Evaluation of an Integrated Fluency and Acceptance and Commitment Therapy Intervention for Adolescents and Adults Who Stutter

PURPOSE

Developmental stuttering is a complex and multifaceted neurodevelopmental disorder that may cause pervasive negative consequences for adults who stutter (AWS). Historically, intervention for AWS has primarily addressed speech fluency, with less focus on the covert psychosocial aspects of the disorder. The purpose of this article is to report on a feasibility trial evaluating a novel integrated intervention that combines traditional stuttering management techniques with Acceptance and Commitment Therapy (ACT) for AWS.

METHOD

Twenty-nine AWS participated in the feasibility trial. All participants successfully completed a combined fluency and ACT intervention, titled the fluency and Acceptance and Commitment Therapy for Stuttering (fACTS) Program. As this was a feasibility study, no control group was included. Intervention was administered by two certified practicing speech-language pathologists, over eight 60- to 90-min sessions.

RESULTS

Generalized linear mixed modeling was used to determine change from pre- to post-intervention and follow-up. Significant pre- and post-intervention improvements in self-efficacy, psychosocial functioning, and psychological flexibility were observed, along with significant reductions in observable stuttering behaviors (i.e., stuttered speech frequency). Intervention gains for all variables of interest were maintained 3 and 6 months post-intervention.

CONCLUSIONS

The fACTS Program was created to be a holistic and flexible intervention to promote self-efficacy beliefs and address stuttering-related psychosocial impacts and speech fluency goals of AWS. Preliminary results indicated positive improvement in all psychosocial outcomes (i.e., self-efficacy, psychosocial impact, and psychological flexibility) and observable speech fluency following completion of the program. Future clinical trials of the fACTS Program with an included control group will further investigate the mechanisms of change for the positive effects observed.

Comparing evaluations of social situations for adults who do and do not stutter

PURPOSE

Numerous research studies indicate that stuttering is associated with increased risk for social anxiety disorder (SAD). Interpretation bias is one of four cognitive biases thought to maintain symptoms associated with SAD. Interpretation bias occurs when one evaluates social situations as more negative than they actually are. The purpose of this study was to investigate if adults who do and do not stutter interpret positive, ambiguous, mildly negative, and profoundly negative social situations similarly, or-if like individuals with SAD-adults who stutter exhibit negative interpretation biases.

METHOD

Forty-eight adults who stutter and 42 age-and gender-matched adults who do not stutter participated. Participants completed the Fear of Negative Evaluation (FNE) and were assigned to one of four groups: adults who stutter with high FNE (AWS-High), adults who stutter with low FNE (AWS-Low), adults who do not stutter with high FNE (AWNS-High), and adults who do not stutter with low FNE (AWNS-Low). All participants completed the trait scale of the State Trait Anxiety Inventory (STAI) and the Interpretation and Judgmental Questionnaire (IJQ). The IJQ contains descriptions of four types of social situations: positive, mildly negative, profoundly negative, and ambiguous. Within each situation type there are five different scenarios, for a total of 20 scenarios across the four situation types. Participants provided written responses to these 20 social scenarios. Qualitative analyses were used to understand how members of each group interpreted the different social scenarios.

RESULTS

Thematic analysis revealed that each group responded in similar ways to each of the social scenarios, regardless of the type of situation. Adults who do and do not stutter with low and high FNE agreed on many themes related to the 20 social scenarios, and they agreed across all four types of social situations. Somewhat surprisingly, the theme "stuttering" was mentioned infrequently by the adults who stutter.

CONCLUSIONS

Results suggested that adults who do and do not stutter with low and high FNE interpret social situations similarly, and that no group demonstrated a negative interpretation bias consistent with what is observed in adults with SAD. The interpretations provided by each group were appropriate to the specific scenarios being evaluated.

