[1] Tic disorders are defined similarly by the World Health Organization (ICD-10 codes).
[4][5] ICD10 diagnosis codes are:[6] Tics should be distinguished from other causes of tourettism, stereotypies, chorea, dyskinesias, myoclonus and obsessive-compulsive disorder.
[8] Although behavioural therapy is the recommended first treatment, many people with tics do not access it due to the lack of trained psychotherapists.
[9][10] Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability.
Although a significant amount of investigative work indicates genetic linkage of the various tic disorders, further study is needed to confirm the relationship.