information:classification, structural:expansion
Classification

Genetic studies indicate that tic disorders cover a spectrum that is not recognized by the clear-cut distinctions in the current diagnostic framework. Since 2008, studies have suggested that Tourette's is not a unitary condition with a distinct mechanism, as described in the existing classification systems. Instead, the studies suggest that subtypes should be recognized to distinguish "pure TS" from TS that is accompanied by attention deficit hyperactivity disorder (ADHD), obsessive–compulsive disorder (OCD) or other disorders, similar to the way that subtypes have been established for other conditions, such as type 1 and type 2 diabetes. Elucidation of these subtypes awaits fuller understanding of the genetic and other causes of tic disorders.