Phenome risk classification enables phenotypic imputation and gene discovery in developmental stuttering

Developmental stuttering is a speech disorder characterized by disruption in the forward movement of speech. This disruption includes part-word and single-syllable repetitions, prolongations, and involuntary tension that blocks syllables and words, and the disorder has a life-time prevalence of 6-12%. Within Vanderbilt's electronic health record (EHR)-linked biorepository (BioVU), only 142 individuals out of 92,762 participants (0.15%) are identified with diagnostic ICD9/10 codes, suggesting a large portion of people who stutter do not have a record of diagnosis within the EHR. To identify individuals affected by stuttering within our EHR, we built a PheCode-driven Gini impurity-based classification and regression tree model, PheML, by using comorbidities enriched in individuals affected by stuttering as predicting features and imputing stuttering status as the outcome variable. Applying PheML in BioVU identified 9,239 genotyped affected individuals (a clinical prevalence of ∼10%) for downstream genetic analysis. Ancestry-stratified GWAS of PheML-imputed affected individuals and matched control individuals identified rs12613255, a variant near CYRIA on chromosome 2 (B = 0.323; p value = 1.31 × 10-8) in European-ancestry analysis and rs7837758 (B = 0.518; p value = 5.07 × 10-8), an intronic variant found within the ZMAT4 gene on chromosome 8, in African-ancestry analysis. Polygenic-risk prediction and concordance analysis in an independent clinically ascertained sample of developmental stuttering cases validate our GWAS findings in PheML-imputed affected and control individuals and demonstrate the clinical relevance of our population-based analysis for stuttering risk.

Population-based genetic effects for developmental stuttering

Despite a lifetime prevalence of at least 5%, developmental stuttering, characterized by prolongations, blocks, and repetitions of speech sounds, remains a largely idiopathic speech disorder. Family, twin, and segregation studies overwhelmingly support a strong genetic influence on stuttering risk; however, its complex mode of inheritance combined with thus-far underpowered genetic studies contribute to the challenge of identifying and reproducing genes implicated in developmental stuttering susceptibility. We conducted a trans-ancestry genome-wide association study (GWAS) and meta-analysis of developmental stuttering in two primary datasets: The International Stuttering Project comprising 1,345 clinically ascertained cases from multiple global sites and 6,759 matched population controls from the biobank at Vanderbilt University Medical Center (VUMC), and 785 self-reported stuttering cases and 7,572 controls ascertained from The National Longitudinal Study of Adolescent to Adult Health (Add Health). Meta-analysis of these genome-wide association studies identified a genome-wide significant (GWS) signal for clinically reported developmental stuttering in the general population: a protective variant in the intronic or genic upstream region of SSUH2 (rs113284510, protective allele frequency = 7.49%, Z = -5.576, p = 2.46 × 10^-8) that acts as an expression quantitative trait locus (eQTL) in esophagus-muscularis tissue by reducing its gene expression. In addition, we identified 15 loci reaching suggestive significance (p < 5 × 10^-6). This foundational population-based genetic study of a common speech disorder reports the findings of a clinically ascertained study of developmental stuttering and highlights the need for further research.

Evaluation of an integrated fluency and Acceptance and Commitment Therapy intervention for adolescents and adults who stutter: Participant perspectives

PURPOSE

Childhood-onset stuttering is a neurodevelopmental disorder that may cause pervasive negative consequences for adults who stutter. In addition to significant challenges in personal, social, and emotional domains, stuttering has been shown to impose an economic burden on adults who stutter. Intervention for adults who stutter has historically addressed speech fluency more so than the covert psychosocial aspects of the disorder. There is an identified clinical need for holistic, efficacious, and cost-effective stuttering interventions that meet consumer needs. The purpose of the present study is to evaluate a novel, integrated intervention that combined traditional fluency techniques with Acceptance and Commitment Therapy, from the perspective of the adults who stutter who participated in the intervention.

METHOD

Twenty-eight adults who stutter completed the intervention program. Participants were invited to complete an online post-program written survey (including qualitative comments) and a semi-structured interview to explore their evaluations of the program with respect to its authenticity, acceptability, and social validity.

RESULTS

Participants perceived positive psychosocial changes as a result of the program, and were satisfied with the program overall. Qualitative thematic analyses of the written survey comments and the semi-structured interviews identified two major themes: factors specific to the intervention and factors specific to the therapeutic process. Several important sub-themes were also identified.

CONCLUSION

Findings support the authenticity, acceptability, and social validity of an integrated fluency and psychosocial intervention for stuttering. Findings also highlight the need for consideration of the consumer voice in the management of stuttering disorders, in keeping with person-centred care.

