The prevalence of Tourette syndrome in a mainstream school population

Abstract

The aim of this study was to ascertain accurately the prevalence of Tourette syndrome (TS) in a mainstream school population. All year 9 pupils (aged 13 to 14 years) in a mainstream secondary school were investigated using a two‐stage procedure. Standardized questionnaires were completed by parents, teachers, and pupils. Class observations were also carried out to identify tics. Those pupils identified as having tics underwent a semistructured interview to determine whether they had TS according to DSM‐III–R criteria. Data were available from at least one source (parent, teacher, or self‐reports) on 166 of the 167 pupils in the year. Five subjects were identified as having TS according to DSM‐III‐R criteria, yielding a prevalence estimate of 299 per 10 000 pupils in this age group. The results of this study suggest that TS in the community as a whole is more common and milder than those prevalence estimates and descriptions of the disorder based on TS encountered in secondary or tertiary health‐care service settings.