Developmental stammering (DS, also known as idiopathic stammering or stuttering) is a disorder of speech fluency that affects approximately 0.75% to 1% of the populations of Great Britain, Australia and America,1^–4 although a recent study puts the point prevalence figure at between 1% and 3% in the UK.5 Prevalence is generally thought to be similar amongst communities worldwide, although there have been occasional suggestions that this figure might be lower in countries where there is less pressure on verbal acuity.6 DS may be distinguished from neurogenic stammering, which can occur subsequent to neurological damage of various aetiologies (for example, stroke, tumour, degenerative disease) and psychogenic stammering, whose onset can be related to a significant psychological event such as bereavement. While a diagnosis of neurogenic stammering might be made in early childhood and adolescence, both neurogenic and psychogenic types are typically associated with an adult onset. DS is by far the most common form of stammering and usually develops in the pre-school years. The mean age at onset is 42, with 75% of cases beginning before the age of 6.1 However, occasionally, stammering onset may be seen as late as 12 or 13 years of age.

EARLY INTERVENTION AND SPONTANEOUS RECOVERY

A feature of DS is that complete recovery, either with or without therapy, is common before adolescence. Approximately 74% of all children diagnosed with stammering will cease to stammer by the time they reach their early teens, although the figure may be as high as 89% in young females.7 8 This latter statistic is consistent with the fact that while equal numbers of males and females are initially diagnosed with stammering, the sex ratio changes to around 4:1 (male:female) in the overall population. The poorest prognosis is for males who experience a later onset to their …