Selective Mutism ICD-11 Diagnostic Requirements Explained
Updated: Oct 8
Author: Ukrainian Psychological Hub · Published: October 1, 2026 · Editorial Policy
Selective Mutism is coded 6B06 in ICD-11 and is classified by the World Health Organization within Anxiety or fear-related disorders. The core pattern is context-selective speaking: a person has adequate spoken-language ability in some situations but consistently does not speak in other situations where speaking is expected. The WHO Clinical Descriptions and Diagnostic Requirements for ICD-11 are the primary clinical source for the diagnostic framework explained here, while the current ICD-11 Mortality and Morbidity Statistics browser retains Selective mutism as 6B06.
ICD-11 diagnosis requires more than noticing that someone is quiet, shy, anxious, reluctant to answer, or silent in one encounter. The clinician has to establish a stable contrast between situations in which speech is available and situations in which it is consistently absent, confirm that the pattern has lasted long enough and causes meaningful interference, evaluate language competence, and consider alternative explanations. A questionnaire score, a school report, an online checklist, or one observation can contribute information but does not establish 6B06 by itself.
This page owns the ICD-11 diagnostic-requirements intent. It does not turn all forms of silence into Selective Mutism, and it does not treat social anxiety, separation anxiety, autism, a language disorder, psychosis, or a multilingual adjustment period as interchangeable labels. For the wider diagnostic family, see Anxiety Disorders: Symptoms, Types, Diagnosis, and Treatment and ICD-11 Anxiety Classification: Anxiety or Fear-Related Disorders.
Selective Mutism in ICD-11 in one sentence
ICD-11 Selective Mutism is a persistent, functionally significant pattern of speaking normally enough in some settings while consistently failing to speak in other settings where speech is expected, when that failure is not adequately explained by unfamiliarity or discomfort with the required language or by a better-fitting clinical explanation.
ICD-11 code 6B06 and where the diagnosis belongs
Selective Mutism is coded 6B06. ICD-11 places it inside Anxiety or fear-related disorders, alongside diagnoses such as generalized anxiety disorder, panic disorder, agoraphobia, specific phobia, social anxiety disorder, and separation anxiety disorder. The classification change matters because Selective Mutism was historically located elsewhere in ICD.
Domschke and Zwanzger's 2025 review of the ICD-10 to ICD-11 taxonomy describes the move from ICD-10 “Elective mutism” (F94.0) to ICD-11 Selective mutism (6B06) within the anxiety or fear-related disorders group. The terminology also moves away from the misleading implication that the person elects or chooses not to speak.
The diagnostic territory remains specific. Selective Mutism is not a generic label for anxiety-related communication difficulty. The defining problem is the patterned availability of spoken communication across contexts. A person may have severe anxiety without Selective Mutism, and a person with Selective Mutism may have additional anxiety symptoms that are clinically important without those symptoms becoming separate diagnostic requirements.
What ICD-11 means by diagnostic requirements
ICD-11 Clinical Descriptions and Diagnostic Requirements are designed for clinical reasoning rather than self-scoring. The framework identifies essential features and boundaries, while allowing clinicians to interpret presentation in developmental, cultural, linguistic, and clinical context. First and colleagues compared ICD-11 diagnostic requirements with DSM-5 and described the systems as strongly convergent for many disorders while differing in how some requirements are operationalized.
For Selective Mutism, this means that the diagnostic task is not “How many anxiety symptoms are present?” The task is to establish whether the speaking pattern itself matches 6B06, whether it persists beyond a brief adjustment period, whether it interferes with functioning, whether the person has sufficient language competence where speech is expected, and whether another explanation better accounts for the silence.
The ICD-11 diagnostic requirements explained
1. There is consistent selectivity in speaking
The first requirement is a reliable contrast across situations. Speech is available in some contexts and consistently absent in others. A common pattern is fluent or ordinary speech at home with familiar people and little or no speech at school, but home-versus-school is only an example. Selectivity can also vary by person, location, activity, perceived audience, or communication demand.
