This disorder, formerly known as transient tic disorder, involves single or multiple motor and/or vocal tics that arise early during childhood (for example, in school-age children. Transient tics occur in 3-8 per every 1,000 children.
Tics can be either simple or complex. Simple motor tics are of short duration (i.e., milliseconds) and can include blinking, shrugging the shoulders, and extending extremities. Simple vocal tics include throat clearing, sniffing, and grunting often caused by contraction of the diaphragm or pharynx muscles.
Complex motor tics are of longer duration (i.e., seconds) and often include a combination of simple tics, such as simultaneous head turning and shoulder shrugging. Complex tics can appear purposeful, such as a tic-like sexual or obscene gesture, or continuous imitation of someone else’s movements (mimicking). Vocal tics that are of the complex category can include continuous repetition of a sound or word, as well as repeated uttering of socially unacceptable content (for example, swear words, ethnic slurs).
To meet diagnostic criteria for the formal disorder, tics must have been present for less than 1 year since the beginning of onset — hence the designation “provisional” or “transient.”
This disorder cannot be better accounted for by Tourette’s disorder.
The tics cannot be due to a general medical condition, like Huntington’s disease, or due to the physiological effects of a substance, such as cocaine.
This entry has been added in line with updated (2013) DSM-5 criteria; diagnostic code: 307.21.