Elective mutism - associated with developmental disorder/delay. Two case studies

Elective mutism (EM) is not regarded as a separate diagnostic category in the ICD-9, but is included under the heading "313: Disturbance of emotions specific to childhood and adolescence." In the ICD-10 EM is acknowledged as a separate diagnosis defined as "a marked, emotionally determined lack of speech in certain situations in a child with a normal or near normal speech/language ability." The diagnosis excludes pervasive developmental disorder and specific developmental disorders of speech and language. Two patients referred for EM to a child and adolescent psychiatry outpatient clinic, showed specific developmental delays and assessment indicated slight mental retardation in one of them. The question arose regarding how extensively EM is reported in the literature as associated with developmental disorder/delay. A search was carried out in four data-bases where most references were listed under the keyword "mutism". This paper presents the two case studies, and the results of the literature inventory. It concludes that EM may be associated with developmental disorder/delay and suggests that this could be a predisposing factor for an emotionally determined lack of speech in certain situations.