The word “selective” describes where speech is accessible; it does not mean the person is deliberately selecting when to cooperate. The American Speech-Language-Hearing Association Selective Mutism Practice Portal emphasizes that people with Selective Mutism do not simply elect where to speak. Context, communication partner, activity, and expectation can all change access to speech.
Consistency matters. A single silent appointment, a child refusing to answer after an upsetting event, a period of fatigue, or occasional low-volume responding does not by itself demonstrate the cross-situational pattern required for Selective Mutism. Assessment asks whether the contrast recurs predictably and whether it has become a stable feature of functioning.
2. Spoken-language competence is adequate in at least some situations
Selective Mutism presupposes that spoken language is available somewhere. The person must show sufficient language competence to speak in at least some contexts. This is why home recordings, reports from caregivers, observations with a trusted person, or other evidence of ordinary speech can be diagnostically useful when speech is unavailable in the clinic or school.
Adequate speech in one context does not rule out a co-occurring speech or language disorder. A child can have articulation, language, fluency, or pragmatic difficulties and also show a selective pattern. The diagnostic question is whether the communication difficulty exists broadly across contexts or whether the striking feature is the context-specific loss of speech. A broad language impairment usually affects communication across settings; Selective Mutism is organized by situational selectivity.
3. Failure to speak occurs in situations where speech is expected
ICD-11 requires more than a preference for nonverbal communication. The person consistently does not speak in situations where speaking is expected and where the person is capable of speaking under other conditions. The expectation can arise in school, work, health care, community activities, or social interactions.
The clinical threshold is not limited to complete silence in every difficult situation. Some people may whisper, speak only to one trusted person, use very short answers, speak only when others are absent, or show substantial variability as the social context changes. The central issue is whether speech access is persistently and markedly restricted in the relevant settings, rather than whether the person literally produces zero words.
4. The pattern lasts at least one month and is not limited to the first month of school
The duration requirement prevents a transient adjustment period from being labeled as a disorder. The Selective Mutism criteria summarized in the assessment review by Rodrigues Pereira and colleagues specify a duration of at least one month and exclude a pattern limited to the first month of school.
The first-month-of-school rule is clinically important because children can be unusually quiet while adjusting to a new teacher, classroom, language environment, or peer group. Persistence beyond that initial period increases diagnostic relevance, but duration alone still does not establish the diagnosis. The full speaking pattern, functional impact, language context, and differential assessment remain necessary.
5. The pattern causes meaningful interference
Selective Mutism becomes a clinical disorder when the speaking pattern interferes with educational achievement or social communication. In practice, impairment may appear as inability to answer teachers, demonstrate knowledge orally, ask for help, participate in group work, communicate needs, form peer relationships, complete oral assessments, or function in age-appropriate social roles.
A child who rarely speaks in class but communicates effectively through alternative means and shows no meaningful impairment still requires careful assessment rather than automatic diagnosis. Conversely, academic grades can look acceptable while the communication restriction imposes major social, emotional, or practical costs. Functional assessment therefore goes beyond grades and counts the effort, accommodations, avoidance, and lost opportunities required to maintain day-to-day functioning.
6. The silence is not explained by lack of knowledge of or comfort with the required language
Language context is part of the diagnostic requirement, not an optional extra. A person cannot be diagnosed with Selective Mutism simply because they do not speak a language they do not yet know well or do not feel comfortable using. Clinicians need to establish which languages the person understands and speaks, where each language is used, with whom, at what proficiency level, and whether silence follows language proficiency or follows social context.
This distinction is especially important for multilingual children. Silence in a newly learned school language may reflect ordinary second-language acquisition, a culturally shaped communication style, or a temporary adjustment period. The ASHA guidance on multilingual service delivery supports culturally and linguistically appropriate assessment rather than interpreting difference as disorder.
Slobodin's 2023 systematic review found that only eight eligible studies directly examined Selective Mutism in culturally and linguistically diverse children. The review suggests an association with bilingual or minority status in parts of the literature while also emphasizing how little the sociocultural mechanisms have been studied. That evidence supports careful assessment; it does not justify treating bilingualism as a cause or diagnostic shortcut.
What ICD-11 does not require
Several features often discussed around Selective Mutism are clinically relevant but are not separate requirements for 6B06. ICD-11 does not require a panic attack, a particular heart rate, a visible freeze response, a specific level of shyness, a fixed number of anxiety symptoms, or a questionnaire score. It also does not require silence in every public setting.
The diagnosis is likewise not defined by motive. Calling the person stubborn, oppositional, manipulative, defiant, or unwilling does not establish the clinical mechanism. A behavioral description may be accurate at the surface level—someone did not speak when asked—but diagnostic reasoning asks what pattern is present across settings and what other explanations must be considered.
Anxiety is strongly associated with Selective Mutism, particularly social anxiety, yet an observer does not need to witness dramatic fear for the speaking pattern to warrant assessment. Some individuals look frozen or visibly distressed; others appear quiet, controlled, neutral, or socially withdrawn. Internal distress and external behavior can diverge.
Selective Mutism is not the same as shyness or a quiet temperament
Shyness and quiet temperament exist on a continuum and are common. Selective Mutism has a sharper functional pattern: speech is available under some conditions but persistently inaccessible under other expected conditions, and the pattern interferes with communication or achievement.
A shy child may take time to warm up and then speak. A child with Selective Mutism may communicate freely at home yet remain unable to speak in a classroom for months despite familiarity with the teacher and language. The diagnostic distinction comes from persistence, context selectivity, functional interference, and exclusion of better explanations—not from whether adults describe the person as “very shy.”
Multilingual and bilingual assessment
Multilingual assessment asks a different question from “Does the child speak at school?” The clinician maps communication across languages and contexts. Which language is spoken at home? Which language is expected at school? How long has the person been exposed to each language? Can the person speak the school language with trusted people outside school? Is silence present only in the less familiar language, or does it persist across languages when the social context becomes demanding?
ASHA's Selective Mutism guidance notes that a valid diagnosis in multilingual populations requires evidence that the pattern is not simply a language-learning phenomenon. In practice, assessment may include interpreters or bilingual clinicians, caregiver and teacher reports, language sampling, and observation in more than one context.
A child who speaks Ukrainian fluently at home but has just entered an English-language school and remains silent in English during the first weeks may be experiencing an ordinary language and school transition. A child who speaks English comfortably with family members yet has persistently failed to speak English or Ukrainian in expected school interactions for months presents a different diagnostic question. The pattern across language and context is more informative than the label “bilingual.”
ICD-11 exclusions and diagnostic boundaries
The current ICD-11 MMS entry for 6B06 lists exclusion relationships with autism spectrum disorder, schizophrenia, and transient mutism occurring as part of separation anxiety in young children. Those exclusions are classification boundaries, not an invitation to decide online that one diagnosis automatically rules another in or out. Clinical presentations can contain overlapping features, and coding questions can be more complex than symptom checklists suggest.
Autism spectrum disorder
Autism and Selective Mutism can both involve reduced speaking, social communication difficulty, atypical eye contact, withdrawal, or distress in demanding environments. The diagnostic pattern differs. Selective Mutism is defined by marked situational selectivity in speech. Autism is a neurodevelopmental condition characterized by a broader developmental pattern of social-communication differences together with restricted or repetitive patterns of behavior or interests.
Muris and Ollendick's 2021 review describes meaningful overlap among Selective Mutism, social anxiety, and autism-related features and argues for careful differential assessment. The research literature also contains debate about how best to classify genuinely overlapping presentations. For an individual person, developmental history and cross-setting communication matter more than matching one shared symptom.
Schizophrenia and other psychotic disorders
A new loss of speech in the context of hallucinations, delusions, disorganization, marked behavioral change, or other signs of psychosis is a different clinical problem from the usual selective pattern. Selective Mutism requires evidence that speech is available in some contexts and unavailable in others in a stable, situation-linked way. New-onset mutism associated with severe psychiatric or neurological change warrants direct clinical assessment rather than attribution to anxiety.
Separation anxiety in young children
Young children can become briefly mute during intense separation distress. ICD-11 specifically distinguishes transient mutism occurring as part of separation anxiety from Selective Mutism. The difference lies in the organizing pattern: is the silence a short-lived component of separation distress, or is there a persistent context-selective speaking pattern that meets the full Selective Mutism requirements?
