(PS3-D85) Impact of Social Interactions on Tic Frequency

Introduction: Although persistent tic disorders (PTDs) have a neurological basis, contextual factors are believed to interact with biological processes to help explain the variability in tics. Few studies have experimentally examined the contextual factor of tic-related conversation on tic frequency. Woods et al. (2001) found that tic-related conversation increased vocal tics, while Dufrene et al. (2013) found that tic-related conversation increased motor tics. Both studies compared tic- to non-tic-related conversations; however, no study has examined differences in tic frequency among tic-related conversation, non-tic-related conversation, and silence. Therefore, the current study assesses the differences among these conditions in individuals with PTDs.

Method: Participants included 12 individuals (8-21 years old) with PTDs. Nine participants completed the study in person, while three completed it over video call. Researchers examined participants’ tics in three 10-minute conditions. In the silence condition, participants sat quietly in a room (or on a video call) with the researcher. Participants were not allowed to have any distractions such as a phone, book, or computer, and they faced a different direction than the researcher. In the tic-related conversation condition, researcher and participant discussed tic-related topics, such as descriptions of tics, premonitory urges, and environmental factors related to increases in tics. In the non-tic-related conversation condition, they discussed non-tic-related topics, such as favorite hobbies, movies, and books. Then, videos were scored using 10-s interval scoring methods to determine the total number of tics in each condition. A second observer scored all sessions, and the mean interobserver reliability was 93%.

Results: A Friedman test demonstrated a statistically significant difference in the number of tics depending on the condition, χ²(2) = 10.67, p < .01. Wilcoxon signed-rank tests showed that participants ticced more in the silence compared to non-tic-related conversation condition (Z = -2.20, p < .05). There was not a statistically significant difference in tic frequency between the tic-related conversation and silence conditions (Z = -1.88, p = .06) or tic-related and non-tic-related conversation conditions (Z = -.71, p = .48). Additionally, a Friedman test demonstrated no differences in the number of motor (χ²(2) = 3.45, p = .18) or vocal (χ²(2) = 5.87, p = .05) tics depending on the condition; however, vocal tics were trending toward significance.

Discussion: Results from this study are not consistent with those reported in past research (Dufrene et al., 2013; Woods et al., 2001). Participants demonstrated an increase in tics in the silence condition, during which no talking occurred. These findings suggest that talking may be a competing action that impacts tic frequency. Further, past studies have found that boredom may be associated with tic exacerbation (Eapen et al., 2004), which could explain the increase in tics in a less stimulating environment with no conversation. Future research with larger sample sizes should continue to examine the relationship between tic- and non-tic-related conversations and silence.