The Lidcombe Program and child language development: Long-term assessment.

This study was driven by the need to understand the mechanisms underlying Lidcombe Program treatment efficacy. The aim of the present study was to extend existing data exploring whether stuttering reductions observed when children successfully treated with the Lidcombe Program are associated with restricted language development. Audio recordings of 10-min parent-child conversations at home were transcribed verbatim for 11 pre-school-age children with various stuttering severities. Language samples from three assessments-pre-treatment, 9 and 18 months after beginning treatment-were analysed using SALT software for lexical diversity, utterance length and sentence complexity. At 18 months posttreatment commencement, the children had attained and maintained statistically significant stuttering reductions. During that period, there was no evidence that Lidcombe Program treatment was associated with restricted language development. The continued search for the mechanisms underlying this successful treatment needs to focus on other domains.