Self-efficacy beliefs: Experiences of adults who stutter

PURPOSE

Childhood-onset stuttering is a complex and multifaceted disorder. Intervention for adults who stutter has historically addressed speech fluency more so than psychosocial aspects of the disorder, including the nature of the individual's self-efficacy beliefs concerning their confidence in their capacity to enact change. Self-efficacy is an important construct related to quality of life, resilience, and maintenance of treatment gains for adults who stutter. The purpose of this qualitative study is to explore the nature of the self-efficacy beliefs expressed by adults who stutter in order to inform efficacious and holistic intervention for these individuals.

METHOD

Semi-structured interviews were conducted with 29 adults who stutter to describe their experiences as a person who stutters and elucidate the nature of their self-efficacy beliefs.

RESULTS

Thematic analysis identified several major themes that provided novel insight into the complex nature of the self-efficacy beliefs experienced by adults who stutter: speaker experiences shaped communicative confidence, there was a conflict between communication and fluency, stuttering was viewed as more than fluency, and individual perspectives shaped communicative confidence, as did the pervading influence of self. The notion that fluency and confidence are inextricably linked was evident within and across each major theme.

CONCLUSION

These preliminary findings provide further support for a multidimensional approach to the treatment of adults who stutter. Findings will be used to inform a novel integrated fluency and psychosocial intervention for adults who stutter that addresses fluency and self-efficacy concurrently, with a view of engendering durable improvements in speech fluency and communicative confidence.

An evaluation of an integrated fluency and resilience program for early developmental stuttering disorders

PURPOSE

The temperament construct of effortful control, an index of self-regulation and resilience, has been found to be predictive of stuttering severity in children and is a potential indicator of clinical prognosis. Evidence supports early intervention for preschool stuttering, and the successful effect of parents as agents of change in their children's stuttering therapy. However, no previous studies have trained parents to improve self-regulation in their children as a component of stuttering therapy. This study aimed to explore the effects of addressing self-regulation, as a component of stuttering treatment, on child fluency as well as parent and child psychosocial outcomes.

METHODS

This study implemented a preliminary parent administered resilience component in conjunction with stuttering therapy for children who stutter, and compared outcomes to a cohort of children who stutter who received stuttering therapy only. Twenty-eight children who stutter were randomly allocated to one of the two treatment groups. Dependent variables tested pre- and post-treatment included stuttered speech severity, parenting practices, and child resilience indicators. Outcomes were compared between groups at post treatment.

RESULTS

Stuttered speech severity decreased in both treatment groups. A reduction in behavioural and emotional problems, and increase in resilience was observed in the children who stutter whose parents received the additional resilience component of therapy. Furthermore, a significant improvement in parenting practices was demonstrated in this group. No significant changes in emotional and behavioural problems in children or parents were observed in the group of children who received fluency therapy only.

CONCLUSION

Results demonstrate that implementation of the resilience component was successful in positively shifting parenting practices and increasing behavioural resilience in children who stutter. This has clinical implications for successfully managing fluency while concurrently targeting the concomitant behavioural and emotional impacts of the disorder on both children and parents, potentially a key future prognostic indicator of the maintenance of fluency outcomes.

Fear of Negative Evaluation, Trait Anxiety, and Judgment Bias in Adults who Stutter

PURPOSE

Persons who stutter (PWS) and those with social anxiety disorder may exhibit fear of negative evaluation (FNE) and anxiety in social situations. However, the information processing biases that perpetuate these characteristics have had limited investigation. This study investigated judgment bias in social situations.

METHOD

Participants included 50 adults who stutter and 45 age- and gender-matched fluent persons who do not stutter (PWNS), who made up the control group. Participants completed the Interpretation and Judgmental Questionnaire (Voncken, Bögels, & deVries, 2003), and threat scores were calculated.

RESULTS

There were no significant differences between PWS and PWNS in social threat or nonsocial threat scores. When the PWS group was divided on the basis of FNE and compared with PWNS participants without heightened anxiety (n = 35), the PWS with high FNE had significantly higher total social threat scores than the PWS with low FNE. The three groups did not differ in threat ratings for ambiguous or profoundly negative social situations.

CONCLUSIONS

Judgment bias in PWS is mediated by the magnitude of FNE present; not all PWS exhibit judgment bias for social situations. Treatment implications include the need for psychosocial support addressing the negative impacts on quality of life and restrictions on social engagement that stuttering may cause in some individuals.

The health professionals' perspectives of support needs of adult head and neck cancer survivors and their families: a Delphi study

PURPOSE

The aim was to identify the views of Australian and New Zealand health professionals regarding the support needs of people with head and neck cancer (HNC) and their families and current gaps in service delivery.

