<prompt> Which of the following disorders may be diagnosed even if the onset is after age 18 years?Tourettes disorderChronic motor or vocal tic disorderTransient tic disorderTic disorder not otherwise specified  <response>: 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 Tourettes disorder all specify onset before age 18 years. 