A New Instrument for Clinical Studies of Tourette's Syndrome

Tourette's syndrome (TS) consists of multiple motor and phonic symptoms with a waxing and waning course. Frequency and type of symptoms may be influenced by environment (home, school, clinic) and the patient's state. Clinical, neurobiological, and other types of research on TS require reliable and valid rating instruments sensitive to individual components of the disorder and patient global status. Ideally such an instrument would not be unduly affected by the variability of individual tics. We have developed a multidimensional scale for rating symptom frequency and disruptiveness in TS; estimates of inter-rater reliability for specific symptoms and the global score are promising. Evidence concerning the validity of the TS Global Scale in the context of a pharmacological study and in an outpatient setting is presented.