Pediatric Social Phobia and Selective Mutism 

Selective mutism is a disorder in which an individual is not able to speak aloud in specific situations when there is an expectation of conversational speech.^[2]Communicative language is generally intact in such individuals, although selective mutism can coexist with language and communication disorders.

Selective mutism can be accompanied by other anxiety disorders such as separation anxiety disorder, social anxiety disorder (formerly called social phobia), agoraphobia, and panic disorder, as well as by shyness and anxiety; however, it can also exist without other anxiety-related disorders.^[3]

Selective mutism generally occurs by age 5 years; however, usually it is not diagnosed until the child starts school. In some cases, adolescents and adults continue to experience an inability to speak in public. This inability is generally most disabling at school, as the child cannot be assertive and speak when called on by teachers. In adults, functional impairment occurs when public speaking or lecturing is required in one's vocation. Often, the child with selective mutism designates a friend or close family member to serve as an interpreter of communication and whispers into that person's ear, so that communication occurs with the designated person as intermediary.

Often, selective mutism can coexist with social phobia, also known as social anxiety, and is defined by marked and persistent fear of social or performance situations in which embarrassment may occur; exposure to the social or performance situation almost always causes an anxiety reaction such as a situationally bound or situationally predisposed panic attack.

Selective mutism can also be the precursor to agoraphobia and/or panic disorder. Agoraphobia is a specific phobia in which the individual fears being in crowded places. People with agoraphobia often become homebound. Panic disorder can result in significant disability and iatrogenically induced illness, especially in situations when invasive medical testing is done, because the severity of symptoms such as chest pain and palpitations and medical testing can intensify the severity of the panic symptoms.

The anxiety reaction is not due to psychosis; individuals are able to recognize their fears as excessive and unreasonable. However, the ability to fully comprehend that the reaction is out of proportion to the precipitant may be less complete in children and may depend on their cognitive-developmental level of functioning due to deficits in emotional regulation. Recent studies have looked at physiological measures reflecting the severity of anxiety. Children with selective mutism were compared with children with social phobia in a study of 35 children (average age, 8 y). Those with social phobia and selective mutism had chronically higher levels of arousal as reflected by respiratory sinus arrhythmia and skin conductance levels. This may help explain why children with selective mutism may appear to others to not be overtly anxious; their silence may serve to decrease outward signs of anxiety observable by others.^[4]

Studies that use physiological measures to objectively measure the severity of anxiety have shown that children with selective mutism and social anxiety as compared with children with social phobia alone have chronically higher levels of arousal (more intense anxiety) as reflected in the presence of respiratory sinus arrhythmia and skin conductance levels. Children with selective mutism may appear to others to not be overtly anxious, especially because of their silence, as their anxiety is not directly observable by others.^[4]

Selective mutism significantly impairs the individual's level of functioning, as the individual is unable to complete required educational, social, and family tasks, and the emotional distress engendered in situations requiring the person to speak out loud can result in school refusal.^[5]

Selective mutism is a disorder that first occurs in childhood and can continue into adolescence and adulthood. In adults with this disorder, functional impairment occurs when public speaking or lecturing are required in one's vocation. Severe social anxiety may not be evident, as the person may actually function in a relaxed manner when using nonverbal (ie, gestures, signing) communication styles.^[6]

Shyness does not necessarily persist in adolescents with social anxiety disorder. A study by Burstein et al found that almost 50% of a group rated themselves shy; however, only 12% of adolescents who identified themselves as shy actually met criteria for lifetime incidence of social anxiety disorder as measured by the World Health Organization Composite International Diagnostic Interview 3.0, and 5.2% of adolescents who did not identify as having shyness had social phobia.^[7]

There is significant comorbidity of social phobia with anxiety disorders, major depressive disorder, and drug use disorders, without regard to the presence or absence of shyness. Adolescents with shyness were more likely to report agoraphobia compared with the no-shyness group. Adolescents with social phobia versus adolescents with shyness had greater impairment in the areas of school/work, family relationships, and social life; however, they were no more likely to obtain professional treatment. Eighty percent of adolescents with social phobia failed to seek or to obtain professional treatment for their anxiety, and rates of prescribed medication use were systematically low across groups: 2.3% of adolescents with social phobia and 0.9% of adolescents with shyness used paroxetine.

Adolescent gender did not have a significant effect on the prevalence of social phobia. However, culture can cause parents to underreport anxiety; a clinically referred sample of 408 parent-youth dyads of African American adolescents versus Latino and white adolescents that used the Screen for Child Anxiety Related Emotional Disorders (SCARED) found that parents tended to significantly underreport anxiety symptoms.^[8]

By Antonella Brunetto