A Test of the Behavioral Model of Tic Disorders Using a Dynamical Systems Framework

Working Mechanisms of Exposure and Response Prevention in the Treatment of Tourette Syndrome and Tic Disorders Revisited: No Evidence for within-Session Habituation to Premonitory Urges

“…The authors concluded that there was no indication of withinsession habituation. Finally, Wellen et al (2023) examined 11 adult TS patients in "free to tic" situations versus those under tic suppression and competing response performance situations [45]. In this study, tic suppression did not result in a reduction in premonitory urges for most participants.…”

“…The course of premonitory urge intensity in this study differs from the linear withinsession reduction found in the study of Verdellen et al [38] and is only partly in line with the results found in the study of Specht et al [46], who found high and stable urge intensity ratings without an initial increase. A recent study by Wellen et al [45] also showed no evidence of within-session habituation; tic suppression did not result in a reduction in premonitory urges. In our study, a small, non-significant decline in urges could be seen in the RMA analyses after 45 min, but this effect disappeared in the LGM analysis.…”

“…The piecewise model showed the lowest AIC/BIC values, and the highest CFI/TLI scores, indicating the best model fit of the three tested models. Figure 3 presents a summarizing graph of the slopes of each tested model, showing that in the piecewise model a significant increase in premonitory urge intensity occurred during the first 15 min of each session, remaining stable at this increased level for the remaining 45 The piecewise model showed the lowest AIC/BIC values, and the highest CFI/TLI scores, indicating the best model fit of the three tested models. Figure 3 presents a summarizing graph of the slopes of each tested model, showing that in the piecewise model a significant increase in premonitory urge intensity occurred during the first 15 min of each session, remaining stable at this increased level for the remaining 45 min.…”

“…Changes in urge intensity seem to be partly independent of the execution of tics, while executing a tic was still associated with a relief in urge intensity [12]. In a recent study by Wellen et al (2023), about half of the patients showed relief following tics and not all tics led to immediate relief. Sometimes, bouts of tics were needed to decrease the urge [45].…”

“…Several studies have examined the course of habituation during tic suppression [38,45,46]. Verdellen et al (2008) [38] tested the habituation hypothesis as a possible underlying mechanism of ERP in 20 TS patients (age 7-55 years) during 10 two-hour sessions.…”