Stammering guidance

Stammering overview

Stammering involves a variation in speech. It is complex in terms of its causes as well as the ways in which it impacts people in their everyday lives. Research indicates that stammering has neurophysiological causes with subtle differences in the brain regions and connectivity pathways which support fluent speech production (Alm et al., 2014; Etchel et al., 2018). Stammering may also have a genetic cause with it commonly running in families. Factors such as childhood speech and language development, biological sex and temperament may exert some influence on whether stammering is more likely to disappear over time or continue. Typically, stammering begins in childhood, although in some cases it may emerge during adolescence or adulthood, usually due to neurological, psychological or pharmacological changes.

People who stammer often experience negative thoughts and feelings about speaking, which may stem from societal attitudes toward stammering, others’ reactions, or their own internal response to the sensation of being ‘stuck’ while trying to speak. They may develop coping strategies, such as avoiding difficult words or situations. Some people experience a widespread negative impact, affecting their mental health and wellbeing, self-image, choices around education/career/lifestyle and quality of life which may lead to them speaking less in many areas of their life.

Speech and language therapists (SLTs) play a role in offering support and therapy for children, young people, and adults who stammer. They support individuals to be the best communicator they can be whether or not they are stammering. SLTs work directly with individuals and their families while also collaborating with others to foster a supportive and accepting communication environment.

Some people who stammer may be comfortable with their speech and do not need help from speech and language therapy. Some have found that stammering has contributed positively to their lives. It has meant that they are part of a community with others who share the same differences in their speech. It may have led them to be interesting speakers who can hold an audience’s attention, or to be good listeners and be empathic towards others who experience differences in their speech or other aspects of their lives.

What is stammering?

The terms stammering and stuttering are used interchangeably. In this guidance the term stammering is used.

Stammering is a variation in speech that has no single definition. However, there is agreement about its complex, multidimensional nature. (Packman & Kuhn, 2009; Ward, 2018). People who stammer have defined their experience of stammering as a sense of loss of speech control with affective, behavioural and cognitive reactions to this experience. They describe the limitations on their opportunities to participate in life as well as the influence of environmental factors on their communication (Tichenor & Yaruss 2019) and may experience the stress of being in a minority.

The stammering iceberg

The experience of stammering can be viewed from different perspectives.

Joseph Sheehan (1970) used the analogy of an iceberg to explain the experience of stammering and the relationship between speech, thoughts and feelings. In this model, the portion of an iceberg above the surface of the sea represents the things a listener might directly hear or see during communication. This could include prolongations, repetitions and breaking eye contact. The part of the iceberg below the surface however, which is often the larger portion, is hidden and invisible to others but these thoughts and feelings can have a significant impact on the person who stammers. This could include fear, anxiety and frustration.

More recently, the iceberg analogy has been expanded to include the water it floats in. The water can be thought of as representing the speaking environment that impacts the experience of stammering. The environment surrounding individuals who stammer can sometimes include stigma, discrimination, fluency privilege, ableism and microaggression, all of which negatively impact the experience of stammering.

A further addition to the analogy envisions how the experience could differ in a stammering-affirming environment. When stammering is viewed in a positive way, it can collaboratively shape the social environment in ways which support and value the stammering experience and perspective. It illustrates the generative potential of stammering through pride, cultural heritage, belonging and community.

Speech

People who stammer experience variations in their speech which may be linked to certain situations or contexts. In a moment of stammering, people may repeat sounds, syllables and part-words, they may prolong sounds or block (Yairi et al., 2001). As a reaction to moments of stammering, people may increase physical effort in their speech or elsewhere in their body (Tichenor et al., 2017). These visible aspects of stammering which are most evident or audible to the listener only represent part of the individual’s experience. The speaker may experience stammering as a sensation of being stuck or unable to move forward, a loss of control.

Thoughts, feelings and behaviours

Some people who stammer may experience feelings such as frustration, embarrassment, fear and anxiety in relation to their speech. They may have negative thoughts about their stammering or themselves. (Tichenor & Yaruss, 2019; Iverach et al., 2016; Boyle, 2015). These emotional and psychological consequences of stammering may arise because of the reactions or anticipated responses of the listener which could be either affirming or hostile (Pierre, 2012). They may also arise due to the uncomfortable internal experience of a loss of speech control. The person who stammers may therefore attempt to conceal their stammering by adopting escape behaviours such as strategies to avoid the possibility of stammering. A significant part of the experience of stammering therefore may be internalised.

