Selective mutism

# Overview
Selective mutism is a social anxiety disorder in which a person who is normally capable of speech is unable to speak in given situations.

# Causes
No single cause has been established, but there is some evidence that there is a hereditary component.

# Differential Diagnosis
- Autism spectrum disorder
- Communication disorders
- Language disorder
- Speech sound disorder (previously phonological disorder)
- Childhood-onset fluency disorder (stuttering)
- Pragmatic (social) communication disorder
- Intellectual disability
- Neuro-developmental disorders
- Psychotic disorders
- Schizophrenia
- Social anxiety disorder (social phobia)

# Epidemiology and Demographics

## Prevalence
The prevalence of selective mutism is 30-1,000 per 100,000 (0.03%-1%) of the overall population.

# Risk Factors
- Behavioral inhibition
- Genetic predisposition
- Negative affectivity (neuroticism)
- Parental history of shyness
- Social anxiety
- Social isolation

# Natural History, Complications, and Prognosis
Children (and adults) with the disorder are fully capable of speech and understanding language, but fail to speak in certain social situations when it is expected of them. They function normally in other areas of behavior and learning, though appear severely withdrawn and some are unable to participate in group activities due to their extreme anxiety. It is like an extreme form of shyness, but the intensity and duration distinguish it. As an example, a child may be completely silent at school, for years at a time, but speak quite freely or even excessively at home.

# Diagnostic Criteria

## DSM-V Diagnostic Criteria for Selective Mutism

## Symptoms
Selective mutism is usually characterised by the following:
- Consistent failure to speak in specific social situations (in which there is an expectation for speaking, e.g., at school) despite speaking in other situations.
- Interference with educational or occupational achievement or with social communication.
- Disturbance lasting at least 1 month (not limited to the first month of school).
- Failure to speak not due to a lack of knowledge of, or comfort with, the spoken language required by the social situation.
- Lack of better cause explained by a Communication Disorder (e.g. stuttering) and disturbance lasting longer than a Pervasive Developmental Disorder, Schizophrenia, or other Psychotic Disorder.
Typical sufferers have some of the following traits when anxious, some of which are often perceived as rudeness:
- Find it difficult to maintain eye contact.
- Often don't smile and have blank expressions.
- Move stiffly and awkwardly.
- Find situations where talking is normally expected particularly hard to handle (answering school registers, saying hello, goodbye, thank you, etc.).
- Tend to worry about things more than others.
- Can be very sensitive to noise and crowds.
- Find it difficult to talk about themselves or express their feelings.

# Treatment
Contrary to popular belief, people suffering from selective mutism don't necessarily improve with age, or grow out of it. Consequently, treatment at an early age is important. If it is not addressed, selective mutism tends to be self-reinforcing: the expectation that one suffering from selective mutism will not speak causes those around them to stop trying to initiate verbal contact, thus making the prospect of talking seem increasingly difficult or foreign. In such a situation, a change of environment (such as changing schools) can decrease the severity of one's selective mutism by eliminating such expectations.
Psychological treatment has also been shown to help the counteract this condition, though treatment in teenage years is sometimes more difficult. Specific courses of treatment differ based on the subject, and must take factors such as age into account.
Attempts to force a child to talk are typically ineffective and often result in higher anxiety levels, consequently worsening the condition.
Some in the psychiatric community believe that anti-anxiety medications may be effective in extremely low dosages while higher doses may worsen the condition. Others in the field advocate that the side-effects of psychiatric medications- in any dose and on any child- are so dangerous that they negate any temporary benefits, preferring behavioral and psychological interventions.

## Stimulus Fading
Stimulus fading is a common treatment for younger children suffering from selective mutism. This sliding-in technique consists of the subject being brought into a controlled environment with someone who they are at ease with and can communicate with. Gradually, another person is introduced into the situation, often in several distinct stages. This process can be relatively long as the first few people are slid (or faded) into the environment and the conversation.

## Desensitization
The subject is prompted to communicate via indirect means in order to prepare them mentally for direct communication. Methods of indirect communication include email, phone, voice recordings, and conversations on the internet.

## Medical Therapy
Some practitioners advocate the use of antidepressants such as fluoxetine (prozac) as treatment for children with selective mutism. While many in the medical community believe that psychiatric medications can decrease anxiety levels enough to allow patients with selective mutism to communicate, others (see articles on Peter Breggin and David Healy (psychiatrist)) stringently decry the use of psychiatric medications on children. These practitioners and activists note the lack of medical evidence that behavioral disorders have genetic bases. The denunciation of psychotropic intervention on children with behavioral anxiety disorders intensified as lawsuits against several drug companies exposed previously unseen internal research documents linking fluoxetine and other SSRI antidepressants with increased risk of suicide, psychosis and damage to areas of the brain which could affect language production and normal social development.