Abstract
OBJECTIVES: Gilles de la Tourette syndrome (GTS) is a chronic tic disorder associated with comorbid psychopathology, including obsessionality, affective instability and attention-deficit hyperactivity disorder. Evidence linking GTS with schizophrenia-like symptoms is limited and equivocal, despite a common putative substrate involving dopaminergic dysfunction within frontostriatal circuits. The aim of this study was to quantify the prevalence of schizotypal traits in GTS and to detail the relationship between schizotypy and comorbid psychopathology. MATERIALS AND METHODS: A total of 102 subjects with GTS were evaluated using the Schizotypal Personality Questionnaire and standardized neurological and psychiatric rating scales. The predictive interrelation between schizotypy, tic-related symptoms and psychiatric comorbidities was investigated using correlation and multiple regression analyses. RESULTS: In our clinical population, 15% of the subjects were diagnosed with the schizotypal personality disorder according to the DSM-IV criteria. The strongest predictors of schizotypy were obsessionality and anxiety ratings. The presence of multiple psychiatric comorbidities correlated positively with schizotypy scores. CONCLUSIONS: Schizotypal traits are relatively common in patients with GTS, and reflect the presence of comorbid psychopathology, related to the anxiety spectrum. In particular, our preliminary results are consistent with a shared neurochemical substrate for the mechanisms underpinning tic expression, obsessionality and specific schizotypal traits.