METHODS

A modified Delphi process assessed support needs of people with HNC following acute medical management. A systematic review of the literature was used to develop items relevant to seven key concepts underpinning the psychological experience of living with HNC. A panel of 105 health professionals was invited to participate in two questionnaire rounds.

RESULTS

Of the potential panellists, 50 (48%) completed round 1, and of these, 39 (78%) completed round 2. Following two rounds, there was consensus agreement on the concepts uncertainty and waiting, disruption to daily life and fear of recurrence. The concepts the diminished self, making sense of and managing the experience, sharing the burden and finding a path did not achieve consensus. There were no differences in responses according to gender, organization type or location. Medical professionals had significantly higher agreement for the concept uncertainty and waiting compared to allied health professionals, and professionals with five years' or more experience had significantly higher agreement than those with less experience.

CONCLUSIONS

Health professionals agreed that many psychosocial support needs of HNC survivors and families are not being met and that they experience difficulties in meeting these needs. Findings may inform evidence-based treatment programs for HNC survivors and their families to promote psychological resilience and quality of life in this vulnerable population.

Anxiety and speaking in people who stutter: an investigation using the emotional Stroop task

People with anxiety disorders show an attentional bias towards threat or negative emotion words. This exploratory study examined whether people who stutter (PWS), who can be anxious when speaking, show similar bias and whether reactions to threat words also influence speech motor planning and execution. Comparisons were made between 31 PWS and 31 fluent controls in a modified emotional Stroop task where, depending on a visual cue, participants named the colour of threat and neutral words at either a normal or fast articulation rate. In a manual version of the same task participants pressed the corresponding colour button with either a long or short duration. PWS but not controls were slower to respond to threat words than neutral words, however, this emotionality effect was only evident for verbal responding. Emotionality did not interact with speech rate, but the size of the emotionality effect among PWS did correlate with frequency of stuttering. Results suggest PWS show an attentional bias to threat words similar to that found in people with anxiety disorder. In addition, this bias appears to be contingent on engaging the speech production system as a response modality. No evidence was found to indicate that emotional reactivity during the Stroop task constrains or destabilises, perhaps via arousal mechanisms, speech motor adjustment or execution for PWS.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) explain the importance of cognitive aspects of anxiety, such as attentional biases, in the possible cause and/or maintenance of anxiety in people who stutter, (2) explain how the emotional Stroop task can be used as a measure of attentional bias to threat information, and (3) evaluate the findings with respect to the relationship between attentional bias to threat information and speech production in people who stutter.

The impact of stuttering on adults who stutter and their partners

This study explored the impact of the stuttering disorder on perceived quality of life, with emphasis on the individual's relationship with their partner or spouse. Specifically, the purposes were: (a) to investigate what personal experiences and themes exist for both members of a couple dyad when one member of the couple stutters and (b) to examine whether the partners have different experiences with respect to the impact of stuttering on their lives. A mixed method research design was used. Participant dyads (adults who stutter and their fluent life partner) each completed one semi-structured qualitative interview and two questionnaires: the Overall Assessment of Speakers' Experience of Stuttering (OASES), and the Medical Short Form 36 (SF-36). Interviews were analysed qualitatively and significant themes evaluated. Quantitative results of the OASES and SF-36 were analysed, and scores correlated to determine the strength of any clinically significant relationships. Results indicated that people who stutter and their fluent partners reported similar experiences in reactions to stuttering and perceived difficulties in communication. However, no relationship was seen between the two groups in perceived impact on quality of life. Qualitative results indicated that the participants shared life experiences including reactions to stuttering, treatment undertaken and support. Such findings lend support to a broad-based clinical programme for adults who stutter that includes the fluent partner as an agent of change in their treatment. Findings also support the utilisation of qualitative and quantitative research techniques to elucidate relevant psychosocial life themes and experiences for those who live with a stutter.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) identify the life themes associated with having a partner who stutters; (b) identify the perceived impact of stuttering for adults who stutter compared to their partners; and (c) discuss the clinical implications of the results with regards to working with adults who stutter.

