The nature of the anxiety in children with selective mutism

Research demonstrates that children with selective mutism (SM) present with symptoms of social anxiety and there is a high comorbidity between SM and social phobia (SP). As a result some researchers have questioned whether SM is a variant of SP rather than a distinct anxiety disorder. This thesis sought to clarify the association between SM and SP. Participants were 25 children with a primary diagnosis of SM, 17 children with a primary diagnosis of SP and 15 children identified as “easy-going” who did not meet criteria for a DSM-IV diagnosis. Children were aged between 4 to 8 years. Data included mother, father, teacher and child reports, a semi-structured clinical interview with the child’s mother, and an observational assessment with the child and their mother. The first paper in the thesis reports on the development and psychometric properties of the child self-report measure of mutism, Selective Mutism Questionnaire – Child (SMQ-C). The SMQ-C was adapted from a similar adult measure and was designed for children aged from 4 years. The SMQ-C showed good internal consistency, convergent and divergent validity. Even young children were able to provide a clear picture of how much they spoke in various contexts. The second paper systematically compared children with SM, SP and non-clinical controls on social anxiety symptomatology and behavioural inhibition. Observational measures showed that children in the SM group were more verbally and nonverbally inhibited than children in the SP group and nonclinical controls, and parent report revealed that they were more fearful of negative evaluation than children in theSP group who did not differ significantly from non-clinical controls. These findings indicate that children with a primary diagnosis of SM show similar or even greater social phobia symptomatology than children with a primary diagnosis of SP and both are more socially anxious than non-clinical controls. The third paper explored relationships between social anxiety, parents’ negative affectivity, and parenting practices among children with SM, SP and controls. No significant differences in the levels of negative emotion or social phobia symptomatology among mothers and fathers were found between the three groups, nor did the study find any significant differences in parent-child interaction with one exception. Mothers and fathers of children with a primary diagnosis of SM reported more thoughts of frustration with their child’s reticence in a novel social situation. Correlational analyses showed a significant association between maternal social phobia and child anxiety in the SM and non-clinical groups. Overall, the findings support the idea postulated in the literature that SM is a more severe form of SP observed in younger children. Speech is the primary form of communication in all social interactions, the high social anxiety together with the spoken and unspoken pressures to speak contribute to maintenance of the disorder.