Professor Menzies is recognised as an international leader in the field of stuttering. Although this condition is clearly a speech-motor disorder, it is well established that anxiety plays a significant role in stuttering. Professor Menzies has led research that has produced the first evidence-based CBT treatment for the disorder. It is now possible to eliminate the social anxiety associated with everyday speaking situations in individuals who stutter. The treatment program developed by Professor Menzies has been shown to be effective in trials within Australia, and in a recent international trial across 22 countries.