What Is Stuttering?

Introduction

Stuttering, also known as stammering or childhood-onset fluency disorder, is a communication disorder that disturbs a person’s fluency of speech. Stuttering is considered the most common type of speech disorder. But it remains a poorly understood condition, which results in sufferers being stigmatised, so it is important to understand stuttering to combat ignorance, increase awareness about the condition, and continue the discovery of things that will benefit people who stutter.^1,2,3

What is stuttering?

Stuttering is a set of disturbances that disrupt the natural flow of speech. It is characterised by certain types of disfluencies that can interrupt the rhythm of speech and can be accompanied by negative reactions to speaking, avoidance and struggling behaviours, as well as physical tension.⁴ 

About 1% of the world’s population is affected by stuttering.⁵ Generally, stuttering is more common in those assigned male at birth (AMAB) than those assigned female at birth (AFAB), with a ratio of over 4:1.^6,7

Stuttering is a variable condition, which means that its features and severity differ from person to person and depend on numerous factors.⁸ If a case of stuttering is identified and treated early, it decreases the probability of it turning into a chronic condition.⁹

The most common characteristics of stuttering are:

• Repetition of sounds, words, syllables, and phrases (e.g., “H-h-how are you?”)
• Blocking (otherwise known as blocks or stoppages), where making sounds is attempted but nothing comes out
• Prolonged sounds (e.g. “Hooooow are you?”)⁶

People who stutter may also have associated secondary complications involving non-verbal behaviours and motor movements. 

Examples include: 

• grimacing 
• tics 
• eye blinks 
• tremors 
• head jerking 
• breathing movements

People with a stutter may also deliberately try to avoid social situations or speaking specific words for fear they will feel embarrassed.^6,10

Factors that influence stuttering

There has been a wide range of theories about the origins of stuttering, but its precise cause within the brain and nervous system has still not been clarified. Therefore, identifying stuttering can be difficult and the use of multifactorial research is necessary because it takes into consideration the impacts of multiple factors such as pathology, psychology, acoustics, and signal processing.^11,1
Factors examined by research include:

Biological factors

Brain mapping studies have identified that people who stutter show differences in their brain anatomy and functioning compared to people who don’t.^12,13 More precisely, people who stutter show reduced activity in their superior temporal gyrus - a temporal lobe area in the human brain that houses Wernicke’s area (an important region of the brain for understanding and generating speech).¹³ 

These changes can contribute to neurodevelopmental disorders which affect speech-motor control. Stuttering also can be the result of psychological, cellular, physiological, and genetic disorders.¹²

Genetic factors

Stuttering is not generally considered a purely genetic disorder. But some studies have found instances of several cases of stuttering in the same family. So, the possibility of there being a hereditary component remains under consideration. 

In support of this, the National Health Service (NHS) maintains that approximately 2 in 3 individuals who stutter have a family history of stuttering. Research has also discovered it is more likely that a case of stuttering will persist over time if there is a history of stuttering in the family.^2,14-16

Neurodevelopmental factors

There is increasing evidence that there are deficits in cognitive and metalinguistic skills in children who stutter. In existing studies, children who stutter have shown poorer executive function.¹⁷ 

Executive function is a blanket term that relates to all the cognitive abilities we rely on in everyday life, including problem-solving, reasoning, emotional control, and working memory.¹⁸ It is thought that the deficits or the delay in the development of these skills might contribute to the start of stuttering in an individual.

Environmental factors

The environment, including other people within it, might affect a person who stutters negatively because speaking for them can become a traumatic experience. People who stutter – especially children – may speak less and conceal their problems with speech to avoid the risk of stigma and to feel safer. This can result in isolation and be confusing.¹⁹ Unfortunately avoiding speaking in this manner, can also make the stuttering worse.²⁰

Parenting styles

It is also important to factor in the attitudes of the parents to stuttering as a possible contributory factor, especially as parents play a central role in the first recognition and identification of stuttering. 

Studies suggest that the way in which a parent responds to stuttering can affect how the person stuttering feels about their stutter, so parental negative attitudes can be damaging.²¹ A negative family attitude toward stuttering could lead to the person feeling anxious and frustrated when having to speak or even to them not speaking at all.²²

Languages

The ability to speak more than one language increases a child’s probability of being diagnosed as stuttering, even if they do not stutter. 

