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).

Classification

DSM-5

The fifth revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published in May 2013, classifies Tourette syndrome and tic disorders as motor disorders listed in the neurodevelopmental disorder category. Tic disorders, in ascending order of severity, are: Developmental coordination disorder and stereotypic movement disorder are also classified as motor disorders.

ICD-10

ICD10 diagnosis codes are:

Diagnosis

Tics should be distinguished from other causes of tourettism, stereotypies, chorea, dyskinesias, myoclonus and obsessive-compulsive disorder.

Treatment

Education, and a "watch and wait" strategy, are the only treatment needed for many, and most individuals with tics do not seek treatment. When needed, management of tic disorders is similar to management of Tourette syndrome. The first line of treatment is behavioural therapy, followed by medication (most often aripiprazole) if the former is unsuccessful. Although behavioural therapy is the recommended first treatment, many people with tics do not access it due to the lack of trained psychotherapists.

Epidemiology

Tic disorders are more commonly diagnosed in males than females. At least one in five children experience some form of tic disorder, most frequently between the ages of seven and twelve. Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability. Nevertheless, most cases of Tourette syndrome are not severe. Although a significant amount of investigative work indicates genetic linkage of the various tic disorders, further study is needed to confirm the relationship.

History

DSM-IV-TR

In the fourth revision of the DSM (DSM-IV-TR), tic disorders were classified as follows:

From DSM-IV-TR to DSM-5

DSM-5 was published in 2013, updating DSM-IV-TR, which was published in 2000. The following changes were made: