Description

The Yale Global Tic Severity Scale (YGTSS) is a psychometric tool used to assess the severity of tics in individuals with tic Yale Global Tic Severity Scale [YGTSS]

Description

The Yale Global Tic Severity Scale (YGTSS) is a clinician-rated instrument used to quantify the severity of motor and vocal tics, particularly in children and adolescents. It combines a semi-structured interview with ratings of tic symptoms across several dimensions.

Dimensions

The YGTSS evaluates tic symptoms according to:

  • Number
  • Frequency
  • Intensity
  • Complexity
  • Interference

It also includes an impairment rating that assesses the impact of tics on daily functioning.

Scoring

The scale provides scores for motor tics, vocal tics, total tic severity, impairment, and global severity. The Total Tic Severity Score ranges from 0 to 50, while the Global Severity Score ranges from 0 to 100. Higher scores indicate greater tic severity or functional impact.

Purpose and Use

The YGTSS is designed to assess tic severity rather than diagnose a tic disorder. It can be used to monitor symptom changes over time and evaluate response to treatment.

References

Leckman, J. F., et al. (1989). The Yale Global Tic Severity Scale: Initial testing of a clinician-rated scale of tic severity. Journal of the American Academy of Child and Adolescent Psychiatry, 28, 566–573.

Storch, E. A., et al. (2005). Reliability and validity of the Yale Global Tic Severity Scale. Psychological Assessment, 17(4), 486.

Storch, E. A., et al. (2011). Defining treatment response in pediatric tic disorders: A signal detection analysis of the Yale Global Tic Severity Scale. Journal of Child and Adolescent Psychopharmacology, 21(6), 621–627.