In bilingual children especially, it can be hard to work out whether their dysfluencies are caused by stuttering or by knowing more than one language.²³

Emotional factors

People who stutter often experience mental health issues such as increased anxiety (especially social anxiety), poor self-esteem, and negative feelings.²⁴ 

Stuttering can diminish a person’s confidence and bear an even larger impact on their quality of life if they begin to limit their participation in social and professional opportunities and activities.²⁵ For children, one of the biggest obstacles arising from stuttering is low resilience, which can make it difficult for them to thrive in schooling and social situations.²⁶

In Briley et al’s study of the link between stuttering and depression, they found that people who stutter reported higher levels of depressive symptoms than people who don’t. Also, there was a larger amount of suicidal ideation (thinking about suicide) in people AMAB who stutter compared to people AMAB who don’t, and the risk of this increasing with age. Therefore, speech and language therapists need to always maintain awareness and knowledge about this relationship between stuttering and depression.²⁷

Types of stuttering

There are two main types of stuttering – developmental and neurogenic.

Developmental stuttering

Developmental stuttering begins in childhood, which is a period during which the human brain is developing and refining complex skills such as speech.²⁸ 

The age range of the start of stuttering is between 2 and 9 years old. At the age of 6, 80-90% of these children typically begin to have symptoms of stuttering.¹⁰ 

This type of stuttering disorder is not always long-term – up to 75% of cases can resolve spontaneously without intervention. In the remaining 25% of cases of developmental stuttering, it persists into adulthood.²⁸

Neurogenic stuttering

Neurogenic stuttering is a type of acquired stuttering and can occur in both adults and children. Neurogenic stuttering can be caused by neurodegenerative disorders such as Parkinson’s disease, traumatic brain injury, stroke, seizure disorders, multiple sclerosis, and drug use. 

Stuttering results when the damaging injury or condition affects the areas of the brain connected with speech production. Whether or not neurogenic stuttering is curable depends on the cause, the extent of damage, and whether the person responds positively to the treatment given.²⁹

Diagnosis

If you are concerned about stuttering for yourself or a loved one, consult your healthcare provider so they can assess your case.

It is likely the individual with a stutter will be referred to a speech and language therapist (SLT), who will work with the person to find ways to improve their speech fluency and diminish the impact that stuttering has on their life. 

A thorough assessment (according to studies) looks at: 

• the background and historical information relevant to the stuttering 
• the person’s speech and language development 
• the person’s fluency of speech and stuttering characteristics 
• the response to the stuttering by the sufferer and other people 
• the negative effects on all areas as a consequence of the stuttering³⁰

Treatment and management of stuttering

Techniques and strategies

Studies indicate that current strategies mostly focus on “fluency-shaping” interventions, which have the goal of improving a person’s motor/speech skills (e.g., the Lidcombe or the Camperdown Program). This sort of strategy looks at slowing the rhythm of speech and its delivery and trying to manage the dysfluencies in a more conducive manner.²⁸

Cognitive-based strategies, such as cognitive behavioural therapy (CBT), and mindfulness-based interventions, such as acceptance and commitment therapy (ACT), have shown themselves useful for reducing anxiety, improving attitudes about stuttering, and reducing the adverse effects of stuttering for both children and adults.³¹

In addition, the evidence indicates that people who stutter have previously benefited psychologically from participating in self-help/support groups where they can potentially connect empathically with other people while sharing their personal experiences.³²

Various approaches to stuttering treatment have proven to be more successful for younger individuals than for adults who stutter. This is believed to be because children’s brain networks can be modified through growth and reorganisation, as opposed to adults’ brains which are fully developed.³³ Therefore, this adds weight to the importance of seeking support for stuttering as early as possible.

Summary

Stuttering is the most common type of speech disorder; it causes involuntary speech disturbances such as repetition, blocks, and prolonging words. Stuttering’s exact cause is still unknown but probably involves a combination of genetic, neurological, and environmental factors. There are two types of stuttering, developmental and neurogenic, and stuttering can physically and mentally affect anyone of any age.

Stuttering affects those AMAB more than those AFAB and, typically, the chances of stuttering being resolved are improved if the dysfluencies are identified early. Even though stuttering might not always be curable, it can hopefully be managed with speech and language interventions, which aim to help the speaker communicate more easily and confidently.