Disorders characterized by recurrent TICS that may interfere with speech and other activities. Tics are sudden, rapid, nonrhythmic, stereotyped motor movements or vocalizations which may be exacerbated by stress and are generally attenuated during absorbing activities. Tic disorders are distinguished from conditions which feature other types of abnormal movements that may accompany another another condition. (From DSM-IV, 1994)

Predominantly psychogenic disorders characterized by involuntary, spasmodic, stereotyped movement of small groups of muscles; seen most predominantly in moments of stress or anxiety, rarely as a result of organic disease.

Tics are brief, sudden, repetitive movements and/or sounds. They are divided into motor tics (e.g., blinking, shrugging shoulders, grimacing, or jerking) or phonic tics (e.g., throat clearing, sniffing, grunting, or more complex utterances). Patients describe an inner urge or a local premonitory sensation, which is then relieved by...