'More than 100 years of silence', elective mutism: a review of the literature.

Elective mutism is a rare disorder of communication, where the child speaks fluently in familiar situations, such as home, despite lack of speech in less familiar settings, for example school. A variety of temperamental and behaviour characteristics, co-morbid psychiatric conditions, neurodevelopmental delay and family factors have been associated with the disorder. EM children are described as excessively shy, withdrawn, 'slow to warm up', inhibited, often avoid eye contact, fear social embarrassment and experience significant separation anxiety, on separation from their attachment figures. Their behaviour is often perceived by others as controlling and oppositional. Onset of EM is typically in early childhood years. A number of constitutional and environmental factors have been considered in its onset, progression and response to intervention. Treatment is generally considered to be multimodal, and occurs in a variety of settings, including home and school. Longterm studies suggest that communication difficulties may extend into adulthood. In addition, outcome studies showing a high rate of phobic disorders suggest that EM may be a developmental precursor of adult social phobia. This article reviews the literature on EM, its presentation, aetiology, epidemiology and the various evidence based biopsychosocial treatments.