Which of the following disorders may be diagnosed even if the onset is after age 18 years?

Ans. D. Tic disorder not otherwise specifiedAll tic disorders with onset after age 18 years must be diagnosed as tic disorder not otherwise specified, a residual category for tics that do not meet the criteria for a specific tic disorder. Transient tic disorder, chronic motor or vocal tic disorder, and Tourette's disorder all specify onset before age 18 years.