Concealing and variability

Traumatic social experiences and ableist messaging about stammering may lead people to hide differences in their speech to protect themselves from stigma (Gerlack-Houck & DeThorne, 2023). People may use a range of strategies to support themselves in concealing stammering which include:

• using filler or starter sounds and words e.g. “um”, “like”
• switching a word on which stammering is anticipated to one that has a similar meaning or re-ordering words within a sentence
• holding back from contributing to a discussion
• not entering situations in which stammering is anticipated
• not forming relationships with certain people when negative consequences of stammering are anticipated.

(Sheehan, 1970)

Stammering naturally varies, with many individuals experiencing periods of more frequent or less frequent stammering (Tichenor & Yaruss, 2021). When a person who stammers feels a desire to speak but simultaneously wishes to conceal their identity as someone who stammers, they may experience an approach–avoidance conflict (Sheehan, 1970). Efforts to avoid stammering can become habitual, making them hard to break (Constantino, 2023) and often increasing the struggle with speech and increasing the duration of a moment of stammering (Bailey et al., 2015).

Some people might choose to reduce the visible or audible features of their stammering by adopting strategies or techniques to modify or change their speech.

Interiorised stammering

Whilst most people who stammer will have internalised aspects to their experience, some are able to and choose to conceal their stammering almost entirely using strategies to pass as a fluent speaker. This is termed covert stammering or interiorised stammering (Cheasman et al. 2013; Douglass et al., 2019) and may not be apparent to the listener. However, the internalised effort to conceal stammering is considerable. Some people may not be able to make sense of their experience of interiorised stammering as they may not have openly stammered for extended periods of time (Douglass et al., 2019). Some people might attempt to pass as a fluent speaker by using speech modification strategies.

Developmental stammering

This refers to stammering that starts in childhood typically (but not always) before the age of four (Yairi and Ambrose, 2005) and can begin gradually over time or have a sudden onset. It can be:

• transient, lasting for only a certain amount of time
• episodic, where there are periods of little or no stammering as well as times when a child stammers frequently
• ongoing, where a child stammers more consistently over time albeit with some variability.

Stammering that begins in childhood may continue into adolescence and adulthood and evolve in its characteristics over time.

Some young children may be unaware of their stammering, while others might become aware and hesitate to speak or abandon their attempts to communicate. The psychosocial and emotional impact of stammering might increase for older school aged children and teens as they become more aware of differing responses and reactions to their speech within their everyday environments. They may increasingly attempt to conceal stammering which may be reflected in increased effort and speech tension.

Acquired stammering

This usually, but not always, refers to stammering that begins after childhood. Stammering may develop following neurological or psychological changes, (Ward, 2010) or be induced by medication (Fetterolf and Marceau, 2013). Stammering may also present as a feature of Functional Neurological Disorder.

Stammering that starts suddenly in adulthood with no known cause requires urgent medical referral, to rule out medical emergencies such as stroke, head injury or brain tumour.

Atypical stammering

This differs from what is usually observed in developmental stammering.

Developmental stammering typically occurs on the first sound or syllable of a word. Atypical stammering comprises repetitions or prolongations in the final part of the word or mid-syllable or between syllables (Plexico et al., 2010). Atypical stammering most commonly occurs in the communication of autistic individuals. (De Marchena & Eigsti, 2016; Engelhardt et al., 2017).

Stammering and intersectionality

Our social identity forms through adolescence into adulthood (Tatum, 2017). Stammering forms one aspect of social identity and intersects with various others such as race, socioeconomic status and gender. The experience of stammering is therefore influenced by the intersection of different identities and the related overlapping of marginalisation or privilege. SLTs consider the individual identities of clients when offering services (Daniels & Boyle, 2023).

Stammering and other needs

Stammering may present in isolation or alongside other differences including:

• Attention Deficit Hyperactivity Disorder
• Autism (Altunel and Altunel, 2017; Preston et al., 2022)
• Cluttering (Scott, 2017; Van Zaalen-op’t Hof et al., 2009).
• Down Syndrome (Hokstad and Næss, K.B. 2023)
• Developmental speech or language disorders
• Functional Neurological Disorder (Baker et al., 2021)

Factors to consider

What are the causes of stammering?

Developmental stammering

Causes of stammering are not well understood and remain an area for further research. However, current understanding is that stammering is multifactorial in nature (Smith and Kelly, 1997). Stammering is not caused by anxiety, although experiencing stammering may lead to feelings of anxiety.

