"Shy" child? Don't Overlook Selective Mutism

Children with selective mutism speak spontaneously in the company of parents, other family members, or a circle of trusted peers, but are consistently mute and noncommunicative, or communicate only nonverbally, with everyone else. The condition occurs in approximately 0.5 to 0.7 of every 1,000 young school-age children: There are likely to be several children with this condition diagnosed in every primary pediatric practice, therefore.

Yet selective mutism is seldom cited in pediatric literature.^1-4 It is discussed briefly in the 17th edition of Nelson's Textbook of Pediatrics. The fourth edition of Hoekelman's Primary Pediatric Care (2001) and the 2002 edition of Gellis and Kagan's Current Pediatric Therapy contain no citations of selective mutism in the index. The third edition of Developmental-Behavioral Pediatrics states that selective mutism is a rare condition with onset before 5 years of age. The brief text goes on to state, erroneously, that "symptoms usually resolve within a few months."

Early psychoanalytic theory held that selective mutism was almost always caused by severe psychological or physical trauma.^5-7 Although psychologically traumatic events occur occasionally in temporal relation to the onset of selective mutism, they are now not believed to cause the psychopathology.

Table 1 Diagnostic criteria for selective mutism

Since 1980, the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders has classified selective mutism as a separate clinical entity under "other disorders of childhood" to separate it from a primary communication disorder. Table 1 lists the diagnostic criteria for selective mutism cited in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR).⁸ These criteria may be modified to include symptoms of anxiety/phobia in forthcoming editions of the DSM.^9,10

Too often, children with selective mutism are misdiagnosed with shyness, autism spectrum disorder, oromotor dyspraxia, or oppositional-defiant disorder, and valuable time is lost during therapeutic misadventures. Early diagnosis and appropriate management can cure the cardinal symptom of selective mutism, although the child's social anxiety usually persists. When appropriate treatment is delayed until after 7 years of age, few children are "cured" during the early primary school years.

Prevalence and natural history Selective mutism is a social and communication anxiety disorder of childhood. Several studies of children with this disorder have determined that more than 90% have all the DSM-IV-TR criteria necessary for diagnosis of an extreme form of social anxiety disorder.^11-13 These criteria include, in addition to selective mutism, symptoms such as social avoidance, distress in social situations, behavioral inhibition, and fear of speaking to strangers.

Estimates of the prevalence of selective mutism in early primary grades range from 0.18/1,000 in a small Swedish study,¹⁴ to 0.5/1,000 in a German and Swiss study,¹⁵ to 0.7/1,000 in studies from Los Angeles and Israel.^16,17 Series of more than 100 children with selective mutism have been reported from Germany, Switzerland, and the United States.^15,18 In most studies, girls with selective mutism outnumbered boys, but this observation has not been fully substantiated.

A point prevalence series of 100 Swiss and German children with selective mutism, based on results of a questionnaire, found that the condition persisted in 54% of the total sample, decreased over time in 35%, and fluctuated over time in 8%.¹⁵ Analysis of interventions indicated that psychotherapy (42%) was the most common form of treatment.¹⁵ R. Lindsey Bergman, PhD, of the Anxiety Center at University of California at Los Angeles estimates that only 30% to 40% of children older than 12 years who are diagnosed and treated appropriately will speak to a wide circle of schoolmates during primary school.¹⁹

In their seminal study of the prevalence of selective mutism in Los Angeles primary schools, Bergman and colleagues followed a cohort of children in kindergarten through second grade. Teachers completed a questionnaire about children identified as having selective mutism and a comparison group of children at entry into the study and six months later. During the observation period, only 28% of the children classified as having selective mutism appeared to improve significantly.¹⁶

Characteristics of selective mutism A child with selective mutism is usually socially insecure and inhibited. As noted, she (or he) typically speaks spontaneously and clearly at home or with trusted peers, but does not speak, or communicates only nonverbally, in the presence of strangers, physicians, teachers, and most classmates. Such a child is not really mute. The core feature of her condition is excessive shyness and fear of embarrassment in certain school, health-care, or social situations. Over time, the avoidance behaviors she develops to deal with her anxieties become conditioned, comfortable, and entrenched. Eventually, these behaviors seriously interfere with her ability to function optimally in educational and social settings.

