Tic disorders are defined in the Diagnostic and Statistical Manual of Mental Disorders (DSM) based on type (motor or phonic) and duration of tics (sudden, rapid, nonrhythmic movements). Tic disorders are defined similarly by the World Health Organization (ICD-10 codes).

What mental illness has tics?

Tourette Syndrome (TS) is a condition of the nervous system. TS causes people to have “tics”. Tics are sudden twitches, movements, or sounds that people do repeatedly.

What causes a person to have a tic?

Tics can happen randomly and they may be associated with something such as stress, anxiety, tiredness, excitement or happiness. They tend to get worse if they're talked about or focused on.