出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/07/11 14:21:46」(JST)
| Selective Mutism (AQ) | |
|---|---|
| Classification and external resources | |
| ICD-10 | F94.0 |
| ICD-9 | 309.83 313.23 |
| MedlinePlus | 001546 |
| eMedicine | ped/2660 |
| MeSH | D009155 |
Selective mutism (SM) is a psychiatric disorder in which a person who is normally capable of speech is unable to speak in given situations or to specific people. Selective mutism usually co-exists with shyness or social anxiety.[1] In fact, the majority of children diagnosed with selective mutism also have social anxiety disorder (100% of participants in two studies and 97% in another).[2][3][4] Some researchers therefore speculate that selective mutism may be an avoidance strategy used by a subgroup of children with social anxiety disorder in order to reduce their distress in social situations.[5][6]
Contents
|
| This section needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (August 2010) |
Children and adults with selective mutism are fully capable of speech and understanding language but fail to speak in certain situations, though speech is expected of them.[7] The behaviour may be perceived as shyness or rudeness by others. A child with selective mutism may be completely silent at school for years but speak quite freely or even excessively at home. There is a hierarchical variation among those suffering from this disorder: some people participate fully in activities and appear social but don't speak, others will speak only to peers but not to adults, others will speak to adults when asked questions requiring short answers but never to peers, and still others speak to no one and participate in few, if any, activities presented to them. In a severe form known as "progressive mutism", the disorder progresses until the sufferer no longer speaks to anyone in any situation, even close family members.
Selective mutism is by definition characterized by the following:
Particularly in young children, SM can sometimes be confused with an autism spectrum disorder, especially if the child acts particularly withdrawn around his or her diagnostician, which can lead to incorrect treatment. Although autistic people may also be selectively mute, they display other behaviors—hand flapping, repetitive behaviors, social isolation even among family members (not always answering to name, for example)—that set them apart from a child with selective mutism. People with higher-functioning autism may be selectively mute due to anxiety in social situations that they do not fully understand. If mutism is entirely due to autism spectrum disorder, it cannot be diagnosed as selective mutism as stated in the last item on the list above.
Selective mutism may co-exist with or cause the child to appear to have attention deficit disorder. Many people with the inattentive form of ADHD show little or no interest in other people primarily. People with inattentive ADHD may appear to be "space cadets" or "out in their own world", and may be slower to respond to social stimuli. Children with selective mutism, especially when they have severe social anxiety, may also look like this. Also, they might be distracted by their anxiety or by sensory input, if they are highly sensitive, or from the task at hand.
Over 90% of people with selective mutism have social phobia, and some have other anxiety disorders such as obsessive compulsive disorder or panic disorder.
The former name elective mutism indicates a widespread misconception among psychologists that selective mute people choose to be silent in certain situations, while the truth is that they often wish to speak but cannot. To reflect the involuntary nature of this disorder, the name was changed to selective mutism in 1994.
The incidence of selective mutism is not certain. Due to the poor understanding of this condition by the general public, many cases are likely undiagnosed. Based on the number of reported cases, the figure is commonly estimated to be 1 in 1000, 0.1%.[8] However, a 2002 study in The Journal of the American Academy of Child and Adolescent Psychiatry estimated the incidence to be 0.71%.[9]
Besides lack of speech, other common behaviors and characteristics displayed by selectively mute people include:
On the positive side, many sufferers have:
Most children with selective mutism are believed to have an inherited predisposition to anxiety. They often have inhibited temperaments, which is hypothesized to be the result of over-excitability of the area of the brain called the amygdala.[12] This area receives indications of possible threats and sets off the fight-or-flight response. Given the very high overlap between social anxiety disorder and selective mutism (as high as 100% in some studies[13][14][15]), it is quite possible that social anxiety disorder causes selective mutism.
Some children with selective mutism may have sensory integration dysfunction (trouble processing some sensory information). This would cause anxiety and a sense of being overwhelmed in unfamiliar situations, which may cause the child to "shut down" and not be able to speak (something that some autistic people also experience). Many children with SM have some auditory processing difficulties.
About 20–30% of children with SM have speech or language disorders that add stress to situations in which the child is expected to speak.[16]
Despite the change of name from "elective" to "selective", a common misconception remains that a selectively mute child is defiant or stubborn. In fact, children with SM have a lower rate of oppositional behavior than their peers in a school setting.[17] Some previous studies on the subject of Selective mutism have been dismissed as containing serious flaws in their design. According to a more recent systematic study it is believed that children who have selective mutism are not more likely than other children to have a history of early trauma or stressful life events.[18] Another recent study by Dummit et al., in 1997 did not find any evidence of trauma in their sample of children. Recent evidence has shown that trauma doesn't explain why most children with selective mutism develop the condition.[19] Many children who have Selective Mutism almost always speak confidently in some situations. Children who have suffered from trauma however are known to suddenly stop speaking.