For the neighboring diagnosis, see Separation Anxiety Disorder: Symptoms, Causes, Diagnosis, and Treatment.
Speech, language, and communication disorders
A speech or language disorder can reduce verbal output across many settings because speech is difficult to produce, understand, formulate, or use. Selective Mutism is different in structure: the person demonstrates substantially greater access to speech in some contexts than in others. These patterns can coexist, so assessment should not stop after finding one communication difficulty.
Shorer's 2025 clinical assessment review recommends a multi-method assessment that can adapt formal testing when anxiety or speech avoidance interferes with standard administration. Nonverbal tasks, alternative response formats, observations, caregiver information, and speech-language evaluation can help separate what the person knows from what the person can demonstrate under a particular communication demand.
Hearing and medical causes
Hearing loss, neurological illness, medication effects, acute illness, or other medical conditions can affect speech and communication. ASHA includes hearing screening in the assessment pathway when Selective Mutism is suspected. A sudden or progressive loss of speech, weakness, confusion, seizures, altered consciousness, new neurological symptoms, or other acute changes should not be explained as Selective Mutism merely because anxiety is also present.
Selective Mutism vs social anxiety disorder
Selective Mutism and Social Anxiety Disorder overlap but have different diagnostic centers. Social Anxiety Disorder is organized around marked fear or anxiety about social situations involving possible scrutiny or negative evaluation. Selective Mutism is organized around persistent context-specific failure to speak despite speaking in other settings.
A person can fear judgment yet continue speaking; that pattern can fit social anxiety without Selective Mutism. Another person may show a striking inability to speak in particular settings and also have broader fear of evaluation. Comorbidity is common enough to deserve assessment, but one diagnosis should not be used as a synonym for the other. For the neighboring disorder, see Social Anxiety Disorder: Symptoms, Causes, Diagnosis, and Treatment.
The Muris and Ollendick review summarizes evidence that social anxiety is prominent in Selective Mutism while also discussing clinically relevant differences and overlap. This is a good example of why a shared mechanism or common comorbidity does not erase diagnostic boundaries.
Selective Mutism vs separation anxiety disorder
Separation Anxiety Disorder is defined by excessive fear or anxiety concerning separation from people to whom the person is deeply attached. Selective Mutism is defined by the selective availability of speech. A young child can be silent during separation distress without having Selective Mutism, and a child with Selective Mutism can speak freely with caregivers at home while becoming silent in school even when separation itself is no longer the central problem.
Assessment therefore asks what organizes the difficulty. If the main problem is separation from an attachment figure, the separation-anxiety framework may be more informative. If the core pattern is reliable context-linked inability to speak despite ordinary speech elsewhere, Selective Mutism becomes the relevant diagnostic territory.
Selective Mutism vs autism: why online symptom matching fails
Online lists often collapse several shared behaviors into one diagnostic story: little speech, reduced eye contact, withdrawal, rigid behavior, social discomfort, or unusual responses to strangers. These signs are not specific enough to identify a disorder.
The key Selective Mutism question is cross-situational speech selectivity. The key autism assessment is developmental and broader: longstanding patterns of social communication together with restricted or repetitive behaviors or interests across development. A child can look socially shut down in one setting because anxiety blocks speech, while displaying reciprocal, flexible communication elsewhere. Another child may show pervasive developmental differences across settings. A third may have features of both, which is why formal differential assessment matters.
How clinicians assess ICD-11 6B06
A strong assessment reconstructs the speaking pattern rather than relying on a single office encounter. Someone with Selective Mutism may say nothing during the very appointment intended to evaluate speech. That makes collateral evidence unusually important.
Multi-informant history
Clinicians commonly gather information from caregivers, teachers, school staff, and the person being assessed when developmentally possible. The history covers when speech is available, when it disappears, who is present, what language is required, how long the pattern has existed, what changed around onset, and how the problem affects education, work, friendships, family life, health care, and everyday needs.
Direct and indirect observation
Observation can include the clinic, classroom, playground, home, telehealth, or recorded speech with consent. Home video can demonstrate fluent speech that is inaccessible in a formal appointment. School observation can show whether speech changes by teacher, peer, group size, activity, or performance demand.
