Reliability and Validity of the Yale Global Tic Severity Scale

Storch, Eric A.
Murphy, Tanya K.
Geffken, Gary R.
Sajid, Muhammad
Allen, Pam
Roberti, Jonathan W.
Goodman, Wayne K.

¹Department of Pediatrics, University of Florida
²Department of Psychology, New College of Florida
³Department of Psychiatry, University of Florida.

⁴Correspondence concerning this article should be addressed to Eric A. Storch, Department of Psychiatry, University of Florida, Box 100234, Gainesville, FL 32610. E-mail [email protected].

This research was funded by grants from the National Institute of Mental Health to Tanya K. Murphy (Grant K23 MH01739) and Wayne K. Goodman (Grant R01 MH45802). We thank Audrey Baumeister, Paula Edge, Natalie Johns, Erin Killiany, Jane Mutch, and Ohel Soto for their contributions to this study.

Received Date: August 19, 2004; Revised Date: March 29, 2005; Accepted Date: June 17, 2005

Psychological Assessment 17(4):p 486-491, December 2005.

To investigate the reliability and validity of the Yale Global Tic Severity Scale (YGTSS), 28 youth aged 6 to 17 years with Tourette's syndrome (TS) participated in the study. Data included clinician reports of tics and obsessive-compulsive disorder (OCD) severity, parent reports of tics, internalizing and externalizing problems, and child reports of depression and anxiety. All children participated in a 2nd YGTSS administration by the same rater 48 days later. Good internal consistency and stability were found for the YGTSS scores. YGTSS scores demonstrated strong correlations with parent-rated tic severity (r = .58–.68). YGTSS scores were not significantly related to measures of clinician ratings of OCD severity (r = .01–.15), parent ratings of externalizing and internalizing behavior (r = −.07–.20), and child ratings of depression (r = .02–.26) and anxiety (r = −.06–.28). Findings suggest that the YGTSS is a reliable and valid instrument for the assessment of pediatric TS.