Selective mutism (SM) is a condition which develops during childhood where a child who is fluent with
language frequently fails to speak in specific situations where language is necessary. Selective mutism is a
relatively rare diagnosis, and, despite current research efforts, there is still much to be learned about the
nature of the disorder. This condition is most common among young children (usually before the age of 5).
Generally, at home children affected by the disorder behave like typical children, but in social situations,
especially at school, they are silent and withdrawn. They might talk to grandparents but not to other
relatives; they might whisper to one other child, or talk to no one. Some do not point, nod or communicate
in any other way.
Consequently, due to the low incidence in reports of SM most experimental research is dependent on case
studies. Further, many contradicting information and unresolved results in the description of people with SM
also exist. Some believe that the silence occurs only in unfamiliar settings which may also include places in
the community. There are accounts of children who refuse to speak in unfamiliar social settings or in the
presence of strangers. Other reports state that these children may limit their speaking to only a select few
individuals, usually parents and/or siblings.
Signs and Symptoms:
• A constant refusal to speak in one or more social settings which includes school.
• The behavior interferes with educational, occupational achievement and social communication.
• The duration of the behavior is at least one month (not including the first month of school).
• The failure to speak is not due to a lack of knowledge of, or comfort with, the spoken language
required in a social situation.
• The speech deficiency is not as result of a communication disorder (e.g., stuttering) and does not
occur exclusively during the course of a pervasive developmental disorder.
The main feature in selective mutism is that the child has the ability to both comprehend and speak, but fails
to do so in certain situations. This syndrome differs from mutism because the child sometimes speaks,
depending on the circumstances. Children with mutism never speak.
Cultural issues, such as recent immigration and bilingual speakers, should be considered during the
evaluation process. Children who are uncomfortable with a new language may be reluctant to use it outside
of a familiar setting. This is not necessarily selective mutism, so it should be noted when searching for a
History of Selective Mutism
Recognized as early as 1877 as a disorder, selective mutism was called aphasia
voluntaria at the time by Kussmaul, a German physician who originally described its characteristics.
Although the child was able to speak, he/she willed not to, in Kussmaul’s view. Fifteen years ago, these
children were known as elective mutes, and their silence was seen as willful and manipulative. "If you look
at psychiatry textbooks from around 1994," said Dr. Bruce Black, a psychiatrist in Wellesley, Mass., and an
early researcher on selective mutism, "you'll see stated as a fact that these were stubborn, oppositional kids,
and their refusal to speak was a manifestation of that."
Although knowledge about selective mutism has improved and altered in the past 130 years, much still
remains unknown and much of what appears to be known remains unconfirmed. For example, little is
known about the long-term course, the efficacy of intervention, and the very nature of this disorder and
documented information is full of varying versions, sometimes conflicting, in epidemiology.
Another popular belief was that selective mutism was a form of post-traumatic stress disorder. There are
stories that these kids were keeping some secret about something terrible that happened. The truth is the
majority of children diagnosed with SM did not become silent as a result of trauma. Although, many families
have said to be suspicious that there child was not talking in school because they were hiding abuse. The
post traumatic stress theory doesn’t hold any validating evidence.
The diagnosis was changed to selective mutism in the fourth edition of the American Psychiatric
Association's diagnostic manual. The important change allows a new perspective on how these children are
perceived and treated.
The term selective mutism seems more appropriate than elective mutism, given the onset in research now
associating this disorder with anxiety. Much attention is now directed to learning about the anxiety
producing situations that result in the child’s mutism. Yet, selective mutism is currently classified in the
DSM-IV under “Other Disorders of Infancy, Childhood, and Adolescence,” which some argue this
description makes it sound as if a child’s defiance is the source to the unwillingness to speak.
Incidence of Selective Mutism
Until recently, the disorder was thought to be rare, affecting about 1 child in 1,000. But a 2002 study in The
Journal of the American Academy of Child and Adolescent Psychiatry put the incidence of selective mutism
closer to 7 children in 1,000, making it almost twice as common as autism. However, research on SM does
not agree on a single prevalence rate. One reason for the lack of agreement on prevalence rates is that
because SM is so uncommon it is not often studied in large groups or sample sizes.
Current rates are estimated to be between 3 and 8 in 10,000. Some researchers state that the occurrence of
SM is probably more frequent than this estimate. Reasons for this assumption focus mainly on the possibility
of underreporting which could be due to families living in isolation, a family not recognizing SM as a
behavior problem that can be treated, or families being unaware of the problem altogether since it usually
does not occur in the home.
Selective mutism, experts say, it probably represents one end of a spectrum of social anxieties that includes
everything from a fear of eating in public to stage fright and claustrophobia (fear of narrow places). Despite
its prevalence, selective mutism is still widely misunderstood and often ignored. Some children are thought
to be shy and parents think they’ll out grow it. Experts say these children pick up cues in the environment
that initiate an adaptive response, which puts them either into a fight-or-flight situation or leads to a
Possible Causes and Risks
Most experts believe that there are environmental, biological, interpersonal, and anxiety related triggers are
the cause of selective mutism. Most children with this condition have some form of extreme social phobia.
Some affected children have a family history of selective mutism, extreme shyness, or anxiety disorders that
may increase their risk for similar problems.
Most researchers now agree that selective mutism is more a result of temperament than of environmental
influences. In the early 1990's two studies, by doctors showed that children with the disorder were not just
shy; they were actively anxious. They came to concluding that the kids had social anxiety disorder, and the
selective mutism was a display of that. Essentially, other than the lack of speech, the only common
characteristic among the individuals was social anxiety. Researchers conclude that for this reason, the failure
to speak may only be a symptom.
One of the most puzzling aspects of selective mutism is the fact that children stay silent even when the
consequences of their silence include shame, social rejection or even punishment. This problem may be
explained by the fact that at the root of the disorder is the instinct for self-defense, a natural reaction to
avoid unpleasant situations. Children with SM will rather refrain from social interactions. Experts say they
don't know how to engage with other people. They learn to avoid eye contact; they learn to turn their heads
and not communicate.
Treatment for Selective Mutism
Current treatment combines behavior modification, family participation, and school involvement. Certain
medications that address symptoms of anxiety and social phobia (extreme social shyness) have been used
safely and successfully.
Few doctors are willing to treat selective mutism, and fewer still achieve results. Many now prescribe
Fluoxetine, the generic version of Prozac, for selective mutism, usually combined with cognitive or
behavioral therapies. Fluoxetine and other antidepressants in the class known as selective serotonin reuptake
inhibitors, or (SSRI), can loosen inhibitions - a factor in explaining their usefulness for social anxiety. This
also means that they are not for everyone. After starting on antidepressants some children show
improvement in social environments but can begin exhibiting inappropriate behaviors, which end when the
medication is withdrawn.
Selective Mutism is a condition that can last anywhere from several weeks to years. Many parents often
think that the child is simply refusing to speak, but in SM usually the child is truly unable to speak in
particular settings. The prognosis for this disorder varies. However, continued therapy and intervention for
shyness and social anxiety into adolescence and adulthood may be required. Behavioral and cognitive
therapies that rely on reducing sensitivity by gradual exposure to distressing situations, with a lot of positive
reinforcement, can also be successful, either on their own or combined with antidepressants.
Clinicians must be careful of labeling children with SM as having speech or language disorders, for this label
can misdirect treatment away from the psychological problems underlying the failure to speak. The best
treatments appear to be behavioral methods implemented in a multidisciplinary setting. Hopefully future
research will help in creating a more consistent profile regarding the prevalence of SM that may contribute
to improvements in early detection and early treatment.