Selective mutism and comorbidity with developmental disorder/delay, anxiety disorder, and elimination disorder

Objectives: To assess the comorbidity of developmental disorder/delay in ch ildren with selective mutism (SM) and to assess other comorbid symptoms suc h as anxiety, enuresis, and encopresis. Method: Subjects with SM and their matched controls were evaluated by a comprehensive assessment of the child and by means of a parental structured diagnostic interview with focus on de velopmental history. Diagnoses were made according to DSM-IV. Results: A to tal of 54 children with SM and 108 control children were evaluated. Of the children with SM, 68.5% met the criteria for a diagnosis reflecting develop mental disorder/delay compared with 13.0% in the control group. The criteri a for any anxiety diagnosis were met by 74.1% in the SM group and for an el imination disorder by 31.5% versus 7.4% and 9.3%, respectively, in the cont rol group. In the SM group, 46.3% of the children met the criteria for both an anxiety diagnosis and a diagnosis reflecting developmental disorder/del ay versus 0.9% in the controls. Conclusions: SM is associated with developm ental disorder/delay nearly as frequently as with anxiety disorders. The mu tism may conceal developmental problems in children with SM. Children with SM often meet diagnostic criteria for both a developmental and an anxiety d isorder.