CHAPTER 7
Selective Mutism and Stammering
Similarities and Differences
Stammering (also known as stuttering or dysfluency) and Selective Mutism (SM) are two different communication difficulties. Historically, it has been considered that the two conditions cannot co-occur: in fact, the DSM-IV (APA 1994) definition of SM highlights SM as a failure to speak in specific social situations, despite the ability to speak in other situations, not explained by another communication disorder. The exclusionary communication disorders are cited, and specifically include stammering. Evidence from clinical practice and discussions with colleagues working within both the fields of SM and stammering indicates, however, that the two conditions can and do co-occur. There has been little research into the co-occurrence of these two conditions, but information drawn from knowledge about both SM and stammering can be usefully compared.
Similarities between SM and stammering are numerous, and include factors relating to causality and onset, presentation, and management. With both SM and stammering there have been many different theories relating to causality, but up-to-date research within both areas suggests a genetic link in some cases. Modern theories also recognize multi-factorial causal and contributory features with both SM and stammering resulting from a variety of predisposing, precipitating and maintaining factors (see Kelman and Nicholas 2008 and Johnson and Wintgens 2001 for summaries of the different factors contributing to stammering and SM respectively, including genetic factors). The predisposing, precipitating and maintaining factors vary with each individual, but some commonalities are evident across the two conditions and can include temperamental traits, anxiety, reactions of others potentially reinforcing the condition, and avoidance of potentially distressing speaking situations acting to maintain the condition.
Other similarities relate to presentation: the potential for both SM and stammering to co-occur with other speech, language, cognitive or motor difficulties; typical age of onset; the variation in speech across different speaking situations; the fact that within both conditions more than just ‘speech’ is affected (with physical secondary behaviours such as loss of eye contact, facial grimacing or concomitant movements being part of stammering for some, and ‘frozen’ posture, lack of eye contact or facial expressions seen at times with SM); and that a continuum of severity is evident within both conditions.
Further similarities can be recognized in relation to the best ways to support both children with SM and those who stammer, with research showing early intervention to be effective for both conditions (Millard, Nicholas and Cook 2008; Johnson and Wintgens 2001). To enable this, full detailed assessment is recommended for both SM and stammering (Cline and Baldwin 2004; Guitar 2006), taking into account the individual’s specific circumstances via information gained from parents, teachers and the child (as appropriate). Information should include: differences in speaking in different situations and environments; any coping strategies the child has developed; any known anxiety triggers; formal assessment of language skills as part of the assessment process (which may not be within the first meeting with the child). Non-directive play and rapport-building will likely play a part within the assessment for both a child who stammers and one presenting with SM in order to ensure the child does not feel under pressure that they ‘must speak’ during the assessment. Additionally, reassuring the child that they are not alone in finding it difficult to speak at times, and reducing any unintentional ‘conspiracy of silence’ about talking about the child’s condition with them, can be a key part of assessment for both conditions.
Management approaches commonly used with SM and stammering following assessment show some overlap. Collaborative work with parents and school staff is important for effective management in both conditions, to ensure that a consistent approach is taken across different settings. In addition, instigating environmental changes to promote a relaxed communicative setting without direct pressure on the child’s speaking is often part of early intervention for both conditions. More direct work often includes setting behavioural experiments in small steps and, for older children, principles of Cognitive Behavioural Therapy (Beck 1995) have been found to be effective with both stammering and SM.
The above examples show that there are a lot of similarities between SM and stammering; however, it is also important to recognize some clear differences between the two. Stammering has a much larger research base than SM alongside a wider prevalence: approximately 1 per cent in the general population (Bloodstein and Bernstein-Ratner 2007). Therapist confidence to work with SM may be less than seen with stammering, possibly reflecting the difference in the research and evidence bases between the two conditions. Another key difference between SM and stammering relates to gender, with stammering being more common in boys and SM more common in girls. Prognosis and relapse also differs – within SM it is generally recognized that once the condition has been successfully managed, relapse is not common, unlike in stammering where a cyclical pattern is freely acknowledged.
Both SM and stammering have many different presentations, and children who present with both stammering and SM do not all stammer in the same way, or present with the same pattern of mutism. Observations from clinical practice and information from discussions with other therapists show a variety of presentations. Both conditions can be evident at initial assessment; or the SM can develop after initial presentation of stammering, possibly due to embarrassment and consequent avoidance. It can be difficult in this circumstance to determine whether the child has developed SM or is showing extreme avoidance as part of their stammering presentation, but management would be similar in either case.
Possibly the most unexpected presentation is this: sometimes parents of children who initially present with SM report their child starting to stammer once the SM is resolving. Anecdotal evidence indicates that in these circumstances the stammer is typically characterized by part word and sound repetitions, usually at the start of utterances. Here a factor contributing to the onset of stammering may be the child’s lack of experience of speaking within social situations, particularly with peers. Lack of practice with social skills such as turn-taking within conversations means that – when the child begins to feel comfortable to converse more – they experience time pressures speaking within social situations, so their turn to speak is ‘marked’ through repetitions at the start of their utterance while they process the rest of what they plan to say. Effective intervention should include acknowledging the stammer to reduce any anxiety the child associates with stammering, while working to develop social communication skills – for example, turn-taking and allowing the child to take the time to think about what they want to say before starting their conversational turn.