Childhood Predictors of Long-Term Tic Severity and Tic Impairment in Tourette's Disorder.

Tics peak in late childhood and decline during adolescence. Yet, for some with Tourette's 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.