Shorer emphasizes multi-informant and multi-method assessment because the setting itself changes the behavior being measured. An assessment method that demands immediate speech can underestimate language, cognition, or knowledge precisely because the symptom interferes with the test response.
Speech, language, and hearing evaluation
Speech-language assessment examines whether communication difficulty extends beyond the selective contexts. Hearing screening addresses a basic alternative explanation. Language evaluation is particularly important when the person is multilingual, has a history of delayed language development, shows difficulties in all settings, or performs differently across receptive and expressive tasks.
Developmental and psychiatric differential diagnosis
Assessment also considers social anxiety disorder, separation anxiety disorder, autism and other neurodevelopmental conditions, trauma-related presentations, mood disorders, psychotic disorders, communication disorders, and medical explanations when clinically indicated. The aim is not to accumulate labels but to identify which pattern best explains the impairment and whether more than one clinically meaningful condition is present.
School and functional assessment
Because Selective Mutism often becomes visible in educational settings, clinicians need to understand what the person is unable to do because speech is inaccessible. Can the student answer factual questions, read aloud, ask to use the restroom, report pain, participate in oral exams, speak to peers, tell an adult about bullying, or ask for clarification? These functions reveal the real clinical burden more accurately than a simple count of spoken words.
Screening tools do not diagnose Selective Mutism
Selective Mutism questionnaires can organize observations and measure severity, but they do not replace diagnosis. The best-known example is the Selective Mutism Questionnaire (SMQ). Bergman and colleagues developed the SMQ as a 17-item parent-report measure of failure to speak across contexts. It is useful for characterizing severity and monitoring change; it does not convert a score into an ICD-11 diagnosis.
Rodrigues Pereira and colleagues' critical review of assessment measures found substantial variation in how research studies assess Selective Mutism and highlighted the need for psychometrically sound, cross-culturally valid tools. The review discusses instruments including the SMQ, School Speech Questionnaire, and diagnostic interviews, while also showing that standardized measurement practices have been inconsistent.
The distinction is practical: screening asks whether the pattern deserves further assessment; severity measurement asks how much difficulty is present or how it changes; clinical assessment integrates history, observation, functioning, language competence, and differential diagnosis; formal diagnosis assigns the disorder only when the complete requirements are met.
ICD-11 vs DSM-5-TR for Selective Mutism
ICD-11 and DSM-5-TR describe highly similar diagnostic territory. Both focus on persistent failure to speak in specific expected situations despite speaking in others, clinically meaningful interference, a minimum duration of one month that is not limited to the first month of school, and the need to exclude silence explained by unfamiliarity with the required language.
First and colleagues judged the ICD-11 and DSM-5 formulations of Selective Mutism to be essentially aligned at the category level. DSM-5-TR provides its own wording concerning communication disorders, autism spectrum disorder, schizophrenia, and other psychotic disorders. The American Psychiatric Association's DSM-5-TR remains the authoritative DSM source.
The systems should still be read as separate classification standards. A clinician documenting ICD-11 should apply ICD-11 requirements and coding conventions rather than copying a DSM checklist and changing the code. The dedicated DSM-5-TR intent also deserves its own page because users searching DSM criteria are asking a different classification question.
From ICD-10 “Elective mutism” to ICD-11 “Selective mutism”
The ICD-10 label “Elective mutism” carried a long-standing problem: “elective” can sound as though silence is chosen. ICD-11 uses “Selective mutism” and places 6B06 within Anxiety or fear-related disorders. Domschke and Zwanzger identify this move as part of the broader reorganization of anxiety disorders in ICD-11.
The change also affects search and records. Historical material may refer to elective mutism, ICD-10 F94.0, or childhood-onset categories, while current ICD-11 material uses 6B06. These terms belong to different classification editions. A historical code in an old chart should not be silently converted into a current diagnosis without considering the current clinical picture and the coding system in use.
Can adolescents and adults meet ICD-11 6B06?