The factors that could contribute to causes of stammering include:

• Neurophysiological factors with differences being shown in the brain structure and function in children and adults who stammer (Chang et al., 2020; Weber-Fox et al., 2013; Watkins, 2007).
• Genetic factors Drayna and Kang (2011) with approximately two-thirds of adults who stammer having a family member who also stammers (Bloodstein et al., 2021). This may be a factor to consider in predicting the continuation of stammering in children (Frigerio-Domingues et al., 2019).
• Biological sex with there being more males who continue to stammer into adulthood than females.

Factors that influence stammering are:

• Linguistic factors which may be associated with the onset of stammering. These include delayed language development, developmental language disorder and phonological disorders. Children may also present with advanced language development or advanced vocabulary development when compared to their phonological skills. (Clark et al., 2015).
• Environmental factors may influence stammering. These include speaking demands, family dynamics, pace of life (Anderson et al., 2003) as well as societal attitudes and responses to stammering.
• Individual temperament factors including emotional regulation and reactivity, as well as behavioural disinhibition, can be associated with stammering (Jones et al., 2014).

Acquired stammering

There are three main causes of acquired stammering:

1. Neurogenic stammering results from a neurological event or disease (Lundgren et al. 2010; Ward, 2010). Stammering may start suddenly after stroke or traumatic brain injury or more gradually or intermittently in people who have neurological conditions such as Parkinson’s Disease or Multiple Sclerosis.
2. Functional stammering is associated with the brain starting to work in a different way. It can present as a response to life stress, physical injury, illness or psychological difficulty although the exact causes may be unclear. It is more common in women than in men. It may co-occur with post-traumatic stress disorder, anxiety and depression, schizophrenia and Functional Neurological Disorder.
3. Pharmacogenic stammering results as a side effect of prescribed medications including antipsychotics and neuroleptics.

Impact of stammering

Stammering may affect the ease with which an individual can communicate. Some people who stammer identify positive consequences of stammering. However, stigmatised perceptions of stammering and the experience of negative listener responses may lead to significant impact on self-esteem and quality of life for people who stammer.

How are people affected by stammering?

Studies outline the positive impact stammering can have on someone’s life such as increased sensitivity to others and stronger interpersonal and intimate relationships and an enrichment of communication (Boyle & Fearon, 2018; Constantino, 2016, 2020).

It has also been shown that over the lifespan, stammering can negatively impact quality of life in various ways (Norman et al., 2023) including mental health and wellbeing (Tichenor et al. 2023).

The stigmatisation of stammering in society affects individuals in multiple ways, including negative reactions from listeners and self-stigmatisation, where individuals who stammer internalise these negative perceptions, reinforcing feelings of stigma (Boyle, 2015).

These responses to stammering may reinforce an individual’s belief that they need to speak fluently and consequently use concealment strategies.

One research study suggests that efforts to speak fluently through concealment strategies or speech techniques, rather than speaking freely and spontaneously, may reduce quality of life (Constantino et al., 2020).

How does stammering affect children?

Children who stammer may:

• have more negative attitudes about speaking than children who don’t stammer as early as the preschool years (Vanryckeghem and Brutten, 2007)
• experience adverse listener reactions from their peers (Langevin et al., 2009).
• be bullied at school which negatively affects their happiness and wellbeing (Crichton-Smith 2002; Davis et al, 2002).
• experience social anxiety because of stammering (Iverach et al., 2016).

How does stammering affect parents?

• Parents of children who stammer may become distressed about how their child is speaking (Kelman et al 2012) and concerned about how it may impact their wellbeing and future. There is no evidence to suggest that stammering is caused by parents (Yaruss and Conture, 1995). However, in response to their child’s continued stammering, parents may alter their own interaction style such as using more turn-taking exchanges and more requests for information. (Kloth et al 1999).

How does stammering affect young people and adults?

Young people and adults who stammer may experience:

• micro-aggressive responses to stammering such as invalidation (e.g. “you don’t really stammer, I haven’t noticed it”) or being given advice about how to speak (e.g. “take a breath, slow down”) (Coalson et al., 2022)
• reduced educational outcomes through reduced participation. (Ribbler, 2006)
• disadvantage and discrimination due to stammering. It has been shown that this has a negative impact on employment outcomes such as reduced likelihood of being promoted and limits to earning capacity (Enderby & Emerson 1995, Klein and Hood, 2004; McAllister et al., 2012; Gerlach et al. 2018)
• mental health difficulties including social anxiety (Iverach et al. 2009; Craig and Tran, 2014)

Role of speech and language therapy

Speech and language therapists play a key role in supporting children, young people and adults who stammer. People who stammer will have varied needs across their life and benefit from different types of support which may involve speech and language therapy. People who stammer may seek support from speech and language therapy at transition points when speech demands change. This might be times such as starting secondary school or university or beginning a new job.

