Relationship of the Commonly Cooccurring Symptoms and Conditions with Tourette’s Disorder

Relationship of the Commonly Cooccurring Symptoms and Conditions with Tourette’s Disorder

Some studies support a broad Tourette’s disorder phenotype that in-clude commonly cooccurring comorbid conditions, whereas others identify a more circumscribed phenotype and define Tourette’s dis-order consistent with DSM-IV diagnosis – impairing multiple motor and vocal tics of 1-year duration. The outcome of this controversy has implications for treatment, but also for the definition of what Tourette’s disorder is. For example, for people with Tourette’s disor-der and multiple comorbid conditions a simple moniker – Tourette’s disorder – can simplify a very complex situation. For example, some parents have noted that it is difficult for them to conceptualize their child as having Tourette’s disorder, OCD, ADHD, major depressive disorder and a learning disorder and prefer to use Tourette’s disor-der as a way to simplify the complexity in their own minds and in the minds of others. On the other hand people with Tourette’s dis-order but without multiple comorbidities may not be appropriately understood or treated if it is assumed that the Tourette’s disorder label means tics plus a variety of other psychiatric disorders.

For clinical purposes we recommend that clinicians use a narrow conceptualization of Tourette’s disorder and describe other problems as they may or may not occur. In this way each individual will carry diagnoses or problems that can be specifi-cally described and appropriately addressed.

In the available research studies there is general agreement that chronic vocal or motor tics are a milder form of Tourette’s disorder and that some forms of OCD are an alternative expres-sion of the Tourette’s disorder genetic diathesis. ADHD is very common in clinically ascertained subjects with Tourette’s disor-der, but may not be as uniformly present in community samples of people with Tourette’s disorder. Within the literature, there are two major hypotheses regarding the relationship of Tourette’s disorder to cooccurring disorders:

·   The putative Tourette’s disorder gene is responsible for Tourette’s disorder, CT, OCD and some forms of ADHD in Tourette’s disorder probands and their families. Other disor-ders that commonly cooccur in Tourette’s disorder subjects are not associated with Tourette’s disorder and are not part of the Tourette’s disorder phenotype. The cooccurrence of these other disorders with Tourette’s disorder reflects either ascer-tainment bias in the sample or the development of disorders secondary to living with Tourette’s disorder.

·    The putative Tourette’s disorder gene is responsible for Tourette’s disorder and the frequently associated psychiatric and behavioral problems seen in Tourette’s disorder subjects.