Yale Global Tic Severity Scale

The Yale Global Tic Severity Scale (YGTTS) is a psychological measure designed to identify symptoms of disorders relating to attention and impulsivity, such as tic disorder, Tourette’s syndrome, and obsessive-compulsive disorder, in children and adolescents between ages 6 to 17. The questionnaire is divided into three parts over the span of 17 pages: one section identifies symptoms of motor and phonic tics, severity, and age of onset. Another section concerns OCD symptoms, severity, and age of onset, and the last section concerns environmental effects on symptoms. The YGTTS is completed by the parent and takes approximately 15-20 minutes to complete. The questionnaire has shown good reliability and validity in assessing tic severity in recent studies.