No long-term follow-up studies have been done to compare children who received timely and effective therapy for selective mutism with children who were never referred or never received appropriate therapy. Based on personal experience and the available literature, we believe that the earlier a child with selective mutism is correctly diagnosed and adequately treated, the shorter the time before real communication and speech occur in stressful situations.^20,21

Although no validated screening procedures exist to differentiate mildly or moderately shy children from those with selective mutism, differences are usually clearly distinguishable in the degree of impediment. A shy child generally can function well in preschool and school. He may be slow to warm up to the teacher but eventually does communicate. A child with selective mutism, by contrast, does not communicate with the teacher or most classmates.

Most children with selective mutism are characterized by hesitancy and impaired ability to initiate verbal communication when they become anxious, particularly in group settings such as preschool or birthday parties. When challenged to speak to strangers or acquaintances, they often withdraw.

Table 2 Selective mutism is manifested on a continuum

Table 2 shows the continuum of selective mutism from the mildest form to the most severe. Mildly affected children may have a wide circle of trusted friends and relatives with whom they are able to speak. More severely affected children may speak in a whisper or faint voice in response to questions from selected people. Some moderately affected children may utter nonlinguistic sounds. A severely affected child may be totally uncommunicative in school or the pediatric office, or may only nod his head, blink his eyes, or use finger movements in response to questions.

The level of the child's anxiety changes from setting to setting and from person to person. Some children instantly freeze up when they are expected to initiate conversations or hesitate, as if words are stuck, when they are expected to reply to questions.

Selective mutism is not primarily a developmental disorder or a speech and language disorder, although a minority of children have either of these two conditions as a dual diagnosis. Fewer than 25% of such children have problems with articulation or fluency when they are at home. For this reason, speech therapy is seldom an effective primary management strategy. The results of a survey of parents of 25 children with selective mutism showed that almost 40% had received speech therapy.²² Only two of them were cured.

Clinical experience indicates that a percentage of children meet the diagnostic criteria for sensory processing disorder, but this is often overlooked. Occupational therapists and other mental health professionals may misclassify a child with selective mutism and suggest therapy to improve balance and coordination. Many such attempts at treatment are counterproductive. Being forced to participate in speech therapy or special education may worsen a child's anxiety and stress.

The speaking impediment and social anxiety of a child with selective mutism may lead to chronic problems with communication, socialization, and, sometimes, academic performance during much of childhood. Standardized follow-up evaluations of a group of 45 German adults 12 years after they were given a diagnosis of selective mutism revealed complete remission in 39%.²³ The remaining adults still had serious problems with communication and self-confidence.

Diagnosis Children with selective mutism are usually identified as such between 4 and 8 years of age. In a study of 68 children with the disorder, onset of mutism occurred during preschool years or earlier in 79%.¹⁶ Yet referral for evaluation and management is typically delayed by four or more years after the correct diagnosis is made.²⁴

Unlike the differential diagnosis of true or progressive acquired mutism—which includes language or other developmental delay, Asperger syndrome, Landau-Kleffner syndrome, and aphasia—the differential diagnosis of selective mutism is very limited. The focal point is one primary symptom: "consistent failure to speak in specific social situations ... despite speaking in other situations."⁸ Selective mutism is virtually the only diagnostic consideration in a preschool child or elementary school student who is silent in school but understands what is said to her (or him) and is reported to speak and act normally at home, as verified by audiotape or videotape documentation.¹

Diagnoses associated with selective mutism include social phobia, general anxiety disorder, separation anxiety disorder, posttraumatic stress disorder—following a frightening experience with an animal, for example—major depressive disorder, and nocturnal enuresis. Several investigators have reported an increased incidence of nocturnal enuresis—25%, 30%, or 40%^15,25,26—in children with selective mutism.

Recognizing the child who may have selective mutism begins with an awareness of normal child development. After a few visits to the pediatrician, most normally developing children older than 3 years should make eye contact and communicate verbally with the doctor.

The family history of a child with suspected selective mutism may reveal a multigenerational history of social anxiety or phobia or selective mutism.^1,2 A few questions directed to the parent can give important clues about the child's linguistic ability in three domains:

A videotape of the child at home playing and spontaneously communicating, speaking, and playing with a sibling or parent is one of the most effective and least inexpensive diagnostic tools to rule out pervasive developmental disorder or language delay.

