TABLE 1.

Summary of recommendations, structure, and clinical utility of recommended and suggested severity rating scales for tics and premonitory urges

Instrument	Panel judgment	Rater	Tic-related dimensions	Features (other than tics) explored	Time of administration	Main advantages of its clinical application	Main limitations
YGTSS	Recommended	Clinician	Number Frequency Intensity Complexity Interference Overall impairment	None	15–20 minutes	Comprehensiveness Availability of a joint tic checklist Availability of thresholds of score change indicating response to clinical treatment	Training for administration required Length of administration
STSS	Recommended	Clinician	Intensity Interference	None	<5 minutes	Brief and easy to administer	Does not assess frequency, complexity, or distribution Uncertain time frame within which tic severity is measured
TS-CGI	Recommended	Clinician	Overall adverse impact	None	<2 minutes	Brief and easy to administer	Does not assess individual dimensions separately
TODS	Recommended	Parent or clinician (2 versions)	Overall severity	Inattention Hyperactivity Obsessions Compulsions Aggression Emotional symptoms	>20 minutes	Joint assessment of tics and main comorbid behavioral features	Does not assess individual dimensions of tics separately Length of administration
PUTS	Recommended in patients older than 10 years	Patient	Premonitory urges	None	5–10 minutes	The only fully validated instrument to measure tic-related premonitory urges specifically Brief and easy to administer	Poor psychometric properties in youth younger than 10 years
RVBTRS	Suggested	Clinician	Number Frequency Complexity	None	>30 minutes (including set-up, filming, and video rating)	The only validated instrument to measure current tics objectively through a videorecording within a specified time window The only instrument that allows to measure the ability of patients to actively inhibit tics	Does not evaluate tics in the time period prior to filming Does not assess interference and adverse impact of tics Requires audio-visual equipment Length of administration Divergent validity with instruments measuring other types of involuntary movements has not been assessed
TSGS	Suggested	Clinician	Frequency Disruption level	Behavioral problems Motor restlessness School or occupational functioning	15–20 minutes	Joint assessment of tics, comorbid behavioral features and functioning	Length of administration Does not assess complexity or distribution Internal consistency and divergent validity have not been assessed
GTRS	Suggested	Clinician or caregiver (parents or teachers)	Frequency Overall severity (without assessing individual dimensions)	None	<2 minutes	Brief and easy to administer	Does not assess individual tic dimensions Internal consistency and divergent validity have not been assessed
MOVES	Suggested	Patient	Frequency	Obsessions and compulsions Echo- and copro-phenomena	<5 minutes	Joint assessment of tics and some comorbid behavioral features Brief and easy to administer	Does not assess individual tic dimensions other than frequency (measured using generic anchor points) Internal consistency and divergent validity have not been assessed
PTQ	Suggested	Parents	Number Frequency Intensity	None	10–20 minutes	The first tic severity rating instrument specifically designed for parent-report Easy to administer	Its scoring refers to a limited list of 14 common motor tics and 14 common vocal tics Field testing is limited (used only by developers)
TSSL	Suggested	Parents	Frequency	Nontic repetitive behaviors (5 of 41 items)	10–20 minutes	Useful to assist parents in daily or weekly ratings of tics Easy to administer	Does not assess individual tic dimensions other than frequency Psychometric properties not formally evaluated

YGTSS, Yale Global Tic Severity Scale; STSS, Shapiro TS Severity Scale; TS-CGI, Tourette Syndrome-Clinical Global Impression; TODS, Tourette’s Disorder Scale; PUTS, Premonitory Urges for Tics Scale; RVBTRS, Rush Video-Based Tic Rating Scale; TSGS, Tourette Syndrome Global Scale; GTRS, Global Tic Rating Scale; MOVES, Motor tic, Obsessions and compulsions, Vocal tic Evaluation Survey; PTQ, Parent Tic Questionnaire; TSSL, Tourette Syndrome Symptom List.