ICD-116B06	SELECTIVE MUTISM Selective mutism
ICD-10F94.0	Elective mutism
DSM-5-TRF94.0	Selective Mutism

1. Definition and nosology

Selective mutism (ICD-11: 6B06; DSM-5-TR: F94.0) — consistent failure to speak in specific social situations (e.g., school) despite mastery of language, with normal speech in other contexts (e.g., home). A typical childhood anxiety disorder, sometimes misperceived as “extreme shyness.”

2. History

• Kussmaul A. (1877) — “aphasia voluntaria”.
• Tramer M. (1934) — “elective mutism” — patient's voluntary choice expression.
• DSM-IV (1994) — Replaced with the term ‘selective’ (not voluntary, due to social anxiety).
• DSM-5 (2013) — moved to the anxiety disorders category.

3. Epidemiology

• Prevalence: 0.7–1% in school-aged children (Bergman R.L. et al. JAACAP 2002).
• Gender: relatively higher in girls (1.5–2:1).
• Onset: 2–5 years; typically detected at school entry.
• Comorbidity: social anxiety disorder ~70%, GAD, other anxiety, speech or language disorder.

4. Aetiology and pathogenesis

• Heritability — anxiety in family history prevalent (~70% families have anxiety disorder).
• Behavioral inhibition (Kagan) — temperamental predisposition is a key factor.
• Comorbid developmental speech and language disorders (especially in bilingual environment) — risk factor.
• Environment — in bilingual families, sometimes mistakenly perceived as a language switch.

5. Clinical features

• Failure to speak in specific social situations (school, public places).
• Normal speech at home with close ones.
• Sometimes the use of whispering or gestures.
• Academic and social impairment (answering questions, peer relationships).
• Comorbid shyness, social withdrawal, somatic complaints.

6. Diagnosis

6.1 Unified diagnostic criteria

A. Persistent not speaking in specific social situations (where speaking is expected), speech normal in other situations.

B. Significant impairment in academic, occupational, or social communication.

C. Duration ≥ 1 month (excluding the first month of school).

D. Does not result from not learning a language or not being comfortable in that language.

E. Not better explained by a communication disorder (e.g., a fluency disorder), autism spectrum disorder, schizophrenia, or another psychotic disorder.

6.2 Source-specific clarifications

• DSM-5-TR / ICD-11 — in the anxiety disorders category; ‘selective’ — not voluntary choice, but situation-specific anxiety response.

6.3 Diagnostic algorithm

1. Parent, teacher interview.
2. Home video recordings of speech — diagnostic confirmation.
3. SMQ (Selective Mutism Questionnaire).
4. Speech-language assessment (SLT) — communication disorder exclusion.
5. Hearing test.
6. Comorbid anxiety, autism, language disorder screening.

6.4 Differential diagnosis

7. Examination and assessment

• SMQ — gold standard; SAS (School Anxiety Scale).
• Speech-language assessment.
• Audiometry.

8. Treatment

1. Behavioral approach as first-line treatment — graded exposure, fading-in technique (gradual introduction of a familiar person into the environment).
2. Integrated Behavioral Therapy (Bergman R.L.) — manualized, with family + school involvement.
3. School-based intervention — gradual increase in communication demands, teacher coordination.
4. SSRI (fluoxetine, sertraline) – in moderate to severe or non-responsive to behavioral intervention cases. Black B. et al. JAACAP 1994 RCT.
5. Reducing accommodation — stopping the parent from speaking for the child.

Source-specific specifications

• AACAP — behavioral intervention first-line, SSRI adjunct.
• NICE — principles of anxiety disorders apply.

Treatment methods

1. Gradual Introduction (Fading-In) Technique — The patient converses with a comfortable person; gradually a stranger is introduced into this context; then the patient transitions to speaking with a stranger.
2. Integrated Behavioral Therapy (IBT) — Bergman (Bergman R.L.) — Staged exposure, positive reinforcement, systematic desensitization; 20 sessions. Evidence: Bergman R.L. et al. JAACAP 2013 RCT.
3. Selective Mutism Questionnaire (SMQ) — Bergman — 23 items; parent form.
4. SSRI — Fluoxetine — Evidence base in pediatric selective mutism; Black B., Uhde T.W. JAACAP 1994 RCT.

9. Prognosis

• Speech recovers in most children with early intervention.
• Without treatment, chronicity and transition to social anxiety disorder.

10. Myths and misconceptions

Myth 1: “Selective mutism is the child's ‘stubbornness’”

Evidence: selective mutism is an anxiety disorder — the child CANNOT speak, the position ‘does not want to speak’ is incorrect.

Myth 2: “If a child does not speak, strong pressure is needed”

Evidence: pressure intensifies anxiety and mutism; stepped exposure recommended.

Myth 3: “It will resolve with age; no intervention is needed”

Evidence: Without early intervention, academic and social impairment persists; risk of transition to social anxiety disorder in adulthood.

Myth 4: “Mutism in a bilingual child is normal”

Evidence: “Silent period” — normal for a few months when learning a new language; mutism lasting ≥ 6 months or occurring in both languages — consider selective mutism diagnosis.

Myth 5: “Only deep psychoanalytic therapy is effective”

Evidence: Behavior-based and CBT approaches are first-line; psychoanalytic intervention lacks evidence base.

11. Sources

1. WHO. ICD-11. 6B06 Selective mutism. 2024.
2. APA. DSM-5-TR. 2022.
3. Bergman R.L. et al. Prevalence and description of selective mutism in a school-based sample. J Am Acad Child Adolesc Psychiatry 2002;41(8):938–946.
4. Bergman R.L., Gonzalez A., Piacentini J., Keller M.L. Integrated Behavior Therapy for Selective Mutism: a randomized controlled pilot study. Behav Res Ther 2013;51(10):680–689.
5. Black B., Uhde T.W. Treatment of elective mutism with fluoxetine: a double-blind, placebo-controlled study. J Am Acad Child Adolesc Psychiatry 1994;33(7):1000–1006.