Tics peak in late childhood and decline during adolescence. Yet, for some with Tourettes disorder, tics persist into adulthood. We evaluated childhood predictors of adult tic severity and tic impairment, and change over time. Eighty adolescents/adults were evaluated 11 years following a randomized-controlled trial of behavior therapy. An independent evaluator rated tic severity and tic impairment at baseline, posttreatment, and long-term follow-up. At baseline, parents completed demographics/medical history, and youth tic, internalizing, and externalizing symptom ratings. Youth rated premonitory urge severity and family functioning. After controlling for prior tic treatment effects, female sex and higher tic severity predicted higher tic severity in adulthood; and female sex, no stimulant medication use, higher tic severity, and poorer family functioning predicted higher tic impairment. Higher tic severity and premonitory urge severity predicted smaller reductions in tic severity, whereas higher externalizing symptoms predicted greater reduction in tic severity. Female sex predicted smaller reduction in tic impairment, and externalizing symptoms predicted greater reduction in tic impairment. Female sex and childhood tic severity are important predictors of tic severity and tic impairment in adulthood. Family functioning, premonitory urge severity, and tic severity are important modifiable targets for early or targeted intervention to improve long-term outcomes.

Background

Individuals with Tourette Syndrome and Persistent Tic Disorders (collectively TS) often experience premonitory urges-aversive physical sensations that precede tics and are temporarily relieved by tic expression. The relationship between tics and premonitory urges plays a key role in the neurobehavioral treatment model of TS, which underlies first-line treatments such as the Comprehensive Behavioral Intervention for Tics (CBIT). Despite the efficacy of CBIT and related behavioral therapies, less than 40% of adults with TS respond to these treatments. Further examination of the relationship between premonitory urges, tic severity, and tic impairment can provide new insights into therapeutic targets to optimize behavioral treatment outcomes. This study examined whether urge intolerance-difficulty tolerating premonitory urges-predicted tic severity and tic-related impairment among adults with TS.

Methods

Participants were 80 adults with TS. Assessments characterized premonitory urge, distress tolerance, tic severity, and tic impairment. We used structural equation modeling (SEM) to examine the construct of urge intolerance-comprised of premonitory urge ratings and distress tolerance ratings. We first evaluated a measurement model of urge intolerance through bifactor modeling, including tests of the incremental value of subfactors that reflect premonitory urge severity and distress tolerance within the model. We then evaluated a structural model where we predicted clinician-rated tic severity and tic impairment by the latent variable of urge intolerance established in our measurement model.

Results

Analyses supported a bifactor measurement model of urge intolerance among adults with TS. Consistent with theoretical models, higher levels of urge intolerance predicted greater levels of clinician-rated tic severity and tic impairment.

Conclusion

This investigation supports the construct of urge intolerance among adults with TS and distinguishes it from subcomponents of urge severity and distress tolerance. Given its predictive relationship with tic severity and tic impairment, urge intolerance represents a promising treatment target to improve therapeutic outcomes in adults with TS.