As the evaluation proceeds, the following questions should be addressed:

Questionnaires that help screen for anxiety disorders in children include the Hamilton Anxiety Scale (HAMA),²⁷ and Screen for Child Anxiety-Related Emotional Disorders (SCARED).²⁸ Tests for hearing acuity are also valuable. They include a passive screening test (one that does not require any communication from the patient) for cochlear dysfunction using distortion-product otoacoustic reflex testing (otoacoustic emissions, or OAE) or automated brainstem evoked potentials and a test for the presence of an acoustic reflex. Both are recommended to rule out profound hearing impairment as the cause of the child's failure to communicate.

Management Dow and colleagues noted that "selectively mute children deserve a comprehensive evaluation to identify primary and comorbid problems that might require treatment. A school-based, multidisciplinary individualized treatment plan is recommended, involving the combined efforts of teachers, clinicians, and parents, with home- and clinic-based interventions (psychotherapy, pharmacotherapy), as required."²⁹

Table 3 General management strategies for selective mutism

Any attempt at communication by the child, such as facial expressions and gestures in response to questions, in school or other social situations must be recognized and rewarded, as must any attempt at speech, even whispering or speaking in a low voice or through an intermediary. Punishing, threatening, or shaming the child, or similar coercive measures, typically are ineffective and can cause psychological harm.

Table 3 lists effective general management strategies for selective mutism. Speech therapy, with the primary goal of getting the child to speak, appears to be less successful than cognitive-behavioral therapy, anxiolytic pharmacotherapy with a selective serotonin reuptake inhibitor (SSRI),^30,31 or a combination of the two. Some children with a comorbid disorder of dysfluency or articulation may benefit from speech therapy, however. Other primary therapies—including traditional psychotherapy, play therapy, group therapy, family therapy, and occupational therapy for sensory integration disorder—have not been subjected to rigorous controlled, randomized trials and are of unproven value. Guiding parents to the Selective Mutism Group-Childhood Anxiety Network Web site (www.selectivemutism.org) can be very helpful, especially for answers to questions about day-to-day problems.

Table 4 After the morning bell: Tips on managing selective mutism at school

Table 4 outlines strategies for managing selective mutism at school.

Cognitive-behavioral therapy Many psychologists consider cognitive-behavioral therapy to be the preferred initial treatment for most young children. It has been shown to be effective for social anxiety-phobia disorders³² and selective mutism. An experienced, certified clinical psychologist or developmental-behavioral pediatrician helps the child to progress slowly through stages by means of six major techniques:

Systematic desensitization. Relaxation techniques, such as biofeedback and clinical hypnosis, can sometimes help the child with social anxiety/phobia and selective mutism reduce anxiety and stress in social situations, particularly when some form of communication is necessary. Systematic desensitization involves small steps over time. For example, initially only close family members are invited to social events at the child's home. Then the social circle is widened gradually to one or two trusted neighborhood friends and, last, to a small group of neighborhood or school friends.

Positive reinforcement uses praise and small gifts to reward every gain, no matter how small, at the beginning of therapy. One such technique is token economy—giving colored chips that can be exchanged for presents, a trip to a favorite shop or video game center, or a special treat such as a sleepover or recreational outing with a trusted friend.

Modeling. The therapist models how to react calmly in a stressful situation, first in the therapist's office and then in a real-life situation. Videotaped vignettes may be used as a teaching tool.

Fading. After the child masters modeling behaviors, the therapist (or parent) assumes first a less dominant role in therapy, then a passive role, and, at last, no role.

Guided imagery. The therapist guides the child in imagining a stressful social situation beginning with the least stressful part of it. For example, the child might imagine a birthday party at which he (or she) is asked what he wants to eat or drink. The child and therapist then plan ways for the child to communicate, such as gesturing, whispering to a friend who serves as an intermediary, or writing down a request. After slowly mastering the least stressful aspect of socialization and social communication, the child goes on to the next most stressful part. Preparing the child for potentially stressful social situations in this way helps to decrease overall anxiety.

Graded real-life exposure starting with the least anxiety-provoking situation and progressing to more threatening circumstances gradually desensitizes the child to stressful situations.

