New-onset functional tics during the COVID-19 pandemic: Clinical characteristics of 105 cases from a single centre

Background and purpose: The COVID-19 pandemic has been associated amongst other things with a sharp increase in adolescents and young adults presenting acutely with functional tics. Initial reports have suggested clinically relevant differences between functional tics and neurodevelopmental tics seen in primary tic disorders such as Tourette syndrome. We aimed to provide confirmatory findings from the largest single-centre cohort to date. Methods: In the present study we present data from 105 consecutive patients who developed functional tics during a 3-year period overlapping with the COVID-19 pandemic (April 2020–March 2023). All patients underwent a comprehensive neuropsychiatric assessment at a single specialist centre for tic disorders. Results: Female adolescents and young adults accounted for 69% of our sample. Functional tics had an acute/subacute onset in most cases (75% with a peak of severity within 1 month). We found a disproportionately high frequency of complex movements (81%) and vocalizations (75%). A subset of patients (23%) had a pre-existing primary tic disorder (Tourette syndrome with functional overlay). The most common psychiatric co-morbidities were anxiety (70%) and affective disorders (40%). Moreover, 41% of patients had at least one functional neurological disorder in addition to functional tics. Exposure to tic-related social media content was reported by half of the patients. Conclusions: Our findings confirm substantial clinical differences between functional tics developed during the pandemic and neurodevelopmental tics. Both patient- and tic-related red flags support the differential diagnostic process and inform ongoing monitoring in the post-pandemic era.