Models of disability

Historically, stammering was viewed through the medical model of disability. This impairment focused model situates the “problem” and responsibility to change with the individual. Aligned to this model, the role of the speech and language therapist is to support children, young people and adults who stammer to make changes in their speech so that they speak with greater ease and fluency. It is also likely to include work on thoughts/feelings around stammering to change the emotional response to stammering, develop resilience, reduce the person’s avoidance behaviours and allow them to move towards their speaking goals.

More recently, stammering has been understood through the lens of the social model of disability (Bailey et al., 2015; Campbell et al., 2019; Constantino et al., 2022). This model suggests that disability is shaped more by social, cultural, environmental, and political structures than by individual differences. It argues that these societal structures create barriers that contribute to the experience of disability. Such barriers include negative societal attitudes and behaviours towards stammering. Consequently, the SLT role has shifted to have an increased focus on confident and effective (rather than fluent) communication skills; valuing the authenticity of stammered speech and connecting with the broader community of people who stammer. Also, the role involves advocating for people who stammer, working with others to reduce barriers, promoting stammering-affirming practices and the reduction of stigma.

In summary, a social model-based approach takes a broader look at stammering within society, framing stammering as part of human communication diversity and moving towards stammering confidently.

Neurodiversity

There is clear evidence that stammering at its core is neurophysiological (Chang et al., 2019) and therefore can at least in part be attributed to neurological differences. However, its transient nature in some children and its overall variability distinguish it from other forms of neurodivergence. The neurodiversity movement has relevance to work with these client groups. This has emphasised a shift away from a binary view of “able-bodied” versus “disability” toward a more inclusive discourse that recognises and values both neurodivergent and neurotypical ways of being. Within this context, the role of the SLT would be one of affirming stammering, promoting an understanding of these speech differences and enabling the voice of these individuals to be heard as equals.

Reconciling different philosophies

When working with children, young people and adults who stammer, SLTs need to base practice on the current evidence base as well as consider the wider context of factors influencing the profession and the future directions of the stammering community. Reconciling the evidence with other theories and philosophies is challenging as there are potential tensions between these different perspectives.

Behavioural approaches are impairment focused and typically seek to reduce stammering to minimal levels. Approaches based on multifactorial or complex models of stammering aim to reduce the impact of the experience of stammering by focussing in on overt and covert aspects as well as improving interaction and the communication environment. Stammering affirming practice challenges ableist views and stigma surrounding stammering and advocates approaches to therapy that support identity work, community building and engagement with stammering culture and community (Sisskin, 2023, Campbell et al., 2019; Simpson, 2019, Constantino et al., 2022).

Decision making can be especially challenging for SLTs who are yet to gain significant experience in working with these client groups and may require support and supervision from more specialist clinicians to support their confidence and skill development. However, irrespective of the approach taken, it is vital to keep the client at the centre, working in partnership to decide upon the most appropriate plan. It is also the role of all SLTs to undertake the following:

• provide information to other professionals and to the public about stammering
• provide information about how to access local services and how to refer to them
• educate other professionals such as Health Visitors, GPs, teachers and employers about stammering and the role of SLT in screening, assessing, identifying, supporting and providing therapy for people who stammer
• provide support and therapy that is holistic and derived from goal setting in partnership with the client
• screen, assess, identify support and provide therapy as required
• provide therapy that is evidence based
• ensure that there is focus on creating a strong therapeutic alliance with the client including with parents when working with children
• refer to other services as appropriate
• signpost to forms of support such as third sector e.g. STAMMA, Action for Stammering Children, 50 Million Voices, especially at the point of discharge from speech and language therapy services
• ensure services are culturally and linguistically relevant
• ensure the role of parents and families is an integral part of support and therapy for children who stammer
• work with others such as teachers to ensure a supportive and inclusive environment
• support and promote awareness and acceptance of stammering.

Statistics

The following data are derived from a range of research studies and so are based on different population samples.

