By Nan Bernstein Ratner, Ed.D.
University of Maryland
“But, my child was fine until that bad experience with a new babysitter,” is what a parent might say. Although stress does not cause stuttering, stress can aggravate it.
Parents often seek an explanation for the onset of stuttering since the child has been, in all documented cases, speaking fluently before the stuttering began. Freud himself observed this unique pattern of onset. He originally hypothesized that stuttering represented a reaction to childhood trauma of some sort, which could be remedied by psychoanalysis, although he was not successful in helping his one adult stuttering patient. In this regard, although he has become somewhat demonized for “blaming” environmental influences for stuttering onset, his goal was to provide a more therapeutically hopeful approach to stuttering, which until then had been viewed as physically-based, and therefore less amenable to treatment. (Notice that science has, as it often does, now come full circle with our current emphasis on genetic and brain imaging studies.) Other psychoanalysts, too many to mention here, but summarized well by Van Riper in The Nature of Stuttering (1982), pursued this approach in more detail, spurred by stuttering’s unique onset timing.
In our experience, parents often do try to identify something that they might have done to “cause” stuttering (or other developmental problems). However, if we step back and consider the broad concept – that some form of experience or trauma has produced a physical malady, we would need to view stuttering as a conversion or somaticizing disorder. How well does stuttering fit this diagnostic category? Very, very poorly. As we discussed in Bloodstein & Bernstein Ratner (2008, pp 201-2), stuttering’s known demographic features stand in stark contrast to the well-documented characteristics of somatic or conversion disorders. These differences include the following: 
Types of somatic distress seen in conversion disorder: In recent studies of conversion disorder and the older literature they reference, stuttering or other speech disorders are completely absent. The majority of somatic disorders involve gross motor ability (e.g., walking), perceptual systems (e.g., vision), overall well-being (e.g., chronic pain or weakness), headache/stomach ache or unexplained seizure-like disorder. Thus, psychiatry does not currently entertain the idea that stuttering is triggered by events or experiences. We shouldn’t do that, either.
Age of onset: conversion disorders are not seen in very young children, and are undocumented before later childhood and the teen years. In recent studies  (e.g., Sar, Islam & Öztürk (2009)), patients were, on average, over 30 years of age, with a lower bound of 18 years. Brown & Lewis-Fernandez’s (2011) review states that, “The limited data available from countries outside the North Atlantic area concur with the DSM-IV-TR suggestion that the onset of conversion disorder is typically between 10 and 35 years of age.”
Gender distribution: conversion reactions tend to affect women more than men, a profile in direct contrast to the typical gender distribution in stuttering. Brown & Lewis-Fernandez (2011) note that, “the statement in DSM-IV-TR that patients with conversion disorder are significantly more likely to be female has been confirmed in several countries.” Sar et al. found that 27 out of 32 of their conversion cases were female.  
General psychiatric status: Brown & Lewis-Fernandez note that many conversion patients also report multiple somatic symptoms in other bodily systems (e.g., motor, perception, weakness, seizures).
Available symptom models: one notable feature of stuttering is that early stuttering often does not resemble advanced stuttering, even that seen in the child’s family. In contrast, Brown & Lewis-Fernandez (2011) note that a “significant proportion of conversion disorder patients have recently encountered similar symptoms in their local environment.”
To summarize, Creed & Gureje (2012) observe that “somatization disorder is associated with female gender, few years of education, low socio-economic status, a general medical illness, a psychiatric disorder (especially anxiety and depressive disorders) (as well as) recent stressful life events” – this doesn’t sound much like children who stutter.
Finally, but very importantly, psychotherapy has been conspicuously unsuccessful in treating stuttering in both children and adults, as the Handbook notes.
Despite this, I have had parents of children who stutter insist that stuttering was “caused” by experiences such as the birth of a sibling, a bad experience away from home, etc.  What might be the most helpful approach to this set of beliefs?  
Medicine has now started to distinguish between “causes” and  “triggers” in disease onset. A cause is just what it sounds like, the underlying basis for the disfunction or disorder.   The cause of stuttering is currently unknown, but appears to involve a heritable disfunction with increasingly obvious bases in brain anatomy and activity. “A trigger is something that either sets off a disease in people who are genetically predisposed to developing the disease, or that causes a certain symptom to occur in a person who has a disease. For example, sunlight can trigger rashes in people with lupus. A trigger is a predisposing event” ( A number of disorders are now known to appear after a person’s system has been weakened by a viral infection, for instance – this would be an example of a trigger that allows an underlying condition to emerge. We could view some family reports of stress just prior to the onset of stuttering as quite analogous to this, and view that stress as a possible trigger for the stuttering. An important concept to remember here is that triggers may vary, but if an underlying condition is susceptible to triggering, it will eventually emerge. Thus, there would be no way for parents to “protect” their child against all known (or unknown) stressors, either medical or experiential that could trigger the onset of stuttering. Finally, although many parents (and people who stutter) might want to understand what causes stuttering, the major goal is to treat its behavioral, affective and cognitive features effectively. Second-guessing as to what “might have been” serves little scientific -  or therapeutic - purpose.
Brown, R. & Lewis-Fernandez, R. (2011) Culture and Conversion Disorder: Implications for DSM-5. Psychiatry: Interpersonal & Biological Processes (PSYCHIATRY INTERPERS BIOL PROCESS), 74 (3): 187-206.
Bloodstein, O. & Bernstein Ratner, N. (2008). A Handbook on Stuttering, 6th edition. Clifton Park, NY: Thomson-Delmar.
Sar, V., Islam, S. & Öztürk, E. (2009). Childhood emotional abuse and dissociation in patients with conversion symptoms. Psychiatry and Clinical Neuroscience, 63, 670-677.
Van Riper, C. (1982). The Nature of Stuttering (2nd ed). Englewood Cliffs, NJ: Prentice-Hall.
From the Fall 2014 Newsletter