BACKGROUND Obsessive-compulsive disorder (OCD) is heterogeneous, with some forms related to Gilles de la Tourette's syndrome (GTS). This is a phenomenological study designed to investigate the nature of these possible OCD subtypes and the relationship between OCD and GTS.
METHOD We evaluated 20 adult outpatients with OCD, 21 with GTS, and 20 with OCD plus GTS using a semi-structured interview designed to assess cognitive, sensory and autonomic phenomena preceding repetitive behaviours.
RESULTS More cognitions and autonomic anxiety and fewer sensory phenomena were reported in OCD than in GTS. Like the GTS group, the OCD plus GTS group reported more sensory phenomena and fewer cognitions than the OCD group.
CONCLUSIONS The presence or absence of cognitions, sensory phenomena, and autonomic anxiety distinguishes repetitive behaviours in patients with OCD from those with OCD plus GTS, and GTS. These subjective experiences may be useful in subtyping OCD and may represent valid predictors of prognosis and treatment response.