Incidence and prevalence

• Research indicates that between 5% to 8% of children will stammer at some point during their development (Bloodstein et al., 2021; Yairi and Ambrose 2013; Månsson, 2000).
• 95% of children who stammer will start to do so by the age of four (Yairi & Ambrose 2005).
• Approximately 80% of children who stammer will go on to develop fluent speech with 20% continuing to stammer in the longer term (Andrews et al., 1983; Bloodstein, 1995). Of children who stammer, one third will develop fluent speech within 18 months and one third within three years (Mansson, 2000; Yairi & Ambrose, 2005).
• At least 1% of school age children are likely to stutter at any one point in time (Andrews et al., 1982; Bloodstein & Bernstein Ratner, 2021).
• A more recent U.S. study estimated that approximately 2% of children ages 3–17 years stutter (Zablotsky et al., 2019).
• Children with a family history of stammering were estimated to be 1.89 times more likely to continue to stammer (Singer et al., 2020).
• The lifetime prevalence of stammering is estimated to be between 0.72% (Craig et al., 2002) to 5% (Brocklehurst 2013).

Gender ratio

• Estimates of male to female ratio in stammering have been as high as 4:1 (St Louis and Hinzman, 1988).
• Younger age of onset may have smaller ratios in gender differences (Yairi and Ambrose, 2013).
• Males are 1.48 times more likely to continue to stammer than females (Singer et al., 2020).

Other needs

• Children who stammer are 5.5 times more likely to have another disabling developmental condition than children who do not stammer (Briley & Ellis, 2018, p. 2895)
• 40% of the children who stammered exhibited disordered phonology compared to 7% of the matched controls (Louko et al., 1990)

Ensuring access to speech and language therapy services

Public health and partnerships

The role of the SLT is to:

• advocate for the existence of speech and language therapy services for people who stammer
• develop appropriate care pathways for children, young people and adults who stammer and want support
• collaborate with the stammering community and organisations that support people who stammer to provide accurate information and advice
• provide training and support to colleagues in Education and Health to increase the identification of stammering and appropriate referrals. This ensures timely support and increases the likelihood of positive outcome.
• work in partnership with parents to increase their awareness of the things that they can do to support their child’s communication confidence and participation
• support children, young people and their families with the possible psychosocial and emotional aspects of stammering.

Awareness raising and early identification

Early identification of stammering is important to facilitate timely support and positive outcomes. When children and their families do not receive timely support, parents may become anxious about their child’s speech and children may start to develop negative thoughts, feelings and responses to stammering.

SLTs play a role in educating others about stammering and when and how to seek support.

Access and referrals / requests for assistance

All speech and language therapy services should provide information about their referral criteria for children, young people and adults who stammer. Details about how to refer should be available in service literature and/or websites. Information must be accessible in accordance with the Information Accessible Standard.

Information should be provided about other forms of support available to people who stammer including signposting to:

• STAMMA
• Action for Stammering Children
• Michael Palin Centre for Stammering Children

The RCSLT recommends that:

• consent guidance is followed (see RCSLT guidance on consent)
• referrals for stammering are processed in a timely manner
• an assessment is offered as soon as service priorities allow, and that both the referrer and client are informed of the waiting time
• when the waiting time will be significant, it is be appropriate to offer some general advice to be implemented during this waiting time and signpost to the available resources.

Please see RCSLT information on screening and referrals for general details about referral management.

Assessment

Assessment of stammering is a detailed process. It aims to establish the nature of the stammering and the possible impact on the client and others around them.  An initial comprehensive assessment would be individualised for the client and typically involves gathering information linked to relevant medical, developmental, communication, psychosocial, environmental and family history factors.

Assessment to consider the following factors

Children

• Parental concern and reasons for seeking support
• Parental and child understanding of stammering
• Child’s confidence and ability to talk openly about stammering
• Child’s opinion about their speech in a way that relates to their age and understanding
• A recognition of the potential challenges a stammering assessment poses for both the child and parents
• Parent child interaction
• Strategies parents have used or are currently using to support their child.
• Assessment of factors relating to likelihood of continuing such as family history, biological sex, time since onset, language development.
• Screen of speech and language skills including stammering
• Detailed assessment of stammering including effort, struggle, secondary behaviours
• Impact of stammering at home, socially at nursery/school / college though gaining additional information from relevant key partner agents
• Impact on academic attainment
• Previous therapy and what helped
• Strategies to manage stammering including concealment
• Level of insight, understanding or concern from the child about their stammering
• Thoughts and feelings about stammering
• Responses of others to stammering.
• Connection to stammering community and sources of support
• Whether the child wants help and their best hopes

Adults

• Is stammering something new or is it typical for the client?
• If stammering is new, have medical investigations being conducted?
• Reasons for seeking help now and hopes from therapy
• History of stammering and changes over time
• Previous therapy and what helped
• What is the client already doing to help / support themselves?
• Strategies to manage stammering including masking strategies such as switching words, not speaking
• Impact of coping strategies and the cost vs benefit of these
• Impact of stammering at home, on relationships, socially and on education or employment
• Thoughts and feelings about stammering
• Variability
• Impact of others’ responses to stammering
• Emotional wellbeing.