Pharmacotherapy Treatment with an SSRI—such as fluoxetine, paroxetine, sertraline, or citalopram—is effective for selective mutism and is believed by most child psychiatrists to be safe if used carefully. SSRIs increase brain levels of the synaptic neurotransmitter serotonin. Seventy percent of children with selective mutism respond rapidly to such drugs, experiencing a reduction in anxiety that facilitates nonverbal and verbal communication and socialization.^31,32 Parents, and many health professionals, are reluctant, however, to administer psychotropic drugs to a child because they fear short- and long-term adverse effects. Negative publicity about serious side effects of SSRIs, including suicidal thoughts and actions, has prompted some parents of children with selective mutism to resist treatment with these medications.

Common adverse effects of SSRIs, as a group, include abdominal pain, nausea, changes in appetite and weight, sleep disturbances (insomnia or hypersomnia), diminished energy level, fatigue, and lightheadedness. Uncommon effects include dysphoria or serious depression, hyperactivity, irritability, temper tantrums, and hypomania or mania. Rare but serious adverse effects include drug hypersensitivity (allergic) reactions, and a serotonin syndrome characterized by confusion, hyperthermia, profuse diaphoresis, muscle spasms (myoclonus), and autonomic nervous system instability, including hypertension. Fluoxetine, available in an unpalatable syrup or capsule or tablet, has a long half-life and may take as long as one month to achieve a steady state. It generally causes more gastrointestinal adverse effects than other SSRIs, such as paroxetine, sertraline, and citalopram, which are also available in liquid or tablet form.

Pediatricians who treat children with anxiety or depression sometimes begin with doses of fluoxetine as low as 1.25 mg per day and gradually increase the dose to a maximum of 20 mg per day. Sertraline may be given at a dose of 12.5 mg per day and citalopram at a dose of 5 mg per day. Psychiatrists who have experience with SSRIs often prescribe higher doses (fluoxetine to 60 mg per day, sertraline to 100 mg per day, and citalopram 40 mg per day). Simultaneous use of two serotonergic drugs increases the risk of serotonin syndrome. SSRIs may interact poorly with H₂ blockers, selected anticonvulsants, and other serotonergic drugs or tryptophan.

Rapid or abrupt discontinuation of an SSRI (except fluoxetine), may provoke a withdrawal syndrome, which includes dysinhibition, dysphoria, emotional ability, headaches, and nausea. For this reason, an SSRI should be tapered in small decrements over several weeks.

Don't miss the silence With an estimated prevalence of 0.5/1,000 to 0.7/1,000, selective mutism is likely to be diagnosed in at least one or two children in every primary care pediatric practice. Children with this condition are often misdiagnosed. The underlying cause is widely believed to be intense anxiety/phobia associated with communication. Almost all children with selective mutism also suffer from social anxiety/phobia. Optimal initial treatment entails cognitive-behavioral therapy. SSRIs also have an important role, particularly in the older child.

DR. SCHWARTZ is clinical professor of pediatrics at University of Virginia School of Medicine, Charlottesville, and Inova-Fairfax Hospital for Children, Falls Church, Va.

DR. SHIPON-BLUM is clinical assistant professor, family medicine and psychology, Philadelphia College of Osteopathic Medicine, Philadelphia, Pa.; president and director, Selective Mutism Anxiety Research and Treatment (SMART) Center, Jenkintown, Pa.; and chief executive officer and executive medical director, Selective Mutism Group-Childhood Anxiety Network. She is the author of several books about selective mutism and anxiety.

The authors have nothing to disclose in regard to affiliations with, or financial interests in, any organization that may have an interest in any part of this article.

REFERENCES 1. Stein MT, Rapin I, Rapko D: Selective mutism. J Dev Behav Pediatr 1999;20:38

2. Joseph PR: Selective mutism—The child who doesn't speak at school. Pediatrics 1999;104:308

3. Stein MT, Rapin I: Selective mutism. J Dev Behav Pediatr 2001;22 (Suppl):S123

4. Standart S, Couteur AL: The quiet child: A literature review of selective mutism. Adolescent Mental Health 2003;8:154

5. Hayden TL: Classification of elective mutism. J Am Acad Child Adolesc Psychiatry 1980;19:118

6. Hesselman S: Elective mutism in children: 1877 to 1981. Acta Paedopsychiatry 1983;49:297

7. Wright HH, Holmes GR, Cuccaro ML, et al: A guided bibliography of the selective mutism (elective mutism) literature. Psychol Rep 1994;74:995

8. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR). Washington, D.C., American Psychiatric Association Press, 2000

9. Anstendig KD: Is selective mutism an anxiety disorder? Rethinking its DSM-IV classification. J Anxiety Disord 1999;13:417

10. Beidel DC, Turner SM, Morris TL: A new inventory to assess childhood anxiety and social phobia: The Social Phobia and Anxiety Inventory for Children. Psychiatric Assessment 1995;7:73

11. Black B, Uhde TW: Elective mutism as a variant of social phobia. J Am Acad Child Adolesc Psychiatry 1992;31:1090

12. Black B, Uhde TW: Psychiatric characteristics of children with selective mutism: A pilot study. J Am Acad Child Adolesc Psychiatry 1995;34:847

13. Dimmit SE, Klein RG, Tancer NK, et al: Systematic assessment of 50 children with selective mutism. J Am Acad Child Adolesc Psychiatry 1997;36:653

14. Kopp S, Gillberg C: Selective mutism: A population-based study: A research note. J Child Psychol Psychiatr 1997;38:257

15. Steinhausen H, Juzi C: Elective mutism: An analysis of 100 cases. J Am Acad Child Adolesc Psychiatry 1996;35:606

16. Bergman RL, Piacentini J, McCracken JT: Prevalence and description of selective mutism in a school-based sample. J Am Acad Child Adolesc Psychiatry 2002;41:938

17. Elizur Y, Perednik R: Prevalence and description of selective mutism in immigrant and native families: A controlled study. J Am Acad Child Adolesc Psychiatry 2003;42:1451

18. Ford MA, Sladeczek IE, Carlson J, et al: Selective mutism: Phenomenological characteristics. School Psychology Quarterly 1998;13:192

19. Selective Mutism Conference, January 2004, San Diego, Calif., presented by the Selective Mutism Anxiety Research and Treatment Center and the Selective Mutism Group Childhood Anxiety Group

20. Krohn DD, Weckstein SM, Wright HA: A study of the effectiveness of a specific treatment of elective mutism. J Am Acad Child Adolesc Psychiatry 1992;31:711

21. Wright HH, Miller D, Cook MA, et al: Early identification and intervention with children who refuse to speak. J Am Acad Child Adolesc Psychiatry 1985;24:739

22. Freedy A, Schwartz RH: Selective mutism: Pediatricians are missing the diagnosis. Poster presentation, Pediatric Academic Societies annual meeting, May 2004, San Francisco

23. Remschmidt H: A follow-up study of 45 patients with elective mutism. Eur Arch Psychiatry Clin Neurosci 2001;251:284

24. Kumpulainen K, Rasanen R, Raaska H, et al: Selective mutism among second-graders in an elementary school. Eur Child Adolesc Psychiatry 1998;7:24

25. Kristensen H: Selective mutism and comorbidity with developmental disorder/delay, anxiety disorder, and elimination disorder. J Am Acad Child Adolesc Psychiatry 2000;39:249

26. Kolvin I, Fundudis T: Elective mute children: Psychological, development, and background factors. J Child Psychol Psychiatry 1981;22:219

27. Hamilton Anxiety Scale (HAMA): www.anxietyhelp.org/information/hama.html.

28. Birmaher B, Brent DA, Chiappetta L: Psycholmetric properties of the Screen for Child Anxiety Related Emotional Disorders (SCARED): A replication study. J Child Psychol Psychiatry 1997;36:1230

29. Dow SP, Sonies BC, Scheib D, et al: Practical guidelines for the assessment and treatment of selective mutism. J Child Psychol Psychiatry 1995;34:836

30. Dummit ES 3rd, Klein RG, Tancer NK, et al: Fluoxetine treatment of children with selective mutism: An open trial. J Child Psychol Psychiatry 1996;35:615

31. Black B, Uhde TW: Treatment of elective mutism with fluoxetine: A double-blind, placebo-controlled study. J Child Psychol Psychiatry 1994;33:1000

32. Mendlowitz S, Manassis K, Bradley S, et al: Cognitive-behavioral group treatments in childhood anxiety disorders: The role of parental involvement. J Child Psychol Psychiatry 1999;23:1223