Thursday, June 29, 2006

Yaruss vs Onslow (Part I)

Here is the discussion I have been edited for the BSA between Mark Onslow and Scott Yaruss: see here.

The diagnosogenic theory stated that stuttering was caused, in part, by parents inappropriately drawing attention to a child’s otherwise normal disfluencies. In recent years, many have commented on the numerous shortcomings of this theory as an explanation for early stuttering, and, in particular, on the negative effects it has had on treatment planning and clinical decision making.

Given your recent research on stuttering treatment, combined with research on early recovery, with what theoretical framework would you replace the diagnosogenic theory, and how would such a theory help to explain basic phenomena associated with childhood stuttering?

There should currently be no replacement for the diagnosogenic theory as a driver of treatment for early stuttering. Many theories are available (for an overview, see Packman & Attanasio, 2004), but none of them has proven to be correct, and only one of them—or perhaps none of them—is correct. Hence for the time being, it is a dubious practice to base treatment on any theory of what causes or perpetuates stuttering.

We are all desperate to find out what causes stuttering. But intervention of early stuttering can occur independent of efforts to uncover its cause. For example, the Lidcombe Program is not driven by a theory of the cause of stuttering, and is nonetheless efficacious according to a recently published randomised controlled trial (Jones et al., 2005).


Few would doubt the efficacy of the Lidcombe program, as described in numerous publications and the recent clinical trials. Still, some may question its effectiveness in daily clinical settings. Further, is Lidcombe the only way to accomplish our common goal of eliminating stuttering in young children?

Of course, it is true that theory has not always served our field well. Many clinicians still cling to ineffective treatments derived from the long-disproved diagnosogenic theory, but would this necessarily have to be the case with other theories?

Improvements in treatment might still be achieved through the rigorous application of theory-driven clinical research aimed at uncovering factors involved in the onset, development, and maintenance of the disorder. Uni-dimensional theories have proven unsatisfactory throughout the history of our field, so I would start with a theory that incorporates more than one factor as a potential cause for stuttering.

I hope that no clinician is still using the diagnosogenic theory to treat stuttering. For example, Bloodstein tried for years to implement the treatment suggested by the theory, but failed completely (see Bloodstein, 1986). I do not think my concerns are an overstatement. A theory of the cause and development of stuttering would certainly be fine as a basis for treatment as you say, but with two provisos. First, the theory is verified with the scientific method. Second, the treatment based on the theory is evaluated with clinical trials of an acceptable standard. Surely it is unethical to provide health care with unproven treatments? The local doctor would not do it for asthma, and neither should the local speech pathologist do it for early stuttering.

Yes, the effectiveness of the Lidcombe program at the population level is not yet well researched. Also, it may not be the only way to treat early stuttering. There might well be other treatments, and I look forward to the publication of clinical trials of other treatments. If clinical trials show that there is a better and quicker treatment, I will be the first to use and endorse it.

However, I would not endorse multifactorial theory of stuttering as a source of treatment development. First, multifactorial theories of stuttering are completely and irretrievably wrong from empirical and logical perspectives. Second, no clinical trial shows the capacity of multifactorial treatments to control stuttering. There is a real risk that the errors of the diagnosogenic era will be repeated if we use multifactorial theories to treat children: that we will think that we know the cause of stuttering when we do not, and that we know what is an efficacious treatment for early stuttering when we do not.

I also do not agree with your claim that one type of theory, such as multifactorial theory, has been more successful than another such as single factor theory. In fact, no theory has been successful in explaining the cause of stuttering (see Packman & Attanasio, 2004).