Selective Mutism is most strongly studied in childhood, and clinical recognition often begins when school makes the speaking contrast visible. The lifespan question is more complicated than saying that the disorder is “only for children.” Domschke and Zwanzger's ICD-10/ICD-11 review notes that the childhood-onset requirement was removed in the ICD-11 reorganization and describes Selective Mutism within the lifespan-oriented anxiety classification.
At the same time, the public ICD-11 6B06 short definition remains written mainly in child-centered language, and the empirical evidence in older age groups is much thinner than the pediatric evidence. A 2026 mixed-methods systematic review by de Jong and colleagues identified 40 studies concerning adolescents and young adults aged 10–24, but those studies represented only 54 participants in total and varied in methodological quality. That is meaningful evidence that the problem can persist or be studied beyond early childhood, while also showing how limited the evidence base remains.
For an adolescent or adult, diagnosis therefore requires the same discipline: establish a persistent selective-speaking pattern, functional interference, language competence, and a careful differential diagnosis. Childhood screening instruments should not simply be applied to adults as though their psychometric meaning were established across the lifespan.
Associated anxiety and broader symptoms
Anxiety is a major part of the clinical picture for many people with Selective Mutism, but associated symptoms should not be confused with the core diagnostic requirements. Fear, freezing, avoidance, reduced eye contact, withdrawal, somatic discomfort, frustration, and nonverbal communication may all appear, yet their presence or absence does not independently decide the diagnosis.
Vogel, Röse, and Schwenck's 2024 study examined symptoms beyond failure to speak and found a broader range of parent-reported difficulties. A later 2025 systematic review by Kleinheinrich and Vogel synthesized 82 studies and found that social and nonspecific anxiety were among the most consistently identified associated features, while other reported features included withdrawal, depressive symptoms, social-skill difficulties, and some externalizing or oppositional behavior.
The evidence supports a clinically richer picture than silence alone, but it does not justify adding every associated feature to the diagnostic definition. Established classification requirements and emerging symptom research answer different questions. A clinician can use broader symptoms to understand severity, comorbidity, and treatment needs while keeping the diagnosis anchored to its formal criteria.
When the diagnosis should be reconsidered
Selective Mutism should be reconsidered when the pattern does not actually show selective access to speech. Examples include silence that occurs only because the required language is unfamiliar; broad expressive-language difficulty in every setting; hearing loss that has not been assessed; a brief period limited to the start of school; a sudden new loss of speech with neurological or psychotic symptoms; or silence that appears only during acute separation distress and resolves when the separation episode ends.
Reconsideration also matters when the person speaks little everywhere. Selective Mutism is defined by contrast. If speech is consistently limited across home, school, community, and trusted relationships, the clinician should investigate other communication, developmental, psychiatric, or medical explanations rather than forcing the presentation into a selective-mutism template.
The reverse error is possible too. A child can have a language disorder or neurodevelopmental condition and still show an additional context-selective communication pattern. Finding one diagnosis should not automatically end the assessment when important features remain unexplained.
What the current evidence can and cannot tell us
Established evidence supports the core diagnostic pattern, the importance of cross-setting assessment, the one-month threshold, functional interference, and the need to distinguish Selective Mutism from language-learning and other clinical explanations. Evidence also strongly supports anxiety—especially social anxiety—as a common part of the presentation.
The evidence is less complete for adults, culturally and linguistically diverse populations, precise prevalence across settings, and the diagnostic meaning of broader symptoms beyond speaking failure. The available multilingual systematic review included only eight eligible studies, and the recent adolescent/young-adult review contained a small total number of participants. These gaps matter because they limit how confidently child-derived findings can be generalized to every population.
A plausible clinical interpretation is that Selective Mutism often reflects an interaction between anxiety, learning history, context, communication demands, and individual vulnerability. That interpretation is useful for formulation, but it is not itself an ICD-11 diagnostic requirement and should not be presented as a single proven cause.
Practical diagnostic examples
Example 1: persistent school silence with fluent home speech
A child speaks fluently with family members at home, uses the same language competently with trusted relatives, but has not spoken to teachers or classmates for four months despite understanding classroom material. The pattern interferes with oral work and asking for help. This presentation contains several elements that support evaluation for 6B06: clear situational selectivity, adequate language competence, persistence beyond one month, and functional interference. A diagnosis still requires differential assessment.