Acceptance and Commitment Therapy for adults who stutter: psychosocial adjustment and speech fluency

The aim of the present study was to assess the effectiveness of an Acceptance and Commitment Therapy group intervention program for adults who stutter (N=20). The program consisted of 2-h therapeutic sessions conducted weekly for eight consecutive weeks. It was an integrated program designed to improve: (a) psychosocial functioning, (b) readiness for therapy and change, (c) utilisation of mindfulness skills and psychological flexibility, and (d) frequency of stuttering. The findings provide innovative evidence for Acceptance and Commitment Therapy as an effective intervention with statistically significant improvements in psychosocial functioning, preparation for change and therapy, utilisation of mindfulness skills, and overall speech fluency. Follow-up data collected at three months post-treatment revealed that therapeutic gains were successfully maintained over time. These findings enhance the understanding of the impact of stuttering on psychological wellbeing and offer a new perspective on what might constitute successful stuttering treatment. Further, clinical research support is provided for Acceptance and Commitment Therapy delivered in a group format as a promising and novel intervention for adults who stutter.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) appreciate the potential for Acceptance and Commitment Therapy for adults who stutter; (b) identify the improvements participants experienced in psychosocial functioning and frequency of stuttered speech; (c) appreciate the six core processes of Acceptance and Commitment Therapy; and (d) appreciate the differences between an ACT model of intervention for adults who stutter compared to a CBT approach.

The Impact of a Stuttering Disorder on Western Australian Children and Adolescents

In this study, we examined the impact of a stuttering disorder on children (n=50) and adolescents (n=45) living in Western Australia. We compared the reactions and experiences of children and adolescents who stutter to children and adolescents who do not stutter. We compared the participants who stuttered and the fluent participants using adapted versions of the Overall Assessment of the Speaker’s Experience of Stuttering (OASES). We also examined the relationship between biopsychosocial impact and stuttered speech frequency. We saw higher levels of adverse impact in young people who stuttered compared to their fluent peers. In addition, we found moderate correlations between OASES scores and stuttered speech frequency in children. These findings provided a baseline for establishing the degree of negative impact that a stuttering disorder may bring about in children and adolescents. The experiences of young people who stuttered were significantly different from the experiences of young people who were typically fluent. These findings reinforce the notion that stuttering is a disorder that can lead to negative impact for young people.

The experiences of living with a sibling who stutters: a preliminary study

Stuttering impacts on the child in a variety of ways, notably in terms of communicative impairment and psychosocial impact. In addition, the stuttering disorder has a holistic impact, affecting those with whom the child who stutters lives. Within the family constellation, the closest person to the individual who stutters is often their sibling. This study investigated the experiences of fluent siblings of children who stutter to examine the impact that stuttering may have on their lives. A mixed methods research design incorporated qualitative semi-structured interviews and quantitative questionnaires. The results of the qualitative investigation revealed four aspects of children's lives that were affected by having a sibling who stuttered: the relationship between siblings, the impact on the fluent sibling, the impact on the parent relationship with both children, and the impact on the sibling's relationship with others. Findings revealed that siblings of children who stutter exhibited strongly negative emotions, and differing levels of responsibility associated with their involvement in the actual stuttering management programme. Furthermore, for the fluent sibling, secondary to having a brother or sister who stuttered, communication with and attention from their parents was variable. The results of the quantitative component of the study revealed children who stutter and their siblings demonstrated significantly greater closeness, and concurrently, increased conflict and status disparity than did the control fluent sibling dyads. The parents of the experimental sibling dyads also demonstrated significantly greater partiality towards a child, namely the child who stuttered, than did the parents of the control sibling dyads.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) identify the themes associated with having a sibling who stutters; (2) identify how the quality of the sibling relationship differs between sibling dyads that do and do not consist of a sibling who stutters; and (3) discuss the clinical implications of the results with regards to working with children who stutter and their families.

Acceptance and Commitment Therapy for People Who Stutter

In contemporary clinical allied health and medical settings, there has been a proliferation of Acceptance and Commitment Therapy (ACT) programs. These clinically effective programs have reduced comorbid anxiety, depression, and stress for individuals suffering from chronic medical and psychosocial issues. However, to date, there has been no published work examining the effectiveness of an integrated ACT program for individuals who stutter. In this review, we will provide a platform from which readers will be able to (a) appraise the literature regarding combined speech pathology and psychology therapeutic programs for people who stutter, (b) appreciate an overview of ACT in the context of stuttering disorders, and (c) understand the relevant psychosocial outcome measures that constitute therapeutic change. This unique review of ACT will distinguish the processes of self-concept, defusion, acceptance, mindfulness, values, and committed action in support for people who stutter who experience psychosocial distress. In the culmination of the review, we advance the integration of ACT into current treatments for individuals who stutter.

