “sliding-in.”
5. Use the child's recorded voice. A short clip of the child speaking at home, played at school, helps demystify the voice and is often a step on the way to in-school speech.
6. Make the environment less demanding. Smaller groups, predictable routines, sensory comfort. Selectively mute children with sensory differences need both addressed.

The UK referral route: GP, SaLT, CAMHS

Coverage varies. Some areas have specialist selective mutism services in NHS speech and language therapy. Others handle it through general SLT or CAMHS.

1. Step one: GP. Use the words “selective mutism” in the booking call. Ask for a referral to community paediatrics or directly to NHS speech and language therapy.
2. Step two: NHS Speech and Language Therapy (SaLT). In many areas, SLTs are the lead clinicians for selective mutism. Some NHS trusts (Oxford Health, Kent CHFT, Devon, NELFT) have dedicated SM pathways with sliding-in protocols.
3. Step three: CAMHS. Sometimes added where anxiety is severe or where the child is older and the mutism is generalised. Adapted CBT is sometimes used alongside SaLT-led work.
4. Step four: school involvement. The most effective treatment is school-based, with a trained teaching assistant doing sliding-in work daily. This is the part the NHS most often cannot deliver alone. School partnership is essential.

SMIRA maintains a UK directory of professionals familiar with selective mutism and can advise on local services. Their parent-information line is the right first non-NHS call. (SMIRA. See References.)

What to ask the school for

Most schools have not met selective mutism before. The phrase that does the work is “reasonable adjustments.”

Under the Equality Act 2010, schools owe reasonable adjustments to disabled pupils. A child with diagnosed or strongly suspected selective mutism qualifies. The SEND Code of Practice 2015 graduated approach (assess, plan, do, review) applies under SEN Support; no EHCP is needed for any of this. (Equality Act 2010 s.20; SEND Code 6.36-6.56. See References.)

What to ask for, specifically:

• No public questioning. No requests to answer in front of the class. No reading aloud unless your child has indicated they want to try.
• Accepted alternative communication. Pointing to a board, written answers, nodding, a whiteboard.
• A named adult to do sliding-in work. Ten to fifteen minutes daily in a quiet room with one consistent adult. The single most evidence-supported school adjustment.
• No rewards for speaking. Specifically named as harmful by SMIRA. Write it down.
• Toilet access by signal. Many selectively mute children will not ask to leave the room.
• A pre-arranged adult check-in for the start of every day so the child does not have to initiate.

When to seek specialist help urgently

Selective mutism is treatable. The window in which it is most treatable is between ages 3 and 8. Earlier is better.

Move quickly if:

• Your child has not spoken at school for more than one full term.
• Your child is starting school next September and does not speak in any setting outside the family.
• The mutism is spreading (formerly spoke in some outside settings, now silent in all).
• Your child is showing physical symptoms in social settings (sweating, freezing, tummy aches at school) consistent with severe anxiety.
• Your child is over 10 and the mutism has not been formally assessed.

Where the NHS pathway is slow, some families pay privately for a specialist SLT assessment to get the diagnosis and a targeted intervention plan that schools can then implement. SMIRA holds a list of qualified independent SLTs with selective mutism experience.

What to do this week

Three things.

1. Read SMIRA's parent pack. Free, specific, UK-authored. The most useful reading you will do this month.
2. Email the SENDCO and class teacher. Three sentences: this is selective mutism (a recognised anxiety disorder), please can you stop prompting speech, please can we agree a sliding-in plan with a named adult.
3. Make the GP appointment. Ask for a referral to NHS Speech and Language Therapy with selective mutism named in the referral letter.