Example 2: a new language at a new school
A child recently moved to an English-language school, understands little English, and is silent in class during the first three weeks while continuing to speak their home language normally. This does not establish Selective Mutism. Language familiarity and the normal adjustment period are central alternative explanations. Follow-up may be appropriate if a selective pattern persists after language competence and context are better understood.
Example 3: limited speech everywhere
A child uses very little spoken language at home, at school, with relatives, and during preferred activities, and also has broad difficulties understanding or formulating language. The lack of a strong context contrast points away from a straightforward Selective Mutism formulation and toward a broader communication or developmental assessment.
Example 4: social anxiety with preserved speech
A teenager fears embarrassment, avoids presentations, worries intensely about being judged, and speaks softly but consistently when required. This may warrant assessment for Social Anxiety Disorder, but the preserved ability to speak across expected settings does not by itself match the core Selective Mutism pattern.
Questions to bring to a clinical assessment
Useful questions focus on pattern and function rather than asking the person to prove the diagnosis: Where does speech come easily? Where does it stop? Does the pattern change by person, location, group size, or activity? Which languages are used in each setting? How long has the pattern existed? What happened during the first month of school? Can the person speak with trusted people in the same setting after others leave? What educational, occupational, social, or practical tasks are being blocked? Are there hearing, language, developmental, neurological, psychiatric, or medication-related factors that could change the explanation?
For children, caregiver and teacher observations are especially useful because each observer sees a different part of the speaking pattern. For adolescents and adults, self-report about internal distress, communication strategies, masking, avoidance, and the effort required to function can add information that may be invisible to others.
Frequently asked questions
What is the ICD-11 code for Selective Mutism?
The ICD-11 code is 6B06. It is classified within Anxiety or fear-related disorders.
How long must Selective Mutism last in ICD-11?
The pattern must last at least one month and should not be diagnosed when the silence is limited to the first month of school. Duration is only one requirement; language context, functional impact, situational selectivity, and differential diagnosis also matter.
Does a child have to be completely silent?
No. The clinically important feature is a consistent, marked restriction of speaking in specific expected situations despite speech in other situations. Some people whisper, give minimal answers, speak only to selected people, or communicate differently as context changes.
Is Selective Mutism a choice?
The term “selective” refers to the selectivity of the situations in which speech is accessible. It should not be interpreted as proof of a voluntary decision to remain silent.
Can a bilingual child have Selective Mutism?
Yes, but clinicians must first establish that silence is not explained by lack of knowledge of or comfort with the required language. Assessment should map speech across languages and settings rather than treating bilingualism itself as evidence for the disorder.
Can an SMQ score diagnose ICD-11 6B06?
No. The Selective Mutism Questionnaire is a parent-report measure useful for describing speaking behavior and severity. A formal diagnosis requires clinical assessment of the full pattern and its alternatives.
Is Selective Mutism the same as Social Anxiety Disorder?
No. The disorders overlap and can co-occur, but their diagnostic centers differ. Selective Mutism is defined by context-specific failure to speak; Social Anxiety Disorder is defined by fear or anxiety about social scrutiny and negative evaluation.
Is Selective Mutism the same as autism?
No. They are distinct diagnostic concepts with some overlapping observable behaviors. Differential assessment uses developmental history, the cross-setting pattern of speech and social communication, and broader neurodevelopmental features rather than one symptom.
Can adults have Selective Mutism?
The ICD-11 anxiety classification takes a lifespan perspective, and recent literature addresses persistence into adolescence and young adulthood. The evidence base is still much stronger for children, so adult assessment should avoid assuming that child screening norms automatically apply.
Are ICD-11 and DSM-5-TR criteria identical?
They describe substantially overlapping diagnostic territory, but they are separate classification systems with their own wording and coding. A clinician should use the requirements of the system being applied rather than substituting one checklist for the other.
Does treatment response prove the diagnosis?
No. Improvement after anxiety-focused, behavioral, school-based, speech-language, or other support does not retrospectively prove a diagnosis. Diagnosis is based on the clinical pattern and differential assessment, not on whether one intervention happened to help.
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References
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