Serotonin Control of Impulsivity in Tourette Disorder

Tourette disorder (TD) is a neurodevelopmental disorder characterized by motor and vocal tics. It is often associated with multiple psychiatric comorbidities involving a high degree of impulsivity such as obsessive-compulsive disorders (OCD), attention-deficit hyperactivity disorders (ADHD), and intermittent explosive disorders (IED). Although a substantial body of clinical studies have emphasized the role of the dopamine system in motor symptoms, little is known about how the serotonergic (5-HT) system modulate both cognitive and affective abilities in TD. Several lines of evidence suggest that different 5-HT receptor subtypes may constitute a crucial factor in the development and maintenance of different symptoms. Because abnormal 5-HT2A receptor bindings have been reported in patients with TD and aripiprazole (drug of first choice) is a 5-HT2A antagonist, we hypothesize that 5-HT2A receptors may play an important role in regulating psychiatric symptoms in TD such as those characterized by impulsive behaviors. To investigate the involvement of 5-HT2A receptors in TD, we propose to perform a multimodal imaging study with 20 adult patients (ON and OFF treatment). Neuroimaging data will be collected with a hybrid system that simultaneously combines the positron emission tomography (PET) and the functional magnetic resonance imaging (fMRI). A highly selective PET radiotracer (\[18F\]-altanserin) will map 5-HT2A receptor bindings in the whole brain, while fMRI will provide detail information regarding the altered brain activities.

NCT Number	NCT05942716
Lead Sponsor	Hospices Civils de Lyon
Conditions	Tourette Disorder
Enrollment	25 participants
Start Date	2024-09-24
Primary Completion	2027-09-24 (estimated)
Study Completion	2028-09-24 (estimated)
Updated on ClinicalTrials.gov	2024-12-04