In addition, these investigators also examined the relation between OCD and two commonly occurring comorbid disorders: tic disorder and anxiety disorders. Their findings support the hypothesis that there are shared etiologic factors for OCD and tics, as well as OCD and other anxiety disorders, and are consistent with the hypothesis that there may be different subtypes of OCD that may have different underlying risk factors.37-41 This hypothesis will be discussed in more depth in the Family Studies section below.
