C. Onset is before age 18 years.
D. The disturbance is not attributable to the physiological effects of a substance (e.g., co-
caine) or another medical condition (e.g., Huntington’s disease, postviral encephalitis).
E. Criteria have never been met for Tourette’s disorder or persistent (chronic) motor or
vocal tic disorder.
Specifiers 
The “motor tics only” or “vocal tics only” spec ifier is only required for persistent (chronic)
motor or vocal tic disorder.
Diagnostic Features
Tic disorders comprise four diagnostic categori es: Tourette’s disorder, persistent (chronic)
motor or vocal tic disorder, pr ovisional tic disorder, and the other specified and unspecified
tic disorders. Diagnosis for any tic disorder is  based on the presence of motor and/or vocal
tics (Criterion A), dura tion of tic symptoms (C riterion B), age at onse t (Criterion C), and ab-
sence of any known cause such as another medical condition or substance use (Criterion D).
The tic disorders are hierarchical in order (i .e., Tourette’s disorder, followed by persistent
[chronic] motor or vocal tic disorder, followed by provisional tic disorder, followed by the