Review of studies that met the trial quality inclusion criterion established for this review suggested that response-contingent principles are the predominant feature of the most powerful treatment procedures for young children who stutter. The most powerful treatments for adults, with respect to both speech outcomes and social, emotional, or cognitive outcomes, appear to combine variants of prolonged speech, self-management, response contingencies, and other infrastructural variables. Other specific clinical recommendations for each age group are provided, as are suggestions for future research.

These results provide further evidence of the importance of phonation variables to (a) our understanding of how FICs may operate and (b) the treatment of stuttering. These findings, along with previous studies that showed how purposefully reducing the number of short PIs resulted in the elimination of stuttering, suggest that treatment programs based on prolonged speech-or PIs, in particular-may benefit from emphasizing a reduction in the number of short PIs and a simultaneous increase in the number of longer PIs.

None of the pharmacological agents tested for stuttering have been shown in methodologically sound reports to improve stuttering frequency to below 5%, to reduce stuttering by at least half, or to improve relevant social, emotional, or cognitive variables. These findings raise questions about the logic supporting the continued use of current pharmacological agents for stuttering.

No abstract

Results confirm that speech rate and instatement style can influence speech production variables during the production of fluency-inducing conditions. Future studies of normally fluent speech and of stuttered speech must control both features and should further explore the importance of voice onset time, which may be influenced by rate during metronome stimulation in a way that the other variables are not.