Formal assessment

There is a range of formal assessment tools which can be used to gather further information about stammering and the client’s experiences. These assessments provide useful but limited information and should be used alongside more informal, client-centred methods.

Some assessments objectively measure the frequency of stammering behaviours such as percentage syllables stammered (%SS) or stammering per minute of speaking time (SMST) as well as the duration of moments of stammering. Measuring stammering in this way provides limited information as it only tells us how much the client is stammering in that moment and is based on the listener’s (i.e. the therapist’s) perception of the stammering, rather than how the speaker experiences their moments of stammering. These measures may also place an unhelpful emphasis on speech behaviours rather than the impact of stammering for the client.

Some assessments are based on self-rating scales where clients rate their experiences of stammering across various dimensions including thought and feelings reactions to stammering, communication in daily situations and quality of life. These assessments enable the client to provide detail about their experiences of stammering but are limited by potential issues with relevance and reliability.

Decision making and therapy

Therapy takes different forms over time and people who stammer may access support across different transition points and stages of life. Therapy for stammering is individualised, based on the client’s priorities and best hopes. Areas to be prioritised in therapy will be agreed with the client and may include one or more of the following:

• psychological change
• speech modification
• facilitating changes in the speaking environment to ensure it is supportive.

The process of decision making when working with people who stammer is complex. In deciding about the best way to support a child, young person or adult who stammers, the following questions need to be addressed:

• What are the priorities or best hopes from therapy for the client or parent?
• Will speech and language therapy help to reduce any negative impact of stammering?
• Will therapy for the child support parents to reduce their concern about their child’s speech?
• Will therapy support the child / young person to communicate more comfortably?
• Will therapy support the child or young person’s confidence in talking?
• Does therapy need to address speech, thoughts, feelings or concealment strategies?
• Could a reduction of any negative impact of stammering be achieved through working with others to create a more supportive communication environment?
• What level of support is needed to facilitate the client’s (child, young person, parent, adult) knowledge and understanding of stammering?
• Would group therapy support be beneficial?
• Are there any other areas within the child or young person’s speech, language and communication profile which require support?
• Would the individual benefit from being a member of the stammering support community?
• Will working directly on speech be beneficial and enable the child to be able to communicate more easily and freely?
• Will working directly on speech be unhelpful and risk reinforcing ableist views about stammering and fluency or reduce spontaneity?
• Will this client’s needs be more appropriately met by another service or professional?

The above questions can support collaboration between the SLT and client to formulate an agreed joint plan which needs to be discussed with the client/child and/or parent. Where it is considered that the client’s needs will be most appropriately met by another professional or service, the SLT will make an onward referral or contact with the GP to request a referral.

Therapy

The RCSLT recommends that SLTs take a holistic approach when providing therapy and consider the range of personal factors to determine the timing and duration of support for the client. SLTs should ensure that there are sufficient therapy resources available to offer effective support.

Early stammering

There are different philosophies and approaches to working on stammering in young children. Some evidence-based approaches are underpinned by the multifactorial model of stammering. They aim to support positive parent child interaction, build communicative confidence and reduce parent anxiety about stammering.  An example of this approach is Palin Parent Child Interaction Therapy which has a comprehensive manual (Kelman et al., 2020). Other evidence-based approaches adopt a direct behavioural approach and aim to make speaking easier through a reduction in stammering. An example of this is the Lidcombe Program which has a Treatment Guide (Onslow et al. 2025). Whichever therapy approach is adopted, it is important that enough sessions are offered; that therapy is carried out fully and as it was intended and that the SLT has access to appropriate supervision.