In 1877, a German physician described children who were able to speak normally but often refused to as having a disorder he named aphasia voluntaria.[20] Although this is now an obsolete term, it was part of an early effort to describe the concept now called selective mutism.
In 1980, a study by Torey Hayden identified what she called four "subtypes" of elective mutism, although this set of subtypes is not in current diagnostic use.[21] First, and most common, she described "symbiotic mutism" characterized by a vocal and dominating mother and absent father and the use of mutism as controlling behavior around other adults. Second, the least common, was the "speech phobic mutism" subtype, in which the child showed distinct fear at hearing a recording of his or her voice. This subtype also involved ritualistic behaviors and was thought to be caused by having been told to keep a family secret.
Hayden's third subtype was "reactive mutism," thought to be caused by trauma or abuse, though not all children put in this category were known to have been abused. These children all showed symptoms of depression and were notably withdrawn, usually showing no facial expressions. In her fourth and last subtype, Hayden described "passive-aggressive mutism" in which silence is used as a display of hostility, connected to antisocial behavior. Some of the children in this group had not been mute until age 9–12. These subtypes are no longer recognized, though "speech phobia" is sometimes used to describe a selectively mute person who appears not to have any symptoms of social anxiety.
The Diagnostic and Statistical Manual of Mental Disorders (DSM), first published in 1952, first included elective mutism in its third edition, published in 1980. Elective mutism was described as "a continuous refusal to speak in almost all social situations" despite normal ability to speak. While "excessive shyness" and other anxiety-related traits were listed as associated features, predisposing factors included "maternal overprotection", mental retardation, and trauma. Elective mutism in the third edition revised (DSM III-R) is described similarly to the third edition except for specifying that the disorder is not related to social phobia.
In 1994, Sue Newman, co-founder of the Selective Mutism Foundation, requested that the fourth edition of the DSM reflect the name change from elective mutism to selective mutism and describe the disorder as a failure to speak. The relation to anxiety disorders was emphasized, particularly in the revised version (DSM IV-TR).
Contrary to popular belief, people suffering from selective mutism do not necessarily improve with age.[22] Effective treatment is necessary for a child to develop properly. Without treatment, selective mutism can contribute to chronic depression, further anxiety, and other social and emotional problems.[23][24]
Consequently, treatment at an early age is important. If not addressed, selective mutism tends to be self-reinforcing. Those around such a person may eventually expect him or her not to speak and therefore stop attempting to initiate verbal contact with the sufferer. Alternatively, they may pressure the child to talk, making him or her have even higher anxiety levels in situations where speech is expected. Because of these problems, a change of environment (such as changing schools) may make a difference, and treatment in teenage or adult years can be more difficult because the sufferer has become accustomed to being mute.
The exact treatment depends on the sufferer's age, other mental illnesses he or she may have, and a number of other factors. For instance, stimulus fading is typically used with younger children, because older children and teenagers recognize the situation as an attempt to make them speak, and older sufferers and people with depression are more likely to need medication.[25]
The child is brought into the classroom or the environment where s/he will not speak and is videotaped answering a series of questions. First, his/her teacher, or adult representative of those to which the child will not speak asks the child questions. The child likely does not answer the questions at this time. A parent or someone to whom the child will converse verbally then comes in the room and the teacher goes out. The comfortable adult asks the child the same questions, this time eliciting a verbal response. The two videos of the conversations are then edited together to make it seem that the child is directly answering the questions posed by the teacher. This video is then shown to the child over a series of several weeks. The child is asked to view the tape and every time s/he sees him/herself answering the teacher verbally, stop the tape to receive a positive reinforcement.
