Environmental factors as potential determinants of premonitory urge severity in youth with Tourette syndrome

Tics associated with Tourette syndrome (TS) are often preceded by aversive somatosensory experiences known as premonitory urges. These urges are highly prevalent among individuals with TS and appear to play a key role in tic expression. Despite the importance of premonitory urges, relatively little is known about environmental factors that may influence their severity. Some data suggest that experiencing environmental consequences for ticcing may increase the severity of premonitory urges, although evidence for this claim is limited. The present study tested this possibility using data from an Internet-based survey of 118 youth with TS and their parents. Results indicated that tic severity and urge severity were positively correlated with each other and with items measuring tic-related impact. Hierarchical linear regression analyses showed that the relationship between urge severity and tic-related impact persisted when accounting for comorbid psychiatric diagnoses and tic severity. These results are consistent with a behavioral model of TS and suggest that experiencing aversive consequences for ticcing may increase the severity of premonitory urges. Future research should further examine factors that influence premonitory urges and more completely test the behavioral model of TS. (C) 2012 Elsevier Inc. All rights reserved.