Therapy will be offered through partnership working with parents and/or carers and others in the child’s life. It will be based on the findings from discussion with the parent/or carer and assessment. Therapy aims to support children to communicate confidently, enjoy speaking and participate in everyday activities.  Therapy may involve one or more of the following depending on the needs of the child and parent / carer:

• Supporting stammering affirming attitudes amongst parents / carers / nursery staff through education about stammering
• Supporting family interaction to create a nurturing and supportive communication environment for the child e.g. limiting demands on the child’s speech such as time pressure or correcting stammering
• Supporting ease of communication
• Supporting the child’s continued or increased participation

School aged children

Therapy for this age group follows an individualised approach, based on assessment discussion and findings and the parent and child’s best hopes for therapy. It aims to promote effective and confident communication through supporting the speech, communication and cognitive/psychological aspects of stammering. It will include elements from the following:

• supporting stammering affirming attitudes amongst parents/carers/school staff through education about stammering
• advocacy through working with the family, school, friends and community to create a supportive communication environment
• support the child, family and school to problem-solve difficult situations linked to stammering e.g. teasing or other challenging reactions to it
• developing confidence and competence in communication skills
• developing general resilience and the ability to be more comfortable during a moment of stammering
• strategies to ease speech tension.

Young people and adults

Therapy for young people and adults is personalised according to the client’s goals and presentation. It will involve working with them to facilitate change in their thoughts, feelings and behaviours relating to their speech. It may include working directly on their speech but often may not. Therapy might include one or more of the following:

• providing information and education about stammering
• working to gain more understanding of individual experiences of stammering
• reducing self-stigma or internalised ableism
• working towards a stammering affirming identity
• advocacy and engagement with stammering culture
• developing greater comfort during a moment of stammering
• reducing concealment
• speech modification strategies

For this age group, access to the wider stammering community via self-help or peer support groups may be beneficial.

Group therapy

Therapy may be offered on a one-to-one basis or in groups either face to face or via telehealth. Group therapy for school aged children, young people and adults who stammer has several benefits:

• fostering a sense of community and shared identity
• promoting acceptance of identity as a person who stammers
• gaining insight and inspiration from others who share similar experiences
• creating a communication environment that is more reflective of communication situations outside of therapy which cannot be as easily achieved in individual therapy
• building resilience
• supporting with problem solving linked to more challenging communication situations or reactions to stammering
• developing confidence in communicating in a group setting
• developing a supportive peer network/community
• optimising therapy resources.

Psychological approaches

At the time of writing, the following approaches are quite commonly used within SLT support for older children and adults who stammer. They can enhance SLT’s skills and require additional training before implementing.

• Acceptance and Commitment Therapy (Cheasman & Everard, 2013; Freud et al., 2020; Naz, 2020)
• Cognitive Behavioural Therapy (Menzies et al., 2019; Nnamani et al., 2019)
• Compassion Focussed Therapy (Israel et al., 2023; Gilbert, 2010)
• Mindfulness (Cheasman, 2013; Boyle, 2011; Emge and Pellowski, 2019)
• Solution Focused Brief Therapy (Berquez & Jeffrey, 2024; Ramos-Heinrichs, 2023, Burns, K. & Northcott, S. 2023)
• Person centred approach (Rogers, 1961; Logan et al, 2013)
• Narrative Therapy (Logan, 2013; Walker, 2019).

Acquired stammering

Therapy for people with acquired stammering is in its infancy and more evidence-based protocols are needed. Good practice currently prioritises information and education about the visible and invisible aspects of stammering. Strong multidisciplinary working is recommended to ensure an accurate diagnosis of acquired stammering and that speech therapy fits within the overall management of need. The MDT may include Neurology, Psychiatry or Psychology, Occupational Therapy, Physiotherapy (Theys & De Nil, 2022; Theys & Tetnowski, 2022).

Stammering affirming therapy

In recent years, aligned with the neurodiversity movement, there has been a move towards stammering affirming therapy (Sisskin, 2023, Campbell et al, 2019; Simpson, 2019; Constantino et al, 2022; Gerlach-Houck & Constantino, 2022). This is an anti-oppressive and trauma-informed approach which is mindful of the potential of stammering therapy to do harm and reinforce stigma and ableist views of stammering.

The development of any evidence-based approach takes several years and so the empirical evidence for this way of working is still emerging. However, it is likely that stammering affirming therapy will increase in prominence over the coming years.

Stammering and other needs

When clients present with stammering alongside other needs, therapy will:

• consider the client’s overall communication differences when setting priorities
• not aim to work towards neurotypical norms
• consider the inclusion of the education of others in the client’s environment about communication differences and that all carry equal value.

Assistive technology

Some people use assistive technology which operate using two different methods:

1. Delayed auditory feedback (DAF) where the individual’s voice is played back into the earpiece with a slight delay
2. Frequency adjusted feedback (FAF) where the speaker’s voice is played back into the earpiece at a different pitch
3. Masking where white noise is played into the earpiece to mask the sound of the voice.