The video can also be shown to the child’s class in order to set an expectation in the classroom by his/her peers that s/he speaks. The classmates now know the sound of the child’s voice and believe they have seen the child conversing with the teacher.[26][27]
Mystery motivation is often seen paired with the self-modeling technique. An envelope is placed in the child’s classroom in a visible place. On the envelope, the child’s name is written along with a question mark. Inside is a prize determined with the child’s parent in order for it to be something the child would want to have. The child is told that when s/he asks for the envelope appropriately and loudly enough for the teacher and his/her peers to hear, s/he may then receive the mystery motivator. The class is also told in this case about the expectation that the child ask for the envelope loudly enough that the class can hear.[26][27][28]
The subject is brought into a controlled environment with someone with whom they are at ease and can communicate. Gradually, another person is introduced into the situation. One example of stimulus fading is the sliding-in technique, where a new person is slowly brought into the talking group. This can take a long time for the first one or two faded-in people but may become faster as the patient gets more comfortable with the technique.
An example of this would be a child playing a board game with a family member in his/her classroom at school. Gradually, the teacher is brought in to play as well. When the child adjusts to his/her presence, then a peer is brought in to be a part of the game. Each person is only brought in if the child continues to engage verbally and positively.[26][27][28]
The subject communicates indirectly with a person he or she is afraid to speak to through such means as email, instant messaging (text, audio, and/or video), online chat, voice or video recordings, and speaking or whispering to an intermediary in the presence of the target person. This can make the subject more comfortable with the idea of communicating with this person.
The subject is slowly encouraged to speak. He or she is reinforced first for interacting nonverbally, then for saying certain sounds (such as the sound that each letter of the alphabet makes) rather than words, then for whispering, and finally saying a word or more.[29]
Spacing is important to integrate, especially with self-modeling. Repeated and spaced out use of interventions is shown to be the most helpful long-term for learning. Viewing videotapes of self-modeling should be shown over a spaced out period of time of approximately 6 weeks.[26][27][28]
Many practitioners believe that there is evidence indicating that antidepressants such as SSRIs may be helpful in treating children and adults with selective mutism and even that medicine is essential to effective treatment.[citation needed] The medication is used to decrease anxiety levels to speed the process of therapy. Use of medication may end after nine to twelve months, once the person has learned skills to cope with anxiety and has become more comfortable in social situations.[30] Medication is more often used for older children, teenagers, and adults whose anxiety has led to depression and other problems.
Medication, when used, should never be considered the entire treatment for a person with selective mutism. While on medication, the person should be in therapy to help them learn how to handle anxiety and prepare him or her for life without medication.[31]
Anti-depressants have been used in addition to self-modeling and mystery motivation in order to aid in the learning process.[26][27]
| This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (June 2013) |
Possibly the most well-known instance of selective (as opposed to total) mutism in popular culture currently is depicted by the character of Rajesh Koothrappali in the television sitcom The Big Bang Theory. Due to social anxiety, he is unable to speak to women who are not family members. Drinking alcohol suppresses his anxiety, allowing him to speak, however it negatively affects his personality, making him an arrogant, obnoxious pervert. In the episode "The Terminator Decoupling", however, he mistakenly drinks alcohol-free beer and due to the placebo effect, is able to hold a conversation with actress Summer Glau. He is later cured in the season six finale "The Bon Voyage Reaction" after his girlfriend Lucy (Kate Micucci) breaks up with him.
Children's books with a selectively mute protagonist include The Secret Voice of Gina Zhang by Dori Jones Yang and Alvin Ho: Allergic to Girls, School, and Other Scary Things by Lenore Look. Both of these books are set in elementary school and specifically mention selective mutism. In addition, several children's picture books have been written with the specific purpose of educating readers about selective mutism, such as Understanding Katie by selective mutism expert Elisa Shipon-Blum.
In young adult literature and films, there are several instances of protagonists who do not speak despite having the ability to do so. They usually are mute in all situations, and trauma is a common cause for the mutism, though some make the choice to stop speaking. One well-known book, Cut by Patricia McCormick, features a main character who is entirely silent after facing problems at home and being sent to a mental hospital.
There are various lesser-known books in both young adult and adult fiction, as well as films that follow the same idea. For example, the 2004 made-for-TV movie Samantha: An American Girl Holiday, where one of the three orphans that the protagonist befriended, never said a word for the majority of the story, likely out of emotional trauma due to the death of their parents. In the children's film Jumanji, after the death of their parents the character Peter speaks only to his sister, and only when they are alone.
In the Saturday Night Live Digital Shorts, "Rihanna and Shy Ronnie", and "Ronnie and Clyde", the character "Shy Ronnie" (portrayed by Andy Samberg) cannot rap in front of Rihanna, but starts as soon as she leaves the room, and stops again when she re-enters.
The film Little Voice centers upon a selectively mute singer.
|
||||||||||||||
全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.
| リンク元 | 「選択緘黙」 |
| 関連記事 | 「selective」 |