Compulsive behaviours in Gilles de la Tourette syndrome

Gilles de la Tourette syndrome (GTS) is a childhood-onset neuropsychiatric disorder characterised by multiple motor and vocal tics. Several obsessive-compulsive symptoms have been described as intrinsic and genetically linked to GTS, however few studies have compared the clinical phenomenology of GTS with and without comorbid obsessive-compulsive disorder (OCD). We analysed the clinical and phenomenological features of tics and behavioural problems in 82 consented adults with GTS, recruited from two tertiary referral centres in United Kingdom (n = 70) and in Italy (n = 12). Two disease groups were identified and compared: 34 patients with a clinical diagnosis of GTS and OCD (GTS+OCD) and 48 with GTS only (GTS-OCD). GTS+OCD patients scored significantly higher on tic severity, obsessionality, depression, and anxiety rating scales. Moreover, diagnosis of attention-deficit hyperactivity disorder and depression, echophenomena, and compulsive stereotyped behaviours showed a higher frequency in the GTS+OCD group. It is suggested that comorbid OCD correlates with more severe tics and associated psychopathology, with relevant prognostic and therapeutic implications.