Discharge

Clients will be discharged from speech and language therapy for the following reasons:

• care has been transferred to another service via onward referral
• therapy is complete and outcomes have been achieved and maintained
• therapy is no longer meeting their needs
• they have been unable to engage with therapy through non-attendance (discharge within local policy).

For whatever reason the client is discharged, they should be signposted to organisations and services that can offer support and provided with information about how to re-enter the service if required later. Care should be transferred to the professional with a universal duty of care i.e. GP and/or headteacher along with information about how to re-refer. See RCSLT guidance on discharge.

Bilingualism

For bilingual clients who stammer, see RCSLT bilingualism guidance.

Professional requirements

Supervision

The RCSLT recommends that all practising SLTs access regular supervision – see RCSLT supervision guidance.

When working with people who stammer, SLTs help parents, children, young people and adults who are experiencing challenging thoughts and feelings. They work in partnership with the client to facilitate psychological change. It is essential that this work is brought to regular supervision sessions to ensure the SLT is well supported in providing high quality care for their clients (Farrell et al, 2024; Maher-Edwards, 2024).

Collaborative working

With consent, SLTs should work with others to ensure that children, young people and adults who stammer are fully supported. This includes but is not limited to:

• providing general advice about stammering to schools, colleges and universities
• providing information to employers
• working with teachers to support a specific child at school
• supporting clients’ self-advocacy

See RCSLT guidance on collaborative working.

Workforce

SLTs have recognised variability with their knowledge, skills and confidence levels when working in the field of stammering (e.g. Crichton-Smith, 2003). In view of this, CPD and workforce development opportunities linked to stammering can ensure an appropriate mix of clinical knowledge and skill across services. As part of CPD and support / supervision, it is helpful for practitioners to understand the post registration level that they are working at so that they are able to access relevant learning and development which supports autonomous practice. It is advisable for services to consider their current workforce skill mix for stammering in terms of access to specialist practitioners e.g. for shadowing, mentoring and supervision opportunities.

It can be helpful for service providers to consider their workforce knowledge and skill mix for stammering across the three defined levels of practice outlined below. Information gathered from a training needs or skill mix analysis can then be integrated as part of local service competencies to facilitate a streamlined and evidence-based approach to CPD, supervision and mentorship within this field.

The following competency level descriptors are based on a project carried out by Northumbria Healthcare NHS Foundation Trust to establish workforce skill mix guidance for Speech and Language Therapist working with children and young people who stammer.

At Level 1, practitioners typically work with a range of stammering cases. This level of practice will usually incorporate early entry clinicians (e.g. newly qualified practitioners) or those who are new to working in the field, often as part of a more generalist caseload. Depending on broader factors, Level 1 practitioners can usually work autonomously within the field to a certain level with appropriate support / supervision and guidance in place.

At Level 2, practitioners will typically demonstrate an emerging specialist level of knowledge and skill and they can work autonomously with stammering cases. This may involve undertaking additional specialist training within the field; being a member of and attending Clinical Excellence Networks as well as offering supervision and second opinions to more generalist practitioners e.g. with complex cases and decision making.

At Level 3, practitioners demonstrate advanced knowledge / skills within the field of stammering. Typically, Level 3 practitioners will lead with areas such as care pathway and training development. In terms of workforce development, Level 3 practitioners will be able to identify learning and CPD opportunities for Level 1 / 2 SLTs as well as offering specialist support and supervision.

Telehealth

Services for stammering can be provided online. See RCSLT telehealth guidance.

Contributors

Lead author

• Corinne Moffatt, Divisional Lead, Speech and Language Therapy, City St George’s, University of London. 

Supporting authors

• Dr Ria Bernard, Expert by experience 
• Kirsten Howells, Speech and Language Therapist, STAMMA 
• Ali Berquez, Clinical Lead Speech and Language Therapist 
• Catherine Pape, National speech, language and communication co-ordinator for babies, children and young people, Welsh Government 
• Elaine Kelman Consultant SLT and Head of the Michael Palin Centre. 
• Jennifer Ryder, Speech and Language Therapist 
• Kerith McCracken, Paediatric Speech & Language Therapist 
• Kevin Fower, Director, The Stammer Specialist Ltd 
• Simon Henderson, Highly Specialist Speech and Language Therapist. Northumbria Healthcare NHS Foundation Trust 
• Sula O’Duffy, Speech and Language Therapist, NHS Ayrshire and Arran 

Partner Organisations

We would also like to thank the following organisations for their support during the production of this guidance 

• Action for Stammering Children 
• Stamma