Introduction: Stuttering may have a holistic effect on the quality of life of a person who stutters by limiting participation in social situations, resulting in feelings of isolation and frustration, leading to difficulties in education and employment and increasing the likelihood of mental health problems. Even young children who stutter may have negative experiences of speaking. Therefore, it is important to treat stuttering behavior effectively in both children and adults. The purpose of this paper was to systematically review group and case studies about the effectiveness of behavioral stuttering interventions to provide evidence-based guidelines for clinicians. Methods: Systematic data retrieval was conducted in four electronic databases (PsycINFO, CINAHL, PubMed, Cochrane). The assessment of search results was conducted according to predetermined inclusion and exclusion criteria by two independent judges. The methodological quality of each paper was assessed using strict criteria to include only high-quality research. Results: The search revealed 2293 results, and 38 papers (systematic reviews N=3, group design studies N=21 and case studies N=14) with acceptable methodological quality were included. The data show that there is most evidence about the treatment of early childhood stuttering, very little evidence about school-aged children and some evidence about adults. The most convincing evidence is about the Lidcombe Program in the treatment of young children who stutter, but also other methods have promising evidence. Our data imply that in the treatment of adults who stutter, holistic treatments may influence speech fluency and overall experience of stuttering behavior. Speech restructuring treatments may have a positive effect on overt characteristics of stuttering, but not on covert stuttering behavior.
Stuttering is characterized by repetitions or prolongations of sounds, syllables, or words, or by hesitations or pauses that disrupt the rhythm of speech, according to the International Classification of Diseases 10 (ICD-10; World Health Organization, WHO, 2016). The forthcoming ICD-11 includes a more comprehensive description of stuttering (WHO, 2019), that resembles the definition in the Diagnostic and Statistical Manual of Mental disorders fifth edition (DSM-5). In DSM-5 the definition of a childhood-onset fluency disorder (315.35) also includes blocking and avoidance or substitution of words. Furthermore, it recognizes the effects of stuttering on social communication, personal, family, educational, occupational, or other important areas of functioning (American Psychiatric Association, 2013). Moreover, the International Classification of Functioning, Disability and Health (ICF) provides a more holistic description of stuttering compared to the ICD-10 and considers the structures and functions of the body, how individual and environmental factors affect stuttering and how these factors influence activity and participation (WHO, 2001; Yaruss & Quesal, 2004; Yaruss, 2007).
Recent studies on the effects of stuttering have revealed the multifaceted nature of stuttering more deeply (see e.g., Gerlach et al., 2018; Iverach, Jones et al., 2009, 2009b, 2010; Iverach & Rapee, 2014). As early as at the age of three years, a child may have more negative experiences around speaking than fluent peers (Vanryckeghem et al., 2005) and in preschool stuttering has the potential to provoke negative peer responses (Langevin et al., 2009). Adolescents who stutter have reported being teased or bullied and having communication competence below average (Erickson & Block, 2013). Parents of children who stutter experience feelings of helplessness, uncertainty, fear, and difficulties managing their child’s frustration, have concerns about academic performance, and feel empathy for their child (Erickson & Block, 2013; Plexico & Burrus, 2012). Even before an overt dysfluency of speech occurs, a person who stutters (PWS) may feel stuck or helpless (Tichenor & Yaruss, 2018, 2019), and start to avoid speaking because of stuttering (Lowe et al., 2017). Thus, stuttering may limit a speaker’s ability to participate in conversations, result in feelings of loneliness and isolation, lead to problems in social interaction, create a sense of helplessness, and be accompanied by social anxiety (see e.g., Iverach et al., 2017; Manning & DiLollo, 2018, 188–189; Yaruss, 2007). For adults who stutter, communicative participation is predicted by self-esteem, self-efficacy, and social support in addition to the severity of speech disfluencies (Boyle et al., 2018). In fact, self-efficacy is a positive predictor of the quality of life for PWS, while a high frequency of stuttering, on the other hand, is a negative predictor of self-efficacy (Carter et al., 2017). Moreover, speech fluency and self-confidence have been reported to be inextricably related (Carter et al., 2019). Therefore, stuttering may have a profound negative emotional, behavioral, and cognitive impact on a speaker’s life regardless of the age of the PWS (Carter et al., 2017; Guttormsen et al., 2021; Tichenor & Yaruss, 2018, 2019; Werle et al., 2021; Yaruss, 2007).
Our results indicate that there are several effective treatment options for young children who stutter. Most evidence is available about the LP, which solely targets reducing %SS. Other treatments targeting multidimensional aspects of stuttering have shown promising results, especially the RESTART-DCM. These results agree with an earlier review (Brignell et al., 2021). The data from the case studies also support Palin PCI therapy. For adults, there are several treatment options available. Speech restructuring treatments reduce stuttering, when measured with %SS. However, they do not reduce covert aspects of stuttering, such as social anxiety. Because of the different inclusion criteria than in earlier reviews or meta-analyses (Brignell et al., 2020; Connery et al., 2021), our data supports treatments that address the multifaceted nature of stuttering and include elements of both speech modification and methods targeting psychological and social effects of stuttering. There are not sufficient effectiveness studies available for school-aged children who stutter, so we need to rely on research about young children and adolescents/adults and perhaps combine elements of both based on the individual situation and the age of the child.