Selective mutism was first described in the 1870s, at which time it was called "aphasia voluntaria." This name shows that the absence of speech was considered to be under the control of the child's will. In 1934 the disorder began to be called selective mutism, a name that still implied purposefulness on the part of the silent child. In the 1994 edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) the disorder was renamed selective mutism. This name is considered preferable because it suggests that the child is mute only
Selective mutism is characterized by a child's inability to speak in one or more types of social situation, although the child is developmentally advanced to the point that speech is possible. The child speaks proficiently in at least one setting, most often at home with one or both parents, and sometimes with siblings or extended family members. Some children also speak to certain friends or to adults that are not related to them, but this variant of selective mutism is somewhat less common.
The most common place for children to exhibit mute behavior is in the classroom, so that the disorder is often first noticed by teachers. Because of this characteristic, selective mutism is most frequently diagnosed in children of preschool age through second grade. As the expectation of speech becomes more evident, selective mutism can have more pronounced negative effects on academic performance. Children who do not talk in classroom settings or other social situations because the language of instruction is not their first tongue are not considered to have the disorder of selective mutism.
Causes and symptoms
The symptoms of selective mutism are fairly obvious. The child does not talk in one or more social situations in which speech is commonly expected and would facilitate understanding. Some children with selective mutism do not communicate in any way in certain settings, and act generally shy and withdrawn. The disorder is also often associated with crying, clinging to the parent, and other signs of social anxiety. Other children with the disorder, however, may smile, gesture, nod, and even giggle, although they do not talk.
Consensus regarding the most common causes of selective mutism has changed significantly over time. When the disorder was first studied, and for many years thereafter, it was thought to be caused by severe trauma in early childhood. Some of these causative traumas were thought to include rape, molestation, incest, severe physical or emotional abuse, and similar experiences. In addition, many researchers attributed selective mutism to family dynamics that included an overprotective mother and an abnormally strict or very distant father. As of 2002, these factors have not been completely eliminated as causes of selective mutism in most cases, but it is generally agreed that they are not the most common causes.
Instead, selective mutism is frequently attributed at present to high levels of social anxiety in children and not to traumatic events in their early years. Children with selective mutism have been found to be more timid and shy than most children in social situations, and to exhibit signs of depression, obsessive-compulsive disorder, and anxiety disorders. Some children have been reported to dislike speaking because they are uncomfortable with the sound of their own voice or because they think their voice sounds abnormal.
Many links have also been found between selective mutism and speech development problems. Language reception problems have also been documented in selectively mute children. Although there is no evidence indicating that selective mutism is the direct result of any of these difficulties in language development, possible connections are being explored.
Selective mutism is generally considered a rare disorder. It is found in about 1% of patients in mental health settings, but it occurs in only about 0.01% of the general United States population. Some researchers maintain, however, that selective mutism occurs more frequently than these data suggest. There may be many unreported cases of selective mutism that resolve with time and require no intervention.
In terms of age grouping, selective mutism may appear at the very beginning of a child's social experience or may begin in later childhood. Some cases have been recorded in which selective mutism does not begin until high school. Onset in late adolescence is unusual, however; the most common age of onset for the disorder is the early elementary school years.
Selective mutism is often associated with social phobia in adult life. Children with selective mutism disorder may be more likely as adults to have a high level of social anxiety even if they do not meet the diagnostic criteria for social phobia. The disorder appears to run in families. Children whose parents are anxious in social settings, were exceptionally timid as children, or suffered from selective mutism themselves in childhood, are at greater risk for developing selective mutism.
The criteria for diagnosing selective mutism disorder given by the reference manual, the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) include the failure to speak in some social situations even though the child may talk at other times. This criterion is not met if the child does not speak at all in any situation.
The child's inability to talk must interfere with the achievement of such relevant goals as schoolwork, play with friends, or communication of needs. In addition, the lack of speech must persist for at least one month. The first month of school should not be included in this measurement because many children are shy and unwilling to talk freely until they feel comfortable with their new teacher, classmates, and surroundings.
Furthermore, the child's lack of speech cannot be attributed to unfamiliarity with the language they must use in school or social settings. The diagnosis of selective mutism does not apply to children from immigrant families who may not feel comfortable conversing in a second language. Moreover, the child's inability to talk cannot be attributed to stuttering or similar speech disorders, which may make the child uncomfortable because they are aware that their speech sounds different from the speech of their peers. The lack of speech also must not be attributable to schizophrenia, autism, or other mental health disorders.
The disorder of selective mutism is usually noticed first by parents or teachers of affected children. It is often hard for doctors to diagnose selective mutism because it is unlikely that the child in question will talk to them. Therefore it may be difficult for a general practitioner to assess the existence of any underlying language or developmental problems that may be either causing or exacerbating the disorder. Tests that evaluate mental development without verbal responses from the patient may be used successfully to evaluate children with selective mutism.
There are also ways to test the child's speech development in the situations in which he or she does talk. One method involves interviews with the parents or whomever the child does speak to on a regular basis. This method can be fairly subjective, however. It is more useful for the doctor to obtain a tape or video recording of the child talking in a situation in which he or she feels comfortable. The child's hearing should be checked, as speech problems are often related to hearing disorders. Observing the child at play activities or asking him or her to draw pictures offer other effective ways to determine the child's reactions in social situations.
A number of different approaches have been used in attempts to treat selective mutism. Recent opinion has moved away from the idea that it is caused by a trauma, and attempts to treat it have followed accordingly. The factors that are most intensively studied at present are underlying anxiety problems. In the few cases in which an underlying trauma is discovered to be the source of the problem, counseling to help treat the underlying problems is recommended. Treatments of any kind are generally found to be more effective when the family of the child is involved in decisions about his or her treatment.
Selective mutism can be treated by using a reinforcement approach. This method gives positive rewards to the child in the form of praise, treats, privileges, or anything else that the child values. In general rewards are given for speech, and withheld for silence. The use of punishments alongside the rewards is not generally recommended because it would place more stress on children who are already severely anxious. The positive reinforcement technique is generally found to be atleast partially successful in most cases.
Another technique for modifying behavior in children with selective mutism is known as stimulus fading. This technique sets goals of increasing difficulty for the child to meet. For example, the child might be encouraged to start talking by whispering, then work up gradually to talking at full volume. Alternately, the child could start by talking to one person who is not a family member and gradually add names until he or she feels comfortable talking to more than one person at a time. Stimulus fading has been found to be particularly effective when it is used in conjunction with positive reinforcement techniques.
Treatment with medications
In some cases, selective mutism is treatable with medication. Fluoxetine (Prozac), which is one of the selective serotonin reuptake inhibitors (SSRIs) is the drug that has been studied most often as a treatment for selective mutism. Treatment with medication is more successful in younger children. Overall, fluoxetine has been found to reduce the symptoms of selective mutism in about three-fourths of children. Other drugs used to treat anxiety and social phobia disorders may also be effective in certain cases.
Selective mutism is frequently treatable, in that many cases of the disorder are thought to resolve on their own. Sometimes reported cases do resolve with time, although treatment can be very effective. There is little information about the long-term outcome of selective mutism. Researchers have noted that while many children with the disorder do show improvement in speech, their anxiety in social situations persists.
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Tish Davidson, A.M.