Everyone with Tourette has tics, but not all tics are due to Tourette syndrome.
To be diagnosed with Tourette, there has to be both motor and vocal tics present. These have lasted longer than a year.
Tourette is different to other tic disorders, and we will get into these differences here.
What are the different types of tic disorder?
The DSM-5 (1) classifies three main types of tic disorder:
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- Provisional Tic Disorder
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- Persistent (Chronic) Tic Disorder
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- Tourette’s Disorder
They give us a clue to their nature in the name… apart from Tourette. This name doesn’t really stick to the theme.
This is because Tourette syndrome is named after the neurologist that published studies of tics in 1885. Georges Gilles de la Tourette.
Who decides on the criteria?
The DSM-5 was briefly mentioned above, this publication describes the tic-disorders that are diagnosed today.
The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) is published by the American Psychiatrics Association and the most up to date publication.
The DSM classification is used to diagnose various mental disorders. It will help us understand what each of these tic disorders consists of and what makes them unique.
What makes tics Tourette syndrome
For tics to be classed as Tourette:
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- Both multiple motor and one or more vocal tics have been present at some time during the illness, although not necessarily concurrently
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- The tics may wax and wane in frequency but have persisted for more than 1 year since first tic onset
For Tourette to be diagnosed, both motor and vocal tics need to be present in an individual.
Motor tics are movement based tics. Vocal tics are sounds, words and/or phrases.
They need to have lasted at least one year.
What makes tics Persistent (Chronic) Tic Disorder
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- Single or multiple motor or vocal tics have been present during the illness, but not both motor and vocal
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- The tics may wax and wane in frequency but have persisted for more than 1 year since first tic onset
- Criteria have never been met for Tourette’s disorder
Instead, it is either motor or vocal tics. These can be simple or complex.
These have to be present for more than a year after the tics started and the person must have not been diagnosed with Tourette previously.
What makes tics Provisional Tic Disorder
Provisional basically means temporary, and to be possibly changed later.
Provisional Tic Disorder is:
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- Single or multiple motor and/or vocal tics
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- The tics have been present for less than 1 year since first tic onset
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- Criteria have never been met for Tourette’s disorder or Persistent (chronic) motor or vocal tic disorder
Provisional Tic Disorder can be diagnosed if tics have lasted less than one year.
These can be simple or complex, and be both motor and vocal tics.
Provisional basically means temporary– and this diagnosis can change if the tics last longer than the year needed to diagnose Persistent Tic Disorder or Tourette.
Current disqualifying factors
The DSM-5 also states that these tic disorders can be diagnosed only if:
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- Onset is before age 18 years
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- The disturbance is not attributable to the physiological effects of a substance or another medical condition
The age qualification is interesting, because more and more people have been experiencing a sudden onset of tics, even in adulthood.
Whether this age criteria remains will have to be seen.
Numerous conditions, medications and drugs can cause tics or tic-like symptoms, that are not tic-disorders. This is why certain conditions and substances can rule out a diagnosis.
Summary
Tourette is the most severe, with both motor and vocal tics present for more than a year.
This is followed by Persistent (Chronic) Tic Disorder. This can be as frequent and severe as Tourette, but with only motor or vocal tics. Not both.
Provisional tic disorder can be the same severity of both Tourette and Persistent Tic Disorder, but needs to pass that one year mark before it can be diagnosed as anything other than Provisional.
Sources:
1. American Psychiatric Association. Desk Reference to the Diagnostic Criteria : from DSM-5 by American Psychiatric Association.