Parenting styles and attachment in school-aged children who stutter

Parental input has been described as influential in early childhood stuttering yet the exact nature of this influence remains equivocal. The present study aimed to examine whether quantitative measures of parenting styles, parent and peer attachment patterns, and parent- and self-reported child behaviour could differentiate between school-aged children who stutter (CWS) (n=10) and their fluent peers (n=10). In addition, qualitative individual semi-structured interviews with all CWS were conducted to gain insight into their life experiences and reflections in relation to stuttering. The interviews were classified into ancillary themes of school, peers and parents. Quantitative findings revealed that CWS perceived their parents with significantly lower attachment, particularly in relation to trust, and parents of CWS perceived their children with significantly higher maladjustments than fluent counterparts. Qualitative themes emerged pertaining to attitudes, perceptions and relationships with teachers, peers and parents, with consistent experiences of teasing and bullying reported as a consequence of the stutter. The majority of participants recounted frustration with the nature in which their parents attempted to remediate their stuttering. Collectively, these findings highlight imperative management considerations for school-aged CWS and their parents. The usefulness of quantitative and qualitative research paradigms is also emphasised.

LEARNING OUTCOMES

The reader will be able to: (1) identify themes associated with the impact a childhood stutter has on parent and peer relationships; (2) identify how the quality of the parent child relationship is influenced by parenting styles and attachment; and (3) discuss the clinical implications of the results for children who stutter and their families.

Speeded verbal responding in adults who stutter: are there deficits in linguistic encoding?

Linguistic encoding deficits in people who stutter (PWS, n=18) were investigated using auditory priming during picture naming and word vs. non-word comparisons during choice and simple verbal reaction time (RT) tasks. During picture naming, PWS did not differ significantly from normally fluent speakers (n=18) in the magnitude of inhibition of RT from semantically related primes and the magnitude of facilitation from phonologically related primes. PWS also did not differ from controls in the degree to which words were faster than non-words during choice RT, although PWS were slower overall than controls. Simple RT showed no difference between groups, or between words and non-words, suggesting differences in speech initiation time do not explain the choice RT results. The findings are consistent with PWS not being deficient in the time course of lexical activation and selection, phonological encoding, and phonetic encoding. Potential deficits underlying slow choice RTs outside of linguistic encoding are discussed.

EDUCATIONAL OBJECTIVES

The reader will be able to (1) describe possible relationships between linguistic encoding processes and speech motor control difficulties in people who stutter; (2) explain the role of lexical priming tasks during speech production in evaluating the efficiency of linguistic encoding; (3) describe the different levels of processing that may be involved in slow verbal responding by people who stutter, and identify which levels could be involved based on the findings of the present study.

Investigating factors related to the effects of time-out on stuttering in adults

BACKGROUND

Response-contingent time-out has been shown to be an effective technique for enhancing fluency in people who stutter. However, the factors that determine individual responsiveness to time-out are not well understood.

AIMS

The study investigated the effectiveness of using response-contingent time-out to reduce stuttering frequency in adults who stutter. In addition, it investigated the predictive value of participants' stutter severity, age, previous treatment history, and type of stutter on the responsiveness to time-out conditioning.

METHODS & PROCEDURES

Sixty people who stutter participated in the study. Half were exposed to time-out following each moment of stuttering over a 40-min period, the remaining participants acted as controls.

OUTCOMES & RESULTS

Results showed that individuals who stutter are highly responsive to time-out, and that the participants with a more severe stutter responded better than those with a mild stutter. To a lesser degree, previous treatment and speech rate also influenced treatment success. Age and type of stutter did not, although the proportion of repetition types of stutters increased over the experiment conditions, with prolongations and blocks decreasing, for the treatment group.

CONCLUSIONS

This simple operant conditioning treatment method is effective in reducing stuttering. Individuals respond to time-out regardless of their age, type of stutter, stuttering severity or treatment history, thus it is a treatment methodology potentially suitable for all clients. This study investigated initial responsiveness to time-out; therefore, further research is necessary to determine the durability of fluency over time.