2.2 Questionnaires Speci fi c to Selective Mutism
2.2.1 Selective Mutism Questionnaire
The Selective Mutism Questionnaire (Bergman et al., 2008) is a 17-item parent questionnaire that assesses the degree and frequency of speech in three- to 11-year- old children and provides a proxy measure of selective mutism severity. Parents report on their children’s behavior with regards to speaking in the previous two weeks across three broad domains (or subscales): at school (five items), at home/with family (five
items), and in social situations (seven items). Parents rate items using a three-point scale that ranges from 0never to 3always. Items are summed to create a total score, with lower total scores suggesting less speech. Six additional items assess the degree of overall interference or distress experienced, although these items are not included in the total score and are used primarily for qualitative purposes.
The psychometric properties of the Selective Mutism Questionnaire were exam- ined in studies of parents of children with or without selective mutism who attended an anxiety clinic (Bergman et al.,2008). The selective mutism group was made up of 48 children (M age 5.83 years;SD 1.65; range 3–10) with a primary DSM-IV (American Psychiatric Association, 1994) diagnosis of selective mutism and 92% having a comorbid DSM-IV (American Psychiatric Association, 1994) social anxiety disorder diagnosis. The non-selective mutism group was made up of 18 children (M age6.33 years;SD1.78; range3–10) with a non-selective mutism anxiety disorder such as obsessive-compulsive disorder, separation anxiety disorder, generalized anxiety disorder, specific phobia, and included three children with social anxiety disorder. In the selective mutism group, internal consistency of the Selective Mutism Questionnaire wasα0.97 for the total score,α0.97 for the school subscale,α0.88 for the home/family subscale, andα0.96 for the social subscale. Additionally, children in the selective mutism group were noted to have significantly less speech (M total score12.99;SD7.23) than children in the non-selective mutism group (Mtotal score46.00;SD5.94),t(64)16.05, p< 0.001.
As seen in Table2.1, to examine convergent validity, Bergman and colleagues (Bergman et al.,2008) compared the total score and subscale scores of the Selec- tive Mutism Questionnaire with various measures of social anxiety that have been used with older children, including the parent report of the Social Anxiety Scale for Children—Revised (La Greca & Stone,1993), an instrument validated for children in grades four to six, the parent version of the Multidimensional Anxiety Scale for Children (March, Parker, Sullivan, Stallings, & Conners,1997), an anxiety screen validated for children eight years and older, and the Clinician Severity Rating of the clinician-administered Anxiety Disorders Interview Schedule (Silverman & Albano, 1996).
As noted in Table2.1, Bergman and colleagues (Bergman et al.,2008) reported significant correlations between the total score on the Selective Mutism Question- naire and (1) the social anxiety subscale score of the parent Multidimensional Anx- iety Scale for Children (March et al., 1997), (2) the Clinician Severity Rating on the Anxiety Disorders Interview Schedule (Silverman & Albano,1996), and (3) the total score of the Social Anxiety Scale for Children—Revised (La Greca & Stone, 1993). Further, when five items related to talking from the Social Anxiety Scale for Children—Revised (La Greca & Stone,1993) were removed, the total score of the Selective Mutism Questionnaire continued to correlate significantly with the score on the remaining items. These findings provide some evidence for the convergent validity of the Selective Mutism Questionnaire with other measures assessing similar and/or related concepts, such as social anxiety symptoms.
Table 2.1 Correlations between Selective Mutism Questionnaire Total Score and other Measures
Measure Selective Mutism Questionnaire Total Score
r(pvalue) Parent MASC social anxiety subscale −0.62 (<0.01) ADIS Clinician Severity Rating −0.67 (<0.001)
SASC-R total score −0.52 (<0.01)
SASC-R without talking items −0.44 (<0.05) Parent MASC harm avoidance subscale 0.32 (n.s.) Parent MASC separation anxiety subscale 0.17 (n.s.) Parent MASC physical symptoms subscale −0.15 (n.s.)
Parent MASC total score −0.21 (n.s.)
SASC-RSocial Anxiety Scale for Children—Revised;MASCMultidimensional Scale for Children;
ADISAnxiety Disorders Interview Schedule
Conversely, as noted in Table2.1, non-significant correlations between the total score of the Selective Mutism Questionnaire and non-social anxiety measures such as the other subscales of the parent version of the Multidimensional Anxiety Scale for Children (March et al.,1997) were observed, thus providing some evidence for discriminant validity of the Selective Mutism Questionnaire.
To assess for sensitivity to treatment response, the Selective Mutism Questionnaire was completed pre- and post-treatment in a small subsample (N11) of children with selective mutism who participated in a behavioral treatment program (Bergman et al., 2008). Paired t-tests demonstrated that the mean total Selective Mutism Question- naire scores increased significantly from pre-treatment to post-treatment (M13.83, SD5.00 vs.M 31.07,SD7.01;p< 0.001), indicating a significant increase in speaking behaviors post-treatment and demonstrating that the Selective Mutism Questionnaire can be used to detect change in treatment studies. Other treatment studies (e.g., Bergman, Gonzalez, Piacentini, & Keller,2013; Sharkey, McNicholas, Barry, Begley, & Ahern,2008) also suggest that the Selective Mutism Questionnaire can detect change in speaking behavior as a result of treatment.
The Selective Mutism Questionnaire is currently the only questionnaire that eval- uates speaking behaviors in a broad age range of children and to date it has been used by most researchers as a proxy measure of symptom severity in selective mutism.
Significant correlations between the Selective Mutism Questionnaire and measures of social anxiety, as described herein, suggest that the Selective Mutism Question- naire is measuring a similar construct. The lack of a significant correlation between the Selective Mutism Questionnaire and anxiety symptoms other than social anxiety, suggests that the Selective Mutism Questionnaire is not measuring these non-social anxiety symptoms. Further research pertaining to the development and validation of screening tools that specifically evaluate the symptoms of selective mutism in four- to seven-year-old children, beyond not speaking, is warranted.