Abstract
Assessment and diagnosis of Tourette Syndrome and other tic disorders relies on clinical observation and self-reported history. However, tics are highly susceptible to contextual influences, including clinical interactions. We used video-based observation to quantify the contextual impact of clinician presence on tics and evaluate the potential for these methods to improve tic detection. Youth ages 12-21 (N = 39) participated in a clinical trial with video-recorded pre- and post-treatment assessments. Established methods for precision video-based behavioral coding were used to quantify tic frequency and type across assessment contexts (clinician presence and instruction to suppress tics). Participants had significantly more tics when alone and ticcing naturally (mean tics per minute [tpm] = 25.03) and when alone with suppression instructions (mean tpm = 9.48) than in the clinician's presence (mean tpm = 3.29), all ps <.001. Further, mixed model results showed a significant decrease in tpm across treatment when alone ((β = -21.85; 95% CI: [-33.99, -9.70]), and with a clinician (β = -20.31; 95% CI: [-35.08, -5.55]), but significantly greater decrease in the alone context (β = -6.01; 95% CI: [-9.74, -2.29]). Tics occurred less frequently in clinician presence than alone (even when specifically asked to suppress tics alone), suggesting that the social context of clinician presence may facilitate tic suppression that is automatic and/or learned. Additionally, results establish objective video-based measurement as a valuable tool to detect tics and tic change not visible to the clinician.