Stuttering, Placebos, and Nocebos

A placebo is a sham medical intervention that may produce a therapeutic effect in a patient. For example, an inert pill can be administered with the suggestion that it may improve the patient's condition. The result, called the placebo effect, is an excellent example of how the mind can affect a physiological reaction and the impact of positive expectations on biological outcomes.

There are also placebo-like effects whereby no physical placebo is administered, the effect being due to the influence of a specific context on the patient's mind (e.g. verbal suggestions of improvement). Regardless of the exact nature of the placebo, expectation of a future outcome is a principal mechanism for the placebo effect.

Also, a conditioned neutral stimulus (e.g., the color of a sham pill) can become a placebo if it is repeatedly associated with an unconditioned stimulus (e.g., the drug inside a real pill). Therefore, a patient who is initially given a real pill and is subsequently switched to a sham pill of the same shape and color may continue to show therapeutic effects. Conditioning leads to the expectation that one event will follow another event on the basis of the information that the conditioned stimulus provides about the unconditioned stimulus. This is called the conditioned response model.

On the other hand, nocebos are essentially the opposite of placebos in that nocebos may lead to negative pathological effects. Beliefs and expectations may sicken or kill, as in the extreme case of voodoo deaths. Negative expectation inducing events or procedures may lead to symptom worsening. The fear/avoidance model of pain can be viewed as a kind of noceba-like effect, whereby the fear of pain may lead to the worsening of pain. As with placebos, we might also expect that nocebos could exhibit a conditioned response mechanism. And this is where nocebos may play a role in stuttering.

A stutterer may have had embarrassing experiences in a given context with his speech (e.g., speaking in front of an audience); this is the conditioned stimulus. Since this stimulus is repeatedly associated with the stuttering, conditioning will lead to the expectation that stuttering will follow standing before an audience. The noceba effect offers a rationale for the diagram shown in the blog posting entitled "Stuttering, the Mind, the Body," in that a context (e.g., public speaking) can result in a worsening of one's fluency.