Speech-Language Pathology/Stuttering/Overview of the Six Factors that Contribute to Stuttering
The experts each say that one thing causes stuttering. They don't agree what that one thing is, but they all insist that their one thing is the only thing that causes stuttering. And each insists that his therapy program is the only effective treatment for stuttering.
But at least six factors contribute to stuttering. No single stuttering therapy is a "miracle cure." Treating stuttering requires a multifactoral approach—different treatments for each of the six factors:
Developmental Disorder
Stuttering is a developmental disorder. In other words, if you're an adult stutterer, the primary reason that you stutter is that you stuttered as a child. That may seem obvious, but the implications are important, as you'll see in the chapter Childhood Stuttering.
Auditory Processing Underactivity
Brain scans have found that the auditory processing area is underactive during stuttering. It appears that stutterers can't integrate what we hear ourselves saying with how we feel our muscles moving. Electronic altered auditory feedback devices appear to correct this neurological abnormality. This factor is presented in the chapter Auditory Processing.
Speech Motor Control Overactivity
Brain scans have also found that stutterers' speech motor (muscle) control area is overactive. Stutterers overtense their respiration (breathing); vocal folds; and lips, jaws, and tongues (articulators). These overtense muscles lock up or fail to coordinate, making speech impossible. Fluency shaping therapy trains stutterers to speak with relaxed speech production muscles. This factor is presented in the chapter Speech Motor Learning and Control.
Response Selection to Stress
Most stutterers speak fluently when relaxed, but stutter under stress. Personal construct therapy trains stutterers to handle stress in ways that result in fluent speech. This factor is presented in the chapter Response Selection Under Stress.
Genes and Neurotransmitter
Another neurological abnormality associated with stuttering involves too-high levels of the neurotransmitter dopamine in the left caudate nucleus speech motor control area. This appears to contribute to speech motor (muscle) overactivity. Dopamine antagonist medications treat this abnormality. This factor is presented in the chapter Genes and Neurotransmitters.
Psychological Effects
Stuttering causes psychological fears and anxieties. For some individuals, these fears and anxieties are more disabling than their physical stuttering. Some individuals use stuttering as an excuse for deeper problems, such as inability to maintain relationships. Some individuals obsessively try to hide their stuttering, e.g., counterproductively refusing to go to speech therapy for fear that someone may see them entering the speech clinic. These individuals may need treatment with a psychologist in addition to speech therapy. This factor is presented in the chapter Psychological Issues.
Multifactoral Treatment
Most stutterers have one or two factors strongly. The other factors may be less significant. You might find a speech clinic that treats you successfully, especially if the speech clinic combines two or more therapies.
But a speech-language pathologist can treat at most three of the six factors. Electronic devices can treat one or two factors. Medications treat one factor. You may have to go to see several speech-language pathologists, and possibly buy an electronic device or get a medication prescription, to treat all of the factors that contribute to your stuttering.
Additional Factors
I have no doubt that additional stuttering factors will be discovered. Likely other genes contribute to stuttering. The neurotransmitter acetylcholine might play a role.[1]
Some advances in stuttering will be treatments for co-existing conditions. In the future children (and adults) will be tested for a variety of disorders, and treatment designed accordingly. E.g., a child with stuttering and phonological dysfunction will be treated differently than a child with stuttering and ADHD. An adult with stuttering and social phobia will be treated differently from an outgoing mentally retarded adult who stutters.
References
- ^ Pharmacist and stutterer Richard Harkness believes: "My long-held hunch, based on my understanding of Parkinson's disease, is that the neurotransmitter acetylcholine (Ach) might be a key player in stuttering. Parkinson's disease is commonly described as a condition of relative imbalance between dopamine (DA) and Ach (low DA/high Ach). Hypothetically at this point, stuttering might be thought of as just the opposite (high DA/low Ach). Research in schizophrenia indicates that a decrease in striatal DA levels is accompanied by an increase in Ach levels. Thus, the tx condition brought about by D2 inhibitors (antipsychotics)—less dopaminergic activity—might result in a relative increase in Ach activity—in effect, could it be that antipsychotic-induced fluency improvement is actually due to increased Ach activity? One problem is that current Ach agonists tend to cause intolerable side effects. But there is ongoing research on Ach agonists/antagonists, primarily for drugs aimed at